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MD 0574 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR ...PARTS OF SWRN TX
Mesoscale Discussion 0574 NWS Storm Prediction Center Norman OK 0255 PM CDT Sun Apr 27 2025 Areas affected...,parts of swrn TX Concerning...Severe potential...Watch possible Valid 271955Z - 272100Z Probability of Watch Issuance...40 percent SUMMARY...The initiation of a couple of storms appears increasingly likely near and northwest through north of Fort Stockton through 4-5 PM CDT. More rapid thunderstorm intensification accompanied by increasing potential for large hail and locally damaging wind gusts may be initially slow, before probably increasing toward early evening around the Midland through Big Spring vicinities. DISCUSSION...The boundary-layer is becoming strongly heated and deeply mixed across the Davis Mountains vicinity of southwest Texas into the Texas South Plains. The dryline is sharpening east through north of Fort Stockton, where 2-hourly surface pressure falls around 2.0+ mb have been observed the past couple of hours, and low-level convergence appears strongest. Deepening convective development is ongoing within the deeper mixed-boundary layer around Fort Stockton, where surface temperature/dew point spreads are around 50 F (95/44), but forecast soundings and HREF guidance suggests that the initiation of at least isolated thunderstorm development is increasingly probable through 21-22Z. It appears that this may be aided by forcing associated with a mid-level speed maximum within southwesterly flow emanating from the northern Mexican Plateau. Downstream of slow moving large-scale mid-level troughing over the southern Great Basin and Southwest, after at least some further eastward mixing of the dryline late this afternoon, it probably will begin to retreat northwest across the Pecos Valley vicinity toward 23-00Z. As this occurs, convection may acquire more substantively unstable updraft inflow (including most unstable CAPE up to 2000-3000+ J/kg), supporting increasing potential for rapid thunderstorm intensification, in the presence of strong deep-layer shear. This may including a splitting supercell or two, posing a risk for large hail and a few strong surface gusts. Until then, though, initial thunderstorm development will probably be more modest in strength, but could still pose some risk for producing severe hail and wind. ..Kerr/Smith.. 04/27/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...SJT...LUB...MAF... LAT...LON 30410326 30870341 31970321 32930244 33180156 32510109 32000117 31040164 30280230 30410326 MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 95 MPH MOST PROBABLE PEAK WIND GUST...55-70 MPH MOST PROBABLE PEAK HAIL SIZE...1.50-2.50 IN Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0252 PM CDT Sun Apr 27 2025 Valid 272000Z - 281200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR MUCH OF THE GREAT PLAINS... ...SUMMARY... Isolated to scattered severe thunderstorms are possible mainly this evening into early morning Monday across parts of the Great Plains. Large to very large hail, severe gusts, and a few tornadoes are all possible. ...20z Update... The previous forecast remains on track with no appreciable changes required. Signs of broad-scale ascent beginning to overspread the High Plains west of the surface trough/dryline are evident in latest GOES imagery. Shallow cumulus is beginning to develop from western NE southward into west TX, which suggests that convective initiation within this corridor should become more probable within the next few hours as we approach peak diurnal heating and dryline circulations are maximized. West Texas Mesonet observations are sampling higher dewpoints (by about 2-3 F) and stronger surface convergence than anticipated by most model solutions. This suggests that the probability of realizing the potent convective environment may be increasing across the TX Panhandle (though confidence in storm coverage remains too limited to warrant any upgrades). Further north, recent RAP analyses show the tightest low-level lapse rate gradient across western KS, indicative of a tighter/stronger dryline circulation. This trend supports some recent high-res guidance that shows convective initiation between 21-00z across this region and warrants maintaining the current risk probabilities. Similarly, steady surface pressure falls across western NE/SD suggest that ascent is strongest across the central High Plains region, which should favor at least isolated thunderstorm development this afternoon. See the previous discussion below for additional details. ..Moore.. 04/27/2025 .PREV DISCUSSION... /ISSUED 1130 AM CDT Sun Apr 27 2025/ ...Synopsis... Water-vapor imagery this morning shows a mid- to upper-level low over NV. A belt of strong southwesterly mid to high-level flow will extend from the base of the western U.S. trough through the southern/central High Plains later today into tonight. A pair of smaller-scale disturbances are forecast to eject east-northeastward into the central High Plains and Black Hills vicinity during the mid-late evening. Concurrently, an upper ridge over the eastern half of the Great Plains states will shift eastward over the MS Valley towards daybreak Monday. Late morning surface analysis shows a developing low centered over southeast WY with a lee trough/dryline extending southward through the southern High Plains. The cyclone will deepen near the WY/NE/CO border through early evening before developing northeast into central SD late tonight. ...Southeast MT...Western Dakotas... A sharpening lee trough is forecast by late this afternoon amidst appreciable heating and moistening, especially across western SD. Model guidance shows a narrow plume of 500-2000 J/kg MLCAPE (highest over SD) developing by mid-late afternoon as large-scale ascent begins to overspread the region. Isolated to widely scattered thunderstorms are forecast to develop from the northern NE Panhandle to the Black Hills, and north of the developing low over southeast MT by late afternoon. The stronger storms will gradually move into richer moisture with an accompanying risk for mainly large hail and severe gusts. Gradual cooling during the evening will favor a transition to elevated storms evolving with time as a LLJ strengthens tonight. A severe risk will probably develop farther east in association with WAA into parts of the eastern Dakotas and MN late. ...Central/Southern High Plains... Visible-satellite imagery indicates a very moist boundary layer with a mix of a cumulus field across central and north TX and eastern NM/CO and stratus from the TX Caprock northward through OK to NE. The depth and quality of moisture sampled by the 12z Midland, Amarillo, and Dodge City raobs is considered seasonably moisture rich, and is located beneath an elevated mixed layer. Additional moistening through advection and evaporation will contribute to 60s dewpoints east of a dryline/lee trough by late afternoon. Strong heating is forecast near the dryline from western NE southward through West TX, which will result in a weakly capped but moderate to very unstable airmass by 21z. Large-scale forcing for ascent across the region will be nebulous, but low-level convergence along the dryline amid little to no convective inhibition may result in convective initiation. With dryline convergence as the mechanism for convective initiation, predictability is low. Dryline circulations will likely be strongest across the TX Panhandle/West TX where temperatures west of the dryline will be warmest, but low-level convergence will likely maximize in the CO/NE/KS border intersection vicinity near a developing surface low. As a result, these two areas may have a greater risk for thunderstorms (isolated, widely spaced storm coverage) late this afternoon into the evening. The overall environment will be very supportive of supercells with any storms that do form, with large to very large hail as the primary risk initially. If any storms manage to develop and become sustained, a strengthening low-level jet will support a tornado threat during the evening with any storms that persist (or develop along the retreating dryline). Nocturnal cooling and increased CINH by mid to late evening will act to eventually weaken storm activity in this region. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0252 PM CDT Sun Apr 27 2025 Valid 272000Z - 281200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR MUCH OF THE GREAT PLAINS... ...SUMMARY... Isolated to scattered severe thunderstorms are possible mainly this evening into early morning Monday across parts of the Great Plains. Large to very large hail, severe gusts, and a few tornadoes are all possible. ...20z Update... The previous forecast remains on track with no appreciable changes required. Signs of broad-scale ascent beginning to overspread the High Plains west of the surface trough/dryline are evident in latest GOES imagery. Shallow cumulus is beginning to develop from western NE southward into west TX, which suggests that convective initiation within this corridor should become more probable within the next few hours as we approach peak diurnal heating and dryline circulations are maximized. West Texas Mesonet observations are sampling higher dewpoints (by about 2-3 F) and stronger surface convergence than anticipated by most model solutions. This suggests that the probability of realizing the potent convective environment may be increasing across the TX Panhandle (though confidence in storm coverage remains too limited to warrant any upgrades). Further north, recent RAP analyses show the tightest low-level lapse rate gradient across western KS, indicative of a tighter/stronger dryline circulation. This trend supports some recent high-res guidance that shows convective initiation between 21-00z across this region and warrants maintaining the current risk probabilities. Similarly, steady surface pressure falls across western NE/SD suggest that ascent is strongest across the central High Plains region, which should favor at least isolated thunderstorm development this afternoon. See the previous discussion below for additional details. ..Moore.. 04/27/2025 .PREV DISCUSSION... /ISSUED 1130 AM CDT Sun Apr 27 2025/ ...Synopsis... Water-vapor imagery this morning shows a mid- to upper-level low over NV. A belt of strong southwesterly mid to high-level flow will extend from the base of the western U.S. trough through the southern/central High Plains later today into tonight. A pair of smaller-scale disturbances are forecast to eject east-northeastward into the central High Plains and Black Hills vicinity during the mid-late evening. Concurrently, an upper ridge over the eastern half of the Great Plains states will shift eastward over the MS Valley towards daybreak Monday. Late morning surface analysis shows a developing low centered over southeast WY with a lee trough/dryline extending southward through the southern High Plains. The cyclone will deepen near the WY/NE/CO border through early evening before developing northeast into central SD late tonight. ...Southeast MT...Western Dakotas... A sharpening lee trough is forecast by late this afternoon amidst appreciable heating and moistening, especially across western SD. Model guidance shows a narrow plume of 500-2000 J/kg MLCAPE (highest over SD) developing by mid-late afternoon as large-scale ascent begins to overspread the region. Isolated to widely scattered thunderstorms are forecast to develop from the northern NE Panhandle to the Black Hills, and north of the developing low over southeast MT by late afternoon. The stronger storms will gradually move into richer moisture with an accompanying risk for mainly large hail and severe gusts. Gradual cooling during the evening will favor a transition to elevated storms evolving with time as a LLJ strengthens tonight. A severe risk will probably develop farther east in association with WAA into parts of the eastern Dakotas and MN late. ...Central/Southern High Plains... Visible-satellite imagery indicates a very moist boundary layer with a mix of a cumulus field across central and north TX and eastern NM/CO and stratus from the TX Caprock northward through OK to NE. The depth and quality of moisture sampled by the 12z Midland, Amarillo, and Dodge City raobs is considered seasonably moisture rich, and is located beneath an elevated mixed layer. Additional moistening through advection and evaporation will contribute to 60s dewpoints east of a dryline/lee trough by late afternoon. Strong heating is forecast near the dryline from western NE southward through West TX, which will result in a weakly capped but moderate to very unstable airmass by 21z. Large-scale forcing for ascent across the region will be nebulous, but low-level convergence along the dryline amid little to no convective inhibition may result in convective initiation. With dryline convergence as the mechanism for convective initiation, predictability is low. Dryline circulations will likely be strongest across the TX Panhandle/West TX where temperatures west of the dryline will be warmest, but low-level convergence will likely maximize in the CO/NE/KS border intersection vicinity near a developing surface low. As a result, these two areas may have a greater risk for thunderstorms (isolated, widely spaced storm coverage) late this afternoon into the evening. The overall environment will be very supportive of supercells with any storms that do form, with large to very large hail as the primary risk initially. If any storms manage to develop and become sustained, a strengthening low-level jet will support a tornado threat during the evening with any storms that persist (or develop along the retreating dryline). Nocturnal cooling and increased CINH by mid to late evening will act to eventually weaken storm activity in this region. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0252 PM CDT Sun Apr 27 2025 Valid 272000Z - 281200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR MUCH OF THE GREAT PLAINS... ...SUMMARY... Isolated to scattered severe thunderstorms are possible mainly this evening into early morning Monday across parts of the Great Plains. Large to very large hail, severe gusts, and a few tornadoes are all possible. ...20z Update... The previous forecast remains on track with no appreciable changes required. Signs of broad-scale ascent beginning to overspread the High Plains west of the surface trough/dryline are evident in latest GOES imagery. Shallow cumulus is beginning to develop from western NE southward into west TX, which suggests that convective initiation within this corridor should become more probable within the next few hours as we approach peak diurnal heating and dryline circulations are maximized. West Texas Mesonet observations are sampling higher dewpoints (by about 2-3 F) and stronger surface convergence than anticipated by most model solutions. This suggests that the probability of realizing the potent convective environment may be increasing across the TX Panhandle (though confidence in storm coverage remains too limited to warrant any upgrades). Further north, recent RAP analyses show the tightest low-level lapse rate gradient across western KS, indicative of a tighter/stronger dryline circulation. This trend supports some recent high-res guidance that shows convective initiation between 21-00z across this region and warrants maintaining the current risk probabilities. Similarly, steady surface pressure falls across western NE/SD suggest that ascent is strongest across the central High Plains region, which should favor at least isolated thunderstorm development this afternoon. See the previous discussion below for additional details. ..Moore.. 04/27/2025 .PREV DISCUSSION... /ISSUED 1130 AM CDT Sun Apr 27 2025/ ...Synopsis... Water-vapor imagery this morning shows a mid- to upper-level low over NV. A belt of strong southwesterly mid to high-level flow will extend from the base of the western U.S. trough through the southern/central High Plains later today into tonight. A pair of smaller-scale disturbances are forecast to eject east-northeastward into the central High Plains and Black Hills vicinity during the mid-late evening. Concurrently, an upper ridge over the eastern half of the Great Plains states will shift eastward over the MS Valley towards daybreak Monday. Late morning surface analysis shows a developing low centered over southeast WY with a lee trough/dryline extending southward through the southern High Plains. The cyclone will deepen near the WY/NE/CO border through early evening before developing northeast into central SD late tonight. ...Southeast MT...Western Dakotas... A sharpening lee trough is forecast by late this afternoon amidst appreciable heating and moistening, especially across western SD. Model guidance shows a narrow plume of 500-2000 J/kg MLCAPE (highest over SD) developing by mid-late afternoon as large-scale ascent begins to overspread the region. Isolated to widely scattered thunderstorms are forecast to develop from the northern NE Panhandle to the Black Hills, and north of the developing low over southeast MT by late afternoon. The stronger storms will gradually move into richer moisture with an accompanying risk for mainly large hail and severe gusts. Gradual cooling during the evening will favor a transition to elevated storms evolving with time as a LLJ strengthens tonight. A severe risk will probably develop farther east in association with WAA into parts of the eastern Dakotas and MN late. ...Central/Southern High Plains... Visible-satellite imagery indicates a very moist boundary layer with a mix of a cumulus field across central and north TX and eastern NM/CO and stratus from the TX Caprock northward through OK to NE. The depth and quality of moisture sampled by the 12z Midland, Amarillo, and Dodge City raobs is considered seasonably moisture rich, and is located beneath an elevated mixed layer. Additional moistening through advection and evaporation will contribute to 60s dewpoints east of a dryline/lee trough by late afternoon. Strong heating is forecast near the dryline from western NE southward through West TX, which will result in a weakly capped but moderate to very unstable airmass by 21z. Large-scale forcing for ascent across the region will be nebulous, but low-level convergence along the dryline amid little to no convective inhibition may result in convective initiation. With dryline convergence as the mechanism for convective initiation, predictability is low. Dryline circulations will likely be strongest across the TX Panhandle/West TX where temperatures west of the dryline will be warmest, but low-level convergence will likely maximize in the CO/NE/KS border intersection vicinity near a developing surface low. As a result, these two areas may have a greater risk for thunderstorms (isolated, widely spaced storm coverage) late this afternoon into the evening. The overall environment will be very supportive of supercells with any storms that do form, with large to very large hail as the primary risk initially. If any storms manage to develop and become sustained, a strengthening low-level jet will support a tornado threat during the evening with any storms that persist (or develop along the retreating dryline). Nocturnal cooling and increased CINH by mid to late evening will act to eventually weaken storm activity in this region. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0252 PM CDT Sun Apr 27 2025 Valid 272000Z - 281200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR MUCH OF THE GREAT PLAINS... ...SUMMARY... Isolated to scattered severe thunderstorms are possible mainly this evening into early morning Monday across parts of the Great Plains. Large to very large hail, severe gusts, and a few tornadoes are all possible. ...20z Update... The previous forecast remains on track with no appreciable changes required. Signs of broad-scale ascent beginning to overspread the High Plains west of the surface trough/dryline are evident in latest GOES imagery. Shallow cumulus is beginning to develop from western NE southward into west TX, which suggests that convective initiation within this corridor should become more probable within the next few hours as we approach peak diurnal heating and dryline circulations are maximized. West Texas Mesonet observations are sampling higher dewpoints (by about 2-3 F) and stronger surface convergence than anticipated by most model solutions. This suggests that the probability of realizing the potent convective environment may be increasing across the TX Panhandle (though confidence in storm coverage remains too limited to warrant any upgrades). Further north, recent RAP analyses show the tightest low-level lapse rate gradient across western KS, indicative of a tighter/stronger dryline circulation. This trend supports some recent high-res guidance that shows convective initiation between 21-00z across this region and warrants maintaining the current risk probabilities. Similarly, steady surface pressure falls across western NE/SD suggest that ascent is strongest across the central High Plains region, which should favor at least isolated thunderstorm development this afternoon. See the previous discussion below for additional details. ..Moore.. 04/27/2025 .PREV DISCUSSION... /ISSUED 1130 AM CDT Sun Apr 27 2025/ ...Synopsis... Water-vapor imagery this morning shows a mid- to upper-level low over NV. A belt of strong southwesterly mid to high-level flow will extend from the base of the western U.S. trough through the southern/central High Plains later today into tonight. A pair of smaller-scale disturbances are forecast to eject east-northeastward into the central High Plains and Black Hills vicinity during the mid-late evening. Concurrently, an upper ridge over the eastern half of the Great Plains states will shift eastward over the MS Valley towards daybreak Monday. Late morning surface analysis shows a developing low centered over southeast WY with a lee trough/dryline extending southward through the southern High Plains. The cyclone will deepen near the WY/NE/CO border through early evening before developing northeast into central SD late tonight. ...Southeast MT...Western Dakotas... A sharpening lee trough is forecast by late this afternoon amidst appreciable heating and moistening, especially across western SD. Model guidance shows a narrow plume of 500-2000 J/kg MLCAPE (highest over SD) developing by mid-late afternoon as large-scale ascent begins to overspread the region. Isolated to widely scattered thunderstorms are forecast to develop from the northern NE Panhandle to the Black Hills, and north of the developing low over southeast MT by late afternoon. The stronger storms will gradually move into richer moisture with an accompanying risk for mainly large hail and severe gusts. Gradual cooling during the evening will favor a transition to elevated storms evolving with time as a LLJ strengthens tonight. A severe risk will probably develop farther east in association with WAA into parts of the eastern Dakotas and MN late. ...Central/Southern High Plains... Visible-satellite imagery indicates a very moist boundary layer with a mix of a cumulus field across central and north TX and eastern NM/CO and stratus from the TX Caprock northward through OK to NE. The depth and quality of moisture sampled by the 12z Midland, Amarillo, and Dodge City raobs is considered seasonably moisture rich, and is located beneath an elevated mixed layer. Additional moistening through advection and evaporation will contribute to 60s dewpoints east of a dryline/lee trough by late afternoon. Strong heating is forecast near the dryline from western NE southward through West TX, which will result in a weakly capped but moderate to very unstable airmass by 21z. Large-scale forcing for ascent across the region will be nebulous, but low-level convergence along the dryline amid little to no convective inhibition may result in convective initiation. With dryline convergence as the mechanism for convective initiation, predictability is low. Dryline circulations will likely be strongest across the TX Panhandle/West TX where temperatures west of the dryline will be warmest, but low-level convergence will likely maximize in the CO/NE/KS border intersection vicinity near a developing surface low. As a result, these two areas may have a greater risk for thunderstorms (isolated, widely spaced storm coverage) late this afternoon into the evening. The overall environment will be very supportive of supercells with any storms that do form, with large to very large hail as the primary risk initially. If any storms manage to develop and become sustained, a strengthening low-level jet will support a tornado threat during the evening with any storms that persist (or develop along the retreating dryline). Nocturnal cooling and increased CINH by mid to late evening will act to eventually weaken storm activity in this region. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0252 PM CDT Sun Apr 27 2025 Valid 272000Z - 281200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR MUCH OF THE GREAT PLAINS... ...SUMMARY... Isolated to scattered severe thunderstorms are possible mainly this evening into early morning Monday across parts of the Great Plains. Large to very large hail, severe gusts, and a few tornadoes are all possible. ...20z Update... The previous forecast remains on track with no appreciable changes required. Signs of broad-scale ascent beginning to overspread the High Plains west of the surface trough/dryline are evident in latest GOES imagery. Shallow cumulus is beginning to develop from western NE southward into west TX, which suggests that convective initiation within this corridor should become more probable within the next few hours as we approach peak diurnal heating and dryline circulations are maximized. West Texas Mesonet observations are sampling higher dewpoints (by about 2-3 F) and stronger surface convergence than anticipated by most model solutions. This suggests that the probability of realizing the potent convective environment may be increasing across the TX Panhandle (though confidence in storm coverage remains too limited to warrant any upgrades). Further north, recent RAP analyses show the tightest low-level lapse rate gradient across western KS, indicative of a tighter/stronger dryline circulation. This trend supports some recent high-res guidance that shows convective initiation between 21-00z across this region and warrants maintaining the current risk probabilities. Similarly, steady surface pressure falls across western NE/SD suggest that ascent is strongest across the central High Plains region, which should favor at least isolated thunderstorm development this afternoon. See the previous discussion below for additional details. ..Moore.. 04/27/2025 .PREV DISCUSSION... /ISSUED 1130 AM CDT Sun Apr 27 2025/ ...Synopsis... Water-vapor imagery this morning shows a mid- to upper-level low over NV. A belt of strong southwesterly mid to high-level flow will extend from the base of the western U.S. trough through the southern/central High Plains later today into tonight. A pair of smaller-scale disturbances are forecast to eject east-northeastward into the central High Plains and Black Hills vicinity during the mid-late evening. Concurrently, an upper ridge over the eastern half of the Great Plains states will shift eastward over the MS Valley towards daybreak Monday. Late morning surface analysis shows a developing low centered over southeast WY with a lee trough/dryline extending southward through the southern High Plains. The cyclone will deepen near the WY/NE/CO border through early evening before developing northeast into central SD late tonight. ...Southeast MT...Western Dakotas... A sharpening lee trough is forecast by late this afternoon amidst appreciable heating and moistening, especially across western SD. Model guidance shows a narrow plume of 500-2000 J/kg MLCAPE (highest over SD) developing by mid-late afternoon as large-scale ascent begins to overspread the region. Isolated to widely scattered thunderstorms are forecast to develop from the northern NE Panhandle to the Black Hills, and north of the developing low over southeast MT by late afternoon. The stronger storms will gradually move into richer moisture with an accompanying risk for mainly large hail and severe gusts. Gradual cooling during the evening will favor a transition to elevated storms evolving with time as a LLJ strengthens tonight. A severe risk will probably develop farther east in association with WAA into parts of the eastern Dakotas and MN late. ...Central/Southern High Plains... Visible-satellite imagery indicates a very moist boundary layer with a mix of a cumulus field across central and north TX and eastern NM/CO and stratus from the TX Caprock northward through OK to NE. The depth and quality of moisture sampled by the 12z Midland, Amarillo, and Dodge City raobs is considered seasonably moisture rich, and is located beneath an elevated mixed layer. Additional moistening through advection and evaporation will contribute to 60s dewpoints east of a dryline/lee trough by late afternoon. Strong heating is forecast near the dryline from western NE southward through West TX, which will result in a weakly capped but moderate to very unstable airmass by 21z. Large-scale forcing for ascent across the region will be nebulous, but low-level convergence along the dryline amid little to no convective inhibition may result in convective initiation. With dryline convergence as the mechanism for convective initiation, predictability is low. Dryline circulations will likely be strongest across the TX Panhandle/West TX where temperatures west of the dryline will be warmest, but low-level convergence will likely maximize in the CO/NE/KS border intersection vicinity near a developing surface low. As a result, these two areas may have a greater risk for thunderstorms (isolated, widely spaced storm coverage) late this afternoon into the evening. The overall environment will be very supportive of supercells with any storms that do form, with large to very large hail as the primary risk initially. If any storms manage to develop and become sustained, a strengthening low-level jet will support a tornado threat during the evening with any storms that persist (or develop along the retreating dryline). Nocturnal cooling and increased CINH by mid to late evening will act to eventually weaken storm activity in this region. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0252 PM CDT Sun Apr 27 2025 Valid 272000Z - 281200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR MUCH OF THE GREAT PLAINS... ...SUMMARY... Isolated to scattered severe thunderstorms are possible mainly this evening into early morning Monday across parts of the Great Plains. Large to very large hail, severe gusts, and a few tornadoes are all possible. ...20z Update... The previous forecast remains on track with no appreciable changes required. Signs of broad-scale ascent beginning to overspread the High Plains west of the surface trough/dryline are evident in latest GOES imagery. Shallow cumulus is beginning to develop from western NE southward into west TX, which suggests that convective initiation within this corridor should become more probable within the next few hours as we approach peak diurnal heating and dryline circulations are maximized. West Texas Mesonet observations are sampling higher dewpoints (by about 2-3 F) and stronger surface convergence than anticipated by most model solutions. This suggests that the probability of realizing the potent convective environment may be increasing across the TX Panhandle (though confidence in storm coverage remains too limited to warrant any upgrades). Further north, recent RAP analyses show the tightest low-level lapse rate gradient across western KS, indicative of a tighter/stronger dryline circulation. This trend supports some recent high-res guidance that shows convective initiation between 21-00z across this region and warrants maintaining the current risk probabilities. Similarly, steady surface pressure falls across western NE/SD suggest that ascent is strongest across the central High Plains region, which should favor at least isolated thunderstorm development this afternoon. See the previous discussion below for additional details. ..Moore.. 04/27/2025 .PREV DISCUSSION... /ISSUED 1130 AM CDT Sun Apr 27 2025/ ...Synopsis... Water-vapor imagery this morning shows a mid- to upper-level low over NV. A belt of strong southwesterly mid to high-level flow will extend from the base of the western U.S. trough through the southern/central High Plains later today into tonight. A pair of smaller-scale disturbances are forecast to eject east-northeastward into the central High Plains and Black Hills vicinity during the mid-late evening. Concurrently, an upper ridge over the eastern half of the Great Plains states will shift eastward over the MS Valley towards daybreak Monday. Late morning surface analysis shows a developing low centered over southeast WY with a lee trough/dryline extending southward through the southern High Plains. The cyclone will deepen near the WY/NE/CO border through early evening before developing northeast into central SD late tonight. ...Southeast MT...Western Dakotas... A sharpening lee trough is forecast by late this afternoon amidst appreciable heating and moistening, especially across western SD. Model guidance shows a narrow plume of 500-2000 J/kg MLCAPE (highest over SD) developing by mid-late afternoon as large-scale ascent begins to overspread the region. Isolated to widely scattered thunderstorms are forecast to develop from the northern NE Panhandle to the Black Hills, and north of the developing low over southeast MT by late afternoon. The stronger storms will gradually move into richer moisture with an accompanying risk for mainly large hail and severe gusts. Gradual cooling during the evening will favor a transition to elevated storms evolving with time as a LLJ strengthens tonight. A severe risk will probably develop farther east in association with WAA into parts of the eastern Dakotas and MN late. ...Central/Southern High Plains... Visible-satellite imagery indicates a very moist boundary layer with a mix of a cumulus field across central and north TX and eastern NM/CO and stratus from the TX Caprock northward through OK to NE. The depth and quality of moisture sampled by the 12z Midland, Amarillo, and Dodge City raobs is considered seasonably moisture rich, and is located beneath an elevated mixed layer. Additional moistening through advection and evaporation will contribute to 60s dewpoints east of a dryline/lee trough by late afternoon. Strong heating is forecast near the dryline from western NE southward through West TX, which will result in a weakly capped but moderate to very unstable airmass by 21z. Large-scale forcing for ascent across the region will be nebulous, but low-level convergence along the dryline amid little to no convective inhibition may result in convective initiation. With dryline convergence as the mechanism for convective initiation, predictability is low. Dryline circulations will likely be strongest across the TX Panhandle/West TX where temperatures west of the dryline will be warmest, but low-level convergence will likely maximize in the CO/NE/KS border intersection vicinity near a developing surface low. As a result, these two areas may have a greater risk for thunderstorms (isolated, widely spaced storm coverage) late this afternoon into the evening. The overall environment will be very supportive of supercells with any storms that do form, with large to very large hail as the primary risk initially. If any storms manage to develop and become sustained, a strengthening low-level jet will support a tornado threat during the evening with any storms that persist (or develop along the retreating dryline). Nocturnal cooling and increased CINH by mid to late evening will act to eventually weaken storm activity in this region. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0252 PM CDT Sun Apr 27 2025 Valid 272000Z - 281200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR MUCH OF THE GREAT PLAINS... ...SUMMARY... Isolated to scattered severe thunderstorms are possible mainly this evening into early morning Monday across parts of the Great Plains. Large to very large hail, severe gusts, and a few tornadoes are all possible. ...20z Update... The previous forecast remains on track with no appreciable changes required. Signs of broad-scale ascent beginning to overspread the High Plains west of the surface trough/dryline are evident in latest GOES imagery. Shallow cumulus is beginning to develop from western NE southward into west TX, which suggests that convective initiation within this corridor should become more probable within the next few hours as we approach peak diurnal heating and dryline circulations are maximized. West Texas Mesonet observations are sampling higher dewpoints (by about 2-3 F) and stronger surface convergence than anticipated by most model solutions. This suggests that the probability of realizing the potent convective environment may be increasing across the TX Panhandle (though confidence in storm coverage remains too limited to warrant any upgrades). Further north, recent RAP analyses show the tightest low-level lapse rate gradient across western KS, indicative of a tighter/stronger dryline circulation. This trend supports some recent high-res guidance that shows convective initiation between 21-00z across this region and warrants maintaining the current risk probabilities. Similarly, steady surface pressure falls across western NE/SD suggest that ascent is strongest across the central High Plains region, which should favor at least isolated thunderstorm development this afternoon. See the previous discussion below for additional details. ..Moore.. 04/27/2025 .PREV DISCUSSION... /ISSUED 1130 AM CDT Sun Apr 27 2025/ ...Synopsis... Water-vapor imagery this morning shows a mid- to upper-level low over NV. A belt of strong southwesterly mid to high-level flow will extend from the base of the western U.S. trough through the southern/central High Plains later today into tonight. A pair of smaller-scale disturbances are forecast to eject east-northeastward into the central High Plains and Black Hills vicinity during the mid-late evening. Concurrently, an upper ridge over the eastern half of the Great Plains states will shift eastward over the MS Valley towards daybreak Monday. Late morning surface analysis shows a developing low centered over southeast WY with a lee trough/dryline extending southward through the southern High Plains. The cyclone will deepen near the WY/NE/CO border through early evening before developing northeast into central SD late tonight. ...Southeast MT...Western Dakotas... A sharpening lee trough is forecast by late this afternoon amidst appreciable heating and moistening, especially across western SD. Model guidance shows a narrow plume of 500-2000 J/kg MLCAPE (highest over SD) developing by mid-late afternoon as large-scale ascent begins to overspread the region. Isolated to widely scattered thunderstorms are forecast to develop from the northern NE Panhandle to the Black Hills, and north of the developing low over southeast MT by late afternoon. The stronger storms will gradually move into richer moisture with an accompanying risk for mainly large hail and severe gusts. Gradual cooling during the evening will favor a transition to elevated storms evolving with time as a LLJ strengthens tonight. A severe risk will probably develop farther east in association with WAA into parts of the eastern Dakotas and MN late. ...Central/Southern High Plains... Visible-satellite imagery indicates a very moist boundary layer with a mix of a cumulus field across central and north TX and eastern NM/CO and stratus from the TX Caprock northward through OK to NE. The depth and quality of moisture sampled by the 12z Midland, Amarillo, and Dodge City raobs is considered seasonably moisture rich, and is located beneath an elevated mixed layer. Additional moistening through advection and evaporation will contribute to 60s dewpoints east of a dryline/lee trough by late afternoon. Strong heating is forecast near the dryline from western NE southward through West TX, which will result in a weakly capped but moderate to very unstable airmass by 21z. Large-scale forcing for ascent across the region will be nebulous, but low-level convergence along the dryline amid little to no convective inhibition may result in convective initiation. With dryline convergence as the mechanism for convective initiation, predictability is low. Dryline circulations will likely be strongest across the TX Panhandle/West TX where temperatures west of the dryline will be warmest, but low-level convergence will likely maximize in the CO/NE/KS border intersection vicinity near a developing surface low. As a result, these two areas may have a greater risk for thunderstorms (isolated, widely spaced storm coverage) late this afternoon into the evening. The overall environment will be very supportive of supercells with any storms that do form, with large to very large hail as the primary risk initially. If any storms manage to develop and become sustained, a strengthening low-level jet will support a tornado threat during the evening with any storms that persist (or develop along the retreating dryline). Nocturnal cooling and increased CINH by mid to late evening will act to eventually weaken storm activity in this region. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0252 PM CDT Sun Apr 27 2025 Valid 272000Z - 281200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR MUCH OF THE GREAT PLAINS... ...SUMMARY... Isolated to scattered severe thunderstorms are possible mainly this evening into early morning Monday across parts of the Great Plains. Large to very large hail, severe gusts, and a few tornadoes are all possible. ...20z Update... The previous forecast remains on track with no appreciable changes required. Signs of broad-scale ascent beginning to overspread the High Plains west of the surface trough/dryline are evident in latest GOES imagery. Shallow cumulus is beginning to develop from western NE southward into west TX, which suggests that convective initiation within this corridor should become more probable within the next few hours as we approach peak diurnal heating and dryline circulations are maximized. West Texas Mesonet observations are sampling higher dewpoints (by about 2-3 F) and stronger surface convergence than anticipated by most model solutions. This suggests that the probability of realizing the potent convective environment may be increasing across the TX Panhandle (though confidence in storm coverage remains too limited to warrant any upgrades). Further north, recent RAP analyses show the tightest low-level lapse rate gradient across western KS, indicative of a tighter/stronger dryline circulation. This trend supports some recent high-res guidance that shows convective initiation between 21-00z across this region and warrants maintaining the current risk probabilities. Similarly, steady surface pressure falls across western NE/SD suggest that ascent is strongest across the central High Plains region, which should favor at least isolated thunderstorm development this afternoon. See the previous discussion below for additional details. ..Moore.. 04/27/2025 .PREV DISCUSSION... /ISSUED 1130 AM CDT Sun Apr 27 2025/ ...Synopsis... Water-vapor imagery this morning shows a mid- to upper-level low over NV. A belt of strong southwesterly mid to high-level flow will extend from the base of the western U.S. trough through the southern/central High Plains later today into tonight. A pair of smaller-scale disturbances are forecast to eject east-northeastward into the central High Plains and Black Hills vicinity during the mid-late evening. Concurrently, an upper ridge over the eastern half of the Great Plains states will shift eastward over the MS Valley towards daybreak Monday. Late morning surface analysis shows a developing low centered over southeast WY with a lee trough/dryline extending southward through the southern High Plains. The cyclone will deepen near the WY/NE/CO border through early evening before developing northeast into central SD late tonight. ...Southeast MT...Western Dakotas... A sharpening lee trough is forecast by late this afternoon amidst appreciable heating and moistening, especially across western SD. Model guidance shows a narrow plume of 500-2000 J/kg MLCAPE (highest over SD) developing by mid-late afternoon as large-scale ascent begins to overspread the region. Isolated to widely scattered thunderstorms are forecast to develop from the northern NE Panhandle to the Black Hills, and north of the developing low over southeast MT by late afternoon. The stronger storms will gradually move into richer moisture with an accompanying risk for mainly large hail and severe gusts. Gradual cooling during the evening will favor a transition to elevated storms evolving with time as a LLJ strengthens tonight. A severe risk will probably develop farther east in association with WAA into parts of the eastern Dakotas and MN late. ...Central/Southern High Plains... Visible-satellite imagery indicates a very moist boundary layer with a mix of a cumulus field across central and north TX and eastern NM/CO and stratus from the TX Caprock northward through OK to NE. The depth and quality of moisture sampled by the 12z Midland, Amarillo, and Dodge City raobs is considered seasonably moisture rich, and is located beneath an elevated mixed layer. Additional moistening through advection and evaporation will contribute to 60s dewpoints east of a dryline/lee trough by late afternoon. Strong heating is forecast near the dryline from western NE southward through West TX, which will result in a weakly capped but moderate to very unstable airmass by 21z. Large-scale forcing for ascent across the region will be nebulous, but low-level convergence along the dryline amid little to no convective inhibition may result in convective initiation. With dryline convergence as the mechanism for convective initiation, predictability is low. Dryline circulations will likely be strongest across the TX Panhandle/West TX where temperatures west of the dryline will be warmest, but low-level convergence will likely maximize in the CO/NE/KS border intersection vicinity near a developing surface low. As a result, these two areas may have a greater risk for thunderstorms (isolated, widely spaced storm coverage) late this afternoon into the evening. The overall environment will be very supportive of supercells with any storms that do form, with large to very large hail as the primary risk initially. If any storms manage to develop and become sustained, a strengthening low-level jet will support a tornado threat during the evening with any storms that persist (or develop along the retreating dryline). Nocturnal cooling and increased CINH by mid to late evening will act to eventually weaken storm activity in this region. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0252 PM CDT Sun Apr 27 2025 Valid 272000Z - 281200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR MUCH OF THE GREAT PLAINS... ...SUMMARY... Isolated to scattered severe thunderstorms are possible mainly this evening into early morning Monday across parts of the Great Plains. Large to very large hail, severe gusts, and a few tornadoes are all possible. ...20z Update... The previous forecast remains on track with no appreciable changes required. Signs of broad-scale ascent beginning to overspread the High Plains west of the surface trough/dryline are evident in latest GOES imagery. Shallow cumulus is beginning to develop from western NE southward into west TX, which suggests that convective initiation within this corridor should become more probable within the next few hours as we approach peak diurnal heating and dryline circulations are maximized. West Texas Mesonet observations are sampling higher dewpoints (by about 2-3 F) and stronger surface convergence than anticipated by most model solutions. This suggests that the probability of realizing the potent convective environment may be increasing across the TX Panhandle (though confidence in storm coverage remains too limited to warrant any upgrades). Further north, recent RAP analyses show the tightest low-level lapse rate gradient across western KS, indicative of a tighter/stronger dryline circulation. This trend supports some recent high-res guidance that shows convective initiation between 21-00z across this region and warrants maintaining the current risk probabilities. Similarly, steady surface pressure falls across western NE/SD suggest that ascent is strongest across the central High Plains region, which should favor at least isolated thunderstorm development this afternoon. See the previous discussion below for additional details. ..Moore.. 04/27/2025 .PREV DISCUSSION... /ISSUED 1130 AM CDT Sun Apr 27 2025/ ...Synopsis... Water-vapor imagery this morning shows a mid- to upper-level low over NV. A belt of strong southwesterly mid to high-level flow will extend from the base of the western U.S. trough through the southern/central High Plains later today into tonight. A pair of smaller-scale disturbances are forecast to eject east-northeastward into the central High Plains and Black Hills vicinity during the mid-late evening. Concurrently, an upper ridge over the eastern half of the Great Plains states will shift eastward over the MS Valley towards daybreak Monday. Late morning surface analysis shows a developing low centered over southeast WY with a lee trough/dryline extending southward through the southern High Plains. The cyclone will deepen near the WY/NE/CO border through early evening before developing northeast into central SD late tonight. ...Southeast MT...Western Dakotas... A sharpening lee trough is forecast by late this afternoon amidst appreciable heating and moistening, especially across western SD. Model guidance shows a narrow plume of 500-2000 J/kg MLCAPE (highest over SD) developing by mid-late afternoon as large-scale ascent begins to overspread the region. Isolated to widely scattered thunderstorms are forecast to develop from the northern NE Panhandle to the Black Hills, and north of the developing low over southeast MT by late afternoon. The stronger storms will gradually move into richer moisture with an accompanying risk for mainly large hail and severe gusts. Gradual cooling during the evening will favor a transition to elevated storms evolving with time as a LLJ strengthens tonight. A severe risk will probably develop farther east in association with WAA into parts of the eastern Dakotas and MN late. ...Central/Southern High Plains... Visible-satellite imagery indicates a very moist boundary layer with a mix of a cumulus field across central and north TX and eastern NM/CO and stratus from the TX Caprock northward through OK to NE. The depth and quality of moisture sampled by the 12z Midland, Amarillo, and Dodge City raobs is considered seasonably moisture rich, and is located beneath an elevated mixed layer. Additional moistening through advection and evaporation will contribute to 60s dewpoints east of a dryline/lee trough by late afternoon. Strong heating is forecast near the dryline from western NE southward through West TX, which will result in a weakly capped but moderate to very unstable airmass by 21z. Large-scale forcing for ascent across the region will be nebulous, but low-level convergence along the dryline amid little to no convective inhibition may result in convective initiation. With dryline convergence as the mechanism for convective initiation, predictability is low. Dryline circulations will likely be strongest across the TX Panhandle/West TX where temperatures west of the dryline will be warmest, but low-level convergence will likely maximize in the CO/NE/KS border intersection vicinity near a developing surface low. As a result, these two areas may have a greater risk for thunderstorms (isolated, widely spaced storm coverage) late this afternoon into the evening. The overall environment will be very supportive of supercells with any storms that do form, with large to very large hail as the primary risk initially. If any storms manage to develop and become sustained, a strengthening low-level jet will support a tornado threat during the evening with any storms that persist (or develop along the retreating dryline). Nocturnal cooling and increased CINH by mid to late evening will act to eventually weaken storm activity in this region. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0252 PM CDT Sun Apr 27 2025 Valid 272000Z - 281200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR MUCH OF THE GREAT PLAINS... ...SUMMARY... Isolated to scattered severe thunderstorms are possible mainly this evening into early morning Monday across parts of the Great Plains. Large to very large hail, severe gusts, and a few tornadoes are all possible. ...20z Update... The previous forecast remains on track with no appreciable changes required. Signs of broad-scale ascent beginning to overspread the High Plains west of the surface trough/dryline are evident in latest GOES imagery. Shallow cumulus is beginning to develop from western NE southward into west TX, which suggests that convective initiation within this corridor should become more probable within the next few hours as we approach peak diurnal heating and dryline circulations are maximized. West Texas Mesonet observations are sampling higher dewpoints (by about 2-3 F) and stronger surface convergence than anticipated by most model solutions. This suggests that the probability of realizing the potent convective environment may be increasing across the TX Panhandle (though confidence in storm coverage remains too limited to warrant any upgrades). Further north, recent RAP analyses show the tightest low-level lapse rate gradient across western KS, indicative of a tighter/stronger dryline circulation. This trend supports some recent high-res guidance that shows convective initiation between 21-00z across this region and warrants maintaining the current risk probabilities. Similarly, steady surface pressure falls across western NE/SD suggest that ascent is strongest across the central High Plains region, which should favor at least isolated thunderstorm development this afternoon. See the previous discussion below for additional details. ..Moore.. 04/27/2025 .PREV DISCUSSION... /ISSUED 1130 AM CDT Sun Apr 27 2025/ ...Synopsis... Water-vapor imagery this morning shows a mid- to upper-level low over NV. A belt of strong southwesterly mid to high-level flow will extend from the base of the western U.S. trough through the southern/central High Plains later today into tonight. A pair of smaller-scale disturbances are forecast to eject east-northeastward into the central High Plains and Black Hills vicinity during the mid-late evening. Concurrently, an upper ridge over the eastern half of the Great Plains states will shift eastward over the MS Valley towards daybreak Monday. Late morning surface analysis shows a developing low centered over southeast WY with a lee trough/dryline extending southward through the southern High Plains. The cyclone will deepen near the WY/NE/CO border through early evening before developing northeast into central SD late tonight. ...Southeast MT...Western Dakotas... A sharpening lee trough is forecast by late this afternoon amidst appreciable heating and moistening, especially across western SD. Model guidance shows a narrow plume of 500-2000 J/kg MLCAPE (highest over SD) developing by mid-late afternoon as large-scale ascent begins to overspread the region. Isolated to widely scattered thunderstorms are forecast to develop from the northern NE Panhandle to the Black Hills, and north of the developing low over southeast MT by late afternoon. The stronger storms will gradually move into richer moisture with an accompanying risk for mainly large hail and severe gusts. Gradual cooling during the evening will favor a transition to elevated storms evolving with time as a LLJ strengthens tonight. A severe risk will probably develop farther east in association with WAA into parts of the eastern Dakotas and MN late. ...Central/Southern High Plains... Visible-satellite imagery indicates a very moist boundary layer with a mix of a cumulus field across central and north TX and eastern NM/CO and stratus from the TX Caprock northward through OK to NE. The depth and quality of moisture sampled by the 12z Midland, Amarillo, and Dodge City raobs is considered seasonably moisture rich, and is located beneath an elevated mixed layer. Additional moistening through advection and evaporation will contribute to 60s dewpoints east of a dryline/lee trough by late afternoon. Strong heating is forecast near the dryline from western NE southward through West TX, which will result in a weakly capped but moderate to very unstable airmass by 21z. Large-scale forcing for ascent across the region will be nebulous, but low-level convergence along the dryline amid little to no convective inhibition may result in convective initiation. With dryline convergence as the mechanism for convective initiation, predictability is low. Dryline circulations will likely be strongest across the TX Panhandle/West TX where temperatures west of the dryline will be warmest, but low-level convergence will likely maximize in the CO/NE/KS border intersection vicinity near a developing surface low. As a result, these two areas may have a greater risk for thunderstorms (isolated, widely spaced storm coverage) late this afternoon into the evening. The overall environment will be very supportive of supercells with any storms that do form, with large to very large hail as the primary risk initially. If any storms manage to develop and become sustained, a strengthening low-level jet will support a tornado threat during the evening with any storms that persist (or develop along the retreating dryline). Nocturnal cooling and increased CINH by mid to late evening will act to eventually weaken storm activity in this region. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0252 PM CDT Sun Apr 27 2025 Valid 272000Z - 281200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR MUCH OF THE GREAT PLAINS... ...SUMMARY... Isolated to scattered severe thunderstorms are possible mainly this evening into early morning Monday across parts of the Great Plains. Large to very large hail, severe gusts, and a few tornadoes are all possible. ...20z Update... The previous forecast remains on track with no appreciable changes required. Signs of broad-scale ascent beginning to overspread the High Plains west of the surface trough/dryline are evident in latest GOES imagery. Shallow cumulus is beginning to develop from western NE southward into west TX, which suggests that convective initiation within this corridor should become more probable within the next few hours as we approach peak diurnal heating and dryline circulations are maximized. West Texas Mesonet observations are sampling higher dewpoints (by about 2-3 F) and stronger surface convergence than anticipated by most model solutions. This suggests that the probability of realizing the potent convective environment may be increasing across the TX Panhandle (though confidence in storm coverage remains too limited to warrant any upgrades). Further north, recent RAP analyses show the tightest low-level lapse rate gradient across western KS, indicative of a tighter/stronger dryline circulation. This trend supports some recent high-res guidance that shows convective initiation between 21-00z across this region and warrants maintaining the current risk probabilities. Similarly, steady surface pressure falls across western NE/SD suggest that ascent is strongest across the central High Plains region, which should favor at least isolated thunderstorm development this afternoon. See the previous discussion below for additional details. ..Moore.. 04/27/2025 .PREV DISCUSSION... /ISSUED 1130 AM CDT Sun Apr 27 2025/ ...Synopsis... Water-vapor imagery this morning shows a mid- to upper-level low over NV. A belt of strong southwesterly mid to high-level flow will extend from the base of the western U.S. trough through the southern/central High Plains later today into tonight. A pair of smaller-scale disturbances are forecast to eject east-northeastward into the central High Plains and Black Hills vicinity during the mid-late evening. Concurrently, an upper ridge over the eastern half of the Great Plains states will shift eastward over the MS Valley towards daybreak Monday. Late morning surface analysis shows a developing low centered over southeast WY with a lee trough/dryline extending southward through the southern High Plains. The cyclone will deepen near the WY/NE/CO border through early evening before developing northeast into central SD late tonight. ...Southeast MT...Western Dakotas... A sharpening lee trough is forecast by late this afternoon amidst appreciable heating and moistening, especially across western SD. Model guidance shows a narrow plume of 500-2000 J/kg MLCAPE (highest over SD) developing by mid-late afternoon as large-scale ascent begins to overspread the region. Isolated to widely scattered thunderstorms are forecast to develop from the northern NE Panhandle to the Black Hills, and north of the developing low over southeast MT by late afternoon. The stronger storms will gradually move into richer moisture with an accompanying risk for mainly large hail and severe gusts. Gradual cooling during the evening will favor a transition to elevated storms evolving with time as a LLJ strengthens tonight. A severe risk will probably develop farther east in association with WAA into parts of the eastern Dakotas and MN late. ...Central/Southern High Plains... Visible-satellite imagery indicates a very moist boundary layer with a mix of a cumulus field across central and north TX and eastern NM/CO and stratus from the TX Caprock northward through OK to NE. The depth and quality of moisture sampled by the 12z Midland, Amarillo, and Dodge City raobs is considered seasonably moisture rich, and is located beneath an elevated mixed layer. Additional moistening through advection and evaporation will contribute to 60s dewpoints east of a dryline/lee trough by late afternoon. Strong heating is forecast near the dryline from western NE southward through West TX, which will result in a weakly capped but moderate to very unstable airmass by 21z. Large-scale forcing for ascent across the region will be nebulous, but low-level convergence along the dryline amid little to no convective inhibition may result in convective initiation. With dryline convergence as the mechanism for convective initiation, predictability is low. Dryline circulations will likely be strongest across the TX Panhandle/West TX where temperatures west of the dryline will be warmest, but low-level convergence will likely maximize in the CO/NE/KS border intersection vicinity near a developing surface low. As a result, these two areas may have a greater risk for thunderstorms (isolated, widely spaced storm coverage) late this afternoon into the evening. The overall environment will be very supportive of supercells with any storms that do form, with large to very large hail as the primary risk initially. If any storms manage to develop and become sustained, a strengthening low-level jet will support a tornado threat during the evening with any storms that persist (or develop along the retreating dryline). Nocturnal cooling and increased CINH by mid to late evening will act to eventually weaken storm activity in this region. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0252 PM CDT Sun Apr 27 2025 Valid 272000Z - 281200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR MUCH OF THE GREAT PLAINS... ...SUMMARY... Isolated to scattered severe thunderstorms are possible mainly this evening into early morning Monday across parts of the Great Plains. Large to very large hail, severe gusts, and a few tornadoes are all possible. ...20z Update... The previous forecast remains on track with no appreciable changes required. Signs of broad-scale ascent beginning to overspread the High Plains west of the surface trough/dryline are evident in latest GOES imagery. Shallow cumulus is beginning to develop from western NE southward into west TX, which suggests that convective initiation within this corridor should become more probable within the next few hours as we approach peak diurnal heating and dryline circulations are maximized. West Texas Mesonet observations are sampling higher dewpoints (by about 2-3 F) and stronger surface convergence than anticipated by most model solutions. This suggests that the probability of realizing the potent convective environment may be increasing across the TX Panhandle (though confidence in storm coverage remains too limited to warrant any upgrades). Further north, recent RAP analyses show the tightest low-level lapse rate gradient across western KS, indicative of a tighter/stronger dryline circulation. This trend supports some recent high-res guidance that shows convective initiation between 21-00z across this region and warrants maintaining the current risk probabilities. Similarly, steady surface pressure falls across western NE/SD suggest that ascent is strongest across the central High Plains region, which should favor at least isolated thunderstorm development this afternoon. See the previous discussion below for additional details. ..Moore.. 04/27/2025 .PREV DISCUSSION... /ISSUED 1130 AM CDT Sun Apr 27 2025/ ...Synopsis... Water-vapor imagery this morning shows a mid- to upper-level low over NV. A belt of strong southwesterly mid to high-level flow will extend from the base of the western U.S. trough through the southern/central High Plains later today into tonight. A pair of smaller-scale disturbances are forecast to eject east-northeastward into the central High Plains and Black Hills vicinity during the mid-late evening. Concurrently, an upper ridge over the eastern half of the Great Plains states will shift eastward over the MS Valley towards daybreak Monday. Late morning surface analysis shows a developing low centered over southeast WY with a lee trough/dryline extending southward through the southern High Plains. The cyclone will deepen near the WY/NE/CO border through early evening before developing northeast into central SD late tonight. ...Southeast MT...Western Dakotas... A sharpening lee trough is forecast by late this afternoon amidst appreciable heating and moistening, especially across western SD. Model guidance shows a narrow plume of 500-2000 J/kg MLCAPE (highest over SD) developing by mid-late afternoon as large-scale ascent begins to overspread the region. Isolated to widely scattered thunderstorms are forecast to develop from the northern NE Panhandle to the Black Hills, and north of the developing low over southeast MT by late afternoon. The stronger storms will gradually move into richer moisture with an accompanying risk for mainly large hail and severe gusts. Gradual cooling during the evening will favor a transition to elevated storms evolving with time as a LLJ strengthens tonight. A severe risk will probably develop farther east in association with WAA into parts of the eastern Dakotas and MN late. ...Central/Southern High Plains... Visible-satellite imagery indicates a very moist boundary layer with a mix of a cumulus field across central and north TX and eastern NM/CO and stratus from the TX Caprock northward through OK to NE. The depth and quality of moisture sampled by the 12z Midland, Amarillo, and Dodge City raobs is considered seasonably moisture rich, and is located beneath an elevated mixed layer. Additional moistening through advection and evaporation will contribute to 60s dewpoints east of a dryline/lee trough by late afternoon. Strong heating is forecast near the dryline from western NE southward through West TX, which will result in a weakly capped but moderate to very unstable airmass by 21z. Large-scale forcing for ascent across the region will be nebulous, but low-level convergence along the dryline amid little to no convective inhibition may result in convective initiation. With dryline convergence as the mechanism for convective initiation, predictability is low. Dryline circulations will likely be strongest across the TX Panhandle/West TX where temperatures west of the dryline will be warmest, but low-level convergence will likely maximize in the CO/NE/KS border intersection vicinity near a developing surface low. As a result, these two areas may have a greater risk for thunderstorms (isolated, widely spaced storm coverage) late this afternoon into the evening. The overall environment will be very supportive of supercells with any storms that do form, with large to very large hail as the primary risk initially. If any storms manage to develop and become sustained, a strengthening low-level jet will support a tornado threat during the evening with any storms that persist (or develop along the retreating dryline). Nocturnal cooling and increased CINH by mid to late evening will act to eventually weaken storm activity in this region. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0252 PM CDT Sun Apr 27 2025 Valid 272000Z - 281200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR MUCH OF THE GREAT PLAINS... ...SUMMARY... Isolated to scattered severe thunderstorms are possible mainly this evening into early morning Monday across parts of the Great Plains. Large to very large hail, severe gusts, and a few tornadoes are all possible. ...20z Update... The previous forecast remains on track with no appreciable changes required. Signs of broad-scale ascent beginning to overspread the High Plains west of the surface trough/dryline are evident in latest GOES imagery. Shallow cumulus is beginning to develop from western NE southward into west TX, which suggests that convective initiation within this corridor should become more probable within the next few hours as we approach peak diurnal heating and dryline circulations are maximized. West Texas Mesonet observations are sampling higher dewpoints (by about 2-3 F) and stronger surface convergence than anticipated by most model solutions. This suggests that the probability of realizing the potent convective environment may be increasing across the TX Panhandle (though confidence in storm coverage remains too limited to warrant any upgrades). Further north, recent RAP analyses show the tightest low-level lapse rate gradient across western KS, indicative of a tighter/stronger dryline circulation. This trend supports some recent high-res guidance that shows convective initiation between 21-00z across this region and warrants maintaining the current risk probabilities. Similarly, steady surface pressure falls across western NE/SD suggest that ascent is strongest across the central High Plains region, which should favor at least isolated thunderstorm development this afternoon. See the previous discussion below for additional details. ..Moore.. 04/27/2025 .PREV DISCUSSION... /ISSUED 1130 AM CDT Sun Apr 27 2025/ ...Synopsis... Water-vapor imagery this morning shows a mid- to upper-level low over NV. A belt of strong southwesterly mid to high-level flow will extend from the base of the western U.S. trough through the southern/central High Plains later today into tonight. A pair of smaller-scale disturbances are forecast to eject east-northeastward into the central High Plains and Black Hills vicinity during the mid-late evening. Concurrently, an upper ridge over the eastern half of the Great Plains states will shift eastward over the MS Valley towards daybreak Monday. Late morning surface analysis shows a developing low centered over southeast WY with a lee trough/dryline extending southward through the southern High Plains. The cyclone will deepen near the WY/NE/CO border through early evening before developing northeast into central SD late tonight. ...Southeast MT...Western Dakotas... A sharpening lee trough is forecast by late this afternoon amidst appreciable heating and moistening, especially across western SD. Model guidance shows a narrow plume of 500-2000 J/kg MLCAPE (highest over SD) developing by mid-late afternoon as large-scale ascent begins to overspread the region. Isolated to widely scattered thunderstorms are forecast to develop from the northern NE Panhandle to the Black Hills, and north of the developing low over southeast MT by late afternoon. The stronger storms will gradually move into richer moisture with an accompanying risk for mainly large hail and severe gusts. Gradual cooling during the evening will favor a transition to elevated storms evolving with time as a LLJ strengthens tonight. A severe risk will probably develop farther east in association with WAA into parts of the eastern Dakotas and MN late. ...Central/Southern High Plains... Visible-satellite imagery indicates a very moist boundary layer with a mix of a cumulus field across central and north TX and eastern NM/CO and stratus from the TX Caprock northward through OK to NE. The depth and quality of moisture sampled by the 12z Midland, Amarillo, and Dodge City raobs is considered seasonably moisture rich, and is located beneath an elevated mixed layer. Additional moistening through advection and evaporation will contribute to 60s dewpoints east of a dryline/lee trough by late afternoon. Strong heating is forecast near the dryline from western NE southward through West TX, which will result in a weakly capped but moderate to very unstable airmass by 21z. Large-scale forcing for ascent across the region will be nebulous, but low-level convergence along the dryline amid little to no convective inhibition may result in convective initiation. With dryline convergence as the mechanism for convective initiation, predictability is low. Dryline circulations will likely be strongest across the TX Panhandle/West TX where temperatures west of the dryline will be warmest, but low-level convergence will likely maximize in the CO/NE/KS border intersection vicinity near a developing surface low. As a result, these two areas may have a greater risk for thunderstorms (isolated, widely spaced storm coverage) late this afternoon into the evening. The overall environment will be very supportive of supercells with any storms that do form, with large to very large hail as the primary risk initially. If any storms manage to develop and become sustained, a strengthening low-level jet will support a tornado threat during the evening with any storms that persist (or develop along the retreating dryline). Nocturnal cooling and increased CINH by mid to late evening will act to eventually weaken storm activity in this region. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0252 PM CDT Sun Apr 27 2025 Valid 272000Z - 281200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR MUCH OF THE GREAT PLAINS... ...SUMMARY... Isolated to scattered severe thunderstorms are possible mainly this evening into early morning Monday across parts of the Great Plains. Large to very large hail, severe gusts, and a few tornadoes are all possible. ...20z Update... The previous forecast remains on track with no appreciable changes required. Signs of broad-scale ascent beginning to overspread the High Plains west of the surface trough/dryline are evident in latest GOES imagery. Shallow cumulus is beginning to develop from western NE southward into west TX, which suggests that convective initiation within this corridor should become more probable within the next few hours as we approach peak diurnal heating and dryline circulations are maximized. West Texas Mesonet observations are sampling higher dewpoints (by about 2-3 F) and stronger surface convergence than anticipated by most model solutions. This suggests that the probability of realizing the potent convective environment may be increasing across the TX Panhandle (though confidence in storm coverage remains too limited to warrant any upgrades). Further north, recent RAP analyses show the tightest low-level lapse rate gradient across western KS, indicative of a tighter/stronger dryline circulation. This trend supports some recent high-res guidance that shows convective initiation between 21-00z across this region and warrants maintaining the current risk probabilities. Similarly, steady surface pressure falls across western NE/SD suggest that ascent is strongest across the central High Plains region, which should favor at least isolated thunderstorm development this afternoon. See the previous discussion below for additional details. ..Moore.. 04/27/2025 .PREV DISCUSSION... /ISSUED 1130 AM CDT Sun Apr 27 2025/ ...Synopsis... Water-vapor imagery this morning shows a mid- to upper-level low over NV. A belt of strong southwesterly mid to high-level flow will extend from the base of the western U.S. trough through the southern/central High Plains later today into tonight. A pair of smaller-scale disturbances are forecast to eject east-northeastward into the central High Plains and Black Hills vicinity during the mid-late evening. Concurrently, an upper ridge over the eastern half of the Great Plains states will shift eastward over the MS Valley towards daybreak Monday. Late morning surface analysis shows a developing low centered over southeast WY with a lee trough/dryline extending southward through the southern High Plains. The cyclone will deepen near the WY/NE/CO border through early evening before developing northeast into central SD late tonight. ...Southeast MT...Western Dakotas... A sharpening lee trough is forecast by late this afternoon amidst appreciable heating and moistening, especially across western SD. Model guidance shows a narrow plume of 500-2000 J/kg MLCAPE (highest over SD) developing by mid-late afternoon as large-scale ascent begins to overspread the region. Isolated to widely scattered thunderstorms are forecast to develop from the northern NE Panhandle to the Black Hills, and north of the developing low over southeast MT by late afternoon. The stronger storms will gradually move into richer moisture with an accompanying risk for mainly large hail and severe gusts. Gradual cooling during the evening will favor a transition to elevated storms evolving with time as a LLJ strengthens tonight. A severe risk will probably develop farther east in association with WAA into parts of the eastern Dakotas and MN late. ...Central/Southern High Plains... Visible-satellite imagery indicates a very moist boundary layer with a mix of a cumulus field across central and north TX and eastern NM/CO and stratus from the TX Caprock northward through OK to NE. The depth and quality of moisture sampled by the 12z Midland, Amarillo, and Dodge City raobs is considered seasonably moisture rich, and is located beneath an elevated mixed layer. Additional moistening through advection and evaporation will contribute to 60s dewpoints east of a dryline/lee trough by late afternoon. Strong heating is forecast near the dryline from western NE southward through West TX, which will result in a weakly capped but moderate to very unstable airmass by 21z. Large-scale forcing for ascent across the region will be nebulous, but low-level convergence along the dryline amid little to no convective inhibition may result in convective initiation. With dryline convergence as the mechanism for convective initiation, predictability is low. Dryline circulations will likely be strongest across the TX Panhandle/West TX where temperatures west of the dryline will be warmest, but low-level convergence will likely maximize in the CO/NE/KS border intersection vicinity near a developing surface low. As a result, these two areas may have a greater risk for thunderstorms (isolated, widely spaced storm coverage) late this afternoon into the evening. The overall environment will be very supportive of supercells with any storms that do form, with large to very large hail as the primary risk initially. If any storms manage to develop and become sustained, a strengthening low-level jet will support a tornado threat during the evening with any storms that persist (or develop along the retreating dryline). Nocturnal cooling and increased CINH by mid to late evening will act to eventually weaken storm activity in this region. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0252 PM CDT Sun Apr 27 2025 Valid 272000Z - 281200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR MUCH OF THE GREAT PLAINS... ...SUMMARY... Isolated to scattered severe thunderstorms are possible mainly this evening into early morning Monday across parts of the Great Plains. Large to very large hail, severe gusts, and a few tornadoes are all possible. ...20z Update... The previous forecast remains on track with no appreciable changes required. Signs of broad-scale ascent beginning to overspread the High Plains west of the surface trough/dryline are evident in latest GOES imagery. Shallow cumulus is beginning to develop from western NE southward into west TX, which suggests that convective initiation within this corridor should become more probable within the next few hours as we approach peak diurnal heating and dryline circulations are maximized. West Texas Mesonet observations are sampling higher dewpoints (by about 2-3 F) and stronger surface convergence than anticipated by most model solutions. This suggests that the probability of realizing the potent convective environment may be increasing across the TX Panhandle (though confidence in storm coverage remains too limited to warrant any upgrades). Further north, recent RAP analyses show the tightest low-level lapse rate gradient across western KS, indicative of a tighter/stronger dryline circulation. This trend supports some recent high-res guidance that shows convective initiation between 21-00z across this region and warrants maintaining the current risk probabilities. Similarly, steady surface pressure falls across western NE/SD suggest that ascent is strongest across the central High Plains region, which should favor at least isolated thunderstorm development this afternoon. See the previous discussion below for additional details. ..Moore.. 04/27/2025 .PREV DISCUSSION... /ISSUED 1130 AM CDT Sun Apr 27 2025/ ...Synopsis... Water-vapor imagery this morning shows a mid- to upper-level low over NV. A belt of strong southwesterly mid to high-level flow will extend from the base of the western U.S. trough through the southern/central High Plains later today into tonight. A pair of smaller-scale disturbances are forecast to eject east-northeastward into the central High Plains and Black Hills vicinity during the mid-late evening. Concurrently, an upper ridge over the eastern half of the Great Plains states will shift eastward over the MS Valley towards daybreak Monday. Late morning surface analysis shows a developing low centered over southeast WY with a lee trough/dryline extending southward through the southern High Plains. The cyclone will deepen near the WY/NE/CO border through early evening before developing northeast into central SD late tonight. ...Southeast MT...Western Dakotas... A sharpening lee trough is forecast by late this afternoon amidst appreciable heating and moistening, especially across western SD. Model guidance shows a narrow plume of 500-2000 J/kg MLCAPE (highest over SD) developing by mid-late afternoon as large-scale ascent begins to overspread the region. Isolated to widely scattered thunderstorms are forecast to develop from the northern NE Panhandle to the Black Hills, and north of the developing low over southeast MT by late afternoon. The stronger storms will gradually move into richer moisture with an accompanying risk for mainly large hail and severe gusts. Gradual cooling during the evening will favor a transition to elevated storms evolving with time as a LLJ strengthens tonight. A severe risk will probably develop farther east in association with WAA into parts of the eastern Dakotas and MN late. ...Central/Southern High Plains... Visible-satellite imagery indicates a very moist boundary layer with a mix of a cumulus field across central and north TX and eastern NM/CO and stratus from the TX Caprock northward through OK to NE. The depth and quality of moisture sampled by the 12z Midland, Amarillo, and Dodge City raobs is considered seasonably moisture rich, and is located beneath an elevated mixed layer. Additional moistening through advection and evaporation will contribute to 60s dewpoints east of a dryline/lee trough by late afternoon. Strong heating is forecast near the dryline from western NE southward through West TX, which will result in a weakly capped but moderate to very unstable airmass by 21z. Large-scale forcing for ascent across the region will be nebulous, but low-level convergence along the dryline amid little to no convective inhibition may result in convective initiation. With dryline convergence as the mechanism for convective initiation, predictability is low. Dryline circulations will likely be strongest across the TX Panhandle/West TX where temperatures west of the dryline will be warmest, but low-level convergence will likely maximize in the CO/NE/KS border intersection vicinity near a developing surface low. As a result, these two areas may have a greater risk for thunderstorms (isolated, widely spaced storm coverage) late this afternoon into the evening. The overall environment will be very supportive of supercells with any storms that do form, with large to very large hail as the primary risk initially. If any storms manage to develop and become sustained, a strengthening low-level jet will support a tornado threat during the evening with any storms that persist (or develop along the retreating dryline). Nocturnal cooling and increased CINH by mid to late evening will act to eventually weaken storm activity in this region. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0252 PM CDT Sun Apr 27 2025 Valid 272000Z - 281200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR MUCH OF THE GREAT PLAINS... ...SUMMARY... Isolated to scattered severe thunderstorms are possible mainly this evening into early morning Monday across parts of the Great Plains. Large to very large hail, severe gusts, and a few tornadoes are all possible. ...20z Update... The previous forecast remains on track with no appreciable changes required. Signs of broad-scale ascent beginning to overspread the High Plains west of the surface trough/dryline are evident in latest GOES imagery. Shallow cumulus is beginning to develop from western NE southward into west TX, which suggests that convective initiation within this corridor should become more probable within the next few hours as we approach peak diurnal heating and dryline circulations are maximized. West Texas Mesonet observations are sampling higher dewpoints (by about 2-3 F) and stronger surface convergence than anticipated by most model solutions. This suggests that the probability of realizing the potent convective environment may be increasing across the TX Panhandle (though confidence in storm coverage remains too limited to warrant any upgrades). Further north, recent RAP analyses show the tightest low-level lapse rate gradient across western KS, indicative of a tighter/stronger dryline circulation. This trend supports some recent high-res guidance that shows convective initiation between 21-00z across this region and warrants maintaining the current risk probabilities. Similarly, steady surface pressure falls across western NE/SD suggest that ascent is strongest across the central High Plains region, which should favor at least isolated thunderstorm development this afternoon. See the previous discussion below for additional details. ..Moore.. 04/27/2025 .PREV DISCUSSION... /ISSUED 1130 AM CDT Sun Apr 27 2025/ ...Synopsis... Water-vapor imagery this morning shows a mid- to upper-level low over NV. A belt of strong southwesterly mid to high-level flow will extend from the base of the western U.S. trough through the southern/central High Plains later today into tonight. A pair of smaller-scale disturbances are forecast to eject east-northeastward into the central High Plains and Black Hills vicinity during the mid-late evening. Concurrently, an upper ridge over the eastern half of the Great Plains states will shift eastward over the MS Valley towards daybreak Monday. Late morning surface analysis shows a developing low centered over southeast WY with a lee trough/dryline extending southward through the southern High Plains. The cyclone will deepen near the WY/NE/CO border through early evening before developing northeast into central SD late tonight. ...Southeast MT...Western Dakotas... A sharpening lee trough is forecast by late this afternoon amidst appreciable heating and moistening, especially across western SD. Model guidance shows a narrow plume of 500-2000 J/kg MLCAPE (highest over SD) developing by mid-late afternoon as large-scale ascent begins to overspread the region. Isolated to widely scattered thunderstorms are forecast to develop from the northern NE Panhandle to the Black Hills, and north of the developing low over southeast MT by late afternoon. The stronger storms will gradually move into richer moisture with an accompanying risk for mainly large hail and severe gusts. Gradual cooling during the evening will favor a transition to elevated storms evolving with time as a LLJ strengthens tonight. A severe risk will probably develop farther east in association with WAA into parts of the eastern Dakotas and MN late. ...Central/Southern High Plains... Visible-satellite imagery indicates a very moist boundary layer with a mix of a cumulus field across central and north TX and eastern NM/CO and stratus from the TX Caprock northward through OK to NE. The depth and quality of moisture sampled by the 12z Midland, Amarillo, and Dodge City raobs is considered seasonably moisture rich, and is located beneath an elevated mixed layer. Additional moistening through advection and evaporation will contribute to 60s dewpoints east of a dryline/lee trough by late afternoon. Strong heating is forecast near the dryline from western NE southward through West TX, which will result in a weakly capped but moderate to very unstable airmass by 21z. Large-scale forcing for ascent across the region will be nebulous, but low-level convergence along the dryline amid little to no convective inhibition may result in convective initiation. With dryline convergence as the mechanism for convective initiation, predictability is low. Dryline circulations will likely be strongest across the TX Panhandle/West TX where temperatures west of the dryline will be warmest, but low-level convergence will likely maximize in the CO/NE/KS border intersection vicinity near a developing surface low. As a result, these two areas may have a greater risk for thunderstorms (isolated, widely spaced storm coverage) late this afternoon into the evening. The overall environment will be very supportive of supercells with any storms that do form, with large to very large hail as the primary risk initially. If any storms manage to develop and become sustained, a strengthening low-level jet will support a tornado threat during the evening with any storms that persist (or develop along the retreating dryline). Nocturnal cooling and increased CINH by mid to late evening will act to eventually weaken storm activity in this region. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0252 PM CDT Sun Apr 27 2025 Valid 272000Z - 281200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR MUCH OF THE GREAT PLAINS... ...SUMMARY... Isolated to scattered severe thunderstorms are possible mainly this evening into early morning Monday across parts of the Great Plains. Large to very large hail, severe gusts, and a few tornadoes are all possible. ...20z Update... The previous forecast remains on track with no appreciable changes required. Signs of broad-scale ascent beginning to overspread the High Plains west of the surface trough/dryline are evident in latest GOES imagery. Shallow cumulus is beginning to develop from western NE southward into west TX, which suggests that convective initiation within this corridor should become more probable within the next few hours as we approach peak diurnal heating and dryline circulations are maximized. West Texas Mesonet observations are sampling higher dewpoints (by about 2-3 F) and stronger surface convergence than anticipated by most model solutions. This suggests that the probability of realizing the potent convective environment may be increasing across the TX Panhandle (though confidence in storm coverage remains too limited to warrant any upgrades). Further north, recent RAP analyses show the tightest low-level lapse rate gradient across western KS, indicative of a tighter/stronger dryline circulation. This trend supports some recent high-res guidance that shows convective initiation between 21-00z across this region and warrants maintaining the current risk probabilities. Similarly, steady surface pressure falls across western NE/SD suggest that ascent is strongest across the central High Plains region, which should favor at least isolated thunderstorm development this afternoon. See the previous discussion below for additional details. ..Moore.. 04/27/2025 .PREV DISCUSSION... /ISSUED 1130 AM CDT Sun Apr 27 2025/ ...Synopsis... Water-vapor imagery this morning shows a mid- to upper-level low over NV. A belt of strong southwesterly mid to high-level flow will extend from the base of the western U.S. trough through the southern/central High Plains later today into tonight. A pair of smaller-scale disturbances are forecast to eject east-northeastward into the central High Plains and Black Hills vicinity during the mid-late evening. Concurrently, an upper ridge over the eastern half of the Great Plains states will shift eastward over the MS Valley towards daybreak Monday. Late morning surface analysis shows a developing low centered over southeast WY with a lee trough/dryline extending southward through the southern High Plains. The cyclone will deepen near the WY/NE/CO border through early evening before developing northeast into central SD late tonight. ...Southeast MT...Western Dakotas... A sharpening lee trough is forecast by late this afternoon amidst appreciable heating and moistening, especially across western SD. Model guidance shows a narrow plume of 500-2000 J/kg MLCAPE (highest over SD) developing by mid-late afternoon as large-scale ascent begins to overspread the region. Isolated to widely scattered thunderstorms are forecast to develop from the northern NE Panhandle to the Black Hills, and north of the developing low over southeast MT by late afternoon. The stronger storms will gradually move into richer moisture with an accompanying risk for mainly large hail and severe gusts. Gradual cooling during the evening will favor a transition to elevated storms evolving with time as a LLJ strengthens tonight. A severe risk will probably develop farther east in association with WAA into parts of the eastern Dakotas and MN late. ...Central/Southern High Plains... Visible-satellite imagery indicates a very moist boundary layer with a mix of a cumulus field across central and north TX and eastern NM/CO and stratus from the TX Caprock northward through OK to NE. The depth and quality of moisture sampled by the 12z Midland, Amarillo, and Dodge City raobs is considered seasonably moisture rich, and is located beneath an elevated mixed layer. Additional moistening through advection and evaporation will contribute to 60s dewpoints east of a dryline/lee trough by late afternoon. Strong heating is forecast near the dryline from western NE southward through West TX, which will result in a weakly capped but moderate to very unstable airmass by 21z. Large-scale forcing for ascent across the region will be nebulous, but low-level convergence along the dryline amid little to no convective inhibition may result in convective initiation. With dryline convergence as the mechanism for convective initiation, predictability is low. Dryline circulations will likely be strongest across the TX Panhandle/West TX where temperatures west of the dryline will be warmest, but low-level convergence will likely maximize in the CO/NE/KS border intersection vicinity near a developing surface low. As a result, these two areas may have a greater risk for thunderstorms (isolated, widely spaced storm coverage) late this afternoon into the evening. The overall environment will be very supportive of supercells with any storms that do form, with large to very large hail as the primary risk initially. If any storms manage to develop and become sustained, a strengthening low-level jet will support a tornado threat during the evening with any storms that persist (or develop along the retreating dryline). Nocturnal cooling and increased CINH by mid to late evening will act to eventually weaken storm activity in this region. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0252 PM CDT Sun Apr 27 2025 Valid 272000Z - 281200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR MUCH OF THE GREAT PLAINS... ...SUMMARY... Isolated to scattered severe thunderstorms are possible mainly this evening into early morning Monday across parts of the Great Plains. Large to very large hail, severe gusts, and a few tornadoes are all possible. ...20z Update... The previous forecast remains on track with no appreciable changes required. Signs of broad-scale ascent beginning to overspread the High Plains west of the surface trough/dryline are evident in latest GOES imagery. Shallow cumulus is beginning to develop from western NE southward into west TX, which suggests that convective initiation within this corridor should become more probable within the next few hours as we approach peak diurnal heating and dryline circulations are maximized. West Texas Mesonet observations are sampling higher dewpoints (by about 2-3 F) and stronger surface convergence than anticipated by most model solutions. This suggests that the probability of realizing the potent convective environment may be increasing across the TX Panhandle (though confidence in storm coverage remains too limited to warrant any upgrades). Further north, recent RAP analyses show the tightest low-level lapse rate gradient across western KS, indicative of a tighter/stronger dryline circulation. This trend supports some recent high-res guidance that shows convective initiation between 21-00z across this region and warrants maintaining the current risk probabilities. Similarly, steady surface pressure falls across western NE/SD suggest that ascent is strongest across the central High Plains region, which should favor at least isolated thunderstorm development this afternoon. See the previous discussion below for additional details. ..Moore.. 04/27/2025 .PREV DISCUSSION... /ISSUED 1130 AM CDT Sun Apr 27 2025/ ...Synopsis... Water-vapor imagery this morning shows a mid- to upper-level low over NV. A belt of strong southwesterly mid to high-level flow will extend from the base of the western U.S. trough through the southern/central High Plains later today into tonight. A pair of smaller-scale disturbances are forecast to eject east-northeastward into the central High Plains and Black Hills vicinity during the mid-late evening. Concurrently, an upper ridge over the eastern half of the Great Plains states will shift eastward over the MS Valley towards daybreak Monday. Late morning surface analysis shows a developing low centered over southeast WY with a lee trough/dryline extending southward through the southern High Plains. The cyclone will deepen near the WY/NE/CO border through early evening before developing northeast into central SD late tonight. ...Southeast MT...Western Dakotas... A sharpening lee trough is forecast by late this afternoon amidst appreciable heating and moistening, especially across western SD. Model guidance shows a narrow plume of 500-2000 J/kg MLCAPE (highest over SD) developing by mid-late afternoon as large-scale ascent begins to overspread the region. Isolated to widely scattered thunderstorms are forecast to develop from the northern NE Panhandle to the Black Hills, and north of the developing low over southeast MT by late afternoon. The stronger storms will gradually move into richer moisture with an accompanying risk for mainly large hail and severe gusts. Gradual cooling during the evening will favor a transition to elevated storms evolving with time as a LLJ strengthens tonight. A severe risk will probably develop farther east in association with WAA into parts of the eastern Dakotas and MN late. ...Central/Southern High Plains... Visible-satellite imagery indicates a very moist boundary layer with a mix of a cumulus field across central and north TX and eastern NM/CO and stratus from the TX Caprock northward through OK to NE. The depth and quality of moisture sampled by the 12z Midland, Amarillo, and Dodge City raobs is considered seasonably moisture rich, and is located beneath an elevated mixed layer. Additional moistening through advection and evaporation will contribute to 60s dewpoints east of a dryline/lee trough by late afternoon. Strong heating is forecast near the dryline from western NE southward through West TX, which will result in a weakly capped but moderate to very unstable airmass by 21z. Large-scale forcing for ascent across the region will be nebulous, but low-level convergence along the dryline amid little to no convective inhibition may result in convective initiation. With dryline convergence as the mechanism for convective initiation, predictability is low. Dryline circulations will likely be strongest across the TX Panhandle/West TX where temperatures west of the dryline will be warmest, but low-level convergence will likely maximize in the CO/NE/KS border intersection vicinity near a developing surface low. As a result, these two areas may have a greater risk for thunderstorms (isolated, widely spaced storm coverage) late this afternoon into the evening. The overall environment will be very supportive of supercells with any storms that do form, with large to very large hail as the primary risk initially. If any storms manage to develop and become sustained, a strengthening low-level jet will support a tornado threat during the evening with any storms that persist (or develop along the retreating dryline). Nocturnal cooling and increased CINH by mid to late evening will act to eventually weaken storm activity in this region. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0252 PM CDT Sun Apr 27 2025 Valid 272000Z - 281200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR MUCH OF THE GREAT PLAINS... ...SUMMARY... Isolated to scattered severe thunderstorms are possible mainly this evening into early morning Monday across parts of the Great Plains. Large to very large hail, severe gusts, and a few tornadoes are all possible. ...20z Update... The previous forecast remains on track with no appreciable changes required. Signs of broad-scale ascent beginning to overspread the High Plains west of the surface trough/dryline are evident in latest GOES imagery. Shallow cumulus is beginning to develop from western NE southward into west TX, which suggests that convective initiation within this corridor should become more probable within the next few hours as we approach peak diurnal heating and dryline circulations are maximized. West Texas Mesonet observations are sampling higher dewpoints (by about 2-3 F) and stronger surface convergence than anticipated by most model solutions. This suggests that the probability of realizing the potent convective environment may be increasing across the TX Panhandle (though confidence in storm coverage remains too limited to warrant any upgrades). Further north, recent RAP analyses show the tightest low-level lapse rate gradient across western KS, indicative of a tighter/stronger dryline circulation. This trend supports some recent high-res guidance that shows convective initiation between 21-00z across this region and warrants maintaining the current risk probabilities. Similarly, steady surface pressure falls across western NE/SD suggest that ascent is strongest across the central High Plains region, which should favor at least isolated thunderstorm development this afternoon. See the previous discussion below for additional details. ..Moore.. 04/27/2025 .PREV DISCUSSION... /ISSUED 1130 AM CDT Sun Apr 27 2025/ ...Synopsis... Water-vapor imagery this morning shows a mid- to upper-level low over NV. A belt of strong southwesterly mid to high-level flow will extend from the base of the western U.S. trough through the southern/central High Plains later today into tonight. A pair of smaller-scale disturbances are forecast to eject east-northeastward into the central High Plains and Black Hills vicinity during the mid-late evening. Concurrently, an upper ridge over the eastern half of the Great Plains states will shift eastward over the MS Valley towards daybreak Monday. Late morning surface analysis shows a developing low centered over southeast WY with a lee trough/dryline extending southward through the southern High Plains. The cyclone will deepen near the WY/NE/CO border through early evening before developing northeast into central SD late tonight. ...Southeast MT...Western Dakotas... A sharpening lee trough is forecast by late this afternoon amidst appreciable heating and moistening, especially across western SD. Model guidance shows a narrow plume of 500-2000 J/kg MLCAPE (highest over SD) developing by mid-late afternoon as large-scale ascent begins to overspread the region. Isolated to widely scattered thunderstorms are forecast to develop from the northern NE Panhandle to the Black Hills, and north of the developing low over southeast MT by late afternoon. The stronger storms will gradually move into richer moisture with an accompanying risk for mainly large hail and severe gusts. Gradual cooling during the evening will favor a transition to elevated storms evolving with time as a LLJ strengthens tonight. A severe risk will probably develop farther east in association with WAA into parts of the eastern Dakotas and MN late. ...Central/Southern High Plains... Visible-satellite imagery indicates a very moist boundary layer with a mix of a cumulus field across central and north TX and eastern NM/CO and stratus from the TX Caprock northward through OK to NE. The depth and quality of moisture sampled by the 12z Midland, Amarillo, and Dodge City raobs is considered seasonably moisture rich, and is located beneath an elevated mixed layer. Additional moistening through advection and evaporation will contribute to 60s dewpoints east of a dryline/lee trough by late afternoon. Strong heating is forecast near the dryline from western NE southward through West TX, which will result in a weakly capped but moderate to very unstable airmass by 21z. Large-scale forcing for ascent across the region will be nebulous, but low-level convergence along the dryline amid little to no convective inhibition may result in convective initiation. With dryline convergence as the mechanism for convective initiation, predictability is low. Dryline circulations will likely be strongest across the TX Panhandle/West TX where temperatures west of the dryline will be warmest, but low-level convergence will likely maximize in the CO/NE/KS border intersection vicinity near a developing surface low. As a result, these two areas may have a greater risk for thunderstorms (isolated, widely spaced storm coverage) late this afternoon into the evening. The overall environment will be very supportive of supercells with any storms that do form, with large to very large hail as the primary risk initially. If any storms manage to develop and become sustained, a strengthening low-level jet will support a tornado threat during the evening with any storms that persist (or develop along the retreating dryline). Nocturnal cooling and increased CINH by mid to late evening will act to eventually weaken storm activity in this region. Read more