Severe Storms

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1232 PM CDT Tue Aug 12 2025 Valid 131200Z - 141200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS SOUTH-CENTRAL SOUTH DAKOTA AND FAR NORTH-CENTRAL NEBRASKA... ...SUMMARY... The evolution of an organized cluster of thunderstorms accompanied by strong to severe wind gusts appears possible across parts of central through eastern South Dakota and far north-central Nebraska by Wednesday evening. ...Synopsis... Upper ridging will remain anchored over the Southwest/Four Corners, with subtropical ridging staying over FL as well. A pair of low-amplitude shortwave troughs will progress through the westerly flow north of this ridging. The easternmost wave will likely move through the Lower OH and TN Valleys while the westernmost wave progresses along the MT/WY border and through SD. This western wave is forecast to interact with an unstable airmass to support strong to severe thunderstorms from eastern WY into the Dakota and NE. Additional thunderstorms are expected across much of the eastern CONUS. Storms over the Northeast will be fostered by glancing ascent attendant to a shortwave trough moving through Quebec while the previously mentioned shortwave trough moving the TN Valley will promote development from KY/TN into northern AL/MS. Weak shear should limit storm organization and strength throughout the eastern CONUS. ...Eastern WY into the Dakotas and NE... Elevated showers and thunderstorms will likely be ongoing across western/central SD Wednesday morning. These storms are generally expected to be subsevere but will likely persist while gradually shifting eastward throughout the morning into the afternoon. The evolution of these storms, and their associated outflow and cloud cover, introduces some uncertainty into the forecast, particularly across southeast SD and northeast NE where there is at least a low probability for reintensification of storms within this cluster. At this time, given potential capping and varied model solutions confidence is low in the reintensification scenario. A more probable severe potential will result from the thunderstorm development that initiates farther west across the Black Hills. Here, increased forcing for ascent attendant to the approaching shortwave trough amid a warm, deeply mixed, and unstable airmass will support convective initiation late Wednesday afternoon. These initially high-based storms will pose a risk for damaging gusts and isolated hail. Moisture and buoyancy will increase with eastern extent, which will combine with moderate vertical shear to support a corridor of higher severe-wind probability across south-central SD and north-central NE during the late evening. Thereafter, increasing convective inhibition should result in gradually diminishing storm intensity. Additionally, elevated thunderstorms with some hail risk may develop ahead of the convective line across eastern SD during the late evening and overnight. Here, a strengthening low-level jet and associated warm-air advection amid steep mid-level lapse rates and moderate deep-layer shear could support a few storms capable of large hail. ..Mosier.. 08/12/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1232 PM CDT Tue Aug 12 2025 Valid 131200Z - 141200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS SOUTH-CENTRAL SOUTH DAKOTA AND FAR NORTH-CENTRAL NEBRASKA... ...SUMMARY... The evolution of an organized cluster of thunderstorms accompanied by strong to severe wind gusts appears possible across parts of central through eastern South Dakota and far north-central Nebraska by Wednesday evening. ...Synopsis... Upper ridging will remain anchored over the Southwest/Four Corners, with subtropical ridging staying over FL as well. A pair of low-amplitude shortwave troughs will progress through the westerly flow north of this ridging. The easternmost wave will likely move through the Lower OH and TN Valleys while the westernmost wave progresses along the MT/WY border and through SD. This western wave is forecast to interact with an unstable airmass to support strong to severe thunderstorms from eastern WY into the Dakota and NE. Additional thunderstorms are expected across much of the eastern CONUS. Storms over the Northeast will be fostered by glancing ascent attendant to a shortwave trough moving through Quebec while the previously mentioned shortwave trough moving the TN Valley will promote development from KY/TN into northern AL/MS. Weak shear should limit storm organization and strength throughout the eastern CONUS. ...Eastern WY into the Dakotas and NE... Elevated showers and thunderstorms will likely be ongoing across western/central SD Wednesday morning. These storms are generally expected to be subsevere but will likely persist while gradually shifting eastward throughout the morning into the afternoon. The evolution of these storms, and their associated outflow and cloud cover, introduces some uncertainty into the forecast, particularly across southeast SD and northeast NE where there is at least a low probability for reintensification of storms within this cluster. At this time, given potential capping and varied model solutions confidence is low in the reintensification scenario. A more probable severe potential will result from the thunderstorm development that initiates farther west across the Black Hills. Here, increased forcing for ascent attendant to the approaching shortwave trough amid a warm, deeply mixed, and unstable airmass will support convective initiation late Wednesday afternoon. These initially high-based storms will pose a risk for damaging gusts and isolated hail. Moisture and buoyancy will increase with eastern extent, which will combine with moderate vertical shear to support a corridor of higher severe-wind probability across south-central SD and north-central NE during the late evening. Thereafter, increasing convective inhibition should result in gradually diminishing storm intensity. Additionally, elevated thunderstorms with some hail risk may develop ahead of the convective line across eastern SD during the late evening and overnight. Here, a strengthening low-level jet and associated warm-air advection amid steep mid-level lapse rates and moderate deep-layer shear could support a few storms capable of large hail. ..Mosier.. 08/12/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1232 PM CDT Tue Aug 12 2025 Valid 131200Z - 141200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS SOUTH-CENTRAL SOUTH DAKOTA AND FAR NORTH-CENTRAL NEBRASKA... ...SUMMARY... The evolution of an organized cluster of thunderstorms accompanied by strong to severe wind gusts appears possible across parts of central through eastern South Dakota and far north-central Nebraska by Wednesday evening. ...Synopsis... Upper ridging will remain anchored over the Southwest/Four Corners, with subtropical ridging staying over FL as well. A pair of low-amplitude shortwave troughs will progress through the westerly flow north of this ridging. The easternmost wave will likely move through the Lower OH and TN Valleys while the westernmost wave progresses along the MT/WY border and through SD. This western wave is forecast to interact with an unstable airmass to support strong to severe thunderstorms from eastern WY into the Dakota and NE. Additional thunderstorms are expected across much of the eastern CONUS. Storms over the Northeast will be fostered by glancing ascent attendant to a shortwave trough moving through Quebec while the previously mentioned shortwave trough moving the TN Valley will promote development from KY/TN into northern AL/MS. Weak shear should limit storm organization and strength throughout the eastern CONUS. ...Eastern WY into the Dakotas and NE... Elevated showers and thunderstorms will likely be ongoing across western/central SD Wednesday morning. These storms are generally expected to be subsevere but will likely persist while gradually shifting eastward throughout the morning into the afternoon. The evolution of these storms, and their associated outflow and cloud cover, introduces some uncertainty into the forecast, particularly across southeast SD and northeast NE where there is at least a low probability for reintensification of storms within this cluster. At this time, given potential capping and varied model solutions confidence is low in the reintensification scenario. A more probable severe potential will result from the thunderstorm development that initiates farther west across the Black Hills. Here, increased forcing for ascent attendant to the approaching shortwave trough amid a warm, deeply mixed, and unstable airmass will support convective initiation late Wednesday afternoon. These initially high-based storms will pose a risk for damaging gusts and isolated hail. Moisture and buoyancy will increase with eastern extent, which will combine with moderate vertical shear to support a corridor of higher severe-wind probability across south-central SD and north-central NE during the late evening. Thereafter, increasing convective inhibition should result in gradually diminishing storm intensity. Additionally, elevated thunderstorms with some hail risk may develop ahead of the convective line across eastern SD during the late evening and overnight. Here, a strengthening low-level jet and associated warm-air advection amid steep mid-level lapse rates and moderate deep-layer shear could support a few storms capable of large hail. ..Mosier.. 08/12/2025 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1140 AM CDT Tue Aug 12 2025 Valid 121700Z - 131200Z No changes are needed to the current D1 Fire Weather Outlook. See previous discussion below for more information. ..Thornton.. 08/12/2025 .PREV DISCUSSION... /ISSUED 0128 AM CDT Tue Aug 12 2025/ ...Synopsis... Fire weather concerns will be focused across parts of central and eastern Arizona this afternoon, though more local concerns may emerge across portions of Oregon. ...Central to eastern Arizona... A mixture of wet and dry thunderstorms is expected again this afternoon along the Mogollon Rim. An evening 00z sounding from ABQ sampled a very deep, dry boundary layer along with steep mid-level lapse rates and PWAT values near 0.5 inch. This dry, but weakly buoyant, thermodynamic environment on the northern fringe of the deeper monsoonal moisture yielded a mix of wet and dry thunderstorms across the region yesterday. Similar conditions are likely today and should pose a fire weather concern over areas with receptive fuels. Dry thunderstorms are possible further east into western NM, but recent rainfall and improved fuels should mitigate the fire risk. ...Oregon... A weak mid-level wave is noted in early-morning water-vapor imagery off the Pacific Northwest coast. This feature will migrate east through the day and overspread the Cascades through peak heating. The associated westerly mid-level flow will not be overly strong, but will still induce a downslope flow regime on the eastern slopes of the Cascades. Compressional heating/drying, coupled with peak heating and full insolation, will promote RH reductions between 10-20%. Sustained winds between 10-15 mph appear most probable based on latest ensemble consensus, but gusts between 20-25 mph (especially wind-prone locations within the terrain) are possible. ...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 1140 AM CDT Tue Aug 12 2025 Valid 121700Z - 131200Z No changes are needed to the current D1 Fire Weather Outlook. See previous discussion below for more information. ..Thornton.. 08/12/2025 .PREV DISCUSSION... /ISSUED 0128 AM CDT Tue Aug 12 2025/ ...Synopsis... Fire weather concerns will be focused across parts of central and eastern Arizona this afternoon, though more local concerns may emerge across portions of Oregon. ...Central to eastern Arizona... A mixture of wet and dry thunderstorms is expected again this afternoon along the Mogollon Rim. An evening 00z sounding from ABQ sampled a very deep, dry boundary layer along with steep mid-level lapse rates and PWAT values near 0.5 inch. This dry, but weakly buoyant, thermodynamic environment on the northern fringe of the deeper monsoonal moisture yielded a mix of wet and dry thunderstorms across the region yesterday. Similar conditions are likely today and should pose a fire weather concern over areas with receptive fuels. Dry thunderstorms are possible further east into western NM, but recent rainfall and improved fuels should mitigate the fire risk. ...Oregon... A weak mid-level wave is noted in early-morning water-vapor imagery off the Pacific Northwest coast. This feature will migrate east through the day and overspread the Cascades through peak heating. The associated westerly mid-level flow will not be overly strong, but will still induce a downslope flow regime on the eastern slopes of the Cascades. Compressional heating/drying, coupled with peak heating and full insolation, will promote RH reductions between 10-20%. Sustained winds between 10-15 mph appear most probable based on latest ensemble consensus, but gusts between 20-25 mph (especially wind-prone locations within the terrain) are possible. ...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 1140 AM CDT Tue Aug 12 2025 Valid 121700Z - 131200Z No changes are needed to the current D1 Fire Weather Outlook. See previous discussion below for more information. ..Thornton.. 08/12/2025 .PREV DISCUSSION... /ISSUED 0128 AM CDT Tue Aug 12 2025/ ...Synopsis... Fire weather concerns will be focused across parts of central and eastern Arizona this afternoon, though more local concerns may emerge across portions of Oregon. ...Central to eastern Arizona... A mixture of wet and dry thunderstorms is expected again this afternoon along the Mogollon Rim. An evening 00z sounding from ABQ sampled a very deep, dry boundary layer along with steep mid-level lapse rates and PWAT values near 0.5 inch. This dry, but weakly buoyant, thermodynamic environment on the northern fringe of the deeper monsoonal moisture yielded a mix of wet and dry thunderstorms across the region yesterday. Similar conditions are likely today and should pose a fire weather concern over areas with receptive fuels. Dry thunderstorms are possible further east into western NM, but recent rainfall and improved fuels should mitigate the fire risk. ...Oregon... A weak mid-level wave is noted in early-morning water-vapor imagery off the Pacific Northwest coast. This feature will migrate east through the day and overspread the Cascades through peak heating. The associated westerly mid-level flow will not be overly strong, but will still induce a downslope flow regime on the eastern slopes of the Cascades. Compressional heating/drying, coupled with peak heating and full insolation, will promote RH reductions between 10-20%. Sustained winds between 10-15 mph appear most probable based on latest ensemble consensus, but gusts between 20-25 mph (especially wind-prone locations within the terrain) are possible. ...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 1140 AM CDT Tue Aug 12 2025 Valid 121700Z - 131200Z No changes are needed to the current D1 Fire Weather Outlook. See previous discussion below for more information. ..Thornton.. 08/12/2025 .PREV DISCUSSION... /ISSUED 0128 AM CDT Tue Aug 12 2025/ ...Synopsis... Fire weather concerns will be focused across parts of central and eastern Arizona this afternoon, though more local concerns may emerge across portions of Oregon. ...Central to eastern Arizona... A mixture of wet and dry thunderstorms is expected again this afternoon along the Mogollon Rim. An evening 00z sounding from ABQ sampled a very deep, dry boundary layer along with steep mid-level lapse rates and PWAT values near 0.5 inch. This dry, but weakly buoyant, thermodynamic environment on the northern fringe of the deeper monsoonal moisture yielded a mix of wet and dry thunderstorms across the region yesterday. Similar conditions are likely today and should pose a fire weather concern over areas with receptive fuels. Dry thunderstorms are possible further east into western NM, but recent rainfall and improved fuels should mitigate the fire risk. ...Oregon... A weak mid-level wave is noted in early-morning water-vapor imagery off the Pacific Northwest coast. This feature will migrate east through the day and overspread the Cascades through peak heating. The associated westerly mid-level flow will not be overly strong, but will still induce a downslope flow regime on the eastern slopes of the Cascades. Compressional heating/drying, coupled with peak heating and full insolation, will promote RH reductions between 10-20%. Sustained winds between 10-15 mph appear most probable based on latest ensemble consensus, but gusts between 20-25 mph (especially wind-prone locations within the terrain) are possible. ...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 1140 AM CDT Tue Aug 12 2025 Valid 121700Z - 131200Z No changes are needed to the current D1 Fire Weather Outlook. See previous discussion below for more information. ..Thornton.. 08/12/2025 .PREV DISCUSSION... /ISSUED 0128 AM CDT Tue Aug 12 2025/ ...Synopsis... Fire weather concerns will be focused across parts of central and eastern Arizona this afternoon, though more local concerns may emerge across portions of Oregon. ...Central to eastern Arizona... A mixture of wet and dry thunderstorms is expected again this afternoon along the Mogollon Rim. An evening 00z sounding from ABQ sampled a very deep, dry boundary layer along with steep mid-level lapse rates and PWAT values near 0.5 inch. This dry, but weakly buoyant, thermodynamic environment on the northern fringe of the deeper monsoonal moisture yielded a mix of wet and dry thunderstorms across the region yesterday. Similar conditions are likely today and should pose a fire weather concern over areas with receptive fuels. Dry thunderstorms are possible further east into western NM, but recent rainfall and improved fuels should mitigate the fire risk. ...Oregon... A weak mid-level wave is noted in early-morning water-vapor imagery off the Pacific Northwest coast. This feature will migrate east through the day and overspread the Cascades through peak heating. The associated westerly mid-level flow will not be overly strong, but will still induce a downslope flow regime on the eastern slopes of the Cascades. Compressional heating/drying, coupled with peak heating and full insolation, will promote RH reductions between 10-20%. Sustained winds between 10-15 mph appear most probable based on latest ensemble consensus, but gusts between 20-25 mph (especially wind-prone locations within the terrain) are possible. ...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 1140 AM CDT Tue Aug 12 2025 Valid 121700Z - 131200Z No changes are needed to the current D1 Fire Weather Outlook. See previous discussion below for more information. ..Thornton.. 08/12/2025 .PREV DISCUSSION... /ISSUED 0128 AM CDT Tue Aug 12 2025/ ...Synopsis... Fire weather concerns will be focused across parts of central and eastern Arizona this afternoon, though more local concerns may emerge across portions of Oregon. ...Central to eastern Arizona... A mixture of wet and dry thunderstorms is expected again this afternoon along the Mogollon Rim. An evening 00z sounding from ABQ sampled a very deep, dry boundary layer along with steep mid-level lapse rates and PWAT values near 0.5 inch. This dry, but weakly buoyant, thermodynamic environment on the northern fringe of the deeper monsoonal moisture yielded a mix of wet and dry thunderstorms across the region yesterday. Similar conditions are likely today and should pose a fire weather concern over areas with receptive fuels. Dry thunderstorms are possible further east into western NM, but recent rainfall and improved fuels should mitigate the fire risk. ...Oregon... A weak mid-level wave is noted in early-morning water-vapor imagery off the Pacific Northwest coast. This feature will migrate east through the day and overspread the Cascades through peak heating. The associated westerly mid-level flow will not be overly strong, but will still induce a downslope flow regime on the eastern slopes of the Cascades. Compressional heating/drying, coupled with peak heating and full insolation, will promote RH reductions between 10-20%. Sustained winds between 10-15 mph appear most probable based on latest ensemble consensus, but gusts between 20-25 mph (especially wind-prone locations within the terrain) are possible. ...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 1140 AM CDT Tue Aug 12 2025 Valid 121700Z - 131200Z No changes are needed to the current D1 Fire Weather Outlook. See previous discussion below for more information. ..Thornton.. 08/12/2025 .PREV DISCUSSION... /ISSUED 0128 AM CDT Tue Aug 12 2025/ ...Synopsis... Fire weather concerns will be focused across parts of central and eastern Arizona this afternoon, though more local concerns may emerge across portions of Oregon. ...Central to eastern Arizona... A mixture of wet and dry thunderstorms is expected again this afternoon along the Mogollon Rim. An evening 00z sounding from ABQ sampled a very deep, dry boundary layer along with steep mid-level lapse rates and PWAT values near 0.5 inch. This dry, but weakly buoyant, thermodynamic environment on the northern fringe of the deeper monsoonal moisture yielded a mix of wet and dry thunderstorms across the region yesterday. Similar conditions are likely today and should pose a fire weather concern over areas with receptive fuels. Dry thunderstorms are possible further east into western NM, but recent rainfall and improved fuels should mitigate the fire risk. ...Oregon... A weak mid-level wave is noted in early-morning water-vapor imagery off the Pacific Northwest coast. This feature will migrate east through the day and overspread the Cascades through peak heating. The associated westerly mid-level flow will not be overly strong, but will still induce a downslope flow regime on the eastern slopes of the Cascades. Compressional heating/drying, coupled with peak heating and full insolation, will promote RH reductions between 10-20%. Sustained winds between 10-15 mph appear most probable based on latest ensemble consensus, but gusts between 20-25 mph (especially wind-prone locations within the terrain) are possible. ...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 1140 AM CDT Tue Aug 12 2025 Valid 121700Z - 131200Z No changes are needed to the current D1 Fire Weather Outlook. See previous discussion below for more information. ..Thornton.. 08/12/2025 .PREV DISCUSSION... /ISSUED 0128 AM CDT Tue Aug 12 2025/ ...Synopsis... Fire weather concerns will be focused across parts of central and eastern Arizona this afternoon, though more local concerns may emerge across portions of Oregon. ...Central to eastern Arizona... A mixture of wet and dry thunderstorms is expected again this afternoon along the Mogollon Rim. An evening 00z sounding from ABQ sampled a very deep, dry boundary layer along with steep mid-level lapse rates and PWAT values near 0.5 inch. This dry, but weakly buoyant, thermodynamic environment on the northern fringe of the deeper monsoonal moisture yielded a mix of wet and dry thunderstorms across the region yesterday. Similar conditions are likely today and should pose a fire weather concern over areas with receptive fuels. Dry thunderstorms are possible further east into western NM, but recent rainfall and improved fuels should mitigate the fire risk. ...Oregon... A weak mid-level wave is noted in early-morning water-vapor imagery off the Pacific Northwest coast. This feature will migrate east through the day and overspread the Cascades through peak heating. The associated westerly mid-level flow will not be overly strong, but will still induce a downslope flow regime on the eastern slopes of the Cascades. Compressional heating/drying, coupled with peak heating and full insolation, will promote RH reductions between 10-20%. Sustained winds between 10-15 mph appear most probable based on latest ensemble consensus, but gusts between 20-25 mph (especially wind-prone locations within the terrain) are possible. ...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 1128 AM CDT Tue Aug 12 2025 Valid 121630Z - 131200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE GREAT LAKES AND SOUTHEAST ARIZONA INTO SOUTHWEST NEW MEXICO... ...SUMMARY... Strong to locally severe thunderstorms are possible over parts of the Great Lakes/Midwest this afternoon with both damaging winds and hail possible. Gusty winds may also occur over southeast Arizona and southwest New Mexico. ...Great Lakes/Midwest... Midday satellite/radar composite show a weakened thunderstorm band moving east-northeast across the eastern part of Lower MI. Surface analysis indicates rain-cooled air north of a gust front/outflow that has become draped from southeast Lower MI into the Michiana region. Heating south of this boundary has resulted in temperatures warming through the mid-upper 80s with dewpoints in the lower 70s. Additional storms will probably develop along the trailing outflow and gradually move east-northeast with the mean wind. Considerably weaker deep-layer shear is present across the eastern part of the Corn Belt into the Lower MI vicinity compared to farther north over the U.P. of MI in closer proximity to a shortwave trough. Nonetheless, scattered thunderstorms will gradually develop within a moist/destabilizing airmass and pose a risk for isolated strong to perhaps locally severe/damaging gusts this afternoon. Farther north in WI into the U.P. of MI, a weak cold front will move into the region later this afternoon. Model guidance shows widely scattered storms developing as filtered sunshine leads to a destabilizing boundary layer. A few stronger thunderstorms are possible and could yield a localized risk for marginally severe hail and damaging gusts during the mid afternoon to early evening period. ...Southeast AZ/southwest NM... Strong heating should result in widely scattered thunderstorms developing near terrain-favored areas. Weak shear will result in disorganized storms, but the development of very steep surface to 500-mb lapse rates will promote strong evaporative cooling with the more intense downdrafts. Isolated severe gusts are possible. ..Smith/Squitieri.. 08/12/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1128 AM CDT Tue Aug 12 2025 Valid 121630Z - 131200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE GREAT LAKES AND SOUTHEAST ARIZONA INTO SOUTHWEST NEW MEXICO... ...SUMMARY... Strong to locally severe thunderstorms are possible over parts of the Great Lakes/Midwest this afternoon with both damaging winds and hail possible. Gusty winds may also occur over southeast Arizona and southwest New Mexico. ...Great Lakes/Midwest... Midday satellite/radar composite show a weakened thunderstorm band moving east-northeast across the eastern part of Lower MI. Surface analysis indicates rain-cooled air north of a gust front/outflow that has become draped from southeast Lower MI into the Michiana region. Heating south of this boundary has resulted in temperatures warming through the mid-upper 80s with dewpoints in the lower 70s. Additional storms will probably develop along the trailing outflow and gradually move east-northeast with the mean wind. Considerably weaker deep-layer shear is present across the eastern part of the Corn Belt into the Lower MI vicinity compared to farther north over the U.P. of MI in closer proximity to a shortwave trough. Nonetheless, scattered thunderstorms will gradually develop within a moist/destabilizing airmass and pose a risk for isolated strong to perhaps locally severe/damaging gusts this afternoon. Farther north in WI into the U.P. of MI, a weak cold front will move into the region later this afternoon. Model guidance shows widely scattered storms developing as filtered sunshine leads to a destabilizing boundary layer. A few stronger thunderstorms are possible and could yield a localized risk for marginally severe hail and damaging gusts during the mid afternoon to early evening period. ...Southeast AZ/southwest NM... Strong heating should result in widely scattered thunderstorms developing near terrain-favored areas. Weak shear will result in disorganized storms, but the development of very steep surface to 500-mb lapse rates will promote strong evaporative cooling with the more intense downdrafts. Isolated severe gusts are possible. ..Smith/Squitieri.. 08/12/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1128 AM CDT Tue Aug 12 2025 Valid 121630Z - 131200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE GREAT LAKES AND SOUTHEAST ARIZONA INTO SOUTHWEST NEW MEXICO... ...SUMMARY... Strong to locally severe thunderstorms are possible over parts of the Great Lakes/Midwest this afternoon with both damaging winds and hail possible. Gusty winds may also occur over southeast Arizona and southwest New Mexico. ...Great Lakes/Midwest... Midday satellite/radar composite show a weakened thunderstorm band moving east-northeast across the eastern part of Lower MI. Surface analysis indicates rain-cooled air north of a gust front/outflow that has become draped from southeast Lower MI into the Michiana region. Heating south of this boundary has resulted in temperatures warming through the mid-upper 80s with dewpoints in the lower 70s. Additional storms will probably develop along the trailing outflow and gradually move east-northeast with the mean wind. Considerably weaker deep-layer shear is present across the eastern part of the Corn Belt into the Lower MI vicinity compared to farther north over the U.P. of MI in closer proximity to a shortwave trough. Nonetheless, scattered thunderstorms will gradually develop within a moist/destabilizing airmass and pose a risk for isolated strong to perhaps locally severe/damaging gusts this afternoon. Farther north in WI into the U.P. of MI, a weak cold front will move into the region later this afternoon. Model guidance shows widely scattered storms developing as filtered sunshine leads to a destabilizing boundary layer. A few stronger thunderstorms are possible and could yield a localized risk for marginally severe hail and damaging gusts during the mid afternoon to early evening period. ...Southeast AZ/southwest NM... Strong heating should result in widely scattered thunderstorms developing near terrain-favored areas. Weak shear will result in disorganized storms, but the development of very steep surface to 500-mb lapse rates will promote strong evaporative cooling with the more intense downdrafts. Isolated severe gusts are possible. ..Smith/Squitieri.. 08/12/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1128 AM CDT Tue Aug 12 2025 Valid 121630Z - 131200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE GREAT LAKES AND SOUTHEAST ARIZONA INTO SOUTHWEST NEW MEXICO... ...SUMMARY... Strong to locally severe thunderstorms are possible over parts of the Great Lakes/Midwest this afternoon with both damaging winds and hail possible. Gusty winds may also occur over southeast Arizona and southwest New Mexico. ...Great Lakes/Midwest... Midday satellite/radar composite show a weakened thunderstorm band moving east-northeast across the eastern part of Lower MI. Surface analysis indicates rain-cooled air north of a gust front/outflow that has become draped from southeast Lower MI into the Michiana region. Heating south of this boundary has resulted in temperatures warming through the mid-upper 80s with dewpoints in the lower 70s. Additional storms will probably develop along the trailing outflow and gradually move east-northeast with the mean wind. Considerably weaker deep-layer shear is present across the eastern part of the Corn Belt into the Lower MI vicinity compared to farther north over the U.P. of MI in closer proximity to a shortwave trough. Nonetheless, scattered thunderstorms will gradually develop within a moist/destabilizing airmass and pose a risk for isolated strong to perhaps locally severe/damaging gusts this afternoon. Farther north in WI into the U.P. of MI, a weak cold front will move into the region later this afternoon. Model guidance shows widely scattered storms developing as filtered sunshine leads to a destabilizing boundary layer. A few stronger thunderstorms are possible and could yield a localized risk for marginally severe hail and damaging gusts during the mid afternoon to early evening period. ...Southeast AZ/southwest NM... Strong heating should result in widely scattered thunderstorms developing near terrain-favored areas. Weak shear will result in disorganized storms, but the development of very steep surface to 500-mb lapse rates will promote strong evaporative cooling with the more intense downdrafts. Isolated severe gusts are possible. ..Smith/Squitieri.. 08/12/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1128 AM CDT Tue Aug 12 2025 Valid 121630Z - 131200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE GREAT LAKES AND SOUTHEAST ARIZONA INTO SOUTHWEST NEW MEXICO... ...SUMMARY... Strong to locally severe thunderstorms are possible over parts of the Great Lakes/Midwest this afternoon with both damaging winds and hail possible. Gusty winds may also occur over southeast Arizona and southwest New Mexico. ...Great Lakes/Midwest... Midday satellite/radar composite show a weakened thunderstorm band moving east-northeast across the eastern part of Lower MI. Surface analysis indicates rain-cooled air north of a gust front/outflow that has become draped from southeast Lower MI into the Michiana region. Heating south of this boundary has resulted in temperatures warming through the mid-upper 80s with dewpoints in the lower 70s. Additional storms will probably develop along the trailing outflow and gradually move east-northeast with the mean wind. Considerably weaker deep-layer shear is present across the eastern part of the Corn Belt into the Lower MI vicinity compared to farther north over the U.P. of MI in closer proximity to a shortwave trough. Nonetheless, scattered thunderstorms will gradually develop within a moist/destabilizing airmass and pose a risk for isolated strong to perhaps locally severe/damaging gusts this afternoon. Farther north in WI into the U.P. of MI, a weak cold front will move into the region later this afternoon. Model guidance shows widely scattered storms developing as filtered sunshine leads to a destabilizing boundary layer. A few stronger thunderstorms are possible and could yield a localized risk for marginally severe hail and damaging gusts during the mid afternoon to early evening period. ...Southeast AZ/southwest NM... Strong heating should result in widely scattered thunderstorms developing near terrain-favored areas. Weak shear will result in disorganized storms, but the development of very steep surface to 500-mb lapse rates will promote strong evaporative cooling with the more intense downdrafts. Isolated severe gusts are possible. ..Smith/Squitieri.. 08/12/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1128 AM CDT Tue Aug 12 2025 Valid 121630Z - 131200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE GREAT LAKES AND SOUTHEAST ARIZONA INTO SOUTHWEST NEW MEXICO... ...SUMMARY... Strong to locally severe thunderstorms are possible over parts of the Great Lakes/Midwest this afternoon with both damaging winds and hail possible. Gusty winds may also occur over southeast Arizona and southwest New Mexico. ...Great Lakes/Midwest... Midday satellite/radar composite show a weakened thunderstorm band moving east-northeast across the eastern part of Lower MI. Surface analysis indicates rain-cooled air north of a gust front/outflow that has become draped from southeast Lower MI into the Michiana region. Heating south of this boundary has resulted in temperatures warming through the mid-upper 80s with dewpoints in the lower 70s. Additional storms will probably develop along the trailing outflow and gradually move east-northeast with the mean wind. Considerably weaker deep-layer shear is present across the eastern part of the Corn Belt into the Lower MI vicinity compared to farther north over the U.P. of MI in closer proximity to a shortwave trough. Nonetheless, scattered thunderstorms will gradually develop within a moist/destabilizing airmass and pose a risk for isolated strong to perhaps locally severe/damaging gusts this afternoon. Farther north in WI into the U.P. of MI, a weak cold front will move into the region later this afternoon. Model guidance shows widely scattered storms developing as filtered sunshine leads to a destabilizing boundary layer. A few stronger thunderstorms are possible and could yield a localized risk for marginally severe hail and damaging gusts during the mid afternoon to early evening period. ...Southeast AZ/southwest NM... Strong heating should result in widely scattered thunderstorms developing near terrain-favored areas. Weak shear will result in disorganized storms, but the development of very steep surface to 500-mb lapse rates will promote strong evaporative cooling with the more intense downdrafts. Isolated severe gusts are possible. ..Smith/Squitieri.. 08/12/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1128 AM CDT Tue Aug 12 2025 Valid 121630Z - 131200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE GREAT LAKES AND SOUTHEAST ARIZONA INTO SOUTHWEST NEW MEXICO... ...SUMMARY... Strong to locally severe thunderstorms are possible over parts of the Great Lakes/Midwest this afternoon with both damaging winds and hail possible. Gusty winds may also occur over southeast Arizona and southwest New Mexico. ...Great Lakes/Midwest... Midday satellite/radar composite show a weakened thunderstorm band moving east-northeast across the eastern part of Lower MI. Surface analysis indicates rain-cooled air north of a gust front/outflow that has become draped from southeast Lower MI into the Michiana region. Heating south of this boundary has resulted in temperatures warming through the mid-upper 80s with dewpoints in the lower 70s. Additional storms will probably develop along the trailing outflow and gradually move east-northeast with the mean wind. Considerably weaker deep-layer shear is present across the eastern part of the Corn Belt into the Lower MI vicinity compared to farther north over the U.P. of MI in closer proximity to a shortwave trough. Nonetheless, scattered thunderstorms will gradually develop within a moist/destabilizing airmass and pose a risk for isolated strong to perhaps locally severe/damaging gusts this afternoon. Farther north in WI into the U.P. of MI, a weak cold front will move into the region later this afternoon. Model guidance shows widely scattered storms developing as filtered sunshine leads to a destabilizing boundary layer. A few stronger thunderstorms are possible and could yield a localized risk for marginally severe hail and damaging gusts during the mid afternoon to early evening period. ...Southeast AZ/southwest NM... Strong heating should result in widely scattered thunderstorms developing near terrain-favored areas. Weak shear will result in disorganized storms, but the development of very steep surface to 500-mb lapse rates will promote strong evaporative cooling with the more intense downdrafts. Isolated severe gusts are possible. ..Smith/Squitieri.. 08/12/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1128 AM CDT Tue Aug 12 2025 Valid 121630Z - 131200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE GREAT LAKES AND SOUTHEAST ARIZONA INTO SOUTHWEST NEW MEXICO... ...SUMMARY... Strong to locally severe thunderstorms are possible over parts of the Great Lakes/Midwest this afternoon with both damaging winds and hail possible. Gusty winds may also occur over southeast Arizona and southwest New Mexico. ...Great Lakes/Midwest... Midday satellite/radar composite show a weakened thunderstorm band moving east-northeast across the eastern part of Lower MI. Surface analysis indicates rain-cooled air north of a gust front/outflow that has become draped from southeast Lower MI into the Michiana region. Heating south of this boundary has resulted in temperatures warming through the mid-upper 80s with dewpoints in the lower 70s. Additional storms will probably develop along the trailing outflow and gradually move east-northeast with the mean wind. Considerably weaker deep-layer shear is present across the eastern part of the Corn Belt into the Lower MI vicinity compared to farther north over the U.P. of MI in closer proximity to a shortwave trough. Nonetheless, scattered thunderstorms will gradually develop within a moist/destabilizing airmass and pose a risk for isolated strong to perhaps locally severe/damaging gusts this afternoon. Farther north in WI into the U.P. of MI, a weak cold front will move into the region later this afternoon. Model guidance shows widely scattered storms developing as filtered sunshine leads to a destabilizing boundary layer. A few stronger thunderstorms are possible and could yield a localized risk for marginally severe hail and damaging gusts during the mid afternoon to early evening period. ...Southeast AZ/southwest NM... Strong heating should result in widely scattered thunderstorms developing near terrain-favored areas. Weak shear will result in disorganized storms, but the development of very steep surface to 500-mb lapse rates will promote strong evaporative cooling with the more intense downdrafts. Isolated severe gusts are possible. ..Smith/Squitieri.. 08/12/2025 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0648 AM CDT Tue Aug 12 2025 Valid 121300Z - 131200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE UPPER GREAT LAKES/MIDWEST...AND PORTIONS OF THE SOUTHWEST... ...SUMMARY... Strong to occasionally severe thunderstorms may impact parts of the upper Great Lakes/Midwest today with both damaging winds and hail possible. Gusty winds may also occur over southeast Arizona and southwest New Mexico. ...Great Lakes/Midwest... A band of thunderstorms associated with an MCV tracked northeastward across parts of IA into northern IL and southern WI early this morning while remaining mostly sub-severe. Still, there may be some potential for strong to locally damaging winds with this activity as it continues northeastward across Lake Michigan into parts of Lower MI this morning/early afternoon as daytime heating gradually destabilizes the boundary layer. Otherwise, additional convection should develop later this afternoon along/ahead of a weak front over parts of WI and the U.P. of MI as the southern portion of a mid/upper-level trough moves eastward over the Upper Midwest/Great Lakes. Instability is forecast to remain fairly modest ahead of the front, but enough deep-layer shear should exist to support some organized convection. Initial cells may be capable of producing marginally severe hail, before clustering potentially increases the threat for occasional strong to damaging winds. A separate area of thunderstorms is forecast to develop this afternoon farther south and ahead of the front from portions of the Midwest into Lower MI. While this region will have relatively weaker mid-level westerly flow and related deep-layer shear compared to locations farther north, greater low-level moisture and instability are expected to be present. As low-level lapse rates become steepened with diurnal heating of the moist airmass, loosely organized clusters may become capable of producing isolated damaging winds as they spread generally east-northeastward through the afternoon and early evening. ...Southwest... Strong daytime heating should encourage diurnally driven convection over the higher terrain of southeast AZ and southwest NM this afternoon. With weak flow aloft and negligible shear, thunderstorms should drift slowly southward. Still, occasional gusty winds may occur with the more robust convection given steepened lapse rates. ..Gleason/Leitman.. 08/12/2025 Read more