SPC MD 1561

1 month 2 weeks ago
MD 1561 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR NORTHERN UTAH INTO WESTERN WYOMING
Mesoscale Discussion 1561 NWS Storm Prediction Center Norman OK 0120 PM CDT Fri Jul 04 2025 Areas affected...Northern Utah into western Wyoming Concerning...Severe potential...Watch unlikely Valid 041820Z - 042015Z Probability of Watch Issuance...20 percent SUMMARY...Thunderstorms developing from northern Utah into western Wyoming will pose a severe wind risk through the afternoon and evening hours. Watch issuance is currently not anticipated due to relatively limited coverage of severe storms. DISCUSSION...Steady vertical development of agitated cumulus and cooling cloud-top temperatures within a few deeper convective towers is noted in latest GOES visible/IR imagery across northern UT, southwest WY, and far southeast ID. Ahead of this activity, temperatures are slowly warming as dewpoints fall into the low 50s/upper 40s amid increasing boundary-layer mixing. Despite steep mid-level lapse rates (as sampled by the 12 UTC SLC sounding) over the region, vertical mixing of low-level moisture will largely limit buoyancy values through the afternoon with MLCAPE expected to only reach around 500-750 J/kg. However, deep mixing through roughly 500 mb and dry boundary-layer conditions will facilitate downdraft accelerations within any deeper convective cores. Additionally, 30-35 knot mid-level flow will support modest, but adequate, bulk wind shear through the CAPE-bearing layer to promote some degree of storm organization and longevity. Initially isolated convection may see some degree of consolidation into one or two cold-pool-driven clusters by late afternoon. The potential for severe gusts will likely be maximized with such clusters - especially any clusters that can develop across northern UT into southwest WY where diurnal heating/boundary-layer mixing will be greatest. However, the modest thermodynamic and kinematic environments should limit the overall number/coverage of severe storms, and limits confidence in the need for a watch. ..Moore/Mosier.. 07/04/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...RIW...GJT...SLC...PIH...LKN... LAT...LON 41151422 41231414 41871286 42461205 43031146 43681098 44041059 44161026 44120927 43750856 43190825 42610817 41990841 41270897 40920957 40011352 40081388 40281414 40761433 41151422 MOST PROBABLE PEAK WIND GUST...55-70 MPH MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN Read more

SPC MD 1559

1 month 2 weeks ago
MD 1559 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR SOUTHEAST OREGON INTO SOUTHERN IDAHO
Mesoscale Discussion 1559 NWS Storm Prediction Center Norman OK 0107 PM CDT Fri Jul 04 2025 Areas affected...Southeast Oregon into southern Idaho Concerning...Severe potential...Watch unlikely Valid 041807Z - 042000Z Probability of Watch Issuance...20 percent SUMMARY...Thunderstorms developing across southeast Oregon will gradually intensify as they migrate into southern Idaho. Storm coverage should remain sufficiently isolated to preclude watch issuance. DISCUSSION...GOES visible imagery shows steady vertical development of cumulus and increasingly lightning activity across southeast OR over the past 30 minutes as heating of a seasonally moist air mass continues under and just ahead of an upper-level low. Additional diurnally-driven destabilization should yield MLCAPE values upwards of 500-1000 J/kg as this activity spreads into southwestern ID where mid-level flow is slightly stronger (30-45 knots). Although buoyancy will remain somewhat limited, increasing deep-layer shear will promote increasing storm organization through late afternoon as a mix of thunderstorm clusters and a few isolated cells emerges (based on recent convective trends). Steepening low-level lapse rates coupled with 30-40 knot flow near the top of the boundary layer may support a few severe gusts with any deep convection, though this potential will be maximized with any organized clusters that can develop. Additionally, buoyancy and effective shear should be adequate for large hail production (most likely between 1 to 1.25 inches in diameter) with more discrete cells. Overall, modest buoyancy and isolated to widely scattered storm coverage should limit the overall severe threat and preclude the need for watch issuance. ..Moore/Mosier.. 07/04/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...PIH...MSO...BOI... LAT...LON 42091810 42391832 42751837 43231834 43571806 44761525 44771481 44581426 44251396 43801376 43221362 42831361 42501366 42171389 42031430 42091810 MOST PROBABLE PEAK WIND GUST...55-70 MPH MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN Read more

SPC Jul 4, 2025 2000 UTC Day 1 Convective Outlook

1 month 2 weeks ago
SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0242 PM CDT Fri Jul 04 2025 Valid 042000Z - 051200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM EASTERN NORTH DAKOTA INTO NORTHERN MINNESOTA... ...SUMMARY... Scattered severe thunderstorms are possible later today into the evening over the Upper Midwest. Severe gusts will be the primary hazard. Isolated severe gusts and hail may also occur from eastern Oregon into portions of the northern Great Basin/Rockies and the Central High Plains. ...20z Update... Minor adjustments were made to the Marginal Risk in Colorado to add low end hail probabilities. Cells are expected to form and move off the high terrain into the lower plains through the afternoon/evening. A few cells may be capable of severe hail, given sufficient CAPE and deep layer shear. For more information, see MCD#1562. The most favorable region for severe storms continues to be the central High Plains into the upper Mississippi Valley. Storms have started to develop across this region and coverage is expected to increase into the evening. Storms will have the potential for damaging wind and large hail. See MCD#1560 for more information. ..Thornton.. 07/04/2025 .PREV DISCUSSION... /ISSUED 1130 AM CDT Fri Jul 04 2025/ ...Central High Plains into the Upper MS Valley... Recent satellite imagery shows expansive upper ridging from the Lower MS Valley into western Ontario, with several disturbances along the periphery of this ridge. The shortwave trough currently moving through the central Rockies/central High Plains will be the most impactful for today's severe potential as it continues northeastward towards the very moist airmass in place across the northern/central Plains and Upper Midwest. Current surface observations reveal a large reservoir of dewpoints greater than 68 deg F across the northern/central Plains, with higher dewpoints (70+ deg F) farther northeastward across the Upper MS Valley. Strong heating is anticipated over the region, particularly the Upper Midwest, destabilizing the airmass by the early afternoon and contributing to strong to very strong buoyancy. Low-level convergence along a southeastward-progressing cold front, as well as along expected pre-frontal troughing, will augment large-scale ascent provided by the approaching shortwave. All of this lift will provide the impetus for convective initiation. Initial development appears most likely in the early afternoon (i.e. around 18Z) over northeast/eastern CO, NE Panhandle/western NE, and western KS. Vertical shear and buoyancy will be modest in this region, limiting storm strength and organization. Even so, steep low-level lapse rates and moderately high cloud bases could result in a few strong gusts. A relatively greater severe potential exists farther north over the eastern Dakotas into northern/central MN. Here, strong buoyancy (i.e. 2500-3500 J/kg of MLCAPE) is expected by the late afternoon. Vertical shear will be relatively modest, but the strong buoyancy should support robust updrafts capable of precipitation loading and water-loaded downbursts. Given the limited shear and progressive cold front, a quick transition to an outflow-dominant, linear structure is anticipated. A few stronger gusts are possible within this line as well. Isolated large hail could occur with the strongest, early-stage cellular storms. ...Eastern Oregon into the Northern Great Basin/Rockies... Extensive cloud cover has begun to clear from south to north as a lead shortwave trough progresses through the region. Secondary shortwave trough currently moving through northern CA is expected to progress eastward/northeastward into the region later this afternoon, fostering additional storm development this afternoon. Buoyancy will be modest, but moderate mid-level flow (i.e. 40-45 kt at 500 mb) will persist, supporting the potential for a few stronger/more organized updrafts. A locally greater severe wind risk may materialize across southern ID and northern UT where stronger heating and deeper mixing is anticipated. Read more

SPC Jul 4, 2025 2000 UTC Day 1 Convective Outlook

1 month 2 weeks ago
SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0242 PM CDT Fri Jul 04 2025 Valid 042000Z - 051200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM EASTERN NORTH DAKOTA INTO NORTHERN MINNESOTA... ...SUMMARY... Scattered severe thunderstorms are possible later today into the evening over the Upper Midwest. Severe gusts will be the primary hazard. Isolated severe gusts and hail may also occur from eastern Oregon into portions of the northern Great Basin/Rockies and the Central High Plains. ...20z Update... Minor adjustments were made to the Marginal Risk in Colorado to add low end hail probabilities. Cells are expected to form and move off the high terrain into the lower plains through the afternoon/evening. A few cells may be capable of severe hail, given sufficient CAPE and deep layer shear. For more information, see MCD#1562. The most favorable region for severe storms continues to be the central High Plains into the upper Mississippi Valley. Storms have started to develop across this region and coverage is expected to increase into the evening. Storms will have the potential for damaging wind and large hail. See MCD#1560 for more information. ..Thornton.. 07/04/2025 .PREV DISCUSSION... /ISSUED 1130 AM CDT Fri Jul 04 2025/ ...Central High Plains into the Upper MS Valley... Recent satellite imagery shows expansive upper ridging from the Lower MS Valley into western Ontario, with several disturbances along the periphery of this ridge. The shortwave trough currently moving through the central Rockies/central High Plains will be the most impactful for today's severe potential as it continues northeastward towards the very moist airmass in place across the northern/central Plains and Upper Midwest. Current surface observations reveal a large reservoir of dewpoints greater than 68 deg F across the northern/central Plains, with higher dewpoints (70+ deg F) farther northeastward across the Upper MS Valley. Strong heating is anticipated over the region, particularly the Upper Midwest, destabilizing the airmass by the early afternoon and contributing to strong to very strong buoyancy. Low-level convergence along a southeastward-progressing cold front, as well as along expected pre-frontal troughing, will augment large-scale ascent provided by the approaching shortwave. All of this lift will provide the impetus for convective initiation. Initial development appears most likely in the early afternoon (i.e. around 18Z) over northeast/eastern CO, NE Panhandle/western NE, and western KS. Vertical shear and buoyancy will be modest in this region, limiting storm strength and organization. Even so, steep low-level lapse rates and moderately high cloud bases could result in a few strong gusts. A relatively greater severe potential exists farther north over the eastern Dakotas into northern/central MN. Here, strong buoyancy (i.e. 2500-3500 J/kg of MLCAPE) is expected by the late afternoon. Vertical shear will be relatively modest, but the strong buoyancy should support robust updrafts capable of precipitation loading and water-loaded downbursts. Given the limited shear and progressive cold front, a quick transition to an outflow-dominant, linear structure is anticipated. A few stronger gusts are possible within this line as well. Isolated large hail could occur with the strongest, early-stage cellular storms. ...Eastern Oregon into the Northern Great Basin/Rockies... Extensive cloud cover has begun to clear from south to north as a lead shortwave trough progresses through the region. Secondary shortwave trough currently moving through northern CA is expected to progress eastward/northeastward into the region later this afternoon, fostering additional storm development this afternoon. Buoyancy will be modest, but moderate mid-level flow (i.e. 40-45 kt at 500 mb) will persist, supporting the potential for a few stronger/more organized updrafts. A locally greater severe wind risk may materialize across southern ID and northern UT where stronger heating and deeper mixing is anticipated. Read more

SPC Jul 4, 2025 2000 UTC Day 1 Convective Outlook

1 month 2 weeks ago
SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0242 PM CDT Fri Jul 04 2025 Valid 042000Z - 051200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM EASTERN NORTH DAKOTA INTO NORTHERN MINNESOTA... ...SUMMARY... Scattered severe thunderstorms are possible later today into the evening over the Upper Midwest. Severe gusts will be the primary hazard. Isolated severe gusts and hail may also occur from eastern Oregon into portions of the northern Great Basin/Rockies and the Central High Plains. ...20z Update... Minor adjustments were made to the Marginal Risk in Colorado to add low end hail probabilities. Cells are expected to form and move off the high terrain into the lower plains through the afternoon/evening. A few cells may be capable of severe hail, given sufficient CAPE and deep layer shear. For more information, see MCD#1562. The most favorable region for severe storms continues to be the central High Plains into the upper Mississippi Valley. Storms have started to develop across this region and coverage is expected to increase into the evening. Storms will have the potential for damaging wind and large hail. See MCD#1560 for more information. ..Thornton.. 07/04/2025 .PREV DISCUSSION... /ISSUED 1130 AM CDT Fri Jul 04 2025/ ...Central High Plains into the Upper MS Valley... Recent satellite imagery shows expansive upper ridging from the Lower MS Valley into western Ontario, with several disturbances along the periphery of this ridge. The shortwave trough currently moving through the central Rockies/central High Plains will be the most impactful for today's severe potential as it continues northeastward towards the very moist airmass in place across the northern/central Plains and Upper Midwest. Current surface observations reveal a large reservoir of dewpoints greater than 68 deg F across the northern/central Plains, with higher dewpoints (70+ deg F) farther northeastward across the Upper MS Valley. Strong heating is anticipated over the region, particularly the Upper Midwest, destabilizing the airmass by the early afternoon and contributing to strong to very strong buoyancy. Low-level convergence along a southeastward-progressing cold front, as well as along expected pre-frontal troughing, will augment large-scale ascent provided by the approaching shortwave. All of this lift will provide the impetus for convective initiation. Initial development appears most likely in the early afternoon (i.e. around 18Z) over northeast/eastern CO, NE Panhandle/western NE, and western KS. Vertical shear and buoyancy will be modest in this region, limiting storm strength and organization. Even so, steep low-level lapse rates and moderately high cloud bases could result in a few strong gusts. A relatively greater severe potential exists farther north over the eastern Dakotas into northern/central MN. Here, strong buoyancy (i.e. 2500-3500 J/kg of MLCAPE) is expected by the late afternoon. Vertical shear will be relatively modest, but the strong buoyancy should support robust updrafts capable of precipitation loading and water-loaded downbursts. Given the limited shear and progressive cold front, a quick transition to an outflow-dominant, linear structure is anticipated. A few stronger gusts are possible within this line as well. Isolated large hail could occur with the strongest, early-stage cellular storms. ...Eastern Oregon into the Northern Great Basin/Rockies... Extensive cloud cover has begun to clear from south to north as a lead shortwave trough progresses through the region. Secondary shortwave trough currently moving through northern CA is expected to progress eastward/northeastward into the region later this afternoon, fostering additional storm development this afternoon. Buoyancy will be modest, but moderate mid-level flow (i.e. 40-45 kt at 500 mb) will persist, supporting the potential for a few stronger/more organized updrafts. A locally greater severe wind risk may materialize across southern ID and northern UT where stronger heating and deeper mixing is anticipated. Read more

SPC Jul 4, 2025 2000 UTC Day 1 Convective Outlook

1 month 2 weeks ago
SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0242 PM CDT Fri Jul 04 2025 Valid 042000Z - 051200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM EASTERN NORTH DAKOTA INTO NORTHERN MINNESOTA... ...SUMMARY... Scattered severe thunderstorms are possible later today into the evening over the Upper Midwest. Severe gusts will be the primary hazard. Isolated severe gusts and hail may also occur from eastern Oregon into portions of the northern Great Basin/Rockies and the Central High Plains. ...20z Update... Minor adjustments were made to the Marginal Risk in Colorado to add low end hail probabilities. Cells are expected to form and move off the high terrain into the lower plains through the afternoon/evening. A few cells may be capable of severe hail, given sufficient CAPE and deep layer shear. For more information, see MCD#1562. The most favorable region for severe storms continues to be the central High Plains into the upper Mississippi Valley. Storms have started to develop across this region and coverage is expected to increase into the evening. Storms will have the potential for damaging wind and large hail. See MCD#1560 for more information. ..Thornton.. 07/04/2025 .PREV DISCUSSION... /ISSUED 1130 AM CDT Fri Jul 04 2025/ ...Central High Plains into the Upper MS Valley... Recent satellite imagery shows expansive upper ridging from the Lower MS Valley into western Ontario, with several disturbances along the periphery of this ridge. The shortwave trough currently moving through the central Rockies/central High Plains will be the most impactful for today's severe potential as it continues northeastward towards the very moist airmass in place across the northern/central Plains and Upper Midwest. Current surface observations reveal a large reservoir of dewpoints greater than 68 deg F across the northern/central Plains, with higher dewpoints (70+ deg F) farther northeastward across the Upper MS Valley. Strong heating is anticipated over the region, particularly the Upper Midwest, destabilizing the airmass by the early afternoon and contributing to strong to very strong buoyancy. Low-level convergence along a southeastward-progressing cold front, as well as along expected pre-frontal troughing, will augment large-scale ascent provided by the approaching shortwave. All of this lift will provide the impetus for convective initiation. Initial development appears most likely in the early afternoon (i.e. around 18Z) over northeast/eastern CO, NE Panhandle/western NE, and western KS. Vertical shear and buoyancy will be modest in this region, limiting storm strength and organization. Even so, steep low-level lapse rates and moderately high cloud bases could result in a few strong gusts. A relatively greater severe potential exists farther north over the eastern Dakotas into northern/central MN. Here, strong buoyancy (i.e. 2500-3500 J/kg of MLCAPE) is expected by the late afternoon. Vertical shear will be relatively modest, but the strong buoyancy should support robust updrafts capable of precipitation loading and water-loaded downbursts. Given the limited shear and progressive cold front, a quick transition to an outflow-dominant, linear structure is anticipated. A few stronger gusts are possible within this line as well. Isolated large hail could occur with the strongest, early-stage cellular storms. ...Eastern Oregon into the Northern Great Basin/Rockies... Extensive cloud cover has begun to clear from south to north as a lead shortwave trough progresses through the region. Secondary shortwave trough currently moving through northern CA is expected to progress eastward/northeastward into the region later this afternoon, fostering additional storm development this afternoon. Buoyancy will be modest, but moderate mid-level flow (i.e. 40-45 kt at 500 mb) will persist, supporting the potential for a few stronger/more organized updrafts. A locally greater severe wind risk may materialize across southern ID and northern UT where stronger heating and deeper mixing is anticipated. Read more

SPC Jul 4, 2025 2000 UTC Day 1 Convective Outlook

1 month 2 weeks ago
SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0242 PM CDT Fri Jul 04 2025 Valid 042000Z - 051200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM EASTERN NORTH DAKOTA INTO NORTHERN MINNESOTA... ...SUMMARY... Scattered severe thunderstorms are possible later today into the evening over the Upper Midwest. Severe gusts will be the primary hazard. Isolated severe gusts and hail may also occur from eastern Oregon into portions of the northern Great Basin/Rockies and the Central High Plains. ...20z Update... Minor adjustments were made to the Marginal Risk in Colorado to add low end hail probabilities. Cells are expected to form and move off the high terrain into the lower plains through the afternoon/evening. A few cells may be capable of severe hail, given sufficient CAPE and deep layer shear. For more information, see MCD#1562. The most favorable region for severe storms continues to be the central High Plains into the upper Mississippi Valley. Storms have started to develop across this region and coverage is expected to increase into the evening. Storms will have the potential for damaging wind and large hail. See MCD#1560 for more information. ..Thornton.. 07/04/2025 .PREV DISCUSSION... /ISSUED 1130 AM CDT Fri Jul 04 2025/ ...Central High Plains into the Upper MS Valley... Recent satellite imagery shows expansive upper ridging from the Lower MS Valley into western Ontario, with several disturbances along the periphery of this ridge. The shortwave trough currently moving through the central Rockies/central High Plains will be the most impactful for today's severe potential as it continues northeastward towards the very moist airmass in place across the northern/central Plains and Upper Midwest. Current surface observations reveal a large reservoir of dewpoints greater than 68 deg F across the northern/central Plains, with higher dewpoints (70+ deg F) farther northeastward across the Upper MS Valley. Strong heating is anticipated over the region, particularly the Upper Midwest, destabilizing the airmass by the early afternoon and contributing to strong to very strong buoyancy. Low-level convergence along a southeastward-progressing cold front, as well as along expected pre-frontal troughing, will augment large-scale ascent provided by the approaching shortwave. All of this lift will provide the impetus for convective initiation. Initial development appears most likely in the early afternoon (i.e. around 18Z) over northeast/eastern CO, NE Panhandle/western NE, and western KS. Vertical shear and buoyancy will be modest in this region, limiting storm strength and organization. Even so, steep low-level lapse rates and moderately high cloud bases could result in a few strong gusts. A relatively greater severe potential exists farther north over the eastern Dakotas into northern/central MN. Here, strong buoyancy (i.e. 2500-3500 J/kg of MLCAPE) is expected by the late afternoon. Vertical shear will be relatively modest, but the strong buoyancy should support robust updrafts capable of precipitation loading and water-loaded downbursts. Given the limited shear and progressive cold front, a quick transition to an outflow-dominant, linear structure is anticipated. A few stronger gusts are possible within this line as well. Isolated large hail could occur with the strongest, early-stage cellular storms. ...Eastern Oregon into the Northern Great Basin/Rockies... Extensive cloud cover has begun to clear from south to north as a lead shortwave trough progresses through the region. Secondary shortwave trough currently moving through northern CA is expected to progress eastward/northeastward into the region later this afternoon, fostering additional storm development this afternoon. Buoyancy will be modest, but moderate mid-level flow (i.e. 40-45 kt at 500 mb) will persist, supporting the potential for a few stronger/more organized updrafts. A locally greater severe wind risk may materialize across southern ID and northern UT where stronger heating and deeper mixing is anticipated. Read more

SPC Jul 4, 2025 2000 UTC Day 1 Convective Outlook

1 month 2 weeks ago
SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0242 PM CDT Fri Jul 04 2025 Valid 042000Z - 051200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM EASTERN NORTH DAKOTA INTO NORTHERN MINNESOTA... ...SUMMARY... Scattered severe thunderstorms are possible later today into the evening over the Upper Midwest. Severe gusts will be the primary hazard. Isolated severe gusts and hail may also occur from eastern Oregon into portions of the northern Great Basin/Rockies and the Central High Plains. ...20z Update... Minor adjustments were made to the Marginal Risk in Colorado to add low end hail probabilities. Cells are expected to form and move off the high terrain into the lower plains through the afternoon/evening. A few cells may be capable of severe hail, given sufficient CAPE and deep layer shear. For more information, see MCD#1562. The most favorable region for severe storms continues to be the central High Plains into the upper Mississippi Valley. Storms have started to develop across this region and coverage is expected to increase into the evening. Storms will have the potential for damaging wind and large hail. See MCD#1560 for more information. ..Thornton.. 07/04/2025 .PREV DISCUSSION... /ISSUED 1130 AM CDT Fri Jul 04 2025/ ...Central High Plains into the Upper MS Valley... Recent satellite imagery shows expansive upper ridging from the Lower MS Valley into western Ontario, with several disturbances along the periphery of this ridge. The shortwave trough currently moving through the central Rockies/central High Plains will be the most impactful for today's severe potential as it continues northeastward towards the very moist airmass in place across the northern/central Plains and Upper Midwest. Current surface observations reveal a large reservoir of dewpoints greater than 68 deg F across the northern/central Plains, with higher dewpoints (70+ deg F) farther northeastward across the Upper MS Valley. Strong heating is anticipated over the region, particularly the Upper Midwest, destabilizing the airmass by the early afternoon and contributing to strong to very strong buoyancy. Low-level convergence along a southeastward-progressing cold front, as well as along expected pre-frontal troughing, will augment large-scale ascent provided by the approaching shortwave. All of this lift will provide the impetus for convective initiation. Initial development appears most likely in the early afternoon (i.e. around 18Z) over northeast/eastern CO, NE Panhandle/western NE, and western KS. Vertical shear and buoyancy will be modest in this region, limiting storm strength and organization. Even so, steep low-level lapse rates and moderately high cloud bases could result in a few strong gusts. A relatively greater severe potential exists farther north over the eastern Dakotas into northern/central MN. Here, strong buoyancy (i.e. 2500-3500 J/kg of MLCAPE) is expected by the late afternoon. Vertical shear will be relatively modest, but the strong buoyancy should support robust updrafts capable of precipitation loading and water-loaded downbursts. Given the limited shear and progressive cold front, a quick transition to an outflow-dominant, linear structure is anticipated. A few stronger gusts are possible within this line as well. Isolated large hail could occur with the strongest, early-stage cellular storms. ...Eastern Oregon into the Northern Great Basin/Rockies... Extensive cloud cover has begun to clear from south to north as a lead shortwave trough progresses through the region. Secondary shortwave trough currently moving through northern CA is expected to progress eastward/northeastward into the region later this afternoon, fostering additional storm development this afternoon. Buoyancy will be modest, but moderate mid-level flow (i.e. 40-45 kt at 500 mb) will persist, supporting the potential for a few stronger/more organized updrafts. A locally greater severe wind risk may materialize across southern ID and northern UT where stronger heating and deeper mixing is anticipated. Read more

SPC Jul 4, 2025 2000 UTC Day 1 Convective Outlook

1 month 2 weeks ago
SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0242 PM CDT Fri Jul 04 2025 Valid 042000Z - 051200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM EASTERN NORTH DAKOTA INTO NORTHERN MINNESOTA... ...SUMMARY... Scattered severe thunderstorms are possible later today into the evening over the Upper Midwest. Severe gusts will be the primary hazard. Isolated severe gusts and hail may also occur from eastern Oregon into portions of the northern Great Basin/Rockies and the Central High Plains. ...20z Update... Minor adjustments were made to the Marginal Risk in Colorado to add low end hail probabilities. Cells are expected to form and move off the high terrain into the lower plains through the afternoon/evening. A few cells may be capable of severe hail, given sufficient CAPE and deep layer shear. For more information, see MCD#1562. The most favorable region for severe storms continues to be the central High Plains into the upper Mississippi Valley. Storms have started to develop across this region and coverage is expected to increase into the evening. Storms will have the potential for damaging wind and large hail. See MCD#1560 for more information. ..Thornton.. 07/04/2025 .PREV DISCUSSION... /ISSUED 1130 AM CDT Fri Jul 04 2025/ ...Central High Plains into the Upper MS Valley... Recent satellite imagery shows expansive upper ridging from the Lower MS Valley into western Ontario, with several disturbances along the periphery of this ridge. The shortwave trough currently moving through the central Rockies/central High Plains will be the most impactful for today's severe potential as it continues northeastward towards the very moist airmass in place across the northern/central Plains and Upper Midwest. Current surface observations reveal a large reservoir of dewpoints greater than 68 deg F across the northern/central Plains, with higher dewpoints (70+ deg F) farther northeastward across the Upper MS Valley. Strong heating is anticipated over the region, particularly the Upper Midwest, destabilizing the airmass by the early afternoon and contributing to strong to very strong buoyancy. Low-level convergence along a southeastward-progressing cold front, as well as along expected pre-frontal troughing, will augment large-scale ascent provided by the approaching shortwave. All of this lift will provide the impetus for convective initiation. Initial development appears most likely in the early afternoon (i.e. around 18Z) over northeast/eastern CO, NE Panhandle/western NE, and western KS. Vertical shear and buoyancy will be modest in this region, limiting storm strength and organization. Even so, steep low-level lapse rates and moderately high cloud bases could result in a few strong gusts. A relatively greater severe potential exists farther north over the eastern Dakotas into northern/central MN. Here, strong buoyancy (i.e. 2500-3500 J/kg of MLCAPE) is expected by the late afternoon. Vertical shear will be relatively modest, but the strong buoyancy should support robust updrafts capable of precipitation loading and water-loaded downbursts. Given the limited shear and progressive cold front, a quick transition to an outflow-dominant, linear structure is anticipated. A few stronger gusts are possible within this line as well. Isolated large hail could occur with the strongest, early-stage cellular storms. ...Eastern Oregon into the Northern Great Basin/Rockies... Extensive cloud cover has begun to clear from south to north as a lead shortwave trough progresses through the region. Secondary shortwave trough currently moving through northern CA is expected to progress eastward/northeastward into the region later this afternoon, fostering additional storm development this afternoon. Buoyancy will be modest, but moderate mid-level flow (i.e. 40-45 kt at 500 mb) will persist, supporting the potential for a few stronger/more organized updrafts. A locally greater severe wind risk may materialize across southern ID and northern UT where stronger heating and deeper mixing is anticipated. Read more

SPC Jul 4, 2025 2000 UTC Day 1 Convective Outlook

1 month 2 weeks ago
SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0242 PM CDT Fri Jul 04 2025 Valid 042000Z - 051200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM EASTERN NORTH DAKOTA INTO NORTHERN MINNESOTA... ...SUMMARY... Scattered severe thunderstorms are possible later today into the evening over the Upper Midwest. Severe gusts will be the primary hazard. Isolated severe gusts and hail may also occur from eastern Oregon into portions of the northern Great Basin/Rockies and the Central High Plains. ...20z Update... Minor adjustments were made to the Marginal Risk in Colorado to add low end hail probabilities. Cells are expected to form and move off the high terrain into the lower plains through the afternoon/evening. A few cells may be capable of severe hail, given sufficient CAPE and deep layer shear. For more information, see MCD#1562. The most favorable region for severe storms continues to be the central High Plains into the upper Mississippi Valley. Storms have started to develop across this region and coverage is expected to increase into the evening. Storms will have the potential for damaging wind and large hail. See MCD#1560 for more information. ..Thornton.. 07/04/2025 .PREV DISCUSSION... /ISSUED 1130 AM CDT Fri Jul 04 2025/ ...Central High Plains into the Upper MS Valley... Recent satellite imagery shows expansive upper ridging from the Lower MS Valley into western Ontario, with several disturbances along the periphery of this ridge. The shortwave trough currently moving through the central Rockies/central High Plains will be the most impactful for today's severe potential as it continues northeastward towards the very moist airmass in place across the northern/central Plains and Upper Midwest. Current surface observations reveal a large reservoir of dewpoints greater than 68 deg F across the northern/central Plains, with higher dewpoints (70+ deg F) farther northeastward across the Upper MS Valley. Strong heating is anticipated over the region, particularly the Upper Midwest, destabilizing the airmass by the early afternoon and contributing to strong to very strong buoyancy. Low-level convergence along a southeastward-progressing cold front, as well as along expected pre-frontal troughing, will augment large-scale ascent provided by the approaching shortwave. All of this lift will provide the impetus for convective initiation. Initial development appears most likely in the early afternoon (i.e. around 18Z) over northeast/eastern CO, NE Panhandle/western NE, and western KS. Vertical shear and buoyancy will be modest in this region, limiting storm strength and organization. Even so, steep low-level lapse rates and moderately high cloud bases could result in a few strong gusts. A relatively greater severe potential exists farther north over the eastern Dakotas into northern/central MN. Here, strong buoyancy (i.e. 2500-3500 J/kg of MLCAPE) is expected by the late afternoon. Vertical shear will be relatively modest, but the strong buoyancy should support robust updrafts capable of precipitation loading and water-loaded downbursts. Given the limited shear and progressive cold front, a quick transition to an outflow-dominant, linear structure is anticipated. A few stronger gusts are possible within this line as well. Isolated large hail could occur with the strongest, early-stage cellular storms. ...Eastern Oregon into the Northern Great Basin/Rockies... Extensive cloud cover has begun to clear from south to north as a lead shortwave trough progresses through the region. Secondary shortwave trough currently moving through northern CA is expected to progress eastward/northeastward into the region later this afternoon, fostering additional storm development this afternoon. Buoyancy will be modest, but moderate mid-level flow (i.e. 40-45 kt at 500 mb) will persist, supporting the potential for a few stronger/more organized updrafts. A locally greater severe wind risk may materialize across southern ID and northern UT where stronger heating and deeper mixing is anticipated. Read more

SPC Jul 4, 2025 2000 UTC Day 1 Convective Outlook

1 month 2 weeks ago
SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0242 PM CDT Fri Jul 04 2025 Valid 042000Z - 051200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM EASTERN NORTH DAKOTA INTO NORTHERN MINNESOTA... ...SUMMARY... Scattered severe thunderstorms are possible later today into the evening over the Upper Midwest. Severe gusts will be the primary hazard. Isolated severe gusts and hail may also occur from eastern Oregon into portions of the northern Great Basin/Rockies and the Central High Plains. ...20z Update... Minor adjustments were made to the Marginal Risk in Colorado to add low end hail probabilities. Cells are expected to form and move off the high terrain into the lower plains through the afternoon/evening. A few cells may be capable of severe hail, given sufficient CAPE and deep layer shear. For more information, see MCD#1562. The most favorable region for severe storms continues to be the central High Plains into the upper Mississippi Valley. Storms have started to develop across this region and coverage is expected to increase into the evening. Storms will have the potential for damaging wind and large hail. See MCD#1560 for more information. ..Thornton.. 07/04/2025 .PREV DISCUSSION... /ISSUED 1130 AM CDT Fri Jul 04 2025/ ...Central High Plains into the Upper MS Valley... Recent satellite imagery shows expansive upper ridging from the Lower MS Valley into western Ontario, with several disturbances along the periphery of this ridge. The shortwave trough currently moving through the central Rockies/central High Plains will be the most impactful for today's severe potential as it continues northeastward towards the very moist airmass in place across the northern/central Plains and Upper Midwest. Current surface observations reveal a large reservoir of dewpoints greater than 68 deg F across the northern/central Plains, with higher dewpoints (70+ deg F) farther northeastward across the Upper MS Valley. Strong heating is anticipated over the region, particularly the Upper Midwest, destabilizing the airmass by the early afternoon and contributing to strong to very strong buoyancy. Low-level convergence along a southeastward-progressing cold front, as well as along expected pre-frontal troughing, will augment large-scale ascent provided by the approaching shortwave. All of this lift will provide the impetus for convective initiation. Initial development appears most likely in the early afternoon (i.e. around 18Z) over northeast/eastern CO, NE Panhandle/western NE, and western KS. Vertical shear and buoyancy will be modest in this region, limiting storm strength and organization. Even so, steep low-level lapse rates and moderately high cloud bases could result in a few strong gusts. A relatively greater severe potential exists farther north over the eastern Dakotas into northern/central MN. Here, strong buoyancy (i.e. 2500-3500 J/kg of MLCAPE) is expected by the late afternoon. Vertical shear will be relatively modest, but the strong buoyancy should support robust updrafts capable of precipitation loading and water-loaded downbursts. Given the limited shear and progressive cold front, a quick transition to an outflow-dominant, linear structure is anticipated. A few stronger gusts are possible within this line as well. Isolated large hail could occur with the strongest, early-stage cellular storms. ...Eastern Oregon into the Northern Great Basin/Rockies... Extensive cloud cover has begun to clear from south to north as a lead shortwave trough progresses through the region. Secondary shortwave trough currently moving through northern CA is expected to progress eastward/northeastward into the region later this afternoon, fostering additional storm development this afternoon. Buoyancy will be modest, but moderate mid-level flow (i.e. 40-45 kt at 500 mb) will persist, supporting the potential for a few stronger/more organized updrafts. A locally greater severe wind risk may materialize across southern ID and northern UT where stronger heating and deeper mixing is anticipated. Read more

SPC Jul 4, 2025 2000 UTC Day 1 Convective Outlook

1 month 2 weeks ago
SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0242 PM CDT Fri Jul 04 2025 Valid 042000Z - 051200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM EASTERN NORTH DAKOTA INTO NORTHERN MINNESOTA... ...SUMMARY... Scattered severe thunderstorms are possible later today into the evening over the Upper Midwest. Severe gusts will be the primary hazard. Isolated severe gusts and hail may also occur from eastern Oregon into portions of the northern Great Basin/Rockies and the Central High Plains. ...20z Update... Minor adjustments were made to the Marginal Risk in Colorado to add low end hail probabilities. Cells are expected to form and move off the high terrain into the lower plains through the afternoon/evening. A few cells may be capable of severe hail, given sufficient CAPE and deep layer shear. For more information, see MCD#1562. The most favorable region for severe storms continues to be the central High Plains into the upper Mississippi Valley. Storms have started to develop across this region and coverage is expected to increase into the evening. Storms will have the potential for damaging wind and large hail. See MCD#1560 for more information. ..Thornton.. 07/04/2025 .PREV DISCUSSION... /ISSUED 1130 AM CDT Fri Jul 04 2025/ ...Central High Plains into the Upper MS Valley... Recent satellite imagery shows expansive upper ridging from the Lower MS Valley into western Ontario, with several disturbances along the periphery of this ridge. The shortwave trough currently moving through the central Rockies/central High Plains will be the most impactful for today's severe potential as it continues northeastward towards the very moist airmass in place across the northern/central Plains and Upper Midwest. Current surface observations reveal a large reservoir of dewpoints greater than 68 deg F across the northern/central Plains, with higher dewpoints (70+ deg F) farther northeastward across the Upper MS Valley. Strong heating is anticipated over the region, particularly the Upper Midwest, destabilizing the airmass by the early afternoon and contributing to strong to very strong buoyancy. Low-level convergence along a southeastward-progressing cold front, as well as along expected pre-frontal troughing, will augment large-scale ascent provided by the approaching shortwave. All of this lift will provide the impetus for convective initiation. Initial development appears most likely in the early afternoon (i.e. around 18Z) over northeast/eastern CO, NE Panhandle/western NE, and western KS. Vertical shear and buoyancy will be modest in this region, limiting storm strength and organization. Even so, steep low-level lapse rates and moderately high cloud bases could result in a few strong gusts. A relatively greater severe potential exists farther north over the eastern Dakotas into northern/central MN. Here, strong buoyancy (i.e. 2500-3500 J/kg of MLCAPE) is expected by the late afternoon. Vertical shear will be relatively modest, but the strong buoyancy should support robust updrafts capable of precipitation loading and water-loaded downbursts. Given the limited shear and progressive cold front, a quick transition to an outflow-dominant, linear structure is anticipated. A few stronger gusts are possible within this line as well. Isolated large hail could occur with the strongest, early-stage cellular storms. ...Eastern Oregon into the Northern Great Basin/Rockies... Extensive cloud cover has begun to clear from south to north as a lead shortwave trough progresses through the region. Secondary shortwave trough currently moving through northern CA is expected to progress eastward/northeastward into the region later this afternoon, fostering additional storm development this afternoon. Buoyancy will be modest, but moderate mid-level flow (i.e. 40-45 kt at 500 mb) will persist, supporting the potential for a few stronger/more organized updrafts. A locally greater severe wind risk may materialize across southern ID and northern UT where stronger heating and deeper mixing is anticipated. Read more

SPC Jul 4, 2025 2000 UTC Day 1 Convective Outlook

1 month 2 weeks ago
SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0242 PM CDT Fri Jul 04 2025 Valid 042000Z - 051200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM EASTERN NORTH DAKOTA INTO NORTHERN MINNESOTA... ...SUMMARY... Scattered severe thunderstorms are possible later today into the evening over the Upper Midwest. Severe gusts will be the primary hazard. Isolated severe gusts and hail may also occur from eastern Oregon into portions of the northern Great Basin/Rockies and the Central High Plains. ...20z Update... Minor adjustments were made to the Marginal Risk in Colorado to add low end hail probabilities. Cells are expected to form and move off the high terrain into the lower plains through the afternoon/evening. A few cells may be capable of severe hail, given sufficient CAPE and deep layer shear. For more information, see MCD#1562. The most favorable region for severe storms continues to be the central High Plains into the upper Mississippi Valley. Storms have started to develop across this region and coverage is expected to increase into the evening. Storms will have the potential for damaging wind and large hail. See MCD#1560 for more information. ..Thornton.. 07/04/2025 .PREV DISCUSSION... /ISSUED 1130 AM CDT Fri Jul 04 2025/ ...Central High Plains into the Upper MS Valley... Recent satellite imagery shows expansive upper ridging from the Lower MS Valley into western Ontario, with several disturbances along the periphery of this ridge. The shortwave trough currently moving through the central Rockies/central High Plains will be the most impactful for today's severe potential as it continues northeastward towards the very moist airmass in place across the northern/central Plains and Upper Midwest. Current surface observations reveal a large reservoir of dewpoints greater than 68 deg F across the northern/central Plains, with higher dewpoints (70+ deg F) farther northeastward across the Upper MS Valley. Strong heating is anticipated over the region, particularly the Upper Midwest, destabilizing the airmass by the early afternoon and contributing to strong to very strong buoyancy. Low-level convergence along a southeastward-progressing cold front, as well as along expected pre-frontal troughing, will augment large-scale ascent provided by the approaching shortwave. All of this lift will provide the impetus for convective initiation. Initial development appears most likely in the early afternoon (i.e. around 18Z) over northeast/eastern CO, NE Panhandle/western NE, and western KS. Vertical shear and buoyancy will be modest in this region, limiting storm strength and organization. Even so, steep low-level lapse rates and moderately high cloud bases could result in a few strong gusts. A relatively greater severe potential exists farther north over the eastern Dakotas into northern/central MN. Here, strong buoyancy (i.e. 2500-3500 J/kg of MLCAPE) is expected by the late afternoon. Vertical shear will be relatively modest, but the strong buoyancy should support robust updrafts capable of precipitation loading and water-loaded downbursts. Given the limited shear and progressive cold front, a quick transition to an outflow-dominant, linear structure is anticipated. A few stronger gusts are possible within this line as well. Isolated large hail could occur with the strongest, early-stage cellular storms. ...Eastern Oregon into the Northern Great Basin/Rockies... Extensive cloud cover has begun to clear from south to north as a lead shortwave trough progresses through the region. Secondary shortwave trough currently moving through northern CA is expected to progress eastward/northeastward into the region later this afternoon, fostering additional storm development this afternoon. Buoyancy will be modest, but moderate mid-level flow (i.e. 40-45 kt at 500 mb) will persist, supporting the potential for a few stronger/more organized updrafts. A locally greater severe wind risk may materialize across southern ID and northern UT where stronger heating and deeper mixing is anticipated. Read more

SPC Jul 4, 2025 2000 UTC Day 1 Convective Outlook

1 month 2 weeks ago
SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0242 PM CDT Fri Jul 04 2025 Valid 042000Z - 051200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM EASTERN NORTH DAKOTA INTO NORTHERN MINNESOTA... ...SUMMARY... Scattered severe thunderstorms are possible later today into the evening over the Upper Midwest. Severe gusts will be the primary hazard. Isolated severe gusts and hail may also occur from eastern Oregon into portions of the northern Great Basin/Rockies and the Central High Plains. ...20z Update... Minor adjustments were made to the Marginal Risk in Colorado to add low end hail probabilities. Cells are expected to form and move off the high terrain into the lower plains through the afternoon/evening. A few cells may be capable of severe hail, given sufficient CAPE and deep layer shear. For more information, see MCD#1562. The most favorable region for severe storms continues to be the central High Plains into the upper Mississippi Valley. Storms have started to develop across this region and coverage is expected to increase into the evening. Storms will have the potential for damaging wind and large hail. See MCD#1560 for more information. ..Thornton.. 07/04/2025 .PREV DISCUSSION... /ISSUED 1130 AM CDT Fri Jul 04 2025/ ...Central High Plains into the Upper MS Valley... Recent satellite imagery shows expansive upper ridging from the Lower MS Valley into western Ontario, with several disturbances along the periphery of this ridge. The shortwave trough currently moving through the central Rockies/central High Plains will be the most impactful for today's severe potential as it continues northeastward towards the very moist airmass in place across the northern/central Plains and Upper Midwest. Current surface observations reveal a large reservoir of dewpoints greater than 68 deg F across the northern/central Plains, with higher dewpoints (70+ deg F) farther northeastward across the Upper MS Valley. Strong heating is anticipated over the region, particularly the Upper Midwest, destabilizing the airmass by the early afternoon and contributing to strong to very strong buoyancy. Low-level convergence along a southeastward-progressing cold front, as well as along expected pre-frontal troughing, will augment large-scale ascent provided by the approaching shortwave. All of this lift will provide the impetus for convective initiation. Initial development appears most likely in the early afternoon (i.e. around 18Z) over northeast/eastern CO, NE Panhandle/western NE, and western KS. Vertical shear and buoyancy will be modest in this region, limiting storm strength and organization. Even so, steep low-level lapse rates and moderately high cloud bases could result in a few strong gusts. A relatively greater severe potential exists farther north over the eastern Dakotas into northern/central MN. Here, strong buoyancy (i.e. 2500-3500 J/kg of MLCAPE) is expected by the late afternoon. Vertical shear will be relatively modest, but the strong buoyancy should support robust updrafts capable of precipitation loading and water-loaded downbursts. Given the limited shear and progressive cold front, a quick transition to an outflow-dominant, linear structure is anticipated. A few stronger gusts are possible within this line as well. Isolated large hail could occur with the strongest, early-stage cellular storms. ...Eastern Oregon into the Northern Great Basin/Rockies... Extensive cloud cover has begun to clear from south to north as a lead shortwave trough progresses through the region. Secondary shortwave trough currently moving through northern CA is expected to progress eastward/northeastward into the region later this afternoon, fostering additional storm development this afternoon. Buoyancy will be modest, but moderate mid-level flow (i.e. 40-45 kt at 500 mb) will persist, supporting the potential for a few stronger/more organized updrafts. A locally greater severe wind risk may materialize across southern ID and northern UT where stronger heating and deeper mixing is anticipated. Read more

SPC Jul 4, 2025 2000 UTC Day 1 Convective Outlook

1 month 2 weeks ago
SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0242 PM CDT Fri Jul 04 2025 Valid 042000Z - 051200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM EASTERN NORTH DAKOTA INTO NORTHERN MINNESOTA... ...SUMMARY... Scattered severe thunderstorms are possible later today into the evening over the Upper Midwest. Severe gusts will be the primary hazard. Isolated severe gusts and hail may also occur from eastern Oregon into portions of the northern Great Basin/Rockies and the Central High Plains. ...20z Update... Minor adjustments were made to the Marginal Risk in Colorado to add low end hail probabilities. Cells are expected to form and move off the high terrain into the lower plains through the afternoon/evening. A few cells may be capable of severe hail, given sufficient CAPE and deep layer shear. For more information, see MCD#1562. The most favorable region for severe storms continues to be the central High Plains into the upper Mississippi Valley. Storms have started to develop across this region and coverage is expected to increase into the evening. Storms will have the potential for damaging wind and large hail. See MCD#1560 for more information. ..Thornton.. 07/04/2025 .PREV DISCUSSION... /ISSUED 1130 AM CDT Fri Jul 04 2025/ ...Central High Plains into the Upper MS Valley... Recent satellite imagery shows expansive upper ridging from the Lower MS Valley into western Ontario, with several disturbances along the periphery of this ridge. The shortwave trough currently moving through the central Rockies/central High Plains will be the most impactful for today's severe potential as it continues northeastward towards the very moist airmass in place across the northern/central Plains and Upper Midwest. Current surface observations reveal a large reservoir of dewpoints greater than 68 deg F across the northern/central Plains, with higher dewpoints (70+ deg F) farther northeastward across the Upper MS Valley. Strong heating is anticipated over the region, particularly the Upper Midwest, destabilizing the airmass by the early afternoon and contributing to strong to very strong buoyancy. Low-level convergence along a southeastward-progressing cold front, as well as along expected pre-frontal troughing, will augment large-scale ascent provided by the approaching shortwave. All of this lift will provide the impetus for convective initiation. Initial development appears most likely in the early afternoon (i.e. around 18Z) over northeast/eastern CO, NE Panhandle/western NE, and western KS. Vertical shear and buoyancy will be modest in this region, limiting storm strength and organization. Even so, steep low-level lapse rates and moderately high cloud bases could result in a few strong gusts. A relatively greater severe potential exists farther north over the eastern Dakotas into northern/central MN. Here, strong buoyancy (i.e. 2500-3500 J/kg of MLCAPE) is expected by the late afternoon. Vertical shear will be relatively modest, but the strong buoyancy should support robust updrafts capable of precipitation loading and water-loaded downbursts. Given the limited shear and progressive cold front, a quick transition to an outflow-dominant, linear structure is anticipated. A few stronger gusts are possible within this line as well. Isolated large hail could occur with the strongest, early-stage cellular storms. ...Eastern Oregon into the Northern Great Basin/Rockies... Extensive cloud cover has begun to clear from south to north as a lead shortwave trough progresses through the region. Secondary shortwave trough currently moving through northern CA is expected to progress eastward/northeastward into the region later this afternoon, fostering additional storm development this afternoon. Buoyancy will be modest, but moderate mid-level flow (i.e. 40-45 kt at 500 mb) will persist, supporting the potential for a few stronger/more organized updrafts. A locally greater severe wind risk may materialize across southern ID and northern UT where stronger heating and deeper mixing is anticipated. Read more

SPC Jul 4, 2025 2000 UTC Day 1 Convective Outlook

1 month 2 weeks ago
SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0242 PM CDT Fri Jul 04 2025 Valid 042000Z - 051200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM EASTERN NORTH DAKOTA INTO NORTHERN MINNESOTA... ...SUMMARY... Scattered severe thunderstorms are possible later today into the evening over the Upper Midwest. Severe gusts will be the primary hazard. Isolated severe gusts and hail may also occur from eastern Oregon into portions of the northern Great Basin/Rockies and the Central High Plains. ...20z Update... Minor adjustments were made to the Marginal Risk in Colorado to add low end hail probabilities. Cells are expected to form and move off the high terrain into the lower plains through the afternoon/evening. A few cells may be capable of severe hail, given sufficient CAPE and deep layer shear. For more information, see MCD#1562. The most favorable region for severe storms continues to be the central High Plains into the upper Mississippi Valley. Storms have started to develop across this region and coverage is expected to increase into the evening. Storms will have the potential for damaging wind and large hail. See MCD#1560 for more information. ..Thornton.. 07/04/2025 .PREV DISCUSSION... /ISSUED 1130 AM CDT Fri Jul 04 2025/ ...Central High Plains into the Upper MS Valley... Recent satellite imagery shows expansive upper ridging from the Lower MS Valley into western Ontario, with several disturbances along the periphery of this ridge. The shortwave trough currently moving through the central Rockies/central High Plains will be the most impactful for today's severe potential as it continues northeastward towards the very moist airmass in place across the northern/central Plains and Upper Midwest. Current surface observations reveal a large reservoir of dewpoints greater than 68 deg F across the northern/central Plains, with higher dewpoints (70+ deg F) farther northeastward across the Upper MS Valley. Strong heating is anticipated over the region, particularly the Upper Midwest, destabilizing the airmass by the early afternoon and contributing to strong to very strong buoyancy. Low-level convergence along a southeastward-progressing cold front, as well as along expected pre-frontal troughing, will augment large-scale ascent provided by the approaching shortwave. All of this lift will provide the impetus for convective initiation. Initial development appears most likely in the early afternoon (i.e. around 18Z) over northeast/eastern CO, NE Panhandle/western NE, and western KS. Vertical shear and buoyancy will be modest in this region, limiting storm strength and organization. Even so, steep low-level lapse rates and moderately high cloud bases could result in a few strong gusts. A relatively greater severe potential exists farther north over the eastern Dakotas into northern/central MN. Here, strong buoyancy (i.e. 2500-3500 J/kg of MLCAPE) is expected by the late afternoon. Vertical shear will be relatively modest, but the strong buoyancy should support robust updrafts capable of precipitation loading and water-loaded downbursts. Given the limited shear and progressive cold front, a quick transition to an outflow-dominant, linear structure is anticipated. A few stronger gusts are possible within this line as well. Isolated large hail could occur with the strongest, early-stage cellular storms. ...Eastern Oregon into the Northern Great Basin/Rockies... Extensive cloud cover has begun to clear from south to north as a lead shortwave trough progresses through the region. Secondary shortwave trough currently moving through northern CA is expected to progress eastward/northeastward into the region later this afternoon, fostering additional storm development this afternoon. Buoyancy will be modest, but moderate mid-level flow (i.e. 40-45 kt at 500 mb) will persist, supporting the potential for a few stronger/more organized updrafts. A locally greater severe wind risk may materialize across southern ID and northern UT where stronger heating and deeper mixing is anticipated. Read more

SPC Day 2 Fire Weather Outlook

1 month 2 weeks ago
SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0212 PM CDT Fri Jul 04 2025 Valid 051200Z - 061200Z ...Update... No changes were required for Saturday's outlook. The forecast remains accurate. A small corridor of breezy southwest winds and low RH is expected from southeastern/eastern NV into western/southwestern UT. Please see the previous discussion for additional details. ..Barnes.. 07/04/2025 .PREV DISCUSSION... /ISSUED 0152 AM CDT Fri Jul 04 2025/ ...Synopsis... A mid-level ridge is expected to build over the southern Rockies during the day on Sunday. Modest mid-level flow around the periphery of the ridge is expected to mix downward during the afternoon hours and promote dry, breezy conditions across portions of the Great Basin and northern Rockies. RH is expected to be in the 5-15% range across much of this region with gusts to 15-20 mph. However, across the northern Rockies recent rainfall has made fuels largely too moist for fire spread. Therefore, have added an Elevated area across portions of southeastern Nevada and southwestern Utah, where the driest fuels overlap with the corridor of strongest winds. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook

1 month 2 weeks ago
SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0212 PM CDT Fri Jul 04 2025 Valid 051200Z - 061200Z ...Update... No changes were required for Saturday's outlook. The forecast remains accurate. A small corridor of breezy southwest winds and low RH is expected from southeastern/eastern NV into western/southwestern UT. Please see the previous discussion for additional details. ..Barnes.. 07/04/2025 .PREV DISCUSSION... /ISSUED 0152 AM CDT Fri Jul 04 2025/ ...Synopsis... A mid-level ridge is expected to build over the southern Rockies during the day on Sunday. Modest mid-level flow around the periphery of the ridge is expected to mix downward during the afternoon hours and promote dry, breezy conditions across portions of the Great Basin and northern Rockies. RH is expected to be in the 5-15% range across much of this region with gusts to 15-20 mph. However, across the northern Rockies recent rainfall has made fuels largely too moist for fire spread. Therefore, have added an Elevated area across portions of southeastern Nevada and southwestern Utah, where the driest fuels overlap with the corridor of strongest winds. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook

1 month 2 weeks ago
SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0212 PM CDT Fri Jul 04 2025 Valid 051200Z - 061200Z ...Update... No changes were required for Saturday's outlook. The forecast remains accurate. A small corridor of breezy southwest winds and low RH is expected from southeastern/eastern NV into western/southwestern UT. Please see the previous discussion for additional details. ..Barnes.. 07/04/2025 .PREV DISCUSSION... /ISSUED 0152 AM CDT Fri Jul 04 2025/ ...Synopsis... A mid-level ridge is expected to build over the southern Rockies during the day on Sunday. Modest mid-level flow around the periphery of the ridge is expected to mix downward during the afternoon hours and promote dry, breezy conditions across portions of the Great Basin and northern Rockies. RH is expected to be in the 5-15% range across much of this region with gusts to 15-20 mph. However, across the northern Rockies recent rainfall has made fuels largely too moist for fire spread. Therefore, have added an Elevated area across portions of southeastern Nevada and southwestern Utah, where the driest fuels overlap with the corridor of strongest winds. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook

1 month 2 weeks ago
SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0212 PM CDT Fri Jul 04 2025 Valid 051200Z - 061200Z ...Update... No changes were required for Saturday's outlook. The forecast remains accurate. A small corridor of breezy southwest winds and low RH is expected from southeastern/eastern NV into western/southwestern UT. Please see the previous discussion for additional details. ..Barnes.. 07/04/2025 .PREV DISCUSSION... /ISSUED 0152 AM CDT Fri Jul 04 2025/ ...Synopsis... A mid-level ridge is expected to build over the southern Rockies during the day on Sunday. Modest mid-level flow around the periphery of the ridge is expected to mix downward during the afternoon hours and promote dry, breezy conditions across portions of the Great Basin and northern Rockies. RH is expected to be in the 5-15% range across much of this region with gusts to 15-20 mph. However, across the northern Rockies recent rainfall has made fuels largely too moist for fire spread. Therefore, have added an Elevated area across portions of southeastern Nevada and southwestern Utah, where the driest fuels overlap with the corridor of strongest winds. ...Please see www.spc.noaa.gov/fire for graphic product... Read more