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SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0750 AM CDT Tue May 13 2025 Valid 131300Z - 141200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE MID-ATLANTIC...NORTHERN GREAT PLAINS...AND DEEP SOUTH... ...SUMMARY... Isolated severe thunderstorms are possible: 1) today in vicinity of Virginia-North Carolina-West Virginia, 2) during the late afternoon to mid-evening over a portion of the Deep South, and 3) this evening into early morning Wednesday in parts of the northern Great Plains. ...NC/VA/WV vicinity... The upper-level low centered near the mid-Mississippi Valley will continue to lift east/northeast through tonight, as a notable shortwave trough rotates northeast across the Mid-Atlantic region. Generally weak surface-based instability (MLCAPE at or below 1000 J/kg) will exist across the coastal plain as a belt of stronger 850 mb flow lifts northeast across eastern sections of NC/VA. This will contribute to enlarged low-level hodograph structures and support the continued potential for transient areas of rotation and a few short-lived tornadoes associated with stronger convective elements. See recently issued Mesoscale Discussion 774 for details on short-term convective trends. Farther west into WV/western VA and NC, subtle large-scale forcing for ascent with the approaching upper low will contribute to thunderstorm development. Although deep-layer shear will tend to relax with westward extent, slightly more favorable mid-level lapse rates and 1000-locally 1500 J/kg MLCAPE will result in the potential for isolated strong/severe gusts and hail. ...AL/MS/TN vicinity... Some hi-res guidance continues to suggest a supercell or two may develop to the west of the departing mid-level trough, where a corridor of differential boundary-layer heating may support a favored zone for late afternoon through mid-evening storm development. Some veering of the wind profile should yield modest hodograph curvature. This, coupled with moderate mid-level west-northwesterly flow, will favor a conditional supercell threat. ...Northern Great Plains... An upstream upper-level trough over the western U.S. will move steadily east, resulting in strengthening southerly mid-level flow across the northern Plains. A Pacific cold front will make modest eastward progress today before becoming quasi-stationary across the western/central Dakotas, however the stronger mid-level flow will remain generally displaced to the west. Weak elevated buoyancy and sufficient deep-layer shear may still result in scattered storms, including supercells, with potential for severe hail. Some risk for strong/severe gusts may also exist with storms closer to the surface front. ..Bunting/Dean.. 05/13/2025 Read more

MD 0773 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR PARTS OF EASTERN NC INTO SOUTHEAST VA
Mesoscale Discussion 0773 NWS Storm Prediction Center Norman OK 0419 AM CDT Tue May 13 2025 Areas affected...Parts of eastern NC into southeast VA Concerning...Severe potential...Watch unlikely Valid 130919Z - 131145Z Probability of Watch Issuance...20 percent SUMMARY...A localized brief-tornado and wind-damage threat will spread northward through dawn. DISCUSSION...Occasional rotation continues to be noted with embedded northward-moving cells across eastern NC. An apparent tornado occurred earlier in Edgecombe County, NC, and the environment remains modestly favorable for transient supercells, with MLCAPE approaching 500 J/kg and effective SRH generally in the 150-200 m2/s2 range. This environment is expected to gradually spread northward with time, in conjunction with a strengthening low-level jet. As this occurs, a localized brief-tornado and wind-damage threat will potentially expand across northeast NC into far southeast VA by dawn. Farther south, some veering and weakening of low-level flow has been noted on the KLTX VWP. However, convection remains somewhat vigorous (as evidenced by recent lightning activity) across southeast NC, and this trailing convective cluster could pose a localized severe threat as it continues to move northeastward. ..Dean/Bunting.. 05/13/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...AKQ...MHX...RAH...ILM...RNK... LAT...LON 35467541 35357549 34547652 34187716 33857815 34147836 34527842 34917859 36417934 36747884 36897799 37017710 36897627 36647601 35937560 35647549 35467541 MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 95 MPH MOST PROBABLE PEAK WIND GUST...UP TO 60 MPH Read more

MD 0772 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR PARTS OF EASTERN NC
Mesoscale Discussion 0772 NWS Storm Prediction Center Norman OK 0140 AM CDT Tue May 13 2025 Areas affected...Parts of eastern NC Concerning...Severe potential...Watch unlikely Valid 130640Z - 130915Z Probability of Watch Issuance...20 percent SUMMARY...Some localized brief-tornado and wind-damage threat may persist overnight. DISCUSSION...Multiple clusters of convection are ongoing from northeast SC into eastern NC early this morning. This activity will continue to be aided by a shortwave trough that is moving northeastward around the periphery of a persistent mid/upper-level cyclone centered over parts of the Mid-South/TN Valley. Rather strong low-level flow (with 35-45 kt at 1-2 km AGL per recent objective analyses and VWPs from KLTX, KRAX, and KMHX) will continue to enlarge hodographs, with effective SRH of 150-200 m2/s2. Weak lapse rates/buoyancy and modest deep-layer shear will continue to be a general limiting factor for severe potential. However, given the relatively favorable low-level wind profiles, MLCAPE approaching 500 J/kg within a moist environment could support occasional transient supercell structures, with some localized brief-tornado and wind-damage potential through the overnight. ..Dean/Bunting.. 05/13/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...AKQ...MHX...RAH...ILM... LAT...LON 34747913 35397896 35627843 36097715 35907608 35237551 34907589 34397669 34067719 33887752 33547815 33747851 33997880 34747913 MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 95 MPH MOST PROBABLE PEAK WIND GUST...UP TO 60 MPH Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0358 AM CDT Tue May 13 2025 Valid 161200Z - 211200Z ...DISCUSSION... An active period of severe weather is anticipated through early next week as a pair of upper-level troughs traverse the U.S. and will be favorably timed to allow moisture recovery into central/southern portions of the CONUS. The upper trough currently over the Pacific Northwest is forecast to migrate into the Great Lakes region by this weekend. In the wake of this feature, a second long-wave trough will begin to deepen across the West before migrating into the Plains by early/mid next week with attendant chances for strong/severe thunderstorms. ...D4/Friday... A stalled boundary will likely be draped from the Ozarks into the OH Valley at the beginning of the forecast period. A weak, low-amplitude mid-level perturbation emanating out of the central Plains will promote secondary surface low development across the southern Plains that will maintain southerly low-level flow. As such, some northward migration of the boundary as an effective warm front appears probable. Thunderstorm development along the boundary is anticipated by late afternoon, and 40-50 knot mid-level flow oriented along the frontal zone should promote initially discrete/semi-discrete cells with the potential for upscale growth into one or more organized clusters. Some disagreement in exactly where the corridor of highest severe threat will become established persists and is associated with the coverage and intensity of ongoing convection Friday morning. Recent GFS/GEFS runs hint that more isolated convection early Friday will allow for more aggressive northward advancement of the front, while ECMWF solutions hint at slower northward progression of the boundary. The 15% risk area has been expanded to best encompass the overlap between these two dichotomous solutions. ...D6/Sunday to D8/Tuesday... A deepening upper level trough over the western states will promote several days of lee troughing/cyclogenesis across the southern to central High Plains beginning this weekend. This will allow for more seasonal moisture return into the Plains with most ensemble members showing dewpoints climbing into the low to mid 60s by D6/Sunday afternoon across TX, OK, and southern KS. Deterministic solutions continue to vary regarding the exact timing and evolution of the upper-level wave (and any embedded impulses), but the general consensus is that severe thunderstorms will be possible as upper-level disturbances overspread the Plains and promote eastward mixing of the dryline into an increasingly buoyant warm sector. Confidence on any particular day remains too limited for risk probabilities, but the overall synoptic regime and convective QPF signals in ensemble guidance suggest that the potential for multiple rounds of severe thunderstorms is increasing for the southern/central Plains beginning D6/Sunday through D8/Tuesday. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0358 AM CDT Tue May 13 2025 Valid 161200Z - 211200Z ...DISCUSSION... An active period of severe weather is anticipated through early next week as a pair of upper-level troughs traverse the U.S. and will be favorably timed to allow moisture recovery into central/southern portions of the CONUS. The upper trough currently over the Pacific Northwest is forecast to migrate into the Great Lakes region by this weekend. In the wake of this feature, a second long-wave trough will begin to deepen across the West before migrating into the Plains by early/mid next week with attendant chances for strong/severe thunderstorms. ...D4/Friday... A stalled boundary will likely be draped from the Ozarks into the OH Valley at the beginning of the forecast period. A weak, low-amplitude mid-level perturbation emanating out of the central Plains will promote secondary surface low development across the southern Plains that will maintain southerly low-level flow. As such, some northward migration of the boundary as an effective warm front appears probable. Thunderstorm development along the boundary is anticipated by late afternoon, and 40-50 knot mid-level flow oriented along the frontal zone should promote initially discrete/semi-discrete cells with the potential for upscale growth into one or more organized clusters. Some disagreement in exactly where the corridor of highest severe threat will become established persists and is associated with the coverage and intensity of ongoing convection Friday morning. Recent GFS/GEFS runs hint that more isolated convection early Friday will allow for more aggressive northward advancement of the front, while ECMWF solutions hint at slower northward progression of the boundary. The 15% risk area has been expanded to best encompass the overlap between these two dichotomous solutions. ...D6/Sunday to D8/Tuesday... A deepening upper level trough over the western states will promote several days of lee troughing/cyclogenesis across the southern to central High Plains beginning this weekend. This will allow for more seasonal moisture return into the Plains with most ensemble members showing dewpoints climbing into the low to mid 60s by D6/Sunday afternoon across TX, OK, and southern KS. Deterministic solutions continue to vary regarding the exact timing and evolution of the upper-level wave (and any embedded impulses), but the general consensus is that severe thunderstorms will be possible as upper-level disturbances overspread the Plains and promote eastward mixing of the dryline into an increasingly buoyant warm sector. Confidence on any particular day remains too limited for risk probabilities, but the overall synoptic regime and convective QPF signals in ensemble guidance suggest that the potential for multiple rounds of severe thunderstorms is increasing for the southern/central Plains beginning D6/Sunday through D8/Tuesday. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0358 AM CDT Tue May 13 2025 Valid 161200Z - 211200Z ...DISCUSSION... An active period of severe weather is anticipated through early next week as a pair of upper-level troughs traverse the U.S. and will be favorably timed to allow moisture recovery into central/southern portions of the CONUS. The upper trough currently over the Pacific Northwest is forecast to migrate into the Great Lakes region by this weekend. In the wake of this feature, a second long-wave trough will begin to deepen across the West before migrating into the Plains by early/mid next week with attendant chances for strong/severe thunderstorms. ...D4/Friday... A stalled boundary will likely be draped from the Ozarks into the OH Valley at the beginning of the forecast period. A weak, low-amplitude mid-level perturbation emanating out of the central Plains will promote secondary surface low development across the southern Plains that will maintain southerly low-level flow. As such, some northward migration of the boundary as an effective warm front appears probable. Thunderstorm development along the boundary is anticipated by late afternoon, and 40-50 knot mid-level flow oriented along the frontal zone should promote initially discrete/semi-discrete cells with the potential for upscale growth into one or more organized clusters. Some disagreement in exactly where the corridor of highest severe threat will become established persists and is associated with the coverage and intensity of ongoing convection Friday morning. Recent GFS/GEFS runs hint that more isolated convection early Friday will allow for more aggressive northward advancement of the front, while ECMWF solutions hint at slower northward progression of the boundary. The 15% risk area has been expanded to best encompass the overlap between these two dichotomous solutions. ...D6/Sunday to D8/Tuesday... A deepening upper level trough over the western states will promote several days of lee troughing/cyclogenesis across the southern to central High Plains beginning this weekend. This will allow for more seasonal moisture return into the Plains with most ensemble members showing dewpoints climbing into the low to mid 60s by D6/Sunday afternoon across TX, OK, and southern KS. Deterministic solutions continue to vary regarding the exact timing and evolution of the upper-level wave (and any embedded impulses), but the general consensus is that severe thunderstorms will be possible as upper-level disturbances overspread the Plains and promote eastward mixing of the dryline into an increasingly buoyant warm sector. Confidence on any particular day remains too limited for risk probabilities, but the overall synoptic regime and convective QPF signals in ensemble guidance suggest that the potential for multiple rounds of severe thunderstorms is increasing for the southern/central Plains beginning D6/Sunday through D8/Tuesday. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0358 AM CDT Tue May 13 2025 Valid 161200Z - 211200Z ...DISCUSSION... An active period of severe weather is anticipated through early next week as a pair of upper-level troughs traverse the U.S. and will be favorably timed to allow moisture recovery into central/southern portions of the CONUS. The upper trough currently over the Pacific Northwest is forecast to migrate into the Great Lakes region by this weekend. In the wake of this feature, a second long-wave trough will begin to deepen across the West before migrating into the Plains by early/mid next week with attendant chances for strong/severe thunderstorms. ...D4/Friday... A stalled boundary will likely be draped from the Ozarks into the OH Valley at the beginning of the forecast period. A weak, low-amplitude mid-level perturbation emanating out of the central Plains will promote secondary surface low development across the southern Plains that will maintain southerly low-level flow. As such, some northward migration of the boundary as an effective warm front appears probable. Thunderstorm development along the boundary is anticipated by late afternoon, and 40-50 knot mid-level flow oriented along the frontal zone should promote initially discrete/semi-discrete cells with the potential for upscale growth into one or more organized clusters. Some disagreement in exactly where the corridor of highest severe threat will become established persists and is associated with the coverage and intensity of ongoing convection Friday morning. Recent GFS/GEFS runs hint that more isolated convection early Friday will allow for more aggressive northward advancement of the front, while ECMWF solutions hint at slower northward progression of the boundary. The 15% risk area has been expanded to best encompass the overlap between these two dichotomous solutions. ...D6/Sunday to D8/Tuesday... A deepening upper level trough over the western states will promote several days of lee troughing/cyclogenesis across the southern to central High Plains beginning this weekend. This will allow for more seasonal moisture return into the Plains with most ensemble members showing dewpoints climbing into the low to mid 60s by D6/Sunday afternoon across TX, OK, and southern KS. Deterministic solutions continue to vary regarding the exact timing and evolution of the upper-level wave (and any embedded impulses), but the general consensus is that severe thunderstorms will be possible as upper-level disturbances overspread the Plains and promote eastward mixing of the dryline into an increasingly buoyant warm sector. Confidence on any particular day remains too limited for risk probabilities, but the overall synoptic regime and convective QPF signals in ensemble guidance suggest that the potential for multiple rounds of severe thunderstorms is increasing for the southern/central Plains beginning D6/Sunday through D8/Tuesday. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0358 AM CDT Tue May 13 2025 Valid 161200Z - 211200Z ...DISCUSSION... An active period of severe weather is anticipated through early next week as a pair of upper-level troughs traverse the U.S. and will be favorably timed to allow moisture recovery into central/southern portions of the CONUS. The upper trough currently over the Pacific Northwest is forecast to migrate into the Great Lakes region by this weekend. In the wake of this feature, a second long-wave trough will begin to deepen across the West before migrating into the Plains by early/mid next week with attendant chances for strong/severe thunderstorms. ...D4/Friday... A stalled boundary will likely be draped from the Ozarks into the OH Valley at the beginning of the forecast period. A weak, low-amplitude mid-level perturbation emanating out of the central Plains will promote secondary surface low development across the southern Plains that will maintain southerly low-level flow. As such, some northward migration of the boundary as an effective warm front appears probable. Thunderstorm development along the boundary is anticipated by late afternoon, and 40-50 knot mid-level flow oriented along the frontal zone should promote initially discrete/semi-discrete cells with the potential for upscale growth into one or more organized clusters. Some disagreement in exactly where the corridor of highest severe threat will become established persists and is associated with the coverage and intensity of ongoing convection Friday morning. Recent GFS/GEFS runs hint that more isolated convection early Friday will allow for more aggressive northward advancement of the front, while ECMWF solutions hint at slower northward progression of the boundary. The 15% risk area has been expanded to best encompass the overlap between these two dichotomous solutions. ...D6/Sunday to D8/Tuesday... A deepening upper level trough over the western states will promote several days of lee troughing/cyclogenesis across the southern to central High Plains beginning this weekend. This will allow for more seasonal moisture return into the Plains with most ensemble members showing dewpoints climbing into the low to mid 60s by D6/Sunday afternoon across TX, OK, and southern KS. Deterministic solutions continue to vary regarding the exact timing and evolution of the upper-level wave (and any embedded impulses), but the general consensus is that severe thunderstorms will be possible as upper-level disturbances overspread the Plains and promote eastward mixing of the dryline into an increasingly buoyant warm sector. Confidence on any particular day remains too limited for risk probabilities, but the overall synoptic regime and convective QPF signals in ensemble guidance suggest that the potential for multiple rounds of severe thunderstorms is increasing for the southern/central Plains beginning D6/Sunday through D8/Tuesday. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0358 AM CDT Tue May 13 2025 Valid 161200Z - 211200Z ...DISCUSSION... An active period of severe weather is anticipated through early next week as a pair of upper-level troughs traverse the U.S. and will be favorably timed to allow moisture recovery into central/southern portions of the CONUS. The upper trough currently over the Pacific Northwest is forecast to migrate into the Great Lakes region by this weekend. In the wake of this feature, a second long-wave trough will begin to deepen across the West before migrating into the Plains by early/mid next week with attendant chances for strong/severe thunderstorms. ...D4/Friday... A stalled boundary will likely be draped from the Ozarks into the OH Valley at the beginning of the forecast period. A weak, low-amplitude mid-level perturbation emanating out of the central Plains will promote secondary surface low development across the southern Plains that will maintain southerly low-level flow. As such, some northward migration of the boundary as an effective warm front appears probable. Thunderstorm development along the boundary is anticipated by late afternoon, and 40-50 knot mid-level flow oriented along the frontal zone should promote initially discrete/semi-discrete cells with the potential for upscale growth into one or more organized clusters. Some disagreement in exactly where the corridor of highest severe threat will become established persists and is associated with the coverage and intensity of ongoing convection Friday morning. Recent GFS/GEFS runs hint that more isolated convection early Friday will allow for more aggressive northward advancement of the front, while ECMWF solutions hint at slower northward progression of the boundary. The 15% risk area has been expanded to best encompass the overlap between these two dichotomous solutions. ...D6/Sunday to D8/Tuesday... A deepening upper level trough over the western states will promote several days of lee troughing/cyclogenesis across the southern to central High Plains beginning this weekend. This will allow for more seasonal moisture return into the Plains with most ensemble members showing dewpoints climbing into the low to mid 60s by D6/Sunday afternoon across TX, OK, and southern KS. Deterministic solutions continue to vary regarding the exact timing and evolution of the upper-level wave (and any embedded impulses), but the general consensus is that severe thunderstorms will be possible as upper-level disturbances overspread the Plains and promote eastward mixing of the dryline into an increasingly buoyant warm sector. Confidence on any particular day remains too limited for risk probabilities, but the overall synoptic regime and convective QPF signals in ensemble guidance suggest that the potential for multiple rounds of severe thunderstorms is increasing for the southern/central Plains beginning D6/Sunday through D8/Tuesday. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0358 AM CDT Tue May 13 2025 Valid 161200Z - 211200Z ...DISCUSSION... An active period of severe weather is anticipated through early next week as a pair of upper-level troughs traverse the U.S. and will be favorably timed to allow moisture recovery into central/southern portions of the CONUS. The upper trough currently over the Pacific Northwest is forecast to migrate into the Great Lakes region by this weekend. In the wake of this feature, a second long-wave trough will begin to deepen across the West before migrating into the Plains by early/mid next week with attendant chances for strong/severe thunderstorms. ...D4/Friday... A stalled boundary will likely be draped from the Ozarks into the OH Valley at the beginning of the forecast period. A weak, low-amplitude mid-level perturbation emanating out of the central Plains will promote secondary surface low development across the southern Plains that will maintain southerly low-level flow. As such, some northward migration of the boundary as an effective warm front appears probable. Thunderstorm development along the boundary is anticipated by late afternoon, and 40-50 knot mid-level flow oriented along the frontal zone should promote initially discrete/semi-discrete cells with the potential for upscale growth into one or more organized clusters. Some disagreement in exactly where the corridor of highest severe threat will become established persists and is associated with the coverage and intensity of ongoing convection Friday morning. Recent GFS/GEFS runs hint that more isolated convection early Friday will allow for more aggressive northward advancement of the front, while ECMWF solutions hint at slower northward progression of the boundary. The 15% risk area has been expanded to best encompass the overlap between these two dichotomous solutions. ...D6/Sunday to D8/Tuesday... A deepening upper level trough over the western states will promote several days of lee troughing/cyclogenesis across the southern to central High Plains beginning this weekend. This will allow for more seasonal moisture return into the Plains with most ensemble members showing dewpoints climbing into the low to mid 60s by D6/Sunday afternoon across TX, OK, and southern KS. Deterministic solutions continue to vary regarding the exact timing and evolution of the upper-level wave (and any embedded impulses), but the general consensus is that severe thunderstorms will be possible as upper-level disturbances overspread the Plains and promote eastward mixing of the dryline into an increasingly buoyant warm sector. Confidence on any particular day remains too limited for risk probabilities, but the overall synoptic regime and convective QPF signals in ensemble guidance suggest that the potential for multiple rounds of severe thunderstorms is increasing for the southern/central Plains beginning D6/Sunday through D8/Tuesday. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0358 AM CDT Tue May 13 2025 Valid 161200Z - 211200Z ...DISCUSSION... An active period of severe weather is anticipated through early next week as a pair of upper-level troughs traverse the U.S. and will be favorably timed to allow moisture recovery into central/southern portions of the CONUS. The upper trough currently over the Pacific Northwest is forecast to migrate into the Great Lakes region by this weekend. In the wake of this feature, a second long-wave trough will begin to deepen across the West before migrating into the Plains by early/mid next week with attendant chances for strong/severe thunderstorms. ...D4/Friday... A stalled boundary will likely be draped from the Ozarks into the OH Valley at the beginning of the forecast period. A weak, low-amplitude mid-level perturbation emanating out of the central Plains will promote secondary surface low development across the southern Plains that will maintain southerly low-level flow. As such, some northward migration of the boundary as an effective warm front appears probable. Thunderstorm development along the boundary is anticipated by late afternoon, and 40-50 knot mid-level flow oriented along the frontal zone should promote initially discrete/semi-discrete cells with the potential for upscale growth into one or more organized clusters. Some disagreement in exactly where the corridor of highest severe threat will become established persists and is associated with the coverage and intensity of ongoing convection Friday morning. Recent GFS/GEFS runs hint that more isolated convection early Friday will allow for more aggressive northward advancement of the front, while ECMWF solutions hint at slower northward progression of the boundary. The 15% risk area has been expanded to best encompass the overlap between these two dichotomous solutions. ...D6/Sunday to D8/Tuesday... A deepening upper level trough over the western states will promote several days of lee troughing/cyclogenesis across the southern to central High Plains beginning this weekend. This will allow for more seasonal moisture return into the Plains with most ensemble members showing dewpoints climbing into the low to mid 60s by D6/Sunday afternoon across TX, OK, and southern KS. Deterministic solutions continue to vary regarding the exact timing and evolution of the upper-level wave (and any embedded impulses), but the general consensus is that severe thunderstorms will be possible as upper-level disturbances overspread the Plains and promote eastward mixing of the dryline into an increasingly buoyant warm sector. Confidence on any particular day remains too limited for risk probabilities, but the overall synoptic regime and convective QPF signals in ensemble guidance suggest that the potential for multiple rounds of severe thunderstorms is increasing for the southern/central Plains beginning D6/Sunday through D8/Tuesday. Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0229 AM CDT Tue May 13 2025 Valid 151200Z - 161200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS PARTS OF THE UPPER MISSISSIPPI RIVER VALLEY AND WESTERN GREAT LAKES... ...SUMMARY... Scattered strong to severe thunderstorms are expected across parts of the western Great Lakes and Midwest Thursday afternoon and evening. A more isolated/conditional severe threat will extend into the mid-Mississippi River Valley during the late evening and overnight hours. ...Synopsis... The upper trough currently situated over the Pacific Northwest is forecast to eject into the Plains/upper MS River Valley through the day Thursday. A surface low will intensify through early afternoon before beginning the occlusion process as a Pacific cold front pushes east. Ahead of this front, southeasterly low-level flow will advect upper 50s to mid 60s dewpoints northeastward into the upper MS River Valley and Midwest regions. Thunderstorm development is likely along the front as it impinges on the returning moisture across the upper MS Valley and western Great Lakes. Strong capping with southward extent will likely result in more isolated thunderstorm development along the front into parts of the Midwest and OH Valley. ...Upper MS Valley into the Western Great Lakes... Thunderstorm development is anticipated by early afternoon across parts of the upper MS River Valley as the Pacific front surges into the region under a 50-60 knot mid-level jet. While higher-quality moisture will likely remain south of the region, dewpoints in the low to mid 60s, coupled with steepening mid-level lapse rates, should support MLCAPE values between 1500-2500 J/kg. Strong mid-level flow will promote supercell wind profiles, and mean storm motions off the front will likely support initially discrete cells that should pose a severe hail/wind threat. Upscale growth into an organized line is possible given strong forcing along the front as an arcing line of storms moves east into the Great Lakes region. Discrete supercells will be most probable on the southern extent of the line of storms, but increasing capping with southwestward extent introduces considerable uncertainty in how far south storms will develop. The best thermodynamic and kinematic environment will likely extend across IN into western OH and southward to the OH river, but most deterministic and ensemble solutions show only weak QPF signals across this region through early evening. 15%/Slight risk probabilities were maintained for IN/western OH due to account for low-probability, but potentially high-impact supercells within this environment, but further refinements are likely as the likelihood of convective initiation becomes more apparent. ...Mid-MS River Valley and lower OH Valley... The Pacific front is forecast to gradually stall across northern AR into the lower OH Valley through the overnight hours as the primary surface low occludes to the north. Thunderstorm development along the front is possible during the late evening/overnight hours with most ensemble solutions showing some QPF signal during the 06-12 UTC period as low-level isentropic ascent increases along the stalled boundary. 40-50 knot mid-level flow will favor organized convection, though storm motions along the boundary may promote clustering with time. Regardless, some severe threat will likely manifest with this activity during the overnight hours into early Friday morning. ..Moore.. 05/13/2025 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0229 AM CDT Tue May 13 2025 Valid 151200Z - 161200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS PARTS OF THE UPPER MISSISSIPPI RIVER VALLEY AND WESTERN GREAT LAKES... ...SUMMARY... Scattered strong to severe thunderstorms are expected across parts of the western Great Lakes and Midwest Thursday afternoon and evening. A more isolated/conditional severe threat will extend into the mid-Mississippi River Valley during the late evening and overnight hours. ...Synopsis... The upper trough currently situated over the Pacific Northwest is forecast to eject into the Plains/upper MS River Valley through the day Thursday. A surface low will intensify through early afternoon before beginning the occlusion process as a Pacific cold front pushes east. Ahead of this front, southeasterly low-level flow will advect upper 50s to mid 60s dewpoints northeastward into the upper MS River Valley and Midwest regions. Thunderstorm development is likely along the front as it impinges on the returning moisture across the upper MS Valley and western Great Lakes. Strong capping with southward extent will likely result in more isolated thunderstorm development along the front into parts of the Midwest and OH Valley. ...Upper MS Valley into the Western Great Lakes... Thunderstorm development is anticipated by early afternoon across parts of the upper MS River Valley as the Pacific front surges into the region under a 50-60 knot mid-level jet. While higher-quality moisture will likely remain south of the region, dewpoints in the low to mid 60s, coupled with steepening mid-level lapse rates, should support MLCAPE values between 1500-2500 J/kg. Strong mid-level flow will promote supercell wind profiles, and mean storm motions off the front will likely support initially discrete cells that should pose a severe hail/wind threat. Upscale growth into an organized line is possible given strong forcing along the front as an arcing line of storms moves east into the Great Lakes region. Discrete supercells will be most probable on the southern extent of the line of storms, but increasing capping with southwestward extent introduces considerable uncertainty in how far south storms will develop. The best thermodynamic and kinematic environment will likely extend across IN into western OH and southward to the OH river, but most deterministic and ensemble solutions show only weak QPF signals across this region through early evening. 15%/Slight risk probabilities were maintained for IN/western OH due to account for low-probability, but potentially high-impact supercells within this environment, but further refinements are likely as the likelihood of convective initiation becomes more apparent. ...Mid-MS River Valley and lower OH Valley... The Pacific front is forecast to gradually stall across northern AR into the lower OH Valley through the overnight hours as the primary surface low occludes to the north. Thunderstorm development along the front is possible during the late evening/overnight hours with most ensemble solutions showing some QPF signal during the 06-12 UTC period as low-level isentropic ascent increases along the stalled boundary. 40-50 knot mid-level flow will favor organized convection, though storm motions along the boundary may promote clustering with time. Regardless, some severe threat will likely manifest with this activity during the overnight hours into early Friday morning. ..Moore.. 05/13/2025 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0229 AM CDT Tue May 13 2025 Valid 151200Z - 161200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS PARTS OF THE UPPER MISSISSIPPI RIVER VALLEY AND WESTERN GREAT LAKES... ...SUMMARY... Scattered strong to severe thunderstorms are expected across parts of the western Great Lakes and Midwest Thursday afternoon and evening. A more isolated/conditional severe threat will extend into the mid-Mississippi River Valley during the late evening and overnight hours. ...Synopsis... The upper trough currently situated over the Pacific Northwest is forecast to eject into the Plains/upper MS River Valley through the day Thursday. A surface low will intensify through early afternoon before beginning the occlusion process as a Pacific cold front pushes east. Ahead of this front, southeasterly low-level flow will advect upper 50s to mid 60s dewpoints northeastward into the upper MS River Valley and Midwest regions. Thunderstorm development is likely along the front as it impinges on the returning moisture across the upper MS Valley and western Great Lakes. Strong capping with southward extent will likely result in more isolated thunderstorm development along the front into parts of the Midwest and OH Valley. ...Upper MS Valley into the Western Great Lakes... Thunderstorm development is anticipated by early afternoon across parts of the upper MS River Valley as the Pacific front surges into the region under a 50-60 knot mid-level jet. While higher-quality moisture will likely remain south of the region, dewpoints in the low to mid 60s, coupled with steepening mid-level lapse rates, should support MLCAPE values between 1500-2500 J/kg. Strong mid-level flow will promote supercell wind profiles, and mean storm motions off the front will likely support initially discrete cells that should pose a severe hail/wind threat. Upscale growth into an organized line is possible given strong forcing along the front as an arcing line of storms moves east into the Great Lakes region. Discrete supercells will be most probable on the southern extent of the line of storms, but increasing capping with southwestward extent introduces considerable uncertainty in how far south storms will develop. The best thermodynamic and kinematic environment will likely extend across IN into western OH and southward to the OH river, but most deterministic and ensemble solutions show only weak QPF signals across this region through early evening. 15%/Slight risk probabilities were maintained for IN/western OH due to account for low-probability, but potentially high-impact supercells within this environment, but further refinements are likely as the likelihood of convective initiation becomes more apparent. ...Mid-MS River Valley and lower OH Valley... The Pacific front is forecast to gradually stall across northern AR into the lower OH Valley through the overnight hours as the primary surface low occludes to the north. Thunderstorm development along the front is possible during the late evening/overnight hours with most ensemble solutions showing some QPF signal during the 06-12 UTC period as low-level isentropic ascent increases along the stalled boundary. 40-50 knot mid-level flow will favor organized convection, though storm motions along the boundary may promote clustering with time. Regardless, some severe threat will likely manifest with this activity during the overnight hours into early Friday morning. ..Moore.. 05/13/2025 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0229 AM CDT Tue May 13 2025 Valid 151200Z - 161200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS PARTS OF THE UPPER MISSISSIPPI RIVER VALLEY AND WESTERN GREAT LAKES... ...SUMMARY... Scattered strong to severe thunderstorms are expected across parts of the western Great Lakes and Midwest Thursday afternoon and evening. A more isolated/conditional severe threat will extend into the mid-Mississippi River Valley during the late evening and overnight hours. ...Synopsis... The upper trough currently situated over the Pacific Northwest is forecast to eject into the Plains/upper MS River Valley through the day Thursday. A surface low will intensify through early afternoon before beginning the occlusion process as a Pacific cold front pushes east. Ahead of this front, southeasterly low-level flow will advect upper 50s to mid 60s dewpoints northeastward into the upper MS River Valley and Midwest regions. Thunderstorm development is likely along the front as it impinges on the returning moisture across the upper MS Valley and western Great Lakes. Strong capping with southward extent will likely result in more isolated thunderstorm development along the front into parts of the Midwest and OH Valley. ...Upper MS Valley into the Western Great Lakes... Thunderstorm development is anticipated by early afternoon across parts of the upper MS River Valley as the Pacific front surges into the region under a 50-60 knot mid-level jet. While higher-quality moisture will likely remain south of the region, dewpoints in the low to mid 60s, coupled with steepening mid-level lapse rates, should support MLCAPE values between 1500-2500 J/kg. Strong mid-level flow will promote supercell wind profiles, and mean storm motions off the front will likely support initially discrete cells that should pose a severe hail/wind threat. Upscale growth into an organized line is possible given strong forcing along the front as an arcing line of storms moves east into the Great Lakes region. Discrete supercells will be most probable on the southern extent of the line of storms, but increasing capping with southwestward extent introduces considerable uncertainty in how far south storms will develop. The best thermodynamic and kinematic environment will likely extend across IN into western OH and southward to the OH river, but most deterministic and ensemble solutions show only weak QPF signals across this region through early evening. 15%/Slight risk probabilities were maintained for IN/western OH due to account for low-probability, but potentially high-impact supercells within this environment, but further refinements are likely as the likelihood of convective initiation becomes more apparent. ...Mid-MS River Valley and lower OH Valley... The Pacific front is forecast to gradually stall across northern AR into the lower OH Valley through the overnight hours as the primary surface low occludes to the north. Thunderstorm development along the front is possible during the late evening/overnight hours with most ensemble solutions showing some QPF signal during the 06-12 UTC period as low-level isentropic ascent increases along the stalled boundary. 40-50 knot mid-level flow will favor organized convection, though storm motions along the boundary may promote clustering with time. Regardless, some severe threat will likely manifest with this activity during the overnight hours into early Friday morning. ..Moore.. 05/13/2025 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0229 AM CDT Tue May 13 2025 Valid 151200Z - 161200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS PARTS OF THE UPPER MISSISSIPPI RIVER VALLEY AND WESTERN GREAT LAKES... ...SUMMARY... Scattered strong to severe thunderstorms are expected across parts of the western Great Lakes and Midwest Thursday afternoon and evening. A more isolated/conditional severe threat will extend into the mid-Mississippi River Valley during the late evening and overnight hours. ...Synopsis... The upper trough currently situated over the Pacific Northwest is forecast to eject into the Plains/upper MS River Valley through the day Thursday. A surface low will intensify through early afternoon before beginning the occlusion process as a Pacific cold front pushes east. Ahead of this front, southeasterly low-level flow will advect upper 50s to mid 60s dewpoints northeastward into the upper MS River Valley and Midwest regions. Thunderstorm development is likely along the front as it impinges on the returning moisture across the upper MS Valley and western Great Lakes. Strong capping with southward extent will likely result in more isolated thunderstorm development along the front into parts of the Midwest and OH Valley. ...Upper MS Valley into the Western Great Lakes... Thunderstorm development is anticipated by early afternoon across parts of the upper MS River Valley as the Pacific front surges into the region under a 50-60 knot mid-level jet. While higher-quality moisture will likely remain south of the region, dewpoints in the low to mid 60s, coupled with steepening mid-level lapse rates, should support MLCAPE values between 1500-2500 J/kg. Strong mid-level flow will promote supercell wind profiles, and mean storm motions off the front will likely support initially discrete cells that should pose a severe hail/wind threat. Upscale growth into an organized line is possible given strong forcing along the front as an arcing line of storms moves east into the Great Lakes region. Discrete supercells will be most probable on the southern extent of the line of storms, but increasing capping with southwestward extent introduces considerable uncertainty in how far south storms will develop. The best thermodynamic and kinematic environment will likely extend across IN into western OH and southward to the OH river, but most deterministic and ensemble solutions show only weak QPF signals across this region through early evening. 15%/Slight risk probabilities were maintained for IN/western OH due to account for low-probability, but potentially high-impact supercells within this environment, but further refinements are likely as the likelihood of convective initiation becomes more apparent. ...Mid-MS River Valley and lower OH Valley... The Pacific front is forecast to gradually stall across northern AR into the lower OH Valley through the overnight hours as the primary surface low occludes to the north. Thunderstorm development along the front is possible during the late evening/overnight hours with most ensemble solutions showing some QPF signal during the 06-12 UTC period as low-level isentropic ascent increases along the stalled boundary. 40-50 knot mid-level flow will favor organized convection, though storm motions along the boundary may promote clustering with time. Regardless, some severe threat will likely manifest with this activity during the overnight hours into early Friday morning. ..Moore.. 05/13/2025 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0229 AM CDT Tue May 13 2025 Valid 151200Z - 161200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS PARTS OF THE UPPER MISSISSIPPI RIVER VALLEY AND WESTERN GREAT LAKES... ...SUMMARY... Scattered strong to severe thunderstorms are expected across parts of the western Great Lakes and Midwest Thursday afternoon and evening. A more isolated/conditional severe threat will extend into the mid-Mississippi River Valley during the late evening and overnight hours. ...Synopsis... The upper trough currently situated over the Pacific Northwest is forecast to eject into the Plains/upper MS River Valley through the day Thursday. A surface low will intensify through early afternoon before beginning the occlusion process as a Pacific cold front pushes east. Ahead of this front, southeasterly low-level flow will advect upper 50s to mid 60s dewpoints northeastward into the upper MS River Valley and Midwest regions. Thunderstorm development is likely along the front as it impinges on the returning moisture across the upper MS Valley and western Great Lakes. Strong capping with southward extent will likely result in more isolated thunderstorm development along the front into parts of the Midwest and OH Valley. ...Upper MS Valley into the Western Great Lakes... Thunderstorm development is anticipated by early afternoon across parts of the upper MS River Valley as the Pacific front surges into the region under a 50-60 knot mid-level jet. While higher-quality moisture will likely remain south of the region, dewpoints in the low to mid 60s, coupled with steepening mid-level lapse rates, should support MLCAPE values between 1500-2500 J/kg. Strong mid-level flow will promote supercell wind profiles, and mean storm motions off the front will likely support initially discrete cells that should pose a severe hail/wind threat. Upscale growth into an organized line is possible given strong forcing along the front as an arcing line of storms moves east into the Great Lakes region. Discrete supercells will be most probable on the southern extent of the line of storms, but increasing capping with southwestward extent introduces considerable uncertainty in how far south storms will develop. The best thermodynamic and kinematic environment will likely extend across IN into western OH and southward to the OH river, but most deterministic and ensemble solutions show only weak QPF signals across this region through early evening. 15%/Slight risk probabilities were maintained for IN/western OH due to account for low-probability, but potentially high-impact supercells within this environment, but further refinements are likely as the likelihood of convective initiation becomes more apparent. ...Mid-MS River Valley and lower OH Valley... The Pacific front is forecast to gradually stall across northern AR into the lower OH Valley through the overnight hours as the primary surface low occludes to the north. Thunderstorm development along the front is possible during the late evening/overnight hours with most ensemble solutions showing some QPF signal during the 06-12 UTC period as low-level isentropic ascent increases along the stalled boundary. 40-50 knot mid-level flow will favor organized convection, though storm motions along the boundary may promote clustering with time. Regardless, some severe threat will likely manifest with this activity during the overnight hours into early Friday morning. ..Moore.. 05/13/2025 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0229 AM CDT Tue May 13 2025 Valid 151200Z - 161200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS PARTS OF THE UPPER MISSISSIPPI RIVER VALLEY AND WESTERN GREAT LAKES... ...SUMMARY... Scattered strong to severe thunderstorms are expected across parts of the western Great Lakes and Midwest Thursday afternoon and evening. A more isolated/conditional severe threat will extend into the mid-Mississippi River Valley during the late evening and overnight hours. ...Synopsis... The upper trough currently situated over the Pacific Northwest is forecast to eject into the Plains/upper MS River Valley through the day Thursday. A surface low will intensify through early afternoon before beginning the occlusion process as a Pacific cold front pushes east. Ahead of this front, southeasterly low-level flow will advect upper 50s to mid 60s dewpoints northeastward into the upper MS River Valley and Midwest regions. Thunderstorm development is likely along the front as it impinges on the returning moisture across the upper MS Valley and western Great Lakes. Strong capping with southward extent will likely result in more isolated thunderstorm development along the front into parts of the Midwest and OH Valley. ...Upper MS Valley into the Western Great Lakes... Thunderstorm development is anticipated by early afternoon across parts of the upper MS River Valley as the Pacific front surges into the region under a 50-60 knot mid-level jet. While higher-quality moisture will likely remain south of the region, dewpoints in the low to mid 60s, coupled with steepening mid-level lapse rates, should support MLCAPE values between 1500-2500 J/kg. Strong mid-level flow will promote supercell wind profiles, and mean storm motions off the front will likely support initially discrete cells that should pose a severe hail/wind threat. Upscale growth into an organized line is possible given strong forcing along the front as an arcing line of storms moves east into the Great Lakes region. Discrete supercells will be most probable on the southern extent of the line of storms, but increasing capping with southwestward extent introduces considerable uncertainty in how far south storms will develop. The best thermodynamic and kinematic environment will likely extend across IN into western OH and southward to the OH river, but most deterministic and ensemble solutions show only weak QPF signals across this region through early evening. 15%/Slight risk probabilities were maintained for IN/western OH due to account for low-probability, but potentially high-impact supercells within this environment, but further refinements are likely as the likelihood of convective initiation becomes more apparent. ...Mid-MS River Valley and lower OH Valley... The Pacific front is forecast to gradually stall across northern AR into the lower OH Valley through the overnight hours as the primary surface low occludes to the north. Thunderstorm development along the front is possible during the late evening/overnight hours with most ensemble solutions showing some QPF signal during the 06-12 UTC period as low-level isentropic ascent increases along the stalled boundary. 40-50 knot mid-level flow will favor organized convection, though storm motions along the boundary may promote clustering with time. Regardless, some severe threat will likely manifest with this activity during the overnight hours into early Friday morning. ..Moore.. 05/13/2025 Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0159 AM CDT Tue May 13 2025 Valid 141200Z - 151200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF THE SOUTHWEST.... ...Synopsis... The upper trough over the western US will continue to intensify as it emerges over the Rockies and onto the Plains Wednesday. Strong mid-level flow will strengthen a lee cyclone with a trailing cold front and dryline across the Great Plains. Dry westerly flow is likely over the Southwest where critical fire-weather conditions are expected. A more conditional threat for locally elevated fire-weather conditions exist over the Plains and Midwest ahead of the cold front. ...Southwest... As the main upper trough begins to move eastward over the Plains, the fire weather threat will persist for portions of Southwest. Moderate mid-level flow at the base of the upper-trough will support westerly downslope winds to 20-25 mph across southern New Mexico and eastern AZ Wednesday afternoon and evening. Amidst a very dry surface pattern with little recent rainfall and abnormally warm temperatures, RH values below 15% are likely. With sufficient fuels in place, and expanding in coverage from recent drying, widespread critical fire-weather conditions are likely Wednesday. ...Central plains and upper Midwest... As the upper trough moves eastward, a lee trough/dryline will gradually sharpen across the central CONUS. To the west, dry downslope flow is possible over parts of the central/northern Plains into the Upper Midwest. With RH minimums below 30% and wind gusting to 20 mph, some elevated fire-weather threat may be possible across parts of CO/KS and NE into the Dakotas. However, the strongest meteorological conditions are not expected to overlap with areas of supportive fuels given rainfall over the past week. Increasing surface moisture and some precipitation potential with the advancing cold front may further limit any appreciable overlap. This will favor a more localized threat with only isolated elevated fire-weather conditions expected. ..Lyons.. 05/13/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0159 AM CDT Tue May 13 2025 Valid 141200Z - 151200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF THE SOUTHWEST.... ...Synopsis... The upper trough over the western US will continue to intensify as it emerges over the Rockies and onto the Plains Wednesday. Strong mid-level flow will strengthen a lee cyclone with a trailing cold front and dryline across the Great Plains. Dry westerly flow is likely over the Southwest where critical fire-weather conditions are expected. A more conditional threat for locally elevated fire-weather conditions exist over the Plains and Midwest ahead of the cold front. ...Southwest... As the main upper trough begins to move eastward over the Plains, the fire weather threat will persist for portions of Southwest. Moderate mid-level flow at the base of the upper-trough will support westerly downslope winds to 20-25 mph across southern New Mexico and eastern AZ Wednesday afternoon and evening. Amidst a very dry surface pattern with little recent rainfall and abnormally warm temperatures, RH values below 15% are likely. With sufficient fuels in place, and expanding in coverage from recent drying, widespread critical fire-weather conditions are likely Wednesday. ...Central plains and upper Midwest... As the upper trough moves eastward, a lee trough/dryline will gradually sharpen across the central CONUS. To the west, dry downslope flow is possible over parts of the central/northern Plains into the Upper Midwest. With RH minimums below 30% and wind gusting to 20 mph, some elevated fire-weather threat may be possible across parts of CO/KS and NE into the Dakotas. However, the strongest meteorological conditions are not expected to overlap with areas of supportive fuels given rainfall over the past week. Increasing surface moisture and some precipitation potential with the advancing cold front may further limit any appreciable overlap. This will favor a more localized threat with only isolated elevated fire-weather conditions expected. ..Lyons.. 05/13/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more