Severe Storms

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

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

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

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

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

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0311 AM CDT Tue Aug 12 2025 Valid 151200Z - 201200Z ...DISCUSSION... From Friday/D4 into Saturday/D5, an upper low will move from Manitoba across Hudson Bay and into Quebec. Moderate midlevel westerlies will exist over the far northern Plains to Upper Great Lakes during this period, with gradual weakening. An upper high will also be centered over the mid MS Valley, while a weak midlevel trough with cool air aloft slowly departs the Great Basin. At the surface, a front is forecast to stall on Friday/D4 from northern NE across southern MN and into northern WI, with a moist and unstable air mass remaining to the south. This front will remain over roughly the same zone into Saturday/D5, and perhaps as late as Sunday/D6. Given that the moist and unstable air mass will persist over parts of the northern Plains/Upper MS Valley, and minor ripples in the flow are hinted at by several models, areas of storms are expected. However, storm/MCS corridors are difficult to pinpoint this far out. In general, the area from SD into WI will bear watching for wind potential. From Sunday/D6 onward, an upper ridge is expected to build over much of the western and central states, with a reduction in severe potential overall. Read more