Severe Storms

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1145 AM CDT Mon Apr 21 2025 Valid 211700Z - 221200Z A passing short wave over the Central Rockies will enhance dry, downslope flow over the Central High Plains today where minimal precipitation has fallen. Elevated highlights were extended into northeastern Colorado where a more receptive fine fuel environment is still likely. ..Williams/Lyons.. 04/21/2025 .PREV DISCUSSION... /ISSUED 0111 AM CDT Mon Apr 21 2025/ ...Synopsis... A mid-level trough will impinge on the East Coast as a second trough traverses the Northern Plains today. Surface lee troughing is expected across the central High Plains as a mass response to the passing of the Northern Plains trough, resulting in dry downslope flow. By afternoon, 15-20 mph sustained southwesterly surface winds will overlap with 15-20 percent RH over much of the Central High Plains. Elevated highlights are in place from far northeast New Mexico into central Nebraska, where fuels are dry. ...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 1145 AM CDT Mon Apr 21 2025 Valid 211700Z - 221200Z A passing short wave over the Central Rockies will enhance dry, downslope flow over the Central High Plains today where minimal precipitation has fallen. Elevated highlights were extended into northeastern Colorado where a more receptive fine fuel environment is still likely. ..Williams/Lyons.. 04/21/2025 .PREV DISCUSSION... /ISSUED 0111 AM CDT Mon Apr 21 2025/ ...Synopsis... A mid-level trough will impinge on the East Coast as a second trough traverses the Northern Plains today. Surface lee troughing is expected across the central High Plains as a mass response to the passing of the Northern Plains trough, resulting in dry downslope flow. By afternoon, 15-20 mph sustained southwesterly surface winds will overlap with 15-20 percent RH over much of the Central High Plains. Elevated highlights are in place from far northeast New Mexico into central Nebraska, where fuels are dry. ...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 1145 AM CDT Mon Apr 21 2025 Valid 211700Z - 221200Z A passing short wave over the Central Rockies will enhance dry, downslope flow over the Central High Plains today where minimal precipitation has fallen. Elevated highlights were extended into northeastern Colorado where a more receptive fine fuel environment is still likely. ..Williams/Lyons.. 04/21/2025 .PREV DISCUSSION... /ISSUED 0111 AM CDT Mon Apr 21 2025/ ...Synopsis... A mid-level trough will impinge on the East Coast as a second trough traverses the Northern Plains today. Surface lee troughing is expected across the central High Plains as a mass response to the passing of the Northern Plains trough, resulting in dry downslope flow. By afternoon, 15-20 mph sustained southwesterly surface winds will overlap with 15-20 percent RH over much of the Central High Plains. Elevated highlights are in place from far northeast New Mexico into central Nebraska, where fuels are dry. ...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 1145 AM CDT Mon Apr 21 2025 Valid 211700Z - 221200Z A passing short wave over the Central Rockies will enhance dry, downslope flow over the Central High Plains today where minimal precipitation has fallen. Elevated highlights were extended into northeastern Colorado where a more receptive fine fuel environment is still likely. ..Williams/Lyons.. 04/21/2025 .PREV DISCUSSION... /ISSUED 0111 AM CDT Mon Apr 21 2025/ ...Synopsis... A mid-level trough will impinge on the East Coast as a second trough traverses the Northern Plains today. Surface lee troughing is expected across the central High Plains as a mass response to the passing of the Northern Plains trough, resulting in dry downslope flow. By afternoon, 15-20 mph sustained southwesterly surface winds will overlap with 15-20 percent RH over much of the Central High Plains. Elevated highlights are in place from far northeast New Mexico into central Nebraska, where fuels are dry. ...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 1145 AM CDT Mon Apr 21 2025 Valid 211700Z - 221200Z A passing short wave over the Central Rockies will enhance dry, downslope flow over the Central High Plains today where minimal precipitation has fallen. Elevated highlights were extended into northeastern Colorado where a more receptive fine fuel environment is still likely. ..Williams/Lyons.. 04/21/2025 .PREV DISCUSSION... /ISSUED 0111 AM CDT Mon Apr 21 2025/ ...Synopsis... A mid-level trough will impinge on the East Coast as a second trough traverses the Northern Plains today. Surface lee troughing is expected across the central High Plains as a mass response to the passing of the Northern Plains trough, resulting in dry downslope flow. By afternoon, 15-20 mph sustained southwesterly surface winds will overlap with 15-20 percent RH over much of the Central High Plains. Elevated highlights are in place from far northeast New Mexico into central Nebraska, where fuels are dry. ...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 1145 AM CDT Mon Apr 21 2025 Valid 211700Z - 221200Z A passing short wave over the Central Rockies will enhance dry, downslope flow over the Central High Plains today where minimal precipitation has fallen. Elevated highlights were extended into northeastern Colorado where a more receptive fine fuel environment is still likely. ..Williams/Lyons.. 04/21/2025 .PREV DISCUSSION... /ISSUED 0111 AM CDT Mon Apr 21 2025/ ...Synopsis... A mid-level trough will impinge on the East Coast as a second trough traverses the Northern Plains today. Surface lee troughing is expected across the central High Plains as a mass response to the passing of the Northern Plains trough, resulting in dry downslope flow. By afternoon, 15-20 mph sustained southwesterly surface winds will overlap with 15-20 percent RH over much of the Central High Plains. Elevated highlights are in place from far northeast New Mexico into central Nebraska, where fuels are dry. ...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 1145 AM CDT Mon Apr 21 2025 Valid 211700Z - 221200Z A passing short wave over the Central Rockies will enhance dry, downslope flow over the Central High Plains today where minimal precipitation has fallen. Elevated highlights were extended into northeastern Colorado where a more receptive fine fuel environment is still likely. ..Williams/Lyons.. 04/21/2025 .PREV DISCUSSION... /ISSUED 0111 AM CDT Mon Apr 21 2025/ ...Synopsis... A mid-level trough will impinge on the East Coast as a second trough traverses the Northern Plains today. Surface lee troughing is expected across the central High Plains as a mass response to the passing of the Northern Plains trough, resulting in dry downslope flow. By afternoon, 15-20 mph sustained southwesterly surface winds will overlap with 15-20 percent RH over much of the Central High Plains. Elevated highlights are in place from far northeast New Mexico into central Nebraska, where fuels are dry. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1124 AM CDT Mon Apr 21 2025 Valid 211630Z - 221200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE UPPER OHIO VALLEY AND LOWER GREAT LAKES...AND PORTIONS OF THE SOUTHEAST... ...SUMMARY... Isolated strong to severe thunderstorms are possible today across the upper Ohio Valley/lower Great Lakes and parts of the Southeast. Damaging winds and marginally severe hail are the primary risks. ...Upper OH Valley... Morning surface analysis and satellite imagery show a cold front sweeping eastward across OH. Considerable cloud cover is present ahead of the front, but a narrow corridor of heating immediately ahead of the front will allow a period of heating - promoting scattered thunderstorms. Low-level moisture is limited with dewpoints only in the 50s, and forecast soundings show CAPE values generally below 1000 J/kg. Nevertheless, strong low and mid-level winds and considerable vertical shear will promote a risk of a few organized/severe storms capable of damaging wind gusts and perhaps a tornado or two. Refer to upcoming MCD #511 for further details. ...LA/MS/AL/GA/TN... The aforementioned surface cold front extends southeastward across west TN. A relatively moist air mass is present ahead of the front from southeast LA into parts of MS/AL and middle/east TN, although considerable cloud cover will limit heating. Most 12z models suggest scattered thunderstorms will form in this zone during the late afternoon and evening, with sufficient CAPE for a few robust updrafts. Low and mid level winds are not particularly strong, and large scale forcing is weak. This should limit the overall organization and severity of storms, but a few cells may produce gusty winds and hail. ...SD... Water vapor imagery shows a mid-level shortwave trough over WY approaching SD. Forcing ahead of this feature will likely lead to scattered high-based showers and thunderstorms across eastern WY and western/central SD this afternoon and evening. There is some chance that a storm or two could produce locally damaging wind gusts. ..Hart/Thornton.. 04/21/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1124 AM CDT Mon Apr 21 2025 Valid 211630Z - 221200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE UPPER OHIO VALLEY AND LOWER GREAT LAKES...AND PORTIONS OF THE SOUTHEAST... ...SUMMARY... Isolated strong to severe thunderstorms are possible today across the upper Ohio Valley/lower Great Lakes and parts of the Southeast. Damaging winds and marginally severe hail are the primary risks. ...Upper OH Valley... Morning surface analysis and satellite imagery show a cold front sweeping eastward across OH. Considerable cloud cover is present ahead of the front, but a narrow corridor of heating immediately ahead of the front will allow a period of heating - promoting scattered thunderstorms. Low-level moisture is limited with dewpoints only in the 50s, and forecast soundings show CAPE values generally below 1000 J/kg. Nevertheless, strong low and mid-level winds and considerable vertical shear will promote a risk of a few organized/severe storms capable of damaging wind gusts and perhaps a tornado or two. Refer to upcoming MCD #511 for further details. ...LA/MS/AL/GA/TN... The aforementioned surface cold front extends southeastward across west TN. A relatively moist air mass is present ahead of the front from southeast LA into parts of MS/AL and middle/east TN, although considerable cloud cover will limit heating. Most 12z models suggest scattered thunderstorms will form in this zone during the late afternoon and evening, with sufficient CAPE for a few robust updrafts. Low and mid level winds are not particularly strong, and large scale forcing is weak. This should limit the overall organization and severity of storms, but a few cells may produce gusty winds and hail. ...SD... Water vapor imagery shows a mid-level shortwave trough over WY approaching SD. Forcing ahead of this feature will likely lead to scattered high-based showers and thunderstorms across eastern WY and western/central SD this afternoon and evening. There is some chance that a storm or two could produce locally damaging wind gusts. ..Hart/Thornton.. 04/21/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1124 AM CDT Mon Apr 21 2025 Valid 211630Z - 221200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE UPPER OHIO VALLEY AND LOWER GREAT LAKES...AND PORTIONS OF THE SOUTHEAST... ...SUMMARY... Isolated strong to severe thunderstorms are possible today across the upper Ohio Valley/lower Great Lakes and parts of the Southeast. Damaging winds and marginally severe hail are the primary risks. ...Upper OH Valley... Morning surface analysis and satellite imagery show a cold front sweeping eastward across OH. Considerable cloud cover is present ahead of the front, but a narrow corridor of heating immediately ahead of the front will allow a period of heating - promoting scattered thunderstorms. Low-level moisture is limited with dewpoints only in the 50s, and forecast soundings show CAPE values generally below 1000 J/kg. Nevertheless, strong low and mid-level winds and considerable vertical shear will promote a risk of a few organized/severe storms capable of damaging wind gusts and perhaps a tornado or two. Refer to upcoming MCD #511 for further details. ...LA/MS/AL/GA/TN... The aforementioned surface cold front extends southeastward across west TN. A relatively moist air mass is present ahead of the front from southeast LA into parts of MS/AL and middle/east TN, although considerable cloud cover will limit heating. Most 12z models suggest scattered thunderstorms will form in this zone during the late afternoon and evening, with sufficient CAPE for a few robust updrafts. Low and mid level winds are not particularly strong, and large scale forcing is weak. This should limit the overall organization and severity of storms, but a few cells may produce gusty winds and hail. ...SD... Water vapor imagery shows a mid-level shortwave trough over WY approaching SD. Forcing ahead of this feature will likely lead to scattered high-based showers and thunderstorms across eastern WY and western/central SD this afternoon and evening. There is some chance that a storm or two could produce locally damaging wind gusts. ..Hart/Thornton.. 04/21/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1124 AM CDT Mon Apr 21 2025 Valid 211630Z - 221200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE UPPER OHIO VALLEY AND LOWER GREAT LAKES...AND PORTIONS OF THE SOUTHEAST... ...SUMMARY... Isolated strong to severe thunderstorms are possible today across the upper Ohio Valley/lower Great Lakes and parts of the Southeast. Damaging winds and marginally severe hail are the primary risks. ...Upper OH Valley... Morning surface analysis and satellite imagery show a cold front sweeping eastward across OH. Considerable cloud cover is present ahead of the front, but a narrow corridor of heating immediately ahead of the front will allow a period of heating - promoting scattered thunderstorms. Low-level moisture is limited with dewpoints only in the 50s, and forecast soundings show CAPE values generally below 1000 J/kg. Nevertheless, strong low and mid-level winds and considerable vertical shear will promote a risk of a few organized/severe storms capable of damaging wind gusts and perhaps a tornado or two. Refer to upcoming MCD #511 for further details. ...LA/MS/AL/GA/TN... The aforementioned surface cold front extends southeastward across west TN. A relatively moist air mass is present ahead of the front from southeast LA into parts of MS/AL and middle/east TN, although considerable cloud cover will limit heating. Most 12z models suggest scattered thunderstorms will form in this zone during the late afternoon and evening, with sufficient CAPE for a few robust updrafts. Low and mid level winds are not particularly strong, and large scale forcing is weak. This should limit the overall organization and severity of storms, but a few cells may produce gusty winds and hail. ...SD... Water vapor imagery shows a mid-level shortwave trough over WY approaching SD. Forcing ahead of this feature will likely lead to scattered high-based showers and thunderstorms across eastern WY and western/central SD this afternoon and evening. There is some chance that a storm or two could produce locally damaging wind gusts. ..Hart/Thornton.. 04/21/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1124 AM CDT Mon Apr 21 2025 Valid 211630Z - 221200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE UPPER OHIO VALLEY AND LOWER GREAT LAKES...AND PORTIONS OF THE SOUTHEAST... ...SUMMARY... Isolated strong to severe thunderstorms are possible today across the upper Ohio Valley/lower Great Lakes and parts of the Southeast. Damaging winds and marginally severe hail are the primary risks. ...Upper OH Valley... Morning surface analysis and satellite imagery show a cold front sweeping eastward across OH. Considerable cloud cover is present ahead of the front, but a narrow corridor of heating immediately ahead of the front will allow a period of heating - promoting scattered thunderstorms. Low-level moisture is limited with dewpoints only in the 50s, and forecast soundings show CAPE values generally below 1000 J/kg. Nevertheless, strong low and mid-level winds and considerable vertical shear will promote a risk of a few organized/severe storms capable of damaging wind gusts and perhaps a tornado or two. Refer to upcoming MCD #511 for further details. ...LA/MS/AL/GA/TN... The aforementioned surface cold front extends southeastward across west TN. A relatively moist air mass is present ahead of the front from southeast LA into parts of MS/AL and middle/east TN, although considerable cloud cover will limit heating. Most 12z models suggest scattered thunderstorms will form in this zone during the late afternoon and evening, with sufficient CAPE for a few robust updrafts. Low and mid level winds are not particularly strong, and large scale forcing is weak. This should limit the overall organization and severity of storms, but a few cells may produce gusty winds and hail. ...SD... Water vapor imagery shows a mid-level shortwave trough over WY approaching SD. Forcing ahead of this feature will likely lead to scattered high-based showers and thunderstorms across eastern WY and western/central SD this afternoon and evening. There is some chance that a storm or two could produce locally damaging wind gusts. ..Hart/Thornton.. 04/21/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1124 AM CDT Mon Apr 21 2025 Valid 211630Z - 221200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE UPPER OHIO VALLEY AND LOWER GREAT LAKES...AND PORTIONS OF THE SOUTHEAST... ...SUMMARY... Isolated strong to severe thunderstorms are possible today across the upper Ohio Valley/lower Great Lakes and parts of the Southeast. Damaging winds and marginally severe hail are the primary risks. ...Upper OH Valley... Morning surface analysis and satellite imagery show a cold front sweeping eastward across OH. Considerable cloud cover is present ahead of the front, but a narrow corridor of heating immediately ahead of the front will allow a period of heating - promoting scattered thunderstorms. Low-level moisture is limited with dewpoints only in the 50s, and forecast soundings show CAPE values generally below 1000 J/kg. Nevertheless, strong low and mid-level winds and considerable vertical shear will promote a risk of a few organized/severe storms capable of damaging wind gusts and perhaps a tornado or two. Refer to upcoming MCD #511 for further details. ...LA/MS/AL/GA/TN... The aforementioned surface cold front extends southeastward across west TN. A relatively moist air mass is present ahead of the front from southeast LA into parts of MS/AL and middle/east TN, although considerable cloud cover will limit heating. Most 12z models suggest scattered thunderstorms will form in this zone during the late afternoon and evening, with sufficient CAPE for a few robust updrafts. Low and mid level winds are not particularly strong, and large scale forcing is weak. This should limit the overall organization and severity of storms, but a few cells may produce gusty winds and hail. ...SD... Water vapor imagery shows a mid-level shortwave trough over WY approaching SD. Forcing ahead of this feature will likely lead to scattered high-based showers and thunderstorms across eastern WY and western/central SD this afternoon and evening. There is some chance that a storm or two could produce locally damaging wind gusts. ..Hart/Thornton.. 04/21/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1124 AM CDT Mon Apr 21 2025 Valid 211630Z - 221200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE UPPER OHIO VALLEY AND LOWER GREAT LAKES...AND PORTIONS OF THE SOUTHEAST... ...SUMMARY... Isolated strong to severe thunderstorms are possible today across the upper Ohio Valley/lower Great Lakes and parts of the Southeast. Damaging winds and marginally severe hail are the primary risks. ...Upper OH Valley... Morning surface analysis and satellite imagery show a cold front sweeping eastward across OH. Considerable cloud cover is present ahead of the front, but a narrow corridor of heating immediately ahead of the front will allow a period of heating - promoting scattered thunderstorms. Low-level moisture is limited with dewpoints only in the 50s, and forecast soundings show CAPE values generally below 1000 J/kg. Nevertheless, strong low and mid-level winds and considerable vertical shear will promote a risk of a few organized/severe storms capable of damaging wind gusts and perhaps a tornado or two. Refer to upcoming MCD #511 for further details. ...LA/MS/AL/GA/TN... The aforementioned surface cold front extends southeastward across west TN. A relatively moist air mass is present ahead of the front from southeast LA into parts of MS/AL and middle/east TN, although considerable cloud cover will limit heating. Most 12z models suggest scattered thunderstorms will form in this zone during the late afternoon and evening, with sufficient CAPE for a few robust updrafts. Low and mid level winds are not particularly strong, and large scale forcing is weak. This should limit the overall organization and severity of storms, but a few cells may produce gusty winds and hail. ...SD... Water vapor imagery shows a mid-level shortwave trough over WY approaching SD. Forcing ahead of this feature will likely lead to scattered high-based showers and thunderstorms across eastern WY and western/central SD this afternoon and evening. There is some chance that a storm or two could produce locally damaging wind gusts. ..Hart/Thornton.. 04/21/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1124 AM CDT Mon Apr 21 2025 Valid 211630Z - 221200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE UPPER OHIO VALLEY AND LOWER GREAT LAKES...AND PORTIONS OF THE SOUTHEAST... ...SUMMARY... Isolated strong to severe thunderstorms are possible today across the upper Ohio Valley/lower Great Lakes and parts of the Southeast. Damaging winds and marginally severe hail are the primary risks. ...Upper OH Valley... Morning surface analysis and satellite imagery show a cold front sweeping eastward across OH. Considerable cloud cover is present ahead of the front, but a narrow corridor of heating immediately ahead of the front will allow a period of heating - promoting scattered thunderstorms. Low-level moisture is limited with dewpoints only in the 50s, and forecast soundings show CAPE values generally below 1000 J/kg. Nevertheless, strong low and mid-level winds and considerable vertical shear will promote a risk of a few organized/severe storms capable of damaging wind gusts and perhaps a tornado or two. Refer to upcoming MCD #511 for further details. ...LA/MS/AL/GA/TN... The aforementioned surface cold front extends southeastward across west TN. A relatively moist air mass is present ahead of the front from southeast LA into parts of MS/AL and middle/east TN, although considerable cloud cover will limit heating. Most 12z models suggest scattered thunderstorms will form in this zone during the late afternoon and evening, with sufficient CAPE for a few robust updrafts. Low and mid level winds are not particularly strong, and large scale forcing is weak. This should limit the overall organization and severity of storms, but a few cells may produce gusty winds and hail. ...SD... Water vapor imagery shows a mid-level shortwave trough over WY approaching SD. Forcing ahead of this feature will likely lead to scattered high-based showers and thunderstorms across eastern WY and western/central SD this afternoon and evening. There is some chance that a storm or two could produce locally damaging wind gusts. ..Hart/Thornton.. 04/21/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1124 AM CDT Mon Apr 21 2025 Valid 211630Z - 221200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE UPPER OHIO VALLEY AND LOWER GREAT LAKES...AND PORTIONS OF THE SOUTHEAST... ...SUMMARY... Isolated strong to severe thunderstorms are possible today across the upper Ohio Valley/lower Great Lakes and parts of the Southeast. Damaging winds and marginally severe hail are the primary risks. ...Upper OH Valley... Morning surface analysis and satellite imagery show a cold front sweeping eastward across OH. Considerable cloud cover is present ahead of the front, but a narrow corridor of heating immediately ahead of the front will allow a period of heating - promoting scattered thunderstorms. Low-level moisture is limited with dewpoints only in the 50s, and forecast soundings show CAPE values generally below 1000 J/kg. Nevertheless, strong low and mid-level winds and considerable vertical shear will promote a risk of a few organized/severe storms capable of damaging wind gusts and perhaps a tornado or two. Refer to upcoming MCD #511 for further details. ...LA/MS/AL/GA/TN... The aforementioned surface cold front extends southeastward across west TN. A relatively moist air mass is present ahead of the front from southeast LA into parts of MS/AL and middle/east TN, although considerable cloud cover will limit heating. Most 12z models suggest scattered thunderstorms will form in this zone during the late afternoon and evening, with sufficient CAPE for a few robust updrafts. Low and mid level winds are not particularly strong, and large scale forcing is weak. This should limit the overall organization and severity of storms, but a few cells may produce gusty winds and hail. ...SD... Water vapor imagery shows a mid-level shortwave trough over WY approaching SD. Forcing ahead of this feature will likely lead to scattered high-based showers and thunderstorms across eastern WY and western/central SD this afternoon and evening. There is some chance that a storm or two could produce locally damaging wind gusts. ..Hart/Thornton.. 04/21/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1124 AM CDT Mon Apr 21 2025 Valid 211630Z - 221200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE UPPER OHIO VALLEY AND LOWER GREAT LAKES...AND PORTIONS OF THE SOUTHEAST... ...SUMMARY... Isolated strong to severe thunderstorms are possible today across the upper Ohio Valley/lower Great Lakes and parts of the Southeast. Damaging winds and marginally severe hail are the primary risks. ...Upper OH Valley... Morning surface analysis and satellite imagery show a cold front sweeping eastward across OH. Considerable cloud cover is present ahead of the front, but a narrow corridor of heating immediately ahead of the front will allow a period of heating - promoting scattered thunderstorms. Low-level moisture is limited with dewpoints only in the 50s, and forecast soundings show CAPE values generally below 1000 J/kg. Nevertheless, strong low and mid-level winds and considerable vertical shear will promote a risk of a few organized/severe storms capable of damaging wind gusts and perhaps a tornado or two. Refer to upcoming MCD #511 for further details. ...LA/MS/AL/GA/TN... The aforementioned surface cold front extends southeastward across west TN. A relatively moist air mass is present ahead of the front from southeast LA into parts of MS/AL and middle/east TN, although considerable cloud cover will limit heating. Most 12z models suggest scattered thunderstorms will form in this zone during the late afternoon and evening, with sufficient CAPE for a few robust updrafts. Low and mid level winds are not particularly strong, and large scale forcing is weak. This should limit the overall organization and severity of storms, but a few cells may produce gusty winds and hail. ...SD... Water vapor imagery shows a mid-level shortwave trough over WY approaching SD. Forcing ahead of this feature will likely lead to scattered high-based showers and thunderstorms across eastern WY and western/central SD this afternoon and evening. There is some chance that a storm or two could produce locally damaging wind gusts. ..Hart/Thornton.. 04/21/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1124 AM CDT Mon Apr 21 2025 Valid 211630Z - 221200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE UPPER OHIO VALLEY AND LOWER GREAT LAKES...AND PORTIONS OF THE SOUTHEAST... ...SUMMARY... Isolated strong to severe thunderstorms are possible today across the upper Ohio Valley/lower Great Lakes and parts of the Southeast. Damaging winds and marginally severe hail are the primary risks. ...Upper OH Valley... Morning surface analysis and satellite imagery show a cold front sweeping eastward across OH. Considerable cloud cover is present ahead of the front, but a narrow corridor of heating immediately ahead of the front will allow a period of heating - promoting scattered thunderstorms. Low-level moisture is limited with dewpoints only in the 50s, and forecast soundings show CAPE values generally below 1000 J/kg. Nevertheless, strong low and mid-level winds and considerable vertical shear will promote a risk of a few organized/severe storms capable of damaging wind gusts and perhaps a tornado or two. Refer to upcoming MCD #511 for further details. ...LA/MS/AL/GA/TN... The aforementioned surface cold front extends southeastward across west TN. A relatively moist air mass is present ahead of the front from southeast LA into parts of MS/AL and middle/east TN, although considerable cloud cover will limit heating. Most 12z models suggest scattered thunderstorms will form in this zone during the late afternoon and evening, with sufficient CAPE for a few robust updrafts. Low and mid level winds are not particularly strong, and large scale forcing is weak. This should limit the overall organization and severity of storms, but a few cells may produce gusty winds and hail. ...SD... Water vapor imagery shows a mid-level shortwave trough over WY approaching SD. Forcing ahead of this feature will likely lead to scattered high-based showers and thunderstorms across eastern WY and western/central SD this afternoon and evening. There is some chance that a storm or two could produce locally damaging wind gusts. ..Hart/Thornton.. 04/21/2025 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0730 AM CDT Mon Apr 21 2025 Valid 211300Z - 221200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE UPPER OHIO VALLEY AND LOWER GREAT LAKES...AND PORTIONS OF THE SOUTHEAST... ...SUMMARY... Isolated strong to severe thunderstorms are possible today across the upper Ohio Valley/lower Great Lakes and parts of the Southeast. Damaging winds and marginally severe hail are the primary risks. ...Upper Ohio Valley to the Lower Great Lakes... An upper trough with an attendant 55-70 kt mid-level jet will advance east-northeastward from the Upper Midwest across the Great Lakes and Northeast today. A related surface low will develop northeastward into Ontario/Quebec, while a cold front sweeps eastward over the OH Valley and parts of the Mid-Atlantic and Northeast through this evening. Modest low-level moisture will advect northward ahead of this front in tandem with a strong southwesterly low-level jet. Even though this moisture will remain somewhat limited, filtered daytime heating and cool mid-level temperatures should aid weak destabilization in a narrow corridor along/ahead of the front by early afternoon. Thunderstorms that develop along the front may pose an isolated severe/damaging wind threat this afternoon and early evening given the expected strength of the low/mid-level flow. Occasional hail may also be noted with the strongest cores, and sufficient low-level shear should exist to support a tornado or two. The Marginal Risk has been expanded northward/eastward some based on latest guidance trends regarding sufficient destabilization to support surface-based convection. ...Southeast... The trailing portion of the surface cold front should make only slow east-southeastward progress today across the Southeast. This region will have weaker low/mid-level winds compared to locations farther north. Still, around 500-1500 J/kg of MLCAPE should develop by this afternoon along/ahead of the front, while 25-35 kt of deep-layer shear aids in modest updraft organization. Any thunderstorms which develop in this regime could pose an isolated threat for marginally severe hail and damaging winds. This threat should peak by mid afternoon, before gradually diminishing through the evening with the loss of daytime heating. ...Northern Plains... Gusty winds may occur with high-based convection this afternoon as a shortwave trough moves eastward over the northern Plains. However, low-level moisture and instability are both expected to remain very meager, which should preclude an organized severe wind threat. ...Upper Midwest... Elevated thunderstorms may develop late tonight across parts of IA in a low-level warm advection regime. With MUCAPE forecast to remain less than 1000 J/kg, the potential for severe hail appears too limited to include low severe probabilities at this time. ..Gleason/Broyles.. 04/21/2025 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0730 AM CDT Mon Apr 21 2025 Valid 211300Z - 221200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE UPPER OHIO VALLEY AND LOWER GREAT LAKES...AND PORTIONS OF THE SOUTHEAST... ...SUMMARY... Isolated strong to severe thunderstorms are possible today across the upper Ohio Valley/lower Great Lakes and parts of the Southeast. Damaging winds and marginally severe hail are the primary risks. ...Upper Ohio Valley to the Lower Great Lakes... An upper trough with an attendant 55-70 kt mid-level jet will advance east-northeastward from the Upper Midwest across the Great Lakes and Northeast today. A related surface low will develop northeastward into Ontario/Quebec, while a cold front sweeps eastward over the OH Valley and parts of the Mid-Atlantic and Northeast through this evening. Modest low-level moisture will advect northward ahead of this front in tandem with a strong southwesterly low-level jet. Even though this moisture will remain somewhat limited, filtered daytime heating and cool mid-level temperatures should aid weak destabilization in a narrow corridor along/ahead of the front by early afternoon. Thunderstorms that develop along the front may pose an isolated severe/damaging wind threat this afternoon and early evening given the expected strength of the low/mid-level flow. Occasional hail may also be noted with the strongest cores, and sufficient low-level shear should exist to support a tornado or two. The Marginal Risk has been expanded northward/eastward some based on latest guidance trends regarding sufficient destabilization to support surface-based convection. ...Southeast... The trailing portion of the surface cold front should make only slow east-southeastward progress today across the Southeast. This region will have weaker low/mid-level winds compared to locations farther north. Still, around 500-1500 J/kg of MLCAPE should develop by this afternoon along/ahead of the front, while 25-35 kt of deep-layer shear aids in modest updraft organization. Any thunderstorms which develop in this regime could pose an isolated threat for marginally severe hail and damaging winds. This threat should peak by mid afternoon, before gradually diminishing through the evening with the loss of daytime heating. ...Northern Plains... Gusty winds may occur with high-based convection this afternoon as a shortwave trough moves eastward over the northern Plains. However, low-level moisture and instability are both expected to remain very meager, which should preclude an organized severe wind threat. ...Upper Midwest... Elevated thunderstorms may develop late tonight across parts of IA in a low-level warm advection regime. With MUCAPE forecast to remain less than 1000 J/kg, the potential for severe hail appears too limited to include low severe probabilities at this time. ..Gleason/Broyles.. 04/21/2025 Read more