Severe Storms

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0152 PM CDT Mon Aug 25 2025 Valid 261200Z - 271200Z The IsoDryT area was modified based on the latest high-resolution forecast guidance. There is a low probability that isolated high-based thunderstorms move into the Coast Ranges of northwest Oregon and western Washington, but high-based showers with perhaps sporadic lightning is more likely. Additionally, the Idaho Panhandle into western Montana along the northern boundary of the Day 2 thunder line will have cloud cover, and the dominant mode of convection is likely to be isolated to scattered high-based showers with potentially sporadic lightning intermixed. Deep pyroconvection remains possible on very active large wildfires near the IsoDryT area and along/near what remains of the thermal trough stretching southward into California. ..Nauslar.. 08/25/2025 .PREV DISCUSSION... /ISSUED 0159 AM CDT Mon Aug 25 2025/ ...Synopsis... Well-established monsoonal moisture will remain in place across the Northwest on Tuesday. Boundary-layer mixing beneath the rich midlevel moisture will contribute to sufficient buoyancy for diurnally driven high-based thunderstorms along the Cascades, where fuels are dry. Inverted-V profiles and 0.80-0.90 inch PW will favor a mix of wet/dry thunderstorms capable of producing gusty/erratic outflow winds and lightning-induced ignitions. A continuation of wet/dry thunderstorms are also expected across parts of northern CA and the northern Rockies, though uncertainty regarding fuel receptiveness in these areas precludes highlights at this time. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0152 PM CDT Mon Aug 25 2025 Valid 261200Z - 271200Z The IsoDryT area was modified based on the latest high-resolution forecast guidance. There is a low probability that isolated high-based thunderstorms move into the Coast Ranges of northwest Oregon and western Washington, but high-based showers with perhaps sporadic lightning is more likely. Additionally, the Idaho Panhandle into western Montana along the northern boundary of the Day 2 thunder line will have cloud cover, and the dominant mode of convection is likely to be isolated to scattered high-based showers with potentially sporadic lightning intermixed. Deep pyroconvection remains possible on very active large wildfires near the IsoDryT area and along/near what remains of the thermal trough stretching southward into California. ..Nauslar.. 08/25/2025 .PREV DISCUSSION... /ISSUED 0159 AM CDT Mon Aug 25 2025/ ...Synopsis... Well-established monsoonal moisture will remain in place across the Northwest on Tuesday. Boundary-layer mixing beneath the rich midlevel moisture will contribute to sufficient buoyancy for diurnally driven high-based thunderstorms along the Cascades, where fuels are dry. Inverted-V profiles and 0.80-0.90 inch PW will favor a mix of wet/dry thunderstorms capable of producing gusty/erratic outflow winds and lightning-induced ignitions. A continuation of wet/dry thunderstorms are also expected across parts of northern CA and the northern Rockies, though uncertainty regarding fuel receptiveness in these areas precludes highlights at this time. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0152 PM CDT Mon Aug 25 2025 Valid 261200Z - 271200Z The IsoDryT area was modified based on the latest high-resolution forecast guidance. There is a low probability that isolated high-based thunderstorms move into the Coast Ranges of northwest Oregon and western Washington, but high-based showers with perhaps sporadic lightning is more likely. Additionally, the Idaho Panhandle into western Montana along the northern boundary of the Day 2 thunder line will have cloud cover, and the dominant mode of convection is likely to be isolated to scattered high-based showers with potentially sporadic lightning intermixed. Deep pyroconvection remains possible on very active large wildfires near the IsoDryT area and along/near what remains of the thermal trough stretching southward into California. ..Nauslar.. 08/25/2025 .PREV DISCUSSION... /ISSUED 0159 AM CDT Mon Aug 25 2025/ ...Synopsis... Well-established monsoonal moisture will remain in place across the Northwest on Tuesday. Boundary-layer mixing beneath the rich midlevel moisture will contribute to sufficient buoyancy for diurnally driven high-based thunderstorms along the Cascades, where fuels are dry. Inverted-V profiles and 0.80-0.90 inch PW will favor a mix of wet/dry thunderstorms capable of producing gusty/erratic outflow winds and lightning-induced ignitions. A continuation of wet/dry thunderstorms are also expected across parts of northern CA and the northern Rockies, though uncertainty regarding fuel receptiveness in these areas precludes highlights at this time. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1225 PM CDT Mon Aug 25 2025 Valid 261200Z - 271200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe storms are not expected across the continental U.S. on Tuesday. ...Synopsis... High pressure will result in cool and/or stable conditions over much of the central and eastern CONUS with the primary upper trough moving to the East Coast by Wednesday morning. Behind this upper trough, a weakening upper ridge will extend from the central Rockies southward towards the Rio Grande Valley. West of this ridge, lower heights with pockets of cooler midlevel temperatures will exist over much of the Intermountain West, which will continue to aid scattered general thunderstorm activity. While gusty winds may occur with afternoon activity coincident with peak heating and due to steep boundary layer lapse rates, severe storm potential appears minimal on the large scale. ..Jewell.. 08/25/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1225 PM CDT Mon Aug 25 2025 Valid 261200Z - 271200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe storms are not expected across the continental U.S. on Tuesday. ...Synopsis... High pressure will result in cool and/or stable conditions over much of the central and eastern CONUS with the primary upper trough moving to the East Coast by Wednesday morning. Behind this upper trough, a weakening upper ridge will extend from the central Rockies southward towards the Rio Grande Valley. West of this ridge, lower heights with pockets of cooler midlevel temperatures will exist over much of the Intermountain West, which will continue to aid scattered general thunderstorm activity. While gusty winds may occur with afternoon activity coincident with peak heating and due to steep boundary layer lapse rates, severe storm potential appears minimal on the large scale. ..Jewell.. 08/25/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1225 PM CDT Mon Aug 25 2025 Valid 261200Z - 271200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe storms are not expected across the continental U.S. on Tuesday. ...Synopsis... High pressure will result in cool and/or stable conditions over much of the central and eastern CONUS with the primary upper trough moving to the East Coast by Wednesday morning. Behind this upper trough, a weakening upper ridge will extend from the central Rockies southward towards the Rio Grande Valley. West of this ridge, lower heights with pockets of cooler midlevel temperatures will exist over much of the Intermountain West, which will continue to aid scattered general thunderstorm activity. While gusty winds may occur with afternoon activity coincident with peak heating and due to steep boundary layer lapse rates, severe storm potential appears minimal on the large scale. ..Jewell.. 08/25/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1225 PM CDT Mon Aug 25 2025 Valid 261200Z - 271200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe storms are not expected across the continental U.S. on Tuesday. ...Synopsis... High pressure will result in cool and/or stable conditions over much of the central and eastern CONUS with the primary upper trough moving to the East Coast by Wednesday morning. Behind this upper trough, a weakening upper ridge will extend from the central Rockies southward towards the Rio Grande Valley. West of this ridge, lower heights with pockets of cooler midlevel temperatures will exist over much of the Intermountain West, which will continue to aid scattered general thunderstorm activity. While gusty winds may occur with afternoon activity coincident with peak heating and due to steep boundary layer lapse rates, severe storm potential appears minimal on the large scale. ..Jewell.. 08/25/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1225 PM CDT Mon Aug 25 2025 Valid 261200Z - 271200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe storms are not expected across the continental U.S. on Tuesday. ...Synopsis... High pressure will result in cool and/or stable conditions over much of the central and eastern CONUS with the primary upper trough moving to the East Coast by Wednesday morning. Behind this upper trough, a weakening upper ridge will extend from the central Rockies southward towards the Rio Grande Valley. West of this ridge, lower heights with pockets of cooler midlevel temperatures will exist over much of the Intermountain West, which will continue to aid scattered general thunderstorm activity. While gusty winds may occur with afternoon activity coincident with peak heating and due to steep boundary layer lapse rates, severe storm potential appears minimal on the large scale. ..Jewell.. 08/25/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1225 PM CDT Mon Aug 25 2025 Valid 261200Z - 271200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe storms are not expected across the continental U.S. on Tuesday. ...Synopsis... High pressure will result in cool and/or stable conditions over much of the central and eastern CONUS with the primary upper trough moving to the East Coast by Wednesday morning. Behind this upper trough, a weakening upper ridge will extend from the central Rockies southward towards the Rio Grande Valley. West of this ridge, lower heights with pockets of cooler midlevel temperatures will exist over much of the Intermountain West, which will continue to aid scattered general thunderstorm activity. While gusty winds may occur with afternoon activity coincident with peak heating and due to steep boundary layer lapse rates, severe storm potential appears minimal on the large scale. ..Jewell.. 08/25/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1225 PM CDT Mon Aug 25 2025 Valid 261200Z - 271200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe storms are not expected across the continental U.S. on Tuesday. ...Synopsis... High pressure will result in cool and/or stable conditions over much of the central and eastern CONUS with the primary upper trough moving to the East Coast by Wednesday morning. Behind this upper trough, a weakening upper ridge will extend from the central Rockies southward towards the Rio Grande Valley. West of this ridge, lower heights with pockets of cooler midlevel temperatures will exist over much of the Intermountain West, which will continue to aid scattered general thunderstorm activity. While gusty winds may occur with afternoon activity coincident with peak heating and due to steep boundary layer lapse rates, severe storm potential appears minimal on the large scale. ..Jewell.. 08/25/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1225 PM CDT Mon Aug 25 2025 Valid 261200Z - 271200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe storms are not expected across the continental U.S. on Tuesday. ...Synopsis... High pressure will result in cool and/or stable conditions over much of the central and eastern CONUS with the primary upper trough moving to the East Coast by Wednesday morning. Behind this upper trough, a weakening upper ridge will extend from the central Rockies southward towards the Rio Grande Valley. West of this ridge, lower heights with pockets of cooler midlevel temperatures will exist over much of the Intermountain West, which will continue to aid scattered general thunderstorm activity. While gusty winds may occur with afternoon activity coincident with peak heating and due to steep boundary layer lapse rates, severe storm potential appears minimal on the large scale. ..Jewell.. 08/25/2025 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1134 AM CDT Mon Aug 25 2025 Valid 251700Z - 261200Z The forecast remains on track, and please see the previous discussion for more details. ..Nauslar.. 08/25/2025 .PREV DISCUSSION... /ISSUED 0159 AM CDT Mon Aug 25 2025/ ...Synopsis... Along the northern periphery of a midlevel ridge centered on the Four Corners region, monsoonal moisture atop a warm/dry boundary layer will support isolated to widely scattered high-based thunderstorms across the Northwest -- with a focus over the higher terrain. Over the Cascades, PW values of 0.70-0.90 inches will favor a mix of wet/dry thunderstorms over receptive fuels, posing a risk of lightning-induced ignitions and gusty/erratic outflow winds. Thunderstorm potential is more uncertain over the WA Cascades owing to limited monsoonal moisture compared to areas farther south. Nevertheless, any storms that do form will be dry and pose a risk of new starts. A continuation of wet/dry thunderstorms are also expected across northern CA, though recent rainfall and 1+ inch PW cast uncertainty on overall ignition potential. For central ID into southwest MT, mixed wet/dry thunderstorms may pose a short-term risk of lightning-induced ignitions; however, increasing rainfall in the coming days should limit the overall risk. ...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 1134 AM CDT Mon Aug 25 2025 Valid 251700Z - 261200Z The forecast remains on track, and please see the previous discussion for more details. ..Nauslar.. 08/25/2025 .PREV DISCUSSION... /ISSUED 0159 AM CDT Mon Aug 25 2025/ ...Synopsis... Along the northern periphery of a midlevel ridge centered on the Four Corners region, monsoonal moisture atop a warm/dry boundary layer will support isolated to widely scattered high-based thunderstorms across the Northwest -- with a focus over the higher terrain. Over the Cascades, PW values of 0.70-0.90 inches will favor a mix of wet/dry thunderstorms over receptive fuels, posing a risk of lightning-induced ignitions and gusty/erratic outflow winds. Thunderstorm potential is more uncertain over the WA Cascades owing to limited monsoonal moisture compared to areas farther south. Nevertheless, any storms that do form will be dry and pose a risk of new starts. A continuation of wet/dry thunderstorms are also expected across northern CA, though recent rainfall and 1+ inch PW cast uncertainty on overall ignition potential. For central ID into southwest MT, mixed wet/dry thunderstorms may pose a short-term risk of lightning-induced ignitions; however, increasing rainfall in the coming days should limit the overall risk. ...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 1134 AM CDT Mon Aug 25 2025 Valid 251700Z - 261200Z The forecast remains on track, and please see the previous discussion for more details. ..Nauslar.. 08/25/2025 .PREV DISCUSSION... /ISSUED 0159 AM CDT Mon Aug 25 2025/ ...Synopsis... Along the northern periphery of a midlevel ridge centered on the Four Corners region, monsoonal moisture atop a warm/dry boundary layer will support isolated to widely scattered high-based thunderstorms across the Northwest -- with a focus over the higher terrain. Over the Cascades, PW values of 0.70-0.90 inches will favor a mix of wet/dry thunderstorms over receptive fuels, posing a risk of lightning-induced ignitions and gusty/erratic outflow winds. Thunderstorm potential is more uncertain over the WA Cascades owing to limited monsoonal moisture compared to areas farther south. Nevertheless, any storms that do form will be dry and pose a risk of new starts. A continuation of wet/dry thunderstorms are also expected across northern CA, though recent rainfall and 1+ inch PW cast uncertainty on overall ignition potential. For central ID into southwest MT, mixed wet/dry thunderstorms may pose a short-term risk of lightning-induced ignitions; however, increasing rainfall in the coming days should limit the overall risk. ...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 1134 AM CDT Mon Aug 25 2025 Valid 251700Z - 261200Z The forecast remains on track, and please see the previous discussion for more details. ..Nauslar.. 08/25/2025 .PREV DISCUSSION... /ISSUED 0159 AM CDT Mon Aug 25 2025/ ...Synopsis... Along the northern periphery of a midlevel ridge centered on the Four Corners region, monsoonal moisture atop a warm/dry boundary layer will support isolated to widely scattered high-based thunderstorms across the Northwest -- with a focus over the higher terrain. Over the Cascades, PW values of 0.70-0.90 inches will favor a mix of wet/dry thunderstorms over receptive fuels, posing a risk of lightning-induced ignitions and gusty/erratic outflow winds. Thunderstorm potential is more uncertain over the WA Cascades owing to limited monsoonal moisture compared to areas farther south. Nevertheless, any storms that do form will be dry and pose a risk of new starts. A continuation of wet/dry thunderstorms are also expected across northern CA, though recent rainfall and 1+ inch PW cast uncertainty on overall ignition potential. For central ID into southwest MT, mixed wet/dry thunderstorms may pose a short-term risk of lightning-induced ignitions; however, increasing rainfall in the coming days should limit the overall risk. ...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 1134 AM CDT Mon Aug 25 2025 Valid 251700Z - 261200Z The forecast remains on track, and please see the previous discussion for more details. ..Nauslar.. 08/25/2025 .PREV DISCUSSION... /ISSUED 0159 AM CDT Mon Aug 25 2025/ ...Synopsis... Along the northern periphery of a midlevel ridge centered on the Four Corners region, monsoonal moisture atop a warm/dry boundary layer will support isolated to widely scattered high-based thunderstorms across the Northwest -- with a focus over the higher terrain. Over the Cascades, PW values of 0.70-0.90 inches will favor a mix of wet/dry thunderstorms over receptive fuels, posing a risk of lightning-induced ignitions and gusty/erratic outflow winds. Thunderstorm potential is more uncertain over the WA Cascades owing to limited monsoonal moisture compared to areas farther south. Nevertheless, any storms that do form will be dry and pose a risk of new starts. A continuation of wet/dry thunderstorms are also expected across northern CA, though recent rainfall and 1+ inch PW cast uncertainty on overall ignition potential. For central ID into southwest MT, mixed wet/dry thunderstorms may pose a short-term risk of lightning-induced ignitions; however, increasing rainfall in the coming days should limit the overall risk. ...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 1134 AM CDT Mon Aug 25 2025 Valid 251700Z - 261200Z The forecast remains on track, and please see the previous discussion for more details. ..Nauslar.. 08/25/2025 .PREV DISCUSSION... /ISSUED 0159 AM CDT Mon Aug 25 2025/ ...Synopsis... Along the northern periphery of a midlevel ridge centered on the Four Corners region, monsoonal moisture atop a warm/dry boundary layer will support isolated to widely scattered high-based thunderstorms across the Northwest -- with a focus over the higher terrain. Over the Cascades, PW values of 0.70-0.90 inches will favor a mix of wet/dry thunderstorms over receptive fuels, posing a risk of lightning-induced ignitions and gusty/erratic outflow winds. Thunderstorm potential is more uncertain over the WA Cascades owing to limited monsoonal moisture compared to areas farther south. Nevertheless, any storms that do form will be dry and pose a risk of new starts. A continuation of wet/dry thunderstorms are also expected across northern CA, though recent rainfall and 1+ inch PW cast uncertainty on overall ignition potential. For central ID into southwest MT, mixed wet/dry thunderstorms may pose a short-term risk of lightning-induced ignitions; however, increasing rainfall in the coming days should limit the overall risk. ...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 1134 AM CDT Mon Aug 25 2025 Valid 251700Z - 261200Z The forecast remains on track, and please see the previous discussion for more details. ..Nauslar.. 08/25/2025 .PREV DISCUSSION... /ISSUED 0159 AM CDT Mon Aug 25 2025/ ...Synopsis... Along the northern periphery of a midlevel ridge centered on the Four Corners region, monsoonal moisture atop a warm/dry boundary layer will support isolated to widely scattered high-based thunderstorms across the Northwest -- with a focus over the higher terrain. Over the Cascades, PW values of 0.70-0.90 inches will favor a mix of wet/dry thunderstorms over receptive fuels, posing a risk of lightning-induced ignitions and gusty/erratic outflow winds. Thunderstorm potential is more uncertain over the WA Cascades owing to limited monsoonal moisture compared to areas farther south. Nevertheless, any storms that do form will be dry and pose a risk of new starts. A continuation of wet/dry thunderstorms are also expected across northern CA, though recent rainfall and 1+ inch PW cast uncertainty on overall ignition potential. For central ID into southwest MT, mixed wet/dry thunderstorms may pose a short-term risk of lightning-induced ignitions; however, increasing rainfall in the coming days should limit the overall risk. ...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 1131 AM CDT Mon Aug 25 2025 Valid 251630Z - 261200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS SOUTHERN ARIZONA... ...SUMMARY... Isolated severe wind gusts are possible over parts of south-central Arizona this afternoon through early evening. Otherwise, the potential for severe storms is low across the remainder of the continental U.S. ...Synopsis... A large upper trough will remain over the eastern CONUS today, as several embedded shortwave troughs progress within its southern periphery. Extensive upper ridging that currently extends from the southern Plains into the northern Intermountain West is forecast to remain largely in place. Some dampening may occur along the northwestern periphery of this ridging as a slow-moving vorticity maximum continues northeastward from the CO/OR/NV border vicinity into more of eastern OR. Ample monsoonal moisture exists beneath this ridging, contributing to scattered to numerous thunderstorms from the southern/central Rockies westward across the Southwest and much of the Great Basin. Limited vertical shear and weak buoyancy will mitigate the severe potential across the majority of the region. The only exceptions are across central Rockies and immediate foothills, and portions of southern AZ. ...Southern AZ... Ample monsoonal moisture is in place across the region, evidenced by PW values of 1.66 and 1.83 inches from the Phoenix and Yuma 12Z soundings, respectively. Filtered diurnal heating within this moist airmass will support modest buoyancy and afternoon thunderstorm development. A belt of stronger mid-level southeasterly flow (20-25 kt) is forecast to overspread the region this afternoon, providing ample shear for some multicell storm clusters. Initial storms which are expected to form across the higher terrain in southeast Arizona may result in congealing outflow with a damaging wind threat as storms move generally west-northwestward through the evening. ...Central Rockies... Thunderstorm development is expected across the high terrain by the early afternoon. Poor lapse rates and cooler temperatures will keep buoyancy will be modest, likely limiting overall updraft strength and tempering the severe potential. Even so, moderate northwesterly flow aloft will support long hodographs and the potential for some storm organization if updrafts can become sufficiently deep. An instance or two of hail is possible with any stronger, more long-lived storms. ..Mosier/Moore.. 08/25/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1131 AM CDT Mon Aug 25 2025 Valid 251630Z - 261200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS SOUTHERN ARIZONA... ...SUMMARY... Isolated severe wind gusts are possible over parts of south-central Arizona this afternoon through early evening. Otherwise, the potential for severe storms is low across the remainder of the continental U.S. ...Synopsis... A large upper trough will remain over the eastern CONUS today, as several embedded shortwave troughs progress within its southern periphery. Extensive upper ridging that currently extends from the southern Plains into the northern Intermountain West is forecast to remain largely in place. Some dampening may occur along the northwestern periphery of this ridging as a slow-moving vorticity maximum continues northeastward from the CO/OR/NV border vicinity into more of eastern OR. Ample monsoonal moisture exists beneath this ridging, contributing to scattered to numerous thunderstorms from the southern/central Rockies westward across the Southwest and much of the Great Basin. Limited vertical shear and weak buoyancy will mitigate the severe potential across the majority of the region. The only exceptions are across central Rockies and immediate foothills, and portions of southern AZ. ...Southern AZ... Ample monsoonal moisture is in place across the region, evidenced by PW values of 1.66 and 1.83 inches from the Phoenix and Yuma 12Z soundings, respectively. Filtered diurnal heating within this moist airmass will support modest buoyancy and afternoon thunderstorm development. A belt of stronger mid-level southeasterly flow (20-25 kt) is forecast to overspread the region this afternoon, providing ample shear for some multicell storm clusters. Initial storms which are expected to form across the higher terrain in southeast Arizona may result in congealing outflow with a damaging wind threat as storms move generally west-northwestward through the evening. ...Central Rockies... Thunderstorm development is expected across the high terrain by the early afternoon. Poor lapse rates and cooler temperatures will keep buoyancy will be modest, likely limiting overall updraft strength and tempering the severe potential. Even so, moderate northwesterly flow aloft will support long hodographs and the potential for some storm organization if updrafts can become sufficiently deep. An instance or two of hail is possible with any stronger, more long-lived storms. ..Mosier/Moore.. 08/25/2025 Read more