Severe Storms

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1114 AM CDT Sun Sep 07 2025 Valid 071630Z - 081200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND EVENING OVER PARTS OF THE CENTRAL AND SOUTHERN HIGH PLAINS... ...SUMMARY... A few stronger thunderstorms capable of marginally severe hail/wind gusts are possible across portions of the central and southern High Plains late this afternoon and evening. ...Central and Southern High Plains... An upper ridge axis is present today over the Rockies, with northwest flow aloft across the high Plains states. A weak shortwave trough will top the ridge axis over CO and spread into the central Plains later today. Weak lift and mid-level moisture associated with this feature will encourage scattered thunderstorm development by mid-afternoon off the foothills and mountains of central CO. The activity will propagate southeastward into a moist and moderately unstable air mass over parts of CO/KS/NM and the TX/OK Panhandles, where dewpoints in the 50s will yield MLCAPE values around 2000 J/kg. Winds below 6km are rather weak, which should limit convective organization. However, steep mid-level lapse rates and strong winds in the upper levels may result in isolated supercell structures capable of hail. Morning visible satellite imagery suggests sufficient cloud cover to limit afternoon heating somewhat. This may tend to decrease the wind damage threat. ..Hart/Weinman.. 09/07/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1114 AM CDT Sun Sep 07 2025 Valid 071630Z - 081200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND EVENING OVER PARTS OF THE CENTRAL AND SOUTHERN HIGH PLAINS... ...SUMMARY... A few stronger thunderstorms capable of marginally severe hail/wind gusts are possible across portions of the central and southern High Plains late this afternoon and evening. ...Central and Southern High Plains... An upper ridge axis is present today over the Rockies, with northwest flow aloft across the high Plains states. A weak shortwave trough will top the ridge axis over CO and spread into the central Plains later today. Weak lift and mid-level moisture associated with this feature will encourage scattered thunderstorm development by mid-afternoon off the foothills and mountains of central CO. The activity will propagate southeastward into a moist and moderately unstable air mass over parts of CO/KS/NM and the TX/OK Panhandles, where dewpoints in the 50s will yield MLCAPE values around 2000 J/kg. Winds below 6km are rather weak, which should limit convective organization. However, steep mid-level lapse rates and strong winds in the upper levels may result in isolated supercell structures capable of hail. Morning visible satellite imagery suggests sufficient cloud cover to limit afternoon heating somewhat. This may tend to decrease the wind damage threat. ..Hart/Weinman.. 09/07/2025 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0709 AM CDT Sun Sep 07 2025 Valid 071300Z - 081200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE CENTRAL AND SOUTHERN HIGH PLAINS... ...SUMMARY... A few stronger thunderstorms capable of marginally severe wind gusts/hail are possible across portions of the central and southern High Plains late this afternoon through the early evening. ...Central/Southern High Plains... Morning water-vapor imagery shows a low/trough over the eastern Pacific with a downstream ridge over the Rockies. A couple of weak disturbances are cresting the ridge and may aid in storm development later this afternoon/evening over the central High Plains later today. In the low levels, a lee trough and an associated moisture plume over the High Plains will provide a focus for isolated to widely scattered storms. Strong heating over the High Plains will contribute to weak to moderate buoyancy by late afternoon. South-southeasterly low-level winds veering to around 20-kt northwesterly mid-level flow will support some modest updraft organization. The stronger storms may yield an isolated severe-hail (diameter 1.5 inches or less) and wind-gust (55-65 mph) threat. A small cluster or two is expected to evolve during the evening coincident with an increase in the LLJ. This activity will likely move east-southeast into western KS and the OK/TX Panhandles, where a cooling boundary layer and increasing CINH will act to limit severe potential by mid-late evening. ..Smith/Broyles.. 09/07/2025 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0709 AM CDT Sun Sep 07 2025 Valid 071300Z - 081200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE CENTRAL AND SOUTHERN HIGH PLAINS... ...SUMMARY... A few stronger thunderstorms capable of marginally severe wind gusts/hail are possible across portions of the central and southern High Plains late this afternoon through the early evening. ...Central/Southern High Plains... Morning water-vapor imagery shows a low/trough over the eastern Pacific with a downstream ridge over the Rockies. A couple of weak disturbances are cresting the ridge and may aid in storm development later this afternoon/evening over the central High Plains later today. In the low levels, a lee trough and an associated moisture plume over the High Plains will provide a focus for isolated to widely scattered storms. Strong heating over the High Plains will contribute to weak to moderate buoyancy by late afternoon. South-southeasterly low-level winds veering to around 20-kt northwesterly mid-level flow will support some modest updraft organization. The stronger storms may yield an isolated severe-hail (diameter 1.5 inches or less) and wind-gust (55-65 mph) threat. A small cluster or two is expected to evolve during the evening coincident with an increase in the LLJ. This activity will likely move east-southeast into western KS and the OK/TX Panhandles, where a cooling boundary layer and increasing CINH will act to limit severe potential by mid-late evening. ..Smith/Broyles.. 09/07/2025 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0709 AM CDT Sun Sep 07 2025 Valid 071300Z - 081200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE CENTRAL AND SOUTHERN HIGH PLAINS... ...SUMMARY... A few stronger thunderstorms capable of marginally severe wind gusts/hail are possible across portions of the central and southern High Plains late this afternoon through the early evening. ...Central/Southern High Plains... Morning water-vapor imagery shows a low/trough over the eastern Pacific with a downstream ridge over the Rockies. A couple of weak disturbances are cresting the ridge and may aid in storm development later this afternoon/evening over the central High Plains later today. In the low levels, a lee trough and an associated moisture plume over the High Plains will provide a focus for isolated to widely scattered storms. Strong heating over the High Plains will contribute to weak to moderate buoyancy by late afternoon. South-southeasterly low-level winds veering to around 20-kt northwesterly mid-level flow will support some modest updraft organization. The stronger storms may yield an isolated severe-hail (diameter 1.5 inches or less) and wind-gust (55-65 mph) threat. A small cluster or two is expected to evolve during the evening coincident with an increase in the LLJ. This activity will likely move east-southeast into western KS and the OK/TX Panhandles, where a cooling boundary layer and increasing CINH will act to limit severe potential by mid-late evening. ..Smith/Broyles.. 09/07/2025 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0709 AM CDT Sun Sep 07 2025 Valid 071300Z - 081200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE CENTRAL AND SOUTHERN HIGH PLAINS... ...SUMMARY... A few stronger thunderstorms capable of marginally severe wind gusts/hail are possible across portions of the central and southern High Plains late this afternoon through the early evening. ...Central/Southern High Plains... Morning water-vapor imagery shows a low/trough over the eastern Pacific with a downstream ridge over the Rockies. A couple of weak disturbances are cresting the ridge and may aid in storm development later this afternoon/evening over the central High Plains later today. In the low levels, a lee trough and an associated moisture plume over the High Plains will provide a focus for isolated to widely scattered storms. Strong heating over the High Plains will contribute to weak to moderate buoyancy by late afternoon. South-southeasterly low-level winds veering to around 20-kt northwesterly mid-level flow will support some modest updraft organization. The stronger storms may yield an isolated severe-hail (diameter 1.5 inches or less) and wind-gust (55-65 mph) threat. A small cluster or two is expected to evolve during the evening coincident with an increase in the LLJ. This activity will likely move east-southeast into western KS and the OK/TX Panhandles, where a cooling boundary layer and increasing CINH will act to limit severe potential by mid-late evening. ..Smith/Broyles.. 09/07/2025 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0709 AM CDT Sun Sep 07 2025 Valid 071300Z - 081200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE CENTRAL AND SOUTHERN HIGH PLAINS... ...SUMMARY... A few stronger thunderstorms capable of marginally severe wind gusts/hail are possible across portions of the central and southern High Plains late this afternoon through the early evening. ...Central/Southern High Plains... Morning water-vapor imagery shows a low/trough over the eastern Pacific with a downstream ridge over the Rockies. A couple of weak disturbances are cresting the ridge and may aid in storm development later this afternoon/evening over the central High Plains later today. In the low levels, a lee trough and an associated moisture plume over the High Plains will provide a focus for isolated to widely scattered storms. Strong heating over the High Plains will contribute to weak to moderate buoyancy by late afternoon. South-southeasterly low-level winds veering to around 20-kt northwesterly mid-level flow will support some modest updraft organization. The stronger storms may yield an isolated severe-hail (diameter 1.5 inches or less) and wind-gust (55-65 mph) threat. A small cluster or two is expected to evolve during the evening coincident with an increase in the LLJ. This activity will likely move east-southeast into western KS and the OK/TX Panhandles, where a cooling boundary layer and increasing CINH will act to limit severe potential by mid-late evening. ..Smith/Broyles.. 09/07/2025 Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0358 AM CDT Sun Sep 07 2025 Valid 101200Z - 151200Z ...DISCUSSION... The mid-level flow pattern across the US is forecast to become more stagnant into the extended-range forecast period as the western US upper low deepens and shortwave ridging over the Plains moves slowly eastward. Broad troughing over the East should gradually consolidate, slowing eastward progress of the upper ridge. As the western trough slowly approaches the Rockies, a lee trough should sharpen each afternoon with a narrow zone of moisture return along and east into parts of the High Plains. Sufficient destabilization is expected to support isolated thunderstorms, and perhaps some severe risk, near the lee trough as smaller embedded perturbations eject eastward periodically. However, with only slow movement of the upper ridge expected, forcing for ascent should remain modest until early next weekend. Somewhat greater severe potential may develop D6/Friday or D7/Saturday as the primary upper trough begins to emerge over the Plains. However, given the uncertainties associated with the smaller scale features, and the timing of the main trough, limited confidence exists regarding severe potential in the extended forecast. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0358 AM CDT Sun Sep 07 2025 Valid 101200Z - 151200Z ...DISCUSSION... The mid-level flow pattern across the US is forecast to become more stagnant into the extended-range forecast period as the western US upper low deepens and shortwave ridging over the Plains moves slowly eastward. Broad troughing over the East should gradually consolidate, slowing eastward progress of the upper ridge. As the western trough slowly approaches the Rockies, a lee trough should sharpen each afternoon with a narrow zone of moisture return along and east into parts of the High Plains. Sufficient destabilization is expected to support isolated thunderstorms, and perhaps some severe risk, near the lee trough as smaller embedded perturbations eject eastward periodically. However, with only slow movement of the upper ridge expected, forcing for ascent should remain modest until early next weekend. Somewhat greater severe potential may develop D6/Friday or D7/Saturday as the primary upper trough begins to emerge over the Plains. However, given the uncertainties associated with the smaller scale features, and the timing of the main trough, limited confidence exists regarding severe potential in the extended forecast. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0358 AM CDT Sun Sep 07 2025 Valid 101200Z - 151200Z ...DISCUSSION... The mid-level flow pattern across the US is forecast to become more stagnant into the extended-range forecast period as the western US upper low deepens and shortwave ridging over the Plains moves slowly eastward. Broad troughing over the East should gradually consolidate, slowing eastward progress of the upper ridge. As the western trough slowly approaches the Rockies, a lee trough should sharpen each afternoon with a narrow zone of moisture return along and east into parts of the High Plains. Sufficient destabilization is expected to support isolated thunderstorms, and perhaps some severe risk, near the lee trough as smaller embedded perturbations eject eastward periodically. However, with only slow movement of the upper ridge expected, forcing for ascent should remain modest until early next weekend. Somewhat greater severe potential may develop D6/Friday or D7/Saturday as the primary upper trough begins to emerge over the Plains. However, given the uncertainties associated with the smaller scale features, and the timing of the main trough, limited confidence exists regarding severe potential in the extended forecast. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0358 AM CDT Sun Sep 07 2025 Valid 101200Z - 151200Z ...DISCUSSION... The mid-level flow pattern across the US is forecast to become more stagnant into the extended-range forecast period as the western US upper low deepens and shortwave ridging over the Plains moves slowly eastward. Broad troughing over the East should gradually consolidate, slowing eastward progress of the upper ridge. As the western trough slowly approaches the Rockies, a lee trough should sharpen each afternoon with a narrow zone of moisture return along and east into parts of the High Plains. Sufficient destabilization is expected to support isolated thunderstorms, and perhaps some severe risk, near the lee trough as smaller embedded perturbations eject eastward periodically. However, with only slow movement of the upper ridge expected, forcing for ascent should remain modest until early next weekend. Somewhat greater severe potential may develop D6/Friday or D7/Saturday as the primary upper trough begins to emerge over the Plains. However, given the uncertainties associated with the smaller scale features, and the timing of the main trough, limited confidence exists regarding severe potential in the extended forecast. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0358 AM CDT Sun Sep 07 2025 Valid 101200Z - 151200Z ...DISCUSSION... The mid-level flow pattern across the US is forecast to become more stagnant into the extended-range forecast period as the western US upper low deepens and shortwave ridging over the Plains moves slowly eastward. Broad troughing over the East should gradually consolidate, slowing eastward progress of the upper ridge. As the western trough slowly approaches the Rockies, a lee trough should sharpen each afternoon with a narrow zone of moisture return along and east into parts of the High Plains. Sufficient destabilization is expected to support isolated thunderstorms, and perhaps some severe risk, near the lee trough as smaller embedded perturbations eject eastward periodically. However, with only slow movement of the upper ridge expected, forcing for ascent should remain modest until early next weekend. Somewhat greater severe potential may develop D6/Friday or D7/Saturday as the primary upper trough begins to emerge over the Plains. However, given the uncertainties associated with the smaller scale features, and the timing of the main trough, limited confidence exists regarding severe potential in the extended forecast. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0358 AM CDT Sun Sep 07 2025 Valid 101200Z - 151200Z ...DISCUSSION... The mid-level flow pattern across the US is forecast to become more stagnant into the extended-range forecast period as the western US upper low deepens and shortwave ridging over the Plains moves slowly eastward. Broad troughing over the East should gradually consolidate, slowing eastward progress of the upper ridge. As the western trough slowly approaches the Rockies, a lee trough should sharpen each afternoon with a narrow zone of moisture return along and east into parts of the High Plains. Sufficient destabilization is expected to support isolated thunderstorms, and perhaps some severe risk, near the lee trough as smaller embedded perturbations eject eastward periodically. However, with only slow movement of the upper ridge expected, forcing for ascent should remain modest until early next weekend. Somewhat greater severe potential may develop D6/Friday or D7/Saturday as the primary upper trough begins to emerge over the Plains. However, given the uncertainties associated with the smaller scale features, and the timing of the main trough, limited confidence exists regarding severe potential in the extended forecast. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0358 AM CDT Sun Sep 07 2025 Valid 101200Z - 151200Z ...DISCUSSION... The mid-level flow pattern across the US is forecast to become more stagnant into the extended-range forecast period as the western US upper low deepens and shortwave ridging over the Plains moves slowly eastward. Broad troughing over the East should gradually consolidate, slowing eastward progress of the upper ridge. As the western trough slowly approaches the Rockies, a lee trough should sharpen each afternoon with a narrow zone of moisture return along and east into parts of the High Plains. Sufficient destabilization is expected to support isolated thunderstorms, and perhaps some severe risk, near the lee trough as smaller embedded perturbations eject eastward periodically. However, with only slow movement of the upper ridge expected, forcing for ascent should remain modest until early next weekend. Somewhat greater severe potential may develop D6/Friday or D7/Saturday as the primary upper trough begins to emerge over the Plains. However, given the uncertainties associated with the smaller scale features, and the timing of the main trough, limited confidence exists regarding severe potential in the extended forecast. Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0229 AM CDT Sun Sep 07 2025 Valid 091200Z - 101200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... A few strong storms are possible over the central Plains and Upper Midwest Tuesday, but overall severe potential is low. ...Synopsis... A broad upper trough across the Pacific Northwest is forecast to intensify as it shifts eastward, impinging on the western flank of a shortwave ridge centered over the Rockies. To the east, persistent troughing should remain in place, with surface high pressure dominating the eastern half of the country. As southwesterly flow aloft increases over the western US and central Rockies, a subtle shortwave trough/vort max will pass over the crest of the ridge and into the Plains Tuesday afternoon and evening. This should aid in strengthening a lee trough over the High Plains, potentially serving as a focus for isolated thunderstorm development. ...Central High Plains.. Continued low-level southerly flow will advect richer surface moisture northwestward across the High Plains beginning early Tuesday. As dewpoints increase into the low to mid 60s F, strong heating should support robust destabilization along and east of the lee trough. 1500-2500 J/kg of MLCAPE will develop beneath substantial capping as mid-level heights will likely remain neutral through much of the day. Eventually, weak ascent from the embedded shortwave trough and low-level upslope flow may allow for isolated storm development along the lee trough over the central High Plains. Northwesterly flow aloft will be marginally supportive of organized storms, including the potential for supercells. However, given the capping and weak ascent, considerable uncertainty remains regarding storm coverage and severity. While sporadic hail and severe gusts cannot be ruled out, confidence remains too low for severe probabilities at this time. ...Northern Plains and Upper Midwest... A diffuse front will stall across the northern Plains/Upper Midwest early Tuesday beneath the western extension of the broad eastern US trough. Weak low-level warm air advection may support scattered showers and thunderstorms through much of Tuesday near the front. These parcels are likely to be elevated along and north of the front with modest buoyancy and vertical shear expected to limit overall severe potential. Still, a few stronger storms with sporadic hail potential may evolve, though confidence in a sustained severe risk is low. ..Lyons.. 09/07/2025 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0229 AM CDT Sun Sep 07 2025 Valid 091200Z - 101200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... A few strong storms are possible over the central Plains and Upper Midwest Tuesday, but overall severe potential is low. ...Synopsis... A broad upper trough across the Pacific Northwest is forecast to intensify as it shifts eastward, impinging on the western flank of a shortwave ridge centered over the Rockies. To the east, persistent troughing should remain in place, with surface high pressure dominating the eastern half of the country. As southwesterly flow aloft increases over the western US and central Rockies, a subtle shortwave trough/vort max will pass over the crest of the ridge and into the Plains Tuesday afternoon and evening. This should aid in strengthening a lee trough over the High Plains, potentially serving as a focus for isolated thunderstorm development. ...Central High Plains.. Continued low-level southerly flow will advect richer surface moisture northwestward across the High Plains beginning early Tuesday. As dewpoints increase into the low to mid 60s F, strong heating should support robust destabilization along and east of the lee trough. 1500-2500 J/kg of MLCAPE will develop beneath substantial capping as mid-level heights will likely remain neutral through much of the day. Eventually, weak ascent from the embedded shortwave trough and low-level upslope flow may allow for isolated storm development along the lee trough over the central High Plains. Northwesterly flow aloft will be marginally supportive of organized storms, including the potential for supercells. However, given the capping and weak ascent, considerable uncertainty remains regarding storm coverage and severity. While sporadic hail and severe gusts cannot be ruled out, confidence remains too low for severe probabilities at this time. ...Northern Plains and Upper Midwest... A diffuse front will stall across the northern Plains/Upper Midwest early Tuesday beneath the western extension of the broad eastern US trough. Weak low-level warm air advection may support scattered showers and thunderstorms through much of Tuesday near the front. These parcels are likely to be elevated along and north of the front with modest buoyancy and vertical shear expected to limit overall severe potential. Still, a few stronger storms with sporadic hail potential may evolve, though confidence in a sustained severe risk is low. ..Lyons.. 09/07/2025 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0229 AM CDT Sun Sep 07 2025 Valid 091200Z - 101200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... A few strong storms are possible over the central Plains and Upper Midwest Tuesday, but overall severe potential is low. ...Synopsis... A broad upper trough across the Pacific Northwest is forecast to intensify as it shifts eastward, impinging on the western flank of a shortwave ridge centered over the Rockies. To the east, persistent troughing should remain in place, with surface high pressure dominating the eastern half of the country. As southwesterly flow aloft increases over the western US and central Rockies, a subtle shortwave trough/vort max will pass over the crest of the ridge and into the Plains Tuesday afternoon and evening. This should aid in strengthening a lee trough over the High Plains, potentially serving as a focus for isolated thunderstorm development. ...Central High Plains.. Continued low-level southerly flow will advect richer surface moisture northwestward across the High Plains beginning early Tuesday. As dewpoints increase into the low to mid 60s F, strong heating should support robust destabilization along and east of the lee trough. 1500-2500 J/kg of MLCAPE will develop beneath substantial capping as mid-level heights will likely remain neutral through much of the day. Eventually, weak ascent from the embedded shortwave trough and low-level upslope flow may allow for isolated storm development along the lee trough over the central High Plains. Northwesterly flow aloft will be marginally supportive of organized storms, including the potential for supercells. However, given the capping and weak ascent, considerable uncertainty remains regarding storm coverage and severity. While sporadic hail and severe gusts cannot be ruled out, confidence remains too low for severe probabilities at this time. ...Northern Plains and Upper Midwest... A diffuse front will stall across the northern Plains/Upper Midwest early Tuesday beneath the western extension of the broad eastern US trough. Weak low-level warm air advection may support scattered showers and thunderstorms through much of Tuesday near the front. These parcels are likely to be elevated along and north of the front with modest buoyancy and vertical shear expected to limit overall severe potential. Still, a few stronger storms with sporadic hail potential may evolve, though confidence in a sustained severe risk is low. ..Lyons.. 09/07/2025 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0229 AM CDT Sun Sep 07 2025 Valid 091200Z - 101200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... A few strong storms are possible over the central Plains and Upper Midwest Tuesday, but overall severe potential is low. ...Synopsis... A broad upper trough across the Pacific Northwest is forecast to intensify as it shifts eastward, impinging on the western flank of a shortwave ridge centered over the Rockies. To the east, persistent troughing should remain in place, with surface high pressure dominating the eastern half of the country. As southwesterly flow aloft increases over the western US and central Rockies, a subtle shortwave trough/vort max will pass over the crest of the ridge and into the Plains Tuesday afternoon and evening. This should aid in strengthening a lee trough over the High Plains, potentially serving as a focus for isolated thunderstorm development. ...Central High Plains.. Continued low-level southerly flow will advect richer surface moisture northwestward across the High Plains beginning early Tuesday. As dewpoints increase into the low to mid 60s F, strong heating should support robust destabilization along and east of the lee trough. 1500-2500 J/kg of MLCAPE will develop beneath substantial capping as mid-level heights will likely remain neutral through much of the day. Eventually, weak ascent from the embedded shortwave trough and low-level upslope flow may allow for isolated storm development along the lee trough over the central High Plains. Northwesterly flow aloft will be marginally supportive of organized storms, including the potential for supercells. However, given the capping and weak ascent, considerable uncertainty remains regarding storm coverage and severity. While sporadic hail and severe gusts cannot be ruled out, confidence remains too low for severe probabilities at this time. ...Northern Plains and Upper Midwest... A diffuse front will stall across the northern Plains/Upper Midwest early Tuesday beneath the western extension of the broad eastern US trough. Weak low-level warm air advection may support scattered showers and thunderstorms through much of Tuesday near the front. These parcels are likely to be elevated along and north of the front with modest buoyancy and vertical shear expected to limit overall severe potential. Still, a few stronger storms with sporadic hail potential may evolve, though confidence in a sustained severe risk is low. ..Lyons.. 09/07/2025 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0229 AM CDT Sun Sep 07 2025 Valid 091200Z - 101200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... A few strong storms are possible over the central Plains and Upper Midwest Tuesday, but overall severe potential is low. ...Synopsis... A broad upper trough across the Pacific Northwest is forecast to intensify as it shifts eastward, impinging on the western flank of a shortwave ridge centered over the Rockies. To the east, persistent troughing should remain in place, with surface high pressure dominating the eastern half of the country. As southwesterly flow aloft increases over the western US and central Rockies, a subtle shortwave trough/vort max will pass over the crest of the ridge and into the Plains Tuesday afternoon and evening. This should aid in strengthening a lee trough over the High Plains, potentially serving as a focus for isolated thunderstorm development. ...Central High Plains.. Continued low-level southerly flow will advect richer surface moisture northwestward across the High Plains beginning early Tuesday. As dewpoints increase into the low to mid 60s F, strong heating should support robust destabilization along and east of the lee trough. 1500-2500 J/kg of MLCAPE will develop beneath substantial capping as mid-level heights will likely remain neutral through much of the day. Eventually, weak ascent from the embedded shortwave trough and low-level upslope flow may allow for isolated storm development along the lee trough over the central High Plains. Northwesterly flow aloft will be marginally supportive of organized storms, including the potential for supercells. However, given the capping and weak ascent, considerable uncertainty remains regarding storm coverage and severity. While sporadic hail and severe gusts cannot be ruled out, confidence remains too low for severe probabilities at this time. ...Northern Plains and Upper Midwest... A diffuse front will stall across the northern Plains/Upper Midwest early Tuesday beneath the western extension of the broad eastern US trough. Weak low-level warm air advection may support scattered showers and thunderstorms through much of Tuesday near the front. These parcels are likely to be elevated along and north of the front with modest buoyancy and vertical shear expected to limit overall severe potential. Still, a few stronger storms with sporadic hail potential may evolve, though confidence in a sustained severe risk is low. ..Lyons.. 09/07/2025 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0229 AM CDT Sun Sep 07 2025 Valid 091200Z - 101200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... A few strong storms are possible over the central Plains and Upper Midwest Tuesday, but overall severe potential is low. ...Synopsis... A broad upper trough across the Pacific Northwest is forecast to intensify as it shifts eastward, impinging on the western flank of a shortwave ridge centered over the Rockies. To the east, persistent troughing should remain in place, with surface high pressure dominating the eastern half of the country. As southwesterly flow aloft increases over the western US and central Rockies, a subtle shortwave trough/vort max will pass over the crest of the ridge and into the Plains Tuesday afternoon and evening. This should aid in strengthening a lee trough over the High Plains, potentially serving as a focus for isolated thunderstorm development. ...Central High Plains.. Continued low-level southerly flow will advect richer surface moisture northwestward across the High Plains beginning early Tuesday. As dewpoints increase into the low to mid 60s F, strong heating should support robust destabilization along and east of the lee trough. 1500-2500 J/kg of MLCAPE will develop beneath substantial capping as mid-level heights will likely remain neutral through much of the day. Eventually, weak ascent from the embedded shortwave trough and low-level upslope flow may allow for isolated storm development along the lee trough over the central High Plains. Northwesterly flow aloft will be marginally supportive of organized storms, including the potential for supercells. However, given the capping and weak ascent, considerable uncertainty remains regarding storm coverage and severity. While sporadic hail and severe gusts cannot be ruled out, confidence remains too low for severe probabilities at this time. ...Northern Plains and Upper Midwest... A diffuse front will stall across the northern Plains/Upper Midwest early Tuesday beneath the western extension of the broad eastern US trough. Weak low-level warm air advection may support scattered showers and thunderstorms through much of Tuesday near the front. These parcels are likely to be elevated along and north of the front with modest buoyancy and vertical shear expected to limit overall severe potential. Still, a few stronger storms with sporadic hail potential may evolve, though confidence in a sustained severe risk is low. ..Lyons.. 09/07/2025 Read more