Severe Storms

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0230 AM CDT Fri Sep 12 2025 Valid 141200Z - 151200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS PORTIONS OF THE NORTHERN AND CENTRAL PLAINS... ...SUMMARY... Strong to severe storms are possible in the parts of the northern and central Plains on Sunday. ...Synopsis... An upper-level trough, initially within the central High Plains, will pivot northeastward into the central/northern Plains on Sunday. A surface low is forecast within the Dakotas with a weaker trough extending into the southern High Plains. ...Northern/central Plains... A surface low is expected to be in the northern Plains. This, along with a surface trough extending to the south and a warm front across the Upper Midwest, should provide some focus for storm development during the afternoon. Given the orientation of the upper trough, hodographs will tend to have some veer-back characteristics in the mid/upper levels. Even so, enough vertical shear should exist to promote organized storms. Cloud cover may hinder surface heating, more so to the north. Temperatures near -10 C at 500 mb will allow for 1000-1500 J/kg MLCAPE with perhaps near 2000 J/kg in Nebraska/Kansas. The highest confidence in storm initiation is within parts of the central/eastern Dakotas where the greater low/mid-level forcing will be. Forcing becomes less certain with southern extent. Large hail and severe gusts are the main hazards. ...Southern High Plains... A more conditional severe threat exists in this area. Model guidance is not consistent with regard to how fast the trough will eject into the Plains and pivot northeast. In either case, the surface trough/convergence will be weak. The slower ECMWF solution would suggest greater potential for initiation even though there still will be slight mid-level height rises during the afternoon/evening. Sufficient mid-level flow across the southern Rockies could promote organized storms, but confidence in initiation/coverage is much too low for probabilities. ..Wendt.. 09/12/2025 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0230 AM CDT Fri Sep 12 2025 Valid 141200Z - 151200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS PORTIONS OF THE NORTHERN AND CENTRAL PLAINS... ...SUMMARY... Strong to severe storms are possible in the parts of the northern and central Plains on Sunday. ...Synopsis... An upper-level trough, initially within the central High Plains, will pivot northeastward into the central/northern Plains on Sunday. A surface low is forecast within the Dakotas with a weaker trough extending into the southern High Plains. ...Northern/central Plains... A surface low is expected to be in the northern Plains. This, along with a surface trough extending to the south and a warm front across the Upper Midwest, should provide some focus for storm development during the afternoon. Given the orientation of the upper trough, hodographs will tend to have some veer-back characteristics in the mid/upper levels. Even so, enough vertical shear should exist to promote organized storms. Cloud cover may hinder surface heating, more so to the north. Temperatures near -10 C at 500 mb will allow for 1000-1500 J/kg MLCAPE with perhaps near 2000 J/kg in Nebraska/Kansas. The highest confidence in storm initiation is within parts of the central/eastern Dakotas where the greater low/mid-level forcing will be. Forcing becomes less certain with southern extent. Large hail and severe gusts are the main hazards. ...Southern High Plains... A more conditional severe threat exists in this area. Model guidance is not consistent with regard to how fast the trough will eject into the Plains and pivot northeast. In either case, the surface trough/convergence will be weak. The slower ECMWF solution would suggest greater potential for initiation even though there still will be slight mid-level height rises during the afternoon/evening. Sufficient mid-level flow across the southern Rockies could promote organized storms, but confidence in initiation/coverage is much too low for probabilities. ..Wendt.. 09/12/2025 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0230 AM CDT Fri Sep 12 2025 Valid 141200Z - 151200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS PORTIONS OF THE NORTHERN AND CENTRAL PLAINS... ...SUMMARY... Strong to severe storms are possible in the parts of the northern and central Plains on Sunday. ...Synopsis... An upper-level trough, initially within the central High Plains, will pivot northeastward into the central/northern Plains on Sunday. A surface low is forecast within the Dakotas with a weaker trough extending into the southern High Plains. ...Northern/central Plains... A surface low is expected to be in the northern Plains. This, along with a surface trough extending to the south and a warm front across the Upper Midwest, should provide some focus for storm development during the afternoon. Given the orientation of the upper trough, hodographs will tend to have some veer-back characteristics in the mid/upper levels. Even so, enough vertical shear should exist to promote organized storms. Cloud cover may hinder surface heating, more so to the north. Temperatures near -10 C at 500 mb will allow for 1000-1500 J/kg MLCAPE with perhaps near 2000 J/kg in Nebraska/Kansas. The highest confidence in storm initiation is within parts of the central/eastern Dakotas where the greater low/mid-level forcing will be. Forcing becomes less certain with southern extent. Large hail and severe gusts are the main hazards. ...Southern High Plains... A more conditional severe threat exists in this area. Model guidance is not consistent with regard to how fast the trough will eject into the Plains and pivot northeast. In either case, the surface trough/convergence will be weak. The slower ECMWF solution would suggest greater potential for initiation even though there still will be slight mid-level height rises during the afternoon/evening. Sufficient mid-level flow across the southern Rockies could promote organized storms, but confidence in initiation/coverage is much too low for probabilities. ..Wendt.. 09/12/2025 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0230 AM CDT Fri Sep 12 2025 Valid 141200Z - 151200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS PORTIONS OF THE NORTHERN AND CENTRAL PLAINS... ...SUMMARY... Strong to severe storms are possible in the parts of the northern and central Plains on Sunday. ...Synopsis... An upper-level trough, initially within the central High Plains, will pivot northeastward into the central/northern Plains on Sunday. A surface low is forecast within the Dakotas with a weaker trough extending into the southern High Plains. ...Northern/central Plains... A surface low is expected to be in the northern Plains. This, along with a surface trough extending to the south and a warm front across the Upper Midwest, should provide some focus for storm development during the afternoon. Given the orientation of the upper trough, hodographs will tend to have some veer-back characteristics in the mid/upper levels. Even so, enough vertical shear should exist to promote organized storms. Cloud cover may hinder surface heating, more so to the north. Temperatures near -10 C at 500 mb will allow for 1000-1500 J/kg MLCAPE with perhaps near 2000 J/kg in Nebraska/Kansas. The highest confidence in storm initiation is within parts of the central/eastern Dakotas where the greater low/mid-level forcing will be. Forcing becomes less certain with southern extent. Large hail and severe gusts are the main hazards. ...Southern High Plains... A more conditional severe threat exists in this area. Model guidance is not consistent with regard to how fast the trough will eject into the Plains and pivot northeast. In either case, the surface trough/convergence will be weak. The slower ECMWF solution would suggest greater potential for initiation even though there still will be slight mid-level height rises during the afternoon/evening. Sufficient mid-level flow across the southern Rockies could promote organized storms, but confidence in initiation/coverage is much too low for probabilities. ..Wendt.. 09/12/2025 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0230 AM CDT Fri Sep 12 2025 Valid 141200Z - 151200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS PORTIONS OF THE NORTHERN AND CENTRAL PLAINS... ...SUMMARY... Strong to severe storms are possible in the parts of the northern and central Plains on Sunday. ...Synopsis... An upper-level trough, initially within the central High Plains, will pivot northeastward into the central/northern Plains on Sunday. A surface low is forecast within the Dakotas with a weaker trough extending into the southern High Plains. ...Northern/central Plains... A surface low is expected to be in the northern Plains. This, along with a surface trough extending to the south and a warm front across the Upper Midwest, should provide some focus for storm development during the afternoon. Given the orientation of the upper trough, hodographs will tend to have some veer-back characteristics in the mid/upper levels. Even so, enough vertical shear should exist to promote organized storms. Cloud cover may hinder surface heating, more so to the north. Temperatures near -10 C at 500 mb will allow for 1000-1500 J/kg MLCAPE with perhaps near 2000 J/kg in Nebraska/Kansas. The highest confidence in storm initiation is within parts of the central/eastern Dakotas where the greater low/mid-level forcing will be. Forcing becomes less certain with southern extent. Large hail and severe gusts are the main hazards. ...Southern High Plains... A more conditional severe threat exists in this area. Model guidance is not consistent with regard to how fast the trough will eject into the Plains and pivot northeast. In either case, the surface trough/convergence will be weak. The slower ECMWF solution would suggest greater potential for initiation even though there still will be slight mid-level height rises during the afternoon/evening. Sufficient mid-level flow across the southern Rockies could promote organized storms, but confidence in initiation/coverage is much too low for probabilities. ..Wendt.. 09/12/2025 Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0151 AM CDT Fri Sep 12 2025 Valid 131200Z - 141200Z ...NO CRITICAL AREAS... ...Synopsis... A mid-level trough will impinge on the West Coast as a preceding upper trough ejects into the Plains states tomorrow (Saturday). The net result will be another day of scattered to numerous thunderstorms across the Rockies toward the Four Corners region in association to the widespread lifting of a buoyant airmass with the upper trough. These storms will likely be more wet than dry, and will traverse areas that may see appreciable rainfall accumulations on Day 1, potentially dampening fuels in the process. While an instance or two of lightning-induced wildfire ignition cannot be ruled out, the coverage of such occurrences should be sparse at best. ..Squitieri.. 09/12/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0151 AM CDT Fri Sep 12 2025 Valid 131200Z - 141200Z ...NO CRITICAL AREAS... ...Synopsis... A mid-level trough will impinge on the West Coast as a preceding upper trough ejects into the Plains states tomorrow (Saturday). The net result will be another day of scattered to numerous thunderstorms across the Rockies toward the Four Corners region in association to the widespread lifting of a buoyant airmass with the upper trough. These storms will likely be more wet than dry, and will traverse areas that may see appreciable rainfall accumulations on Day 1, potentially dampening fuels in the process. While an instance or two of lightning-induced wildfire ignition cannot be ruled out, the coverage of such occurrences should be sparse at best. ..Squitieri.. 09/12/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0151 AM CDT Fri Sep 12 2025 Valid 131200Z - 141200Z ...NO CRITICAL AREAS... ...Synopsis... A mid-level trough will impinge on the West Coast as a preceding upper trough ejects into the Plains states tomorrow (Saturday). The net result will be another day of scattered to numerous thunderstorms across the Rockies toward the Four Corners region in association to the widespread lifting of a buoyant airmass with the upper trough. These storms will likely be more wet than dry, and will traverse areas that may see appreciable rainfall accumulations on Day 1, potentially dampening fuels in the process. While an instance or two of lightning-induced wildfire ignition cannot be ruled out, the coverage of such occurrences should be sparse at best. ..Squitieri.. 09/12/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0151 AM CDT Fri Sep 12 2025 Valid 131200Z - 141200Z ...NO CRITICAL AREAS... ...Synopsis... A mid-level trough will impinge on the West Coast as a preceding upper trough ejects into the Plains states tomorrow (Saturday). The net result will be another day of scattered to numerous thunderstorms across the Rockies toward the Four Corners region in association to the widespread lifting of a buoyant airmass with the upper trough. These storms will likely be more wet than dry, and will traverse areas that may see appreciable rainfall accumulations on Day 1, potentially dampening fuels in the process. While an instance or two of lightning-induced wildfire ignition cannot be ruled out, the coverage of such occurrences should be sparse at best. ..Squitieri.. 09/12/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0151 AM CDT Fri Sep 12 2025 Valid 131200Z - 141200Z ...NO CRITICAL AREAS... ...Synopsis... A mid-level trough will impinge on the West Coast as a preceding upper trough ejects into the Plains states tomorrow (Saturday). The net result will be another day of scattered to numerous thunderstorms across the Rockies toward the Four Corners region in association to the widespread lifting of a buoyant airmass with the upper trough. These storms will likely be more wet than dry, and will traverse areas that may see appreciable rainfall accumulations on Day 1, potentially dampening fuels in the process. While an instance or two of lightning-induced wildfire ignition cannot be ruled out, the coverage of such occurrences should be sparse at best. ..Squitieri.. 09/12/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0151 AM CDT Fri Sep 12 2025 Valid 131200Z - 141200Z ...NO CRITICAL AREAS... ...Synopsis... A mid-level trough will impinge on the West Coast as a preceding upper trough ejects into the Plains states tomorrow (Saturday). The net result will be another day of scattered to numerous thunderstorms across the Rockies toward the Four Corners region in association to the widespread lifting of a buoyant airmass with the upper trough. These storms will likely be more wet than dry, and will traverse areas that may see appreciable rainfall accumulations on Day 1, potentially dampening fuels in the process. While an instance or two of lightning-induced wildfire ignition cannot be ruled out, the coverage of such occurrences should be sparse at best. ..Squitieri.. 09/12/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0150 AM CDT Fri Sep 12 2025 Valid 121200Z - 131200Z ...NO CRITICAL AREAS... ...Synopsis... A mid-level trough will overspread the Interior West as upper ridging persists over the central U.S. today. The broad upper troughing west of the Rockies will encourage the widespread lifting of a buoyant airmass, supporting scattered to numerous thunderstorms from the Great Basin to the northern Rockies and points east. Most of these storms are expected to be on the wet side, and given multiple past days of scattered to numerous thunderstorms, fuels are not expected to be quite as dry as in previous days/weeks. While a couple of lightning-induced fire ignitions are possible, the overall threat seems too sparse to warrant isolated dry thunderstorm highlights this outlook. ..Squitieri.. 09/12/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0150 AM CDT Fri Sep 12 2025 Valid 121200Z - 131200Z ...NO CRITICAL AREAS... ...Synopsis... A mid-level trough will overspread the Interior West as upper ridging persists over the central U.S. today. The broad upper troughing west of the Rockies will encourage the widespread lifting of a buoyant airmass, supporting scattered to numerous thunderstorms from the Great Basin to the northern Rockies and points east. Most of these storms are expected to be on the wet side, and given multiple past days of scattered to numerous thunderstorms, fuels are not expected to be quite as dry as in previous days/weeks. While a couple of lightning-induced fire ignitions are possible, the overall threat seems too sparse to warrant isolated dry thunderstorm highlights this outlook. ..Squitieri.. 09/12/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0150 AM CDT Fri Sep 12 2025 Valid 121200Z - 131200Z ...NO CRITICAL AREAS... ...Synopsis... A mid-level trough will overspread the Interior West as upper ridging persists over the central U.S. today. The broad upper troughing west of the Rockies will encourage the widespread lifting of a buoyant airmass, supporting scattered to numerous thunderstorms from the Great Basin to the northern Rockies and points east. Most of these storms are expected to be on the wet side, and given multiple past days of scattered to numerous thunderstorms, fuels are not expected to be quite as dry as in previous days/weeks. While a couple of lightning-induced fire ignitions are possible, the overall threat seems too sparse to warrant isolated dry thunderstorm highlights this outlook. ..Squitieri.. 09/12/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0150 AM CDT Fri Sep 12 2025 Valid 121200Z - 131200Z ...NO CRITICAL AREAS... ...Synopsis... A mid-level trough will overspread the Interior West as upper ridging persists over the central U.S. today. The broad upper troughing west of the Rockies will encourage the widespread lifting of a buoyant airmass, supporting scattered to numerous thunderstorms from the Great Basin to the northern Rockies and points east. Most of these storms are expected to be on the wet side, and given multiple past days of scattered to numerous thunderstorms, fuels are not expected to be quite as dry as in previous days/weeks. While a couple of lightning-induced fire ignitions are possible, the overall threat seems too sparse to warrant isolated dry thunderstorm highlights this outlook. ..Squitieri.. 09/12/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0150 AM CDT Fri Sep 12 2025 Valid 121200Z - 131200Z ...NO CRITICAL AREAS... ...Synopsis... A mid-level trough will overspread the Interior West as upper ridging persists over the central U.S. today. The broad upper troughing west of the Rockies will encourage the widespread lifting of a buoyant airmass, supporting scattered to numerous thunderstorms from the Great Basin to the northern Rockies and points east. Most of these storms are expected to be on the wet side, and given multiple past days of scattered to numerous thunderstorms, fuels are not expected to be quite as dry as in previous days/weeks. While a couple of lightning-induced fire ignitions are possible, the overall threat seems too sparse to warrant isolated dry thunderstorm highlights this outlook. ..Squitieri.. 09/12/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0150 AM CDT Fri Sep 12 2025 Valid 121200Z - 131200Z ...NO CRITICAL AREAS... ...Synopsis... A mid-level trough will overspread the Interior West as upper ridging persists over the central U.S. today. The broad upper troughing west of the Rockies will encourage the widespread lifting of a buoyant airmass, supporting scattered to numerous thunderstorms from the Great Basin to the northern Rockies and points east. Most of these storms are expected to be on the wet side, and given multiple past days of scattered to numerous thunderstorms, fuels are not expected to be quite as dry as in previous days/weeks. While a couple of lightning-induced fire ignitions are possible, the overall threat seems too sparse to warrant isolated dry thunderstorm highlights this outlook. ..Squitieri.. 09/12/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 0100 AM CDT Fri Sep 12 2025 Valid 131200Z - 141200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE SOUTHERN AND CENTRAL HIGH PLAINS AND THE NORTHERN PLAINS... ...SUMMARY... Strong to severe storms are possible over parts of the southern and central High Plains and northern Plains Saturday. ...Synopsis... The western upper trough will continue its slow progress eastward on Saturday. The trough is expected to eject into central Plains by early Sunday morning. A few embedded shortwave troughs will pivot into the northern Plains and stronger mid-level winds will extend into the southern Rockies. At the surface, a low in the northern Plains will become more diffuse during the period. ...Southern/Central High Plains... On the southern edge of the broad western trough, stronger mid-level flow will be perpendicular to the southern Rockies into part of the Front Range. Low-level moisture will advect into the regions given surface southeasterly winds. Moisture will be greatest in New Mexico with mid/upper 50s F dewpoints. Farther north, flow will become much more meridional and moisture will be more limited. Within the southern Rockies, cloud cover associated with the trough will generally keep low-level lapse rates weak. However, modestly steep mid-level lapse rates with the cooler air aloft and 35-40 kts of effective shear will promote some risk for a few supercell structures by the afternoon. Isolated large hail will be the main risk. While a similar hail threat will be present for much of the Front Range, this area is also more likely to receive greater surface heating. Steeper low-level lapse rates will support a threat for isolated severe gusts with the strongest storms. ...Northern Plains... Scattered thunderstorms will likely be ongoing at the start of the period. By this time, steeper mid-level lapse rates will likely have diminished for much of the western Dakotas into eastern Montana and Wyoming. This activity will be driven by a northward moving shortwave trough and low-level warm advection. Despite cloud cover complicating the low-level thermodynamic environment and the surface low gradually weakening with time, there may still be zone of greater potential in the eastern Dakotas where steeper mid-level lapse rates will be. Greater shear/forcing will overlap greater buoyancy during the afternoon in this area as well. The strongest storms, if they develop, will likely be near and east of the Missouri River. Small to isolated marginally severe hail appears to be the primary hazard. ...Upper Midwest... A weak shortwave trough is expected to move through southern Wisconsin into the southern Lake Michigan vicinity. This will promote a zone of warm advection that will allow potentially scattered storms to develop. While shear will be modestly enhanced with the shortwave, greater buoyancy and lapse rates will be displaced to the west. A stronger storm or two could occur, but limited confidence in greater severe storm coverage precludes probabilities. ..Wendt.. 09/12/2025 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 0100 AM CDT Fri Sep 12 2025 Valid 131200Z - 141200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE SOUTHERN AND CENTRAL HIGH PLAINS AND THE NORTHERN PLAINS... ...SUMMARY... Strong to severe storms are possible over parts of the southern and central High Plains and northern Plains Saturday. ...Synopsis... The western upper trough will continue its slow progress eastward on Saturday. The trough is expected to eject into central Plains by early Sunday morning. A few embedded shortwave troughs will pivot into the northern Plains and stronger mid-level winds will extend into the southern Rockies. At the surface, a low in the northern Plains will become more diffuse during the period. ...Southern/Central High Plains... On the southern edge of the broad western trough, stronger mid-level flow will be perpendicular to the southern Rockies into part of the Front Range. Low-level moisture will advect into the regions given surface southeasterly winds. Moisture will be greatest in New Mexico with mid/upper 50s F dewpoints. Farther north, flow will become much more meridional and moisture will be more limited. Within the southern Rockies, cloud cover associated with the trough will generally keep low-level lapse rates weak. However, modestly steep mid-level lapse rates with the cooler air aloft and 35-40 kts of effective shear will promote some risk for a few supercell structures by the afternoon. Isolated large hail will be the main risk. While a similar hail threat will be present for much of the Front Range, this area is also more likely to receive greater surface heating. Steeper low-level lapse rates will support a threat for isolated severe gusts with the strongest storms. ...Northern Plains... Scattered thunderstorms will likely be ongoing at the start of the period. By this time, steeper mid-level lapse rates will likely have diminished for much of the western Dakotas into eastern Montana and Wyoming. This activity will be driven by a northward moving shortwave trough and low-level warm advection. Despite cloud cover complicating the low-level thermodynamic environment and the surface low gradually weakening with time, there may still be zone of greater potential in the eastern Dakotas where steeper mid-level lapse rates will be. Greater shear/forcing will overlap greater buoyancy during the afternoon in this area as well. The strongest storms, if they develop, will likely be near and east of the Missouri River. Small to isolated marginally severe hail appears to be the primary hazard. ...Upper Midwest... A weak shortwave trough is expected to move through southern Wisconsin into the southern Lake Michigan vicinity. This will promote a zone of warm advection that will allow potentially scattered storms to develop. While shear will be modestly enhanced with the shortwave, greater buoyancy and lapse rates will be displaced to the west. A stronger storm or two could occur, but limited confidence in greater severe storm coverage precludes probabilities. ..Wendt.. 09/12/2025 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 0100 AM CDT Fri Sep 12 2025 Valid 131200Z - 141200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE SOUTHERN AND CENTRAL HIGH PLAINS AND THE NORTHERN PLAINS... ...SUMMARY... Strong to severe storms are possible over parts of the southern and central High Plains and northern Plains Saturday. ...Synopsis... The western upper trough will continue its slow progress eastward on Saturday. The trough is expected to eject into central Plains by early Sunday morning. A few embedded shortwave troughs will pivot into the northern Plains and stronger mid-level winds will extend into the southern Rockies. At the surface, a low in the northern Plains will become more diffuse during the period. ...Southern/Central High Plains... On the southern edge of the broad western trough, stronger mid-level flow will be perpendicular to the southern Rockies into part of the Front Range. Low-level moisture will advect into the regions given surface southeasterly winds. Moisture will be greatest in New Mexico with mid/upper 50s F dewpoints. Farther north, flow will become much more meridional and moisture will be more limited. Within the southern Rockies, cloud cover associated with the trough will generally keep low-level lapse rates weak. However, modestly steep mid-level lapse rates with the cooler air aloft and 35-40 kts of effective shear will promote some risk for a few supercell structures by the afternoon. Isolated large hail will be the main risk. While a similar hail threat will be present for much of the Front Range, this area is also more likely to receive greater surface heating. Steeper low-level lapse rates will support a threat for isolated severe gusts with the strongest storms. ...Northern Plains... Scattered thunderstorms will likely be ongoing at the start of the period. By this time, steeper mid-level lapse rates will likely have diminished for much of the western Dakotas into eastern Montana and Wyoming. This activity will be driven by a northward moving shortwave trough and low-level warm advection. Despite cloud cover complicating the low-level thermodynamic environment and the surface low gradually weakening with time, there may still be zone of greater potential in the eastern Dakotas where steeper mid-level lapse rates will be. Greater shear/forcing will overlap greater buoyancy during the afternoon in this area as well. The strongest storms, if they develop, will likely be near and east of the Missouri River. Small to isolated marginally severe hail appears to be the primary hazard. ...Upper Midwest... A weak shortwave trough is expected to move through southern Wisconsin into the southern Lake Michigan vicinity. This will promote a zone of warm advection that will allow potentially scattered storms to develop. While shear will be modestly enhanced with the shortwave, greater buoyancy and lapse rates will be displaced to the west. A stronger storm or two could occur, but limited confidence in greater severe storm coverage precludes probabilities. ..Wendt.. 09/12/2025 Read more