Aggregator

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0253 PM CDT Fri Sep 19 2025 Valid 201200Z - 211200Z ...Columbia Basin... Increasing west/southwest flow aloft ahead of the next Pacific Northwest mid-level trough as well as an increasing onshore pressure gradient will promote enhanced downslope winds leeward of the Cascades and into the Columbia Basin Saturday. Breezy winds of 10-15 mph (localized Cascade gap winds of 20 mph) and relative humidity as low as 10% amid dry fuels will support an elevated fire weather threat for the Columbia Basin. No significant changes were made to the existing Elevated highlight area. ..Williams.. 09/19/2025 .PREV DISCUSSION... /ISSUED 0127 AM CDT Fri Sep 19 2025/ ...Synopsis... Elevated fire-weather conditions are forecast across portions of the northern Cascades as a mid-level trough approaches the Pacific Northwest. Otherwise, generally weak surface winds across the U.S. and higher precipitable water content where convection is expected will diminish any widespread fire-weather concerns. ...Northern Cascades... Ridging and an intensifying height gradient aloft from an approaching mid-level trough will result in some downslope westerly surface winds through the Cascade gaps. These winds are expected to reach 15-20 MPH, with relative humidity values as low as 10-15%. With ERCs hovering around the 80th annual percentile, and some additional curing of fuels expected on Friday, at least Elevated fire-weather highlights are warranted at this time. ...Southern Cascades... Some potential for thunderstorm activity exists Saturday evening across portions of the Oregon Cascades. However, precipitable water content at or exceeding 1 inch, slow storm motions, low buoyancy, and meager fuels will limit the overall threat of lightning-based ignitions. ...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 0253 PM CDT Fri Sep 19 2025 Valid 201200Z - 211200Z ...Columbia Basin... Increasing west/southwest flow aloft ahead of the next Pacific Northwest mid-level trough as well as an increasing onshore pressure gradient will promote enhanced downslope winds leeward of the Cascades and into the Columbia Basin Saturday. Breezy winds of 10-15 mph (localized Cascade gap winds of 20 mph) and relative humidity as low as 10% amid dry fuels will support an elevated fire weather threat for the Columbia Basin. No significant changes were made to the existing Elevated highlight area. ..Williams.. 09/19/2025 .PREV DISCUSSION... /ISSUED 0127 AM CDT Fri Sep 19 2025/ ...Synopsis... Elevated fire-weather conditions are forecast across portions of the northern Cascades as a mid-level trough approaches the Pacific Northwest. Otherwise, generally weak surface winds across the U.S. and higher precipitable water content where convection is expected will diminish any widespread fire-weather concerns. ...Northern Cascades... Ridging and an intensifying height gradient aloft from an approaching mid-level trough will result in some downslope westerly surface winds through the Cascade gaps. These winds are expected to reach 15-20 MPH, with relative humidity values as low as 10-15%. With ERCs hovering around the 80th annual percentile, and some additional curing of fuels expected on Friday, at least Elevated fire-weather highlights are warranted at this time. ...Southern Cascades... Some potential for thunderstorm activity exists Saturday evening across portions of the Oregon Cascades. However, precipitable water content at or exceeding 1 inch, slow storm motions, low buoyancy, and meager fuels will limit the overall threat of lightning-based ignitions. ...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 0253 PM CDT Fri Sep 19 2025 Valid 201200Z - 211200Z ...Columbia Basin... Increasing west/southwest flow aloft ahead of the next Pacific Northwest mid-level trough as well as an increasing onshore pressure gradient will promote enhanced downslope winds leeward of the Cascades and into the Columbia Basin Saturday. Breezy winds of 10-15 mph (localized Cascade gap winds of 20 mph) and relative humidity as low as 10% amid dry fuels will support an elevated fire weather threat for the Columbia Basin. No significant changes were made to the existing Elevated highlight area. ..Williams.. 09/19/2025 .PREV DISCUSSION... /ISSUED 0127 AM CDT Fri Sep 19 2025/ ...Synopsis... Elevated fire-weather conditions are forecast across portions of the northern Cascades as a mid-level trough approaches the Pacific Northwest. Otherwise, generally weak surface winds across the U.S. and higher precipitable water content where convection is expected will diminish any widespread fire-weather concerns. ...Northern Cascades... Ridging and an intensifying height gradient aloft from an approaching mid-level trough will result in some downslope westerly surface winds through the Cascade gaps. These winds are expected to reach 15-20 MPH, with relative humidity values as low as 10-15%. With ERCs hovering around the 80th annual percentile, and some additional curing of fuels expected on Friday, at least Elevated fire-weather highlights are warranted at this time. ...Southern Cascades... Some potential for thunderstorm activity exists Saturday evening across portions of the Oregon Cascades. However, precipitable water content at or exceeding 1 inch, slow storm motions, low buoyancy, and meager fuels will limit the overall threat of lightning-based ignitions. ...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 0253 PM CDT Fri Sep 19 2025 Valid 201200Z - 211200Z ...Columbia Basin... Increasing west/southwest flow aloft ahead of the next Pacific Northwest mid-level trough as well as an increasing onshore pressure gradient will promote enhanced downslope winds leeward of the Cascades and into the Columbia Basin Saturday. Breezy winds of 10-15 mph (localized Cascade gap winds of 20 mph) and relative humidity as low as 10% amid dry fuels will support an elevated fire weather threat for the Columbia Basin. No significant changes were made to the existing Elevated highlight area. ..Williams.. 09/19/2025 .PREV DISCUSSION... /ISSUED 0127 AM CDT Fri Sep 19 2025/ ...Synopsis... Elevated fire-weather conditions are forecast across portions of the northern Cascades as a mid-level trough approaches the Pacific Northwest. Otherwise, generally weak surface winds across the U.S. and higher precipitable water content where convection is expected will diminish any widespread fire-weather concerns. ...Northern Cascades... Ridging and an intensifying height gradient aloft from an approaching mid-level trough will result in some downslope westerly surface winds through the Cascade gaps. These winds are expected to reach 15-20 MPH, with relative humidity values as low as 10-15%. With ERCs hovering around the 80th annual percentile, and some additional curing of fuels expected on Friday, at least Elevated fire-weather highlights are warranted at this time. ...Southern Cascades... Some potential for thunderstorm activity exists Saturday evening across portions of the Oregon Cascades. However, precipitable water content at or exceeding 1 inch, slow storm motions, low buoyancy, and meager fuels will limit the overall threat of lightning-based ignitions. ...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 0253 PM CDT Fri Sep 19 2025 Valid 201200Z - 211200Z ...Columbia Basin... Increasing west/southwest flow aloft ahead of the next Pacific Northwest mid-level trough as well as an increasing onshore pressure gradient will promote enhanced downslope winds leeward of the Cascades and into the Columbia Basin Saturday. Breezy winds of 10-15 mph (localized Cascade gap winds of 20 mph) and relative humidity as low as 10% amid dry fuels will support an elevated fire weather threat for the Columbia Basin. No significant changes were made to the existing Elevated highlight area. ..Williams.. 09/19/2025 .PREV DISCUSSION... /ISSUED 0127 AM CDT Fri Sep 19 2025/ ...Synopsis... Elevated fire-weather conditions are forecast across portions of the northern Cascades as a mid-level trough approaches the Pacific Northwest. Otherwise, generally weak surface winds across the U.S. and higher precipitable water content where convection is expected will diminish any widespread fire-weather concerns. ...Northern Cascades... Ridging and an intensifying height gradient aloft from an approaching mid-level trough will result in some downslope westerly surface winds through the Cascade gaps. These winds are expected to reach 15-20 MPH, with relative humidity values as low as 10-15%. With ERCs hovering around the 80th annual percentile, and some additional curing of fuels expected on Friday, at least Elevated fire-weather highlights are warranted at this time. ...Southern Cascades... Some potential for thunderstorm activity exists Saturday evening across portions of the Oregon Cascades. However, precipitable water content at or exceeding 1 inch, slow storm motions, low buoyancy, and meager fuels will limit the overall threat of lightning-based ignitions. ...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 0253 PM CDT Fri Sep 19 2025 Valid 201200Z - 211200Z ...Columbia Basin... Increasing west/southwest flow aloft ahead of the next Pacific Northwest mid-level trough as well as an increasing onshore pressure gradient will promote enhanced downslope winds leeward of the Cascades and into the Columbia Basin Saturday. Breezy winds of 10-15 mph (localized Cascade gap winds of 20 mph) and relative humidity as low as 10% amid dry fuels will support an elevated fire weather threat for the Columbia Basin. No significant changes were made to the existing Elevated highlight area. ..Williams.. 09/19/2025 .PREV DISCUSSION... /ISSUED 0127 AM CDT Fri Sep 19 2025/ ...Synopsis... Elevated fire-weather conditions are forecast across portions of the northern Cascades as a mid-level trough approaches the Pacific Northwest. Otherwise, generally weak surface winds across the U.S. and higher precipitable water content where convection is expected will diminish any widespread fire-weather concerns. ...Northern Cascades... Ridging and an intensifying height gradient aloft from an approaching mid-level trough will result in some downslope westerly surface winds through the Cascade gaps. These winds are expected to reach 15-20 MPH, with relative humidity values as low as 10-15%. With ERCs hovering around the 80th annual percentile, and some additional curing of fuels expected on Friday, at least Elevated fire-weather highlights are warranted at this time. ...Southern Cascades... Some potential for thunderstorm activity exists Saturday evening across portions of the Oregon Cascades. However, precipitable water content at or exceeding 1 inch, slow storm motions, low buoyancy, and meager fuels will limit the overall threat of lightning-based ignitions. ...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 0253 PM CDT Fri Sep 19 2025 Valid 201200Z - 211200Z ...Columbia Basin... Increasing west/southwest flow aloft ahead of the next Pacific Northwest mid-level trough as well as an increasing onshore pressure gradient will promote enhanced downslope winds leeward of the Cascades and into the Columbia Basin Saturday. Breezy winds of 10-15 mph (localized Cascade gap winds of 20 mph) and relative humidity as low as 10% amid dry fuels will support an elevated fire weather threat for the Columbia Basin. No significant changes were made to the existing Elevated highlight area. ..Williams.. 09/19/2025 .PREV DISCUSSION... /ISSUED 0127 AM CDT Fri Sep 19 2025/ ...Synopsis... Elevated fire-weather conditions are forecast across portions of the northern Cascades as a mid-level trough approaches the Pacific Northwest. Otherwise, generally weak surface winds across the U.S. and higher precipitable water content where convection is expected will diminish any widespread fire-weather concerns. ...Northern Cascades... Ridging and an intensifying height gradient aloft from an approaching mid-level trough will result in some downslope westerly surface winds through the Cascade gaps. These winds are expected to reach 15-20 MPH, with relative humidity values as low as 10-15%. With ERCs hovering around the 80th annual percentile, and some additional curing of fuels expected on Friday, at least Elevated fire-weather highlights are warranted at this time. ...Southern Cascades... Some potential for thunderstorm activity exists Saturday evening across portions of the Oregon Cascades. However, precipitable water content at or exceeding 1 inch, slow storm motions, low buoyancy, and meager fuels will limit the overall threat of lightning-based ignitions. ...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 0253 PM CDT Fri Sep 19 2025 Valid 201200Z - 211200Z ...Columbia Basin... Increasing west/southwest flow aloft ahead of the next Pacific Northwest mid-level trough as well as an increasing onshore pressure gradient will promote enhanced downslope winds leeward of the Cascades and into the Columbia Basin Saturday. Breezy winds of 10-15 mph (localized Cascade gap winds of 20 mph) and relative humidity as low as 10% amid dry fuels will support an elevated fire weather threat for the Columbia Basin. No significant changes were made to the existing Elevated highlight area. ..Williams.. 09/19/2025 .PREV DISCUSSION... /ISSUED 0127 AM CDT Fri Sep 19 2025/ ...Synopsis... Elevated fire-weather conditions are forecast across portions of the northern Cascades as a mid-level trough approaches the Pacific Northwest. Otherwise, generally weak surface winds across the U.S. and higher precipitable water content where convection is expected will diminish any widespread fire-weather concerns. ...Northern Cascades... Ridging and an intensifying height gradient aloft from an approaching mid-level trough will result in some downslope westerly surface winds through the Cascade gaps. These winds are expected to reach 15-20 MPH, with relative humidity values as low as 10-15%. With ERCs hovering around the 80th annual percentile, and some additional curing of fuels expected on Friday, at least Elevated fire-weather highlights are warranted at this time. ...Southern Cascades... Some potential for thunderstorm activity exists Saturday evening across portions of the Oregon Cascades. However, precipitable water content at or exceeding 1 inch, slow storm motions, low buoyancy, and meager fuels will limit the overall threat of lightning-based ignitions. ...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 0253 PM CDT Fri Sep 19 2025 Valid 201200Z - 211200Z ...Columbia Basin... Increasing west/southwest flow aloft ahead of the next Pacific Northwest mid-level trough as well as an increasing onshore pressure gradient will promote enhanced downslope winds leeward of the Cascades and into the Columbia Basin Saturday. Breezy winds of 10-15 mph (localized Cascade gap winds of 20 mph) and relative humidity as low as 10% amid dry fuels will support an elevated fire weather threat for the Columbia Basin. No significant changes were made to the existing Elevated highlight area. ..Williams.. 09/19/2025 .PREV DISCUSSION... /ISSUED 0127 AM CDT Fri Sep 19 2025/ ...Synopsis... Elevated fire-weather conditions are forecast across portions of the northern Cascades as a mid-level trough approaches the Pacific Northwest. Otherwise, generally weak surface winds across the U.S. and higher precipitable water content where convection is expected will diminish any widespread fire-weather concerns. ...Northern Cascades... Ridging and an intensifying height gradient aloft from an approaching mid-level trough will result in some downslope westerly surface winds through the Cascade gaps. These winds are expected to reach 15-20 MPH, with relative humidity values as low as 10-15%. With ERCs hovering around the 80th annual percentile, and some additional curing of fuels expected on Friday, at least Elevated fire-weather highlights are warranted at this time. ...Southern Cascades... Some potential for thunderstorm activity exists Saturday evening across portions of the Oregon Cascades. However, precipitable water content at or exceeding 1 inch, slow storm motions, low buoyancy, and meager fuels will limit the overall threat of lightning-based ignitions. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

No Mesoscale Discussions are in effect as of Fri Sep 19 19:55:02 UTC 2025.

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0243 PM CDT Fri Sep 19 2025 Valid 192000Z - 201200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF FAR SOUTHERN NEBRASKA INTO NORTHWEST AND CENTRAL KANSAS... ...SUMMARY... Isolated severe thunderstorms may impact parts of far southern Nebraska into northwestern and central Kansas late this afternoon and evening, accompanied by some risk for severe hail and wind. ...20z Update... The previous forecast largely remains on track. Latest GOES imagery shows initial thunderstorm development along a weak front across far northwest KS. Ahead of this boundary, modest moisture return across western KS has yielded dewpoints in the upper 50s to low 60s with MLCAPE values increasing to around 1000 J/kg. With temperatures warming into the low 80s, MLCIN is gradually being removed as the front impinges on the returning moisture. Regional VWPs continue to sample 35-40 knot flow at around 4 km AGL, which will support adequate deep-layer shear for organized convection as thunderstorms continue to develop through late afternoon/early evening. Strong/severe thunderstorm coverage remains uncertain with southeastward extent into central KS, but latest observational trends suggest that the severe threat should be relatively greatest across northwest KS through early evening (that said, expected coverage/intensity should remain sufficiently limited to maintain Marginal risk highlights). Elsewhere, the previous forecast (below) remains on track. Instances of sporadic hail and/or wind damage will be possible from eastern AR into northern MS and northwest AL through early evening; however, the convective environment is favorable for mainly short-lived pulse convection (per observed radar trends and regional VWPs), making predictability of any substantial severe threat very limited. ..Moore.. 09/19/2025 .PREV DISCUSSION... /ISSUED 1130 AM CDT Fri Sep 19 2025/ ...Central Plains... Increasing large-scale ascent associated with the embedded shortwave trough and modestly enhanced west-northwesterly jet should influence isolated thunderstorm development by late afternoon/early evening across parts of southwest Nebraska into western Kansas. This region should have a modestly moist low-level airmass in place, with enough daytime heating forecast to support around 1000-1500 J/kg of MLCAPE. Even though mid-level lapse rates are not expected to become overly steep, strong deep-layer shear should aid in convective updraft organization. Any thunderstorms that can form and be sustained could produce isolated severe hail and/or wind gusts as they spread southeastward across western/central Kansas through the evening. ...Midwest/Mississippi Valley... An eastward-moving shortwave trough over the Upper Midwest will more directly influence the middle/upper Mississippi Valley, with moderate destabilization expected this afternoon from the middle Mississippi Valley southward into the Mid-South where MLCAPE will tend to reach 1500-2000 J/kg. Weak deep tropospheric winds will be prevalent along with weak mid-level lapse rates. Even so, some strong to locally severe pulse storms may occur this afternoon through early evening in a broad region spanning parts of Wisconsin/Illinois southward to the Mid-South. ...Western/south-central Minnesota and vicinity... Pending cloud breaks/sufficient heating, scenario may be conducive for funnels and possibly a low chance of a brief tornado in proximity to the upper low and residual surface front, where low-level CAPE/ambient vorticity will be maximized. It is a generally similar regime as to yesterday's reported brief tornado in far southeast North Dakota, although today's setup may be less supportive and more uncertain. ...Southwest States including southeast Arizona... Showers and thunderstorms are ongoing early today across parts of central/eastern Arizona, and on a more isolated basis into western New Mexico and far west Texas. This activity is related to weak ascent aloft associated with minor perturbations rotating through/around a weak upper ridge over the Southwest. Some guidance shows potential for additional robust thunderstorm development by late afternoon/early evening, likely aided by orographic lift and other weak mid-level disturbances. While a localized severe storm or two could occur, substantial uncertainty exists regarding the intensity of these thunderstorms later today owing to ongoing clouds/precipitation, lack of a notable EML, and limited forecast instability. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0243 PM CDT Fri Sep 19 2025 Valid 192000Z - 201200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF FAR SOUTHERN NEBRASKA INTO NORTHWEST AND CENTRAL KANSAS... ...SUMMARY... Isolated severe thunderstorms may impact parts of far southern Nebraska into northwestern and central Kansas late this afternoon and evening, accompanied by some risk for severe hail and wind. ...20z Update... The previous forecast largely remains on track. Latest GOES imagery shows initial thunderstorm development along a weak front across far northwest KS. Ahead of this boundary, modest moisture return across western KS has yielded dewpoints in the upper 50s to low 60s with MLCAPE values increasing to around 1000 J/kg. With temperatures warming into the low 80s, MLCIN is gradually being removed as the front impinges on the returning moisture. Regional VWPs continue to sample 35-40 knot flow at around 4 km AGL, which will support adequate deep-layer shear for organized convection as thunderstorms continue to develop through late afternoon/early evening. Strong/severe thunderstorm coverage remains uncertain with southeastward extent into central KS, but latest observational trends suggest that the severe threat should be relatively greatest across northwest KS through early evening (that said, expected coverage/intensity should remain sufficiently limited to maintain Marginal risk highlights). Elsewhere, the previous forecast (below) remains on track. Instances of sporadic hail and/or wind damage will be possible from eastern AR into northern MS and northwest AL through early evening; however, the convective environment is favorable for mainly short-lived pulse convection (per observed radar trends and regional VWPs), making predictability of any substantial severe threat very limited. ..Moore.. 09/19/2025 .PREV DISCUSSION... /ISSUED 1130 AM CDT Fri Sep 19 2025/ ...Central Plains... Increasing large-scale ascent associated with the embedded shortwave trough and modestly enhanced west-northwesterly jet should influence isolated thunderstorm development by late afternoon/early evening across parts of southwest Nebraska into western Kansas. This region should have a modestly moist low-level airmass in place, with enough daytime heating forecast to support around 1000-1500 J/kg of MLCAPE. Even though mid-level lapse rates are not expected to become overly steep, strong deep-layer shear should aid in convective updraft organization. Any thunderstorms that can form and be sustained could produce isolated severe hail and/or wind gusts as they spread southeastward across western/central Kansas through the evening. ...Midwest/Mississippi Valley... An eastward-moving shortwave trough over the Upper Midwest will more directly influence the middle/upper Mississippi Valley, with moderate destabilization expected this afternoon from the middle Mississippi Valley southward into the Mid-South where MLCAPE will tend to reach 1500-2000 J/kg. Weak deep tropospheric winds will be prevalent along with weak mid-level lapse rates. Even so, some strong to locally severe pulse storms may occur this afternoon through early evening in a broad region spanning parts of Wisconsin/Illinois southward to the Mid-South. ...Western/south-central Minnesota and vicinity... Pending cloud breaks/sufficient heating, scenario may be conducive for funnels and possibly a low chance of a brief tornado in proximity to the upper low and residual surface front, where low-level CAPE/ambient vorticity will be maximized. It is a generally similar regime as to yesterday's reported brief tornado in far southeast North Dakota, although today's setup may be less supportive and more uncertain. ...Southwest States including southeast Arizona... Showers and thunderstorms are ongoing early today across parts of central/eastern Arizona, and on a more isolated basis into western New Mexico and far west Texas. This activity is related to weak ascent aloft associated with minor perturbations rotating through/around a weak upper ridge over the Southwest. Some guidance shows potential for additional robust thunderstorm development by late afternoon/early evening, likely aided by orographic lift and other weak mid-level disturbances. While a localized severe storm or two could occur, substantial uncertainty exists regarding the intensity of these thunderstorms later today owing to ongoing clouds/precipitation, lack of a notable EML, and limited forecast instability. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0243 PM CDT Fri Sep 19 2025 Valid 192000Z - 201200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF FAR SOUTHERN NEBRASKA INTO NORTHWEST AND CENTRAL KANSAS... ...SUMMARY... Isolated severe thunderstorms may impact parts of far southern Nebraska into northwestern and central Kansas late this afternoon and evening, accompanied by some risk for severe hail and wind. ...20z Update... The previous forecast largely remains on track. Latest GOES imagery shows initial thunderstorm development along a weak front across far northwest KS. Ahead of this boundary, modest moisture return across western KS has yielded dewpoints in the upper 50s to low 60s with MLCAPE values increasing to around 1000 J/kg. With temperatures warming into the low 80s, MLCIN is gradually being removed as the front impinges on the returning moisture. Regional VWPs continue to sample 35-40 knot flow at around 4 km AGL, which will support adequate deep-layer shear for organized convection as thunderstorms continue to develop through late afternoon/early evening. Strong/severe thunderstorm coverage remains uncertain with southeastward extent into central KS, but latest observational trends suggest that the severe threat should be relatively greatest across northwest KS through early evening (that said, expected coverage/intensity should remain sufficiently limited to maintain Marginal risk highlights). Elsewhere, the previous forecast (below) remains on track. Instances of sporadic hail and/or wind damage will be possible from eastern AR into northern MS and northwest AL through early evening; however, the convective environment is favorable for mainly short-lived pulse convection (per observed radar trends and regional VWPs), making predictability of any substantial severe threat very limited. ..Moore.. 09/19/2025 .PREV DISCUSSION... /ISSUED 1130 AM CDT Fri Sep 19 2025/ ...Central Plains... Increasing large-scale ascent associated with the embedded shortwave trough and modestly enhanced west-northwesterly jet should influence isolated thunderstorm development by late afternoon/early evening across parts of southwest Nebraska into western Kansas. This region should have a modestly moist low-level airmass in place, with enough daytime heating forecast to support around 1000-1500 J/kg of MLCAPE. Even though mid-level lapse rates are not expected to become overly steep, strong deep-layer shear should aid in convective updraft organization. Any thunderstorms that can form and be sustained could produce isolated severe hail and/or wind gusts as they spread southeastward across western/central Kansas through the evening. ...Midwest/Mississippi Valley... An eastward-moving shortwave trough over the Upper Midwest will more directly influence the middle/upper Mississippi Valley, with moderate destabilization expected this afternoon from the middle Mississippi Valley southward into the Mid-South where MLCAPE will tend to reach 1500-2000 J/kg. Weak deep tropospheric winds will be prevalent along with weak mid-level lapse rates. Even so, some strong to locally severe pulse storms may occur this afternoon through early evening in a broad region spanning parts of Wisconsin/Illinois southward to the Mid-South. ...Western/south-central Minnesota and vicinity... Pending cloud breaks/sufficient heating, scenario may be conducive for funnels and possibly a low chance of a brief tornado in proximity to the upper low and residual surface front, where low-level CAPE/ambient vorticity will be maximized. It is a generally similar regime as to yesterday's reported brief tornado in far southeast North Dakota, although today's setup may be less supportive and more uncertain. ...Southwest States including southeast Arizona... Showers and thunderstorms are ongoing early today across parts of central/eastern Arizona, and on a more isolated basis into western New Mexico and far west Texas. This activity is related to weak ascent aloft associated with minor perturbations rotating through/around a weak upper ridge over the Southwest. Some guidance shows potential for additional robust thunderstorm development by late afternoon/early evening, likely aided by orographic lift and other weak mid-level disturbances. While a localized severe storm or two could occur, substantial uncertainty exists regarding the intensity of these thunderstorms later today owing to ongoing clouds/precipitation, lack of a notable EML, and limited forecast instability. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0243 PM CDT Fri Sep 19 2025 Valid 192000Z - 201200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF FAR SOUTHERN NEBRASKA INTO NORTHWEST AND CENTRAL KANSAS... ...SUMMARY... Isolated severe thunderstorms may impact parts of far southern Nebraska into northwestern and central Kansas late this afternoon and evening, accompanied by some risk for severe hail and wind. ...20z Update... The previous forecast largely remains on track. Latest GOES imagery shows initial thunderstorm development along a weak front across far northwest KS. Ahead of this boundary, modest moisture return across western KS has yielded dewpoints in the upper 50s to low 60s with MLCAPE values increasing to around 1000 J/kg. With temperatures warming into the low 80s, MLCIN is gradually being removed as the front impinges on the returning moisture. Regional VWPs continue to sample 35-40 knot flow at around 4 km AGL, which will support adequate deep-layer shear for organized convection as thunderstorms continue to develop through late afternoon/early evening. Strong/severe thunderstorm coverage remains uncertain with southeastward extent into central KS, but latest observational trends suggest that the severe threat should be relatively greatest across northwest KS through early evening (that said, expected coverage/intensity should remain sufficiently limited to maintain Marginal risk highlights). Elsewhere, the previous forecast (below) remains on track. Instances of sporadic hail and/or wind damage will be possible from eastern AR into northern MS and northwest AL through early evening; however, the convective environment is favorable for mainly short-lived pulse convection (per observed radar trends and regional VWPs), making predictability of any substantial severe threat very limited. ..Moore.. 09/19/2025 .PREV DISCUSSION... /ISSUED 1130 AM CDT Fri Sep 19 2025/ ...Central Plains... Increasing large-scale ascent associated with the embedded shortwave trough and modestly enhanced west-northwesterly jet should influence isolated thunderstorm development by late afternoon/early evening across parts of southwest Nebraska into western Kansas. This region should have a modestly moist low-level airmass in place, with enough daytime heating forecast to support around 1000-1500 J/kg of MLCAPE. Even though mid-level lapse rates are not expected to become overly steep, strong deep-layer shear should aid in convective updraft organization. Any thunderstorms that can form and be sustained could produce isolated severe hail and/or wind gusts as they spread southeastward across western/central Kansas through the evening. ...Midwest/Mississippi Valley... An eastward-moving shortwave trough over the Upper Midwest will more directly influence the middle/upper Mississippi Valley, with moderate destabilization expected this afternoon from the middle Mississippi Valley southward into the Mid-South where MLCAPE will tend to reach 1500-2000 J/kg. Weak deep tropospheric winds will be prevalent along with weak mid-level lapse rates. Even so, some strong to locally severe pulse storms may occur this afternoon through early evening in a broad region spanning parts of Wisconsin/Illinois southward to the Mid-South. ...Western/south-central Minnesota and vicinity... Pending cloud breaks/sufficient heating, scenario may be conducive for funnels and possibly a low chance of a brief tornado in proximity to the upper low and residual surface front, where low-level CAPE/ambient vorticity will be maximized. It is a generally similar regime as to yesterday's reported brief tornado in far southeast North Dakota, although today's setup may be less supportive and more uncertain. ...Southwest States including southeast Arizona... Showers and thunderstorms are ongoing early today across parts of central/eastern Arizona, and on a more isolated basis into western New Mexico and far west Texas. This activity is related to weak ascent aloft associated with minor perturbations rotating through/around a weak upper ridge over the Southwest. Some guidance shows potential for additional robust thunderstorm development by late afternoon/early evening, likely aided by orographic lift and other weak mid-level disturbances. While a localized severe storm or two could occur, substantial uncertainty exists regarding the intensity of these thunderstorms later today owing to ongoing clouds/precipitation, lack of a notable EML, and limited forecast instability. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0243 PM CDT Fri Sep 19 2025 Valid 192000Z - 201200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF FAR SOUTHERN NEBRASKA INTO NORTHWEST AND CENTRAL KANSAS... ...SUMMARY... Isolated severe thunderstorms may impact parts of far southern Nebraska into northwestern and central Kansas late this afternoon and evening, accompanied by some risk for severe hail and wind. ...20z Update... The previous forecast largely remains on track. Latest GOES imagery shows initial thunderstorm development along a weak front across far northwest KS. Ahead of this boundary, modest moisture return across western KS has yielded dewpoints in the upper 50s to low 60s with MLCAPE values increasing to around 1000 J/kg. With temperatures warming into the low 80s, MLCIN is gradually being removed as the front impinges on the returning moisture. Regional VWPs continue to sample 35-40 knot flow at around 4 km AGL, which will support adequate deep-layer shear for organized convection as thunderstorms continue to develop through late afternoon/early evening. Strong/severe thunderstorm coverage remains uncertain with southeastward extent into central KS, but latest observational trends suggest that the severe threat should be relatively greatest across northwest KS through early evening (that said, expected coverage/intensity should remain sufficiently limited to maintain Marginal risk highlights). Elsewhere, the previous forecast (below) remains on track. Instances of sporadic hail and/or wind damage will be possible from eastern AR into northern MS and northwest AL through early evening; however, the convective environment is favorable for mainly short-lived pulse convection (per observed radar trends and regional VWPs), making predictability of any substantial severe threat very limited. ..Moore.. 09/19/2025 .PREV DISCUSSION... /ISSUED 1130 AM CDT Fri Sep 19 2025/ ...Central Plains... Increasing large-scale ascent associated with the embedded shortwave trough and modestly enhanced west-northwesterly jet should influence isolated thunderstorm development by late afternoon/early evening across parts of southwest Nebraska into western Kansas. This region should have a modestly moist low-level airmass in place, with enough daytime heating forecast to support around 1000-1500 J/kg of MLCAPE. Even though mid-level lapse rates are not expected to become overly steep, strong deep-layer shear should aid in convective updraft organization. Any thunderstorms that can form and be sustained could produce isolated severe hail and/or wind gusts as they spread southeastward across western/central Kansas through the evening. ...Midwest/Mississippi Valley... An eastward-moving shortwave trough over the Upper Midwest will more directly influence the middle/upper Mississippi Valley, with moderate destabilization expected this afternoon from the middle Mississippi Valley southward into the Mid-South where MLCAPE will tend to reach 1500-2000 J/kg. Weak deep tropospheric winds will be prevalent along with weak mid-level lapse rates. Even so, some strong to locally severe pulse storms may occur this afternoon through early evening in a broad region spanning parts of Wisconsin/Illinois southward to the Mid-South. ...Western/south-central Minnesota and vicinity... Pending cloud breaks/sufficient heating, scenario may be conducive for funnels and possibly a low chance of a brief tornado in proximity to the upper low and residual surface front, where low-level CAPE/ambient vorticity will be maximized. It is a generally similar regime as to yesterday's reported brief tornado in far southeast North Dakota, although today's setup may be less supportive and more uncertain. ...Southwest States including southeast Arizona... Showers and thunderstorms are ongoing early today across parts of central/eastern Arizona, and on a more isolated basis into western New Mexico and far west Texas. This activity is related to weak ascent aloft associated with minor perturbations rotating through/around a weak upper ridge over the Southwest. Some guidance shows potential for additional robust thunderstorm development by late afternoon/early evening, likely aided by orographic lift and other weak mid-level disturbances. While a localized severe storm or two could occur, substantial uncertainty exists regarding the intensity of these thunderstorms later today owing to ongoing clouds/precipitation, lack of a notable EML, and limited forecast instability. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0243 PM CDT Fri Sep 19 2025 Valid 192000Z - 201200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF FAR SOUTHERN NEBRASKA INTO NORTHWEST AND CENTRAL KANSAS... ...SUMMARY... Isolated severe thunderstorms may impact parts of far southern Nebraska into northwestern and central Kansas late this afternoon and evening, accompanied by some risk for severe hail and wind. ...20z Update... The previous forecast largely remains on track. Latest GOES imagery shows initial thunderstorm development along a weak front across far northwest KS. Ahead of this boundary, modest moisture return across western KS has yielded dewpoints in the upper 50s to low 60s with MLCAPE values increasing to around 1000 J/kg. With temperatures warming into the low 80s, MLCIN is gradually being removed as the front impinges on the returning moisture. Regional VWPs continue to sample 35-40 knot flow at around 4 km AGL, which will support adequate deep-layer shear for organized convection as thunderstorms continue to develop through late afternoon/early evening. Strong/severe thunderstorm coverage remains uncertain with southeastward extent into central KS, but latest observational trends suggest that the severe threat should be relatively greatest across northwest KS through early evening (that said, expected coverage/intensity should remain sufficiently limited to maintain Marginal risk highlights). Elsewhere, the previous forecast (below) remains on track. Instances of sporadic hail and/or wind damage will be possible from eastern AR into northern MS and northwest AL through early evening; however, the convective environment is favorable for mainly short-lived pulse convection (per observed radar trends and regional VWPs), making predictability of any substantial severe threat very limited. ..Moore.. 09/19/2025 .PREV DISCUSSION... /ISSUED 1130 AM CDT Fri Sep 19 2025/ ...Central Plains... Increasing large-scale ascent associated with the embedded shortwave trough and modestly enhanced west-northwesterly jet should influence isolated thunderstorm development by late afternoon/early evening across parts of southwest Nebraska into western Kansas. This region should have a modestly moist low-level airmass in place, with enough daytime heating forecast to support around 1000-1500 J/kg of MLCAPE. Even though mid-level lapse rates are not expected to become overly steep, strong deep-layer shear should aid in convective updraft organization. Any thunderstorms that can form and be sustained could produce isolated severe hail and/or wind gusts as they spread southeastward across western/central Kansas through the evening. ...Midwest/Mississippi Valley... An eastward-moving shortwave trough over the Upper Midwest will more directly influence the middle/upper Mississippi Valley, with moderate destabilization expected this afternoon from the middle Mississippi Valley southward into the Mid-South where MLCAPE will tend to reach 1500-2000 J/kg. Weak deep tropospheric winds will be prevalent along with weak mid-level lapse rates. Even so, some strong to locally severe pulse storms may occur this afternoon through early evening in a broad region spanning parts of Wisconsin/Illinois southward to the Mid-South. ...Western/south-central Minnesota and vicinity... Pending cloud breaks/sufficient heating, scenario may be conducive for funnels and possibly a low chance of a brief tornado in proximity to the upper low and residual surface front, where low-level CAPE/ambient vorticity will be maximized. It is a generally similar regime as to yesterday's reported brief tornado in far southeast North Dakota, although today's setup may be less supportive and more uncertain. ...Southwest States including southeast Arizona... Showers and thunderstorms are ongoing early today across parts of central/eastern Arizona, and on a more isolated basis into western New Mexico and far west Texas. This activity is related to weak ascent aloft associated with minor perturbations rotating through/around a weak upper ridge over the Southwest. Some guidance shows potential for additional robust thunderstorm development by late afternoon/early evening, likely aided by orographic lift and other weak mid-level disturbances. While a localized severe storm or two could occur, substantial uncertainty exists regarding the intensity of these thunderstorms later today owing to ongoing clouds/precipitation, lack of a notable EML, and limited forecast instability. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0243 PM CDT Fri Sep 19 2025 Valid 192000Z - 201200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF FAR SOUTHERN NEBRASKA INTO NORTHWEST AND CENTRAL KANSAS... ...SUMMARY... Isolated severe thunderstorms may impact parts of far southern Nebraska into northwestern and central Kansas late this afternoon and evening, accompanied by some risk for severe hail and wind. ...20z Update... The previous forecast largely remains on track. Latest GOES imagery shows initial thunderstorm development along a weak front across far northwest KS. Ahead of this boundary, modest moisture return across western KS has yielded dewpoints in the upper 50s to low 60s with MLCAPE values increasing to around 1000 J/kg. With temperatures warming into the low 80s, MLCIN is gradually being removed as the front impinges on the returning moisture. Regional VWPs continue to sample 35-40 knot flow at around 4 km AGL, which will support adequate deep-layer shear for organized convection as thunderstorms continue to develop through late afternoon/early evening. Strong/severe thunderstorm coverage remains uncertain with southeastward extent into central KS, but latest observational trends suggest that the severe threat should be relatively greatest across northwest KS through early evening (that said, expected coverage/intensity should remain sufficiently limited to maintain Marginal risk highlights). Elsewhere, the previous forecast (below) remains on track. Instances of sporadic hail and/or wind damage will be possible from eastern AR into northern MS and northwest AL through early evening; however, the convective environment is favorable for mainly short-lived pulse convection (per observed radar trends and regional VWPs), making predictability of any substantial severe threat very limited. ..Moore.. 09/19/2025 .PREV DISCUSSION... /ISSUED 1130 AM CDT Fri Sep 19 2025/ ...Central Plains... Increasing large-scale ascent associated with the embedded shortwave trough and modestly enhanced west-northwesterly jet should influence isolated thunderstorm development by late afternoon/early evening across parts of southwest Nebraska into western Kansas. This region should have a modestly moist low-level airmass in place, with enough daytime heating forecast to support around 1000-1500 J/kg of MLCAPE. Even though mid-level lapse rates are not expected to become overly steep, strong deep-layer shear should aid in convective updraft organization. Any thunderstorms that can form and be sustained could produce isolated severe hail and/or wind gusts as they spread southeastward across western/central Kansas through the evening. ...Midwest/Mississippi Valley... An eastward-moving shortwave trough over the Upper Midwest will more directly influence the middle/upper Mississippi Valley, with moderate destabilization expected this afternoon from the middle Mississippi Valley southward into the Mid-South where MLCAPE will tend to reach 1500-2000 J/kg. Weak deep tropospheric winds will be prevalent along with weak mid-level lapse rates. Even so, some strong to locally severe pulse storms may occur this afternoon through early evening in a broad region spanning parts of Wisconsin/Illinois southward to the Mid-South. ...Western/south-central Minnesota and vicinity... Pending cloud breaks/sufficient heating, scenario may be conducive for funnels and possibly a low chance of a brief tornado in proximity to the upper low and residual surface front, where low-level CAPE/ambient vorticity will be maximized. It is a generally similar regime as to yesterday's reported brief tornado in far southeast North Dakota, although today's setup may be less supportive and more uncertain. ...Southwest States including southeast Arizona... Showers and thunderstorms are ongoing early today across parts of central/eastern Arizona, and on a more isolated basis into western New Mexico and far west Texas. This activity is related to weak ascent aloft associated with minor perturbations rotating through/around a weak upper ridge over the Southwest. Some guidance shows potential for additional robust thunderstorm development by late afternoon/early evening, likely aided by orographic lift and other weak mid-level disturbances. While a localized severe storm or two could occur, substantial uncertainty exists regarding the intensity of these thunderstorms later today owing to ongoing clouds/precipitation, lack of a notable EML, and limited forecast instability. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0243 PM CDT Fri Sep 19 2025 Valid 192000Z - 201200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF FAR SOUTHERN NEBRASKA INTO NORTHWEST AND CENTRAL KANSAS... ...SUMMARY... Isolated severe thunderstorms may impact parts of far southern Nebraska into northwestern and central Kansas late this afternoon and evening, accompanied by some risk for severe hail and wind. ...20z Update... The previous forecast largely remains on track. Latest GOES imagery shows initial thunderstorm development along a weak front across far northwest KS. Ahead of this boundary, modest moisture return across western KS has yielded dewpoints in the upper 50s to low 60s with MLCAPE values increasing to around 1000 J/kg. With temperatures warming into the low 80s, MLCIN is gradually being removed as the front impinges on the returning moisture. Regional VWPs continue to sample 35-40 knot flow at around 4 km AGL, which will support adequate deep-layer shear for organized convection as thunderstorms continue to develop through late afternoon/early evening. Strong/severe thunderstorm coverage remains uncertain with southeastward extent into central KS, but latest observational trends suggest that the severe threat should be relatively greatest across northwest KS through early evening (that said, expected coverage/intensity should remain sufficiently limited to maintain Marginal risk highlights). Elsewhere, the previous forecast (below) remains on track. Instances of sporadic hail and/or wind damage will be possible from eastern AR into northern MS and northwest AL through early evening; however, the convective environment is favorable for mainly short-lived pulse convection (per observed radar trends and regional VWPs), making predictability of any substantial severe threat very limited. ..Moore.. 09/19/2025 .PREV DISCUSSION... /ISSUED 1130 AM CDT Fri Sep 19 2025/ ...Central Plains... Increasing large-scale ascent associated with the embedded shortwave trough and modestly enhanced west-northwesterly jet should influence isolated thunderstorm development by late afternoon/early evening across parts of southwest Nebraska into western Kansas. This region should have a modestly moist low-level airmass in place, with enough daytime heating forecast to support around 1000-1500 J/kg of MLCAPE. Even though mid-level lapse rates are not expected to become overly steep, strong deep-layer shear should aid in convective updraft organization. Any thunderstorms that can form and be sustained could produce isolated severe hail and/or wind gusts as they spread southeastward across western/central Kansas through the evening. ...Midwest/Mississippi Valley... An eastward-moving shortwave trough over the Upper Midwest will more directly influence the middle/upper Mississippi Valley, with moderate destabilization expected this afternoon from the middle Mississippi Valley southward into the Mid-South where MLCAPE will tend to reach 1500-2000 J/kg. Weak deep tropospheric winds will be prevalent along with weak mid-level lapse rates. Even so, some strong to locally severe pulse storms may occur this afternoon through early evening in a broad region spanning parts of Wisconsin/Illinois southward to the Mid-South. ...Western/south-central Minnesota and vicinity... Pending cloud breaks/sufficient heating, scenario may be conducive for funnels and possibly a low chance of a brief tornado in proximity to the upper low and residual surface front, where low-level CAPE/ambient vorticity will be maximized. It is a generally similar regime as to yesterday's reported brief tornado in far southeast North Dakota, although today's setup may be less supportive and more uncertain. ...Southwest States including southeast Arizona... Showers and thunderstorms are ongoing early today across parts of central/eastern Arizona, and on a more isolated basis into western New Mexico and far west Texas. This activity is related to weak ascent aloft associated with minor perturbations rotating through/around a weak upper ridge over the Southwest. Some guidance shows potential for additional robust thunderstorm development by late afternoon/early evening, likely aided by orographic lift and other weak mid-level disturbances. While a localized severe storm or two could occur, substantial uncertainty exists regarding the intensity of these thunderstorms later today owing to ongoing clouds/precipitation, lack of a notable EML, and limited forecast instability. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0243 PM CDT Fri Sep 19 2025 Valid 192000Z - 201200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF FAR SOUTHERN NEBRASKA INTO NORTHWEST AND CENTRAL KANSAS... ...SUMMARY... Isolated severe thunderstorms may impact parts of far southern Nebraska into northwestern and central Kansas late this afternoon and evening, accompanied by some risk for severe hail and wind. ...20z Update... The previous forecast largely remains on track. Latest GOES imagery shows initial thunderstorm development along a weak front across far northwest KS. Ahead of this boundary, modest moisture return across western KS has yielded dewpoints in the upper 50s to low 60s with MLCAPE values increasing to around 1000 J/kg. With temperatures warming into the low 80s, MLCIN is gradually being removed as the front impinges on the returning moisture. Regional VWPs continue to sample 35-40 knot flow at around 4 km AGL, which will support adequate deep-layer shear for organized convection as thunderstorms continue to develop through late afternoon/early evening. Strong/severe thunderstorm coverage remains uncertain with southeastward extent into central KS, but latest observational trends suggest that the severe threat should be relatively greatest across northwest KS through early evening (that said, expected coverage/intensity should remain sufficiently limited to maintain Marginal risk highlights). Elsewhere, the previous forecast (below) remains on track. Instances of sporadic hail and/or wind damage will be possible from eastern AR into northern MS and northwest AL through early evening; however, the convective environment is favorable for mainly short-lived pulse convection (per observed radar trends and regional VWPs), making predictability of any substantial severe threat very limited. ..Moore.. 09/19/2025 .PREV DISCUSSION... /ISSUED 1130 AM CDT Fri Sep 19 2025/ ...Central Plains... Increasing large-scale ascent associated with the embedded shortwave trough and modestly enhanced west-northwesterly jet should influence isolated thunderstorm development by late afternoon/early evening across parts of southwest Nebraska into western Kansas. This region should have a modestly moist low-level airmass in place, with enough daytime heating forecast to support around 1000-1500 J/kg of MLCAPE. Even though mid-level lapse rates are not expected to become overly steep, strong deep-layer shear should aid in convective updraft organization. Any thunderstorms that can form and be sustained could produce isolated severe hail and/or wind gusts as they spread southeastward across western/central Kansas through the evening. ...Midwest/Mississippi Valley... An eastward-moving shortwave trough over the Upper Midwest will more directly influence the middle/upper Mississippi Valley, with moderate destabilization expected this afternoon from the middle Mississippi Valley southward into the Mid-South where MLCAPE will tend to reach 1500-2000 J/kg. Weak deep tropospheric winds will be prevalent along with weak mid-level lapse rates. Even so, some strong to locally severe pulse storms may occur this afternoon through early evening in a broad region spanning parts of Wisconsin/Illinois southward to the Mid-South. ...Western/south-central Minnesota and vicinity... Pending cloud breaks/sufficient heating, scenario may be conducive for funnels and possibly a low chance of a brief tornado in proximity to the upper low and residual surface front, where low-level CAPE/ambient vorticity will be maximized. It is a generally similar regime as to yesterday's reported brief tornado in far southeast North Dakota, although today's setup may be less supportive and more uncertain. ...Southwest States including southeast Arizona... Showers and thunderstorms are ongoing early today across parts of central/eastern Arizona, and on a more isolated basis into western New Mexico and far west Texas. This activity is related to weak ascent aloft associated with minor perturbations rotating through/around a weak upper ridge over the Southwest. Some guidance shows potential for additional robust thunderstorm development by late afternoon/early evening, likely aided by orographic lift and other weak mid-level disturbances. While a localized severe storm or two could occur, substantial uncertainty exists regarding the intensity of these thunderstorms later today owing to ongoing clouds/precipitation, lack of a notable EML, and limited forecast instability. Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0227 PM CDT Fri Sep 19 2025 Valid 211200Z - 221200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... A few strong thunderstorms are possible across parts of the Great Plains and the Ohio Valley on Sunday, though organized severe thunderstorm potential remains uncertain. ...Discussion... A compact midlevel trough will advance eastward across the Upper Midwest on Sunday, while a broader large-scale trough encompasses much of the central CONUS. Several embedded shortwave impulses (some convectively induced/enhanced) will track eastward within the zonal midlevel flow across parts of the Ohio Valley, central Plains and northern Plains through the period. Given the low-amplitude nature of these impulses (and large differences in timing/evolution among model guidance), organized severe thunderstorm potential remains uncertain at this time. Nevertheless, a moist/moderately unstable air mass will be in place from the southern/central Plains eastward into parts of the OH Valley, and given the subtle areas of large-scale lift and locally enhanced midlevel flow, a broad area of strong-thunderstorm potential is evident. As the details regarding timing/evolution of the embedded shortwave troughs and related destabilization become clearer, one or more Marginal Risk areas may be warranted over the central/southern Plains and the Ohio Valley. ..Weinman.. 09/19/2025 Read more