Severe Storms

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0748 AM CDT Tue Aug 26 2025 Valid 261300Z - 271200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Organized severe storms are not expected across the continental U.S. today. ...Synopsis... An expansive upper-level trough will persist across the eastern CONUS today, where a cool, dry airmass and high pressure will be prevalent and limit thunderstorm potential aside from Florida. Monsoon-related scattered thunderstorms will be common across much of the non-coastal West. ...Southern Arizona/Lower Colorado River Valley... A northward-moving mid-level impulse/MCV will spread from the Lower Colorado River Valley/northern Arizona this morning into Utah, allowing for subsequent clearing/heating across southern Arizona toward the Lower Colorado River Valley. Thunderstorms will again develop and increase this afternoon especially in vicinity of higher terrain. A few instances of strong thunderstorm winds/wet microbursts could occur regionally this afternoon into evening, but the overall potential is expected to remain quite isolated and marginal overall. ..Guyer/Kerr.. 08/26/2025 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0748 AM CDT Tue Aug 26 2025 Valid 261300Z - 271200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Organized severe storms are not expected across the continental U.S. today. ...Synopsis... An expansive upper-level trough will persist across the eastern CONUS today, where a cool, dry airmass and high pressure will be prevalent and limit thunderstorm potential aside from Florida. Monsoon-related scattered thunderstorms will be common across much of the non-coastal West. ...Southern Arizona/Lower Colorado River Valley... A northward-moving mid-level impulse/MCV will spread from the Lower Colorado River Valley/northern Arizona this morning into Utah, allowing for subsequent clearing/heating across southern Arizona toward the Lower Colorado River Valley. Thunderstorms will again develop and increase this afternoon especially in vicinity of higher terrain. A few instances of strong thunderstorm winds/wet microbursts could occur regionally this afternoon into evening, but the overall potential is expected to remain quite isolated and marginal overall. ..Guyer/Kerr.. 08/26/2025 Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0247 AM CDT Tue Aug 26 2025 Valid 291200Z - 031200Z ...DISCUSSION... An upper trough will eject into the Atlantic this weekend as weak upper ridging builds into the central U.S. and an upper-low meanders over the Pacific Northwest. An upper trough will then develop and gradually amplify over the Upper MS Valley through early next week. A surface cold front will sag southward through the day on Day 4/Friday across portions of the southern Plains into the Lower MS Valley, where rich moisture and appreciable instability will be in place to support a threat for at least scattered strong thunderstorms. By the weekend into early next week, surface lee troughing across the Plains will encourage the northwestward advection of low-level moisture beneath modest lapse rates, resulting in marginal to moderate instability across the High Plains Days 5-8/Saturday-Tuesday. Southeasterly 850 mb winds, overspread by northwesterly flow at 500 mb, may encourage enough wind shear to support isolated severe storms along the central High Plains Saturday-Tuesday. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0247 AM CDT Tue Aug 26 2025 Valid 291200Z - 031200Z ...DISCUSSION... An upper trough will eject into the Atlantic this weekend as weak upper ridging builds into the central U.S. and an upper-low meanders over the Pacific Northwest. An upper trough will then develop and gradually amplify over the Upper MS Valley through early next week. A surface cold front will sag southward through the day on Day 4/Friday across portions of the southern Plains into the Lower MS Valley, where rich moisture and appreciable instability will be in place to support a threat for at least scattered strong thunderstorms. By the weekend into early next week, surface lee troughing across the Plains will encourage the northwestward advection of low-level moisture beneath modest lapse rates, resulting in marginal to moderate instability across the High Plains Days 5-8/Saturday-Tuesday. Southeasterly 850 mb winds, overspread by northwesterly flow at 500 mb, may encourage enough wind shear to support isolated severe storms along the central High Plains Saturday-Tuesday. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0247 AM CDT Tue Aug 26 2025 Valid 291200Z - 031200Z ...DISCUSSION... An upper trough will eject into the Atlantic this weekend as weak upper ridging builds into the central U.S. and an upper-low meanders over the Pacific Northwest. An upper trough will then develop and gradually amplify over the Upper MS Valley through early next week. A surface cold front will sag southward through the day on Day 4/Friday across portions of the southern Plains into the Lower MS Valley, where rich moisture and appreciable instability will be in place to support a threat for at least scattered strong thunderstorms. By the weekend into early next week, surface lee troughing across the Plains will encourage the northwestward advection of low-level moisture beneath modest lapse rates, resulting in marginal to moderate instability across the High Plains Days 5-8/Saturday-Tuesday. Southeasterly 850 mb winds, overspread by northwesterly flow at 500 mb, may encourage enough wind shear to support isolated severe storms along the central High Plains Saturday-Tuesday. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0247 AM CDT Tue Aug 26 2025 Valid 291200Z - 031200Z ...DISCUSSION... An upper trough will eject into the Atlantic this weekend as weak upper ridging builds into the central U.S. and an upper-low meanders over the Pacific Northwest. An upper trough will then develop and gradually amplify over the Upper MS Valley through early next week. A surface cold front will sag southward through the day on Day 4/Friday across portions of the southern Plains into the Lower MS Valley, where rich moisture and appreciable instability will be in place to support a threat for at least scattered strong thunderstorms. By the weekend into early next week, surface lee troughing across the Plains will encourage the northwestward advection of low-level moisture beneath modest lapse rates, resulting in marginal to moderate instability across the High Plains Days 5-8/Saturday-Tuesday. Southeasterly 850 mb winds, overspread by northwesterly flow at 500 mb, may encourage enough wind shear to support isolated severe storms along the central High Plains Saturday-Tuesday. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0247 AM CDT Tue Aug 26 2025 Valid 291200Z - 031200Z ...DISCUSSION... An upper trough will eject into the Atlantic this weekend as weak upper ridging builds into the central U.S. and an upper-low meanders over the Pacific Northwest. An upper trough will then develop and gradually amplify over the Upper MS Valley through early next week. A surface cold front will sag southward through the day on Day 4/Friday across portions of the southern Plains into the Lower MS Valley, where rich moisture and appreciable instability will be in place to support a threat for at least scattered strong thunderstorms. By the weekend into early next week, surface lee troughing across the Plains will encourage the northwestward advection of low-level moisture beneath modest lapse rates, resulting in marginal to moderate instability across the High Plains Days 5-8/Saturday-Tuesday. Southeasterly 850 mb winds, overspread by northwesterly flow at 500 mb, may encourage enough wind shear to support isolated severe storms along the central High Plains Saturday-Tuesday. Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0224 AM CDT Tue Aug 26 2025 Valid 281200Z - 291200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... A few strong thunderstorms are possible across parts of the southern Plains Thursday afternoon and evening. ...Synopsis... Upper troughing will persist over the eastern CONUS while an upper ridge remains in place across the Southwest on Thursday. Multiple mid-level perturbations will rotate around the broader upper trough, promoting enough lift to support thunderstorms across portions of the Great Lakes. Multiple rounds of south-southeastward progressing thunderstorms are also likely across the southern Plains into the Southeast along a frontal boundary through the day. Rich low-level moisture and associated ample buoyancy will precede the southern Plains storms during the afternoon, which may promote strong storm potential given modest wind shear. ...Southern Plains... An MCS may be ongoing across portions of the Southern Plains at the start of the period, leaving an outflow boundary in its wake. South of the outflow boundary, robust surface heating will take place, supporting surface temperatures reaching 90 F amid low 70s F dewpoints. Despite poor (i.e. 6-6.5 C/km) mid-level lapse rates, the rich low-level moisture may support 2000-3000 J/kg MLCAPE. Modest veering and strengthening of the flow with height will result in 35 kts of effective bulk shear. The development of multicells and/or the southwestward back-building of an older MCS is anticipated by mid to late afternoon, with strong thunderstorms possible. The main uncertainty at this point is the placement and movement of the outflow boundary, which will directly influence where any isolated severe thunderstorms may occur. As such, Category 1/Marginal risk probabilities have been withheld given placement uncertainties, though severe probabilities may be needed in future outlooks. ..Squitieri.. 08/26/2025 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0224 AM CDT Tue Aug 26 2025 Valid 281200Z - 291200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... A few strong thunderstorms are possible across parts of the southern Plains Thursday afternoon and evening. ...Synopsis... Upper troughing will persist over the eastern CONUS while an upper ridge remains in place across the Southwest on Thursday. Multiple mid-level perturbations will rotate around the broader upper trough, promoting enough lift to support thunderstorms across portions of the Great Lakes. Multiple rounds of south-southeastward progressing thunderstorms are also likely across the southern Plains into the Southeast along a frontal boundary through the day. Rich low-level moisture and associated ample buoyancy will precede the southern Plains storms during the afternoon, which may promote strong storm potential given modest wind shear. ...Southern Plains... An MCS may be ongoing across portions of the Southern Plains at the start of the period, leaving an outflow boundary in its wake. South of the outflow boundary, robust surface heating will take place, supporting surface temperatures reaching 90 F amid low 70s F dewpoints. Despite poor (i.e. 6-6.5 C/km) mid-level lapse rates, the rich low-level moisture may support 2000-3000 J/kg MLCAPE. Modest veering and strengthening of the flow with height will result in 35 kts of effective bulk shear. The development of multicells and/or the southwestward back-building of an older MCS is anticipated by mid to late afternoon, with strong thunderstorms possible. The main uncertainty at this point is the placement and movement of the outflow boundary, which will directly influence where any isolated severe thunderstorms may occur. As such, Category 1/Marginal risk probabilities have been withheld given placement uncertainties, though severe probabilities may be needed in future outlooks. ..Squitieri.. 08/26/2025 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0224 AM CDT Tue Aug 26 2025 Valid 281200Z - 291200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... A few strong thunderstorms are possible across parts of the southern Plains Thursday afternoon and evening. ...Synopsis... Upper troughing will persist over the eastern CONUS while an upper ridge remains in place across the Southwest on Thursday. Multiple mid-level perturbations will rotate around the broader upper trough, promoting enough lift to support thunderstorms across portions of the Great Lakes. Multiple rounds of south-southeastward progressing thunderstorms are also likely across the southern Plains into the Southeast along a frontal boundary through the day. Rich low-level moisture and associated ample buoyancy will precede the southern Plains storms during the afternoon, which may promote strong storm potential given modest wind shear. ...Southern Plains... An MCS may be ongoing across portions of the Southern Plains at the start of the period, leaving an outflow boundary in its wake. South of the outflow boundary, robust surface heating will take place, supporting surface temperatures reaching 90 F amid low 70s F dewpoints. Despite poor (i.e. 6-6.5 C/km) mid-level lapse rates, the rich low-level moisture may support 2000-3000 J/kg MLCAPE. Modest veering and strengthening of the flow with height will result in 35 kts of effective bulk shear. The development of multicells and/or the southwestward back-building of an older MCS is anticipated by mid to late afternoon, with strong thunderstorms possible. The main uncertainty at this point is the placement and movement of the outflow boundary, which will directly influence where any isolated severe thunderstorms may occur. As such, Category 1/Marginal risk probabilities have been withheld given placement uncertainties, though severe probabilities may be needed in future outlooks. ..Squitieri.. 08/26/2025 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0224 AM CDT Tue Aug 26 2025 Valid 281200Z - 291200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... A few strong thunderstorms are possible across parts of the southern Plains Thursday afternoon and evening. ...Synopsis... Upper troughing will persist over the eastern CONUS while an upper ridge remains in place across the Southwest on Thursday. Multiple mid-level perturbations will rotate around the broader upper trough, promoting enough lift to support thunderstorms across portions of the Great Lakes. Multiple rounds of south-southeastward progressing thunderstorms are also likely across the southern Plains into the Southeast along a frontal boundary through the day. Rich low-level moisture and associated ample buoyancy will precede the southern Plains storms during the afternoon, which may promote strong storm potential given modest wind shear. ...Southern Plains... An MCS may be ongoing across portions of the Southern Plains at the start of the period, leaving an outflow boundary in its wake. South of the outflow boundary, robust surface heating will take place, supporting surface temperatures reaching 90 F amid low 70s F dewpoints. Despite poor (i.e. 6-6.5 C/km) mid-level lapse rates, the rich low-level moisture may support 2000-3000 J/kg MLCAPE. Modest veering and strengthening of the flow with height will result in 35 kts of effective bulk shear. The development of multicells and/or the southwestward back-building of an older MCS is anticipated by mid to late afternoon, with strong thunderstorms possible. The main uncertainty at this point is the placement and movement of the outflow boundary, which will directly influence where any isolated severe thunderstorms may occur. As such, Category 1/Marginal risk probabilities have been withheld given placement uncertainties, though severe probabilities may be needed in future outlooks. ..Squitieri.. 08/26/2025 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0224 AM CDT Tue Aug 26 2025 Valid 281200Z - 291200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... A few strong thunderstorms are possible across parts of the southern Plains Thursday afternoon and evening. ...Synopsis... Upper troughing will persist over the eastern CONUS while an upper ridge remains in place across the Southwest on Thursday. Multiple mid-level perturbations will rotate around the broader upper trough, promoting enough lift to support thunderstorms across portions of the Great Lakes. Multiple rounds of south-southeastward progressing thunderstorms are also likely across the southern Plains into the Southeast along a frontal boundary through the day. Rich low-level moisture and associated ample buoyancy will precede the southern Plains storms during the afternoon, which may promote strong storm potential given modest wind shear. ...Southern Plains... An MCS may be ongoing across portions of the Southern Plains at the start of the period, leaving an outflow boundary in its wake. South of the outflow boundary, robust surface heating will take place, supporting surface temperatures reaching 90 F amid low 70s F dewpoints. Despite poor (i.e. 6-6.5 C/km) mid-level lapse rates, the rich low-level moisture may support 2000-3000 J/kg MLCAPE. Modest veering and strengthening of the flow with height will result in 35 kts of effective bulk shear. The development of multicells and/or the southwestward back-building of an older MCS is anticipated by mid to late afternoon, with strong thunderstorms possible. The main uncertainty at this point is the placement and movement of the outflow boundary, which will directly influence where any isolated severe thunderstorms may occur. As such, Category 1/Marginal risk probabilities have been withheld given placement uncertainties, though severe probabilities may be needed in future outlooks. ..Squitieri.. 08/26/2025 Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0200 AM CDT Tue Aug 26 2025 Valid 271200Z - 281200Z ...Synopsis... Monsoonal moisture will continue spreading northward across parts of the Northwest and northern Rockies, while a pair of convectively augmented midlevel lows overspread the region. The associated forcing for ascent and weak buoyancy will support some potential for isolated/embedded lightning within high-based showers. Given dry/receptive fuels, any lightning that does occur will pose a risk of new ignitions along the leading edge of the deeper monsoonal moisture plume. Additionally, another day of mixed wet/dry thunderstorms are expected across parts of northern CA into southern OR. Similar to Day 1/Tuesday, several days of rainfall limits confidence in the overall fire-weather threat, though isolated lightning-induced ignitions will still be possible where fuels remain dry. ..Weinman.. 08/26/2025 ...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 0200 AM CDT Tue Aug 26 2025 Valid 271200Z - 281200Z ...Synopsis... Monsoonal moisture will continue spreading northward across parts of the Northwest and northern Rockies, while a pair of convectively augmented midlevel lows overspread the region. The associated forcing for ascent and weak buoyancy will support some potential for isolated/embedded lightning within high-based showers. Given dry/receptive fuels, any lightning that does occur will pose a risk of new ignitions along the leading edge of the deeper monsoonal moisture plume. Additionally, another day of mixed wet/dry thunderstorms are expected across parts of northern CA into southern OR. Similar to Day 1/Tuesday, several days of rainfall limits confidence in the overall fire-weather threat, though isolated lightning-induced ignitions will still be possible where fuels remain dry. ..Weinman.. 08/26/2025 ...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 0200 AM CDT Tue Aug 26 2025 Valid 271200Z - 281200Z ...Synopsis... Monsoonal moisture will continue spreading northward across parts of the Northwest and northern Rockies, while a pair of convectively augmented midlevel lows overspread the region. The associated forcing for ascent and weak buoyancy will support some potential for isolated/embedded lightning within high-based showers. Given dry/receptive fuels, any lightning that does occur will pose a risk of new ignitions along the leading edge of the deeper monsoonal moisture plume. Additionally, another day of mixed wet/dry thunderstorms are expected across parts of northern CA into southern OR. Similar to Day 1/Tuesday, several days of rainfall limits confidence in the overall fire-weather threat, though isolated lightning-induced ignitions will still be possible where fuels remain dry. ..Weinman.. 08/26/2025 ...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 0200 AM CDT Tue Aug 26 2025 Valid 271200Z - 281200Z ...Synopsis... Monsoonal moisture will continue spreading northward across parts of the Northwest and northern Rockies, while a pair of convectively augmented midlevel lows overspread the region. The associated forcing for ascent and weak buoyancy will support some potential for isolated/embedded lightning within high-based showers. Given dry/receptive fuels, any lightning that does occur will pose a risk of new ignitions along the leading edge of the deeper monsoonal moisture plume. Additionally, another day of mixed wet/dry thunderstorms are expected across parts of northern CA into southern OR. Similar to Day 1/Tuesday, several days of rainfall limits confidence in the overall fire-weather threat, though isolated lightning-induced ignitions will still be possible where fuels remain dry. ..Weinman.. 08/26/2025 ...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 0200 AM CDT Tue Aug 26 2025 Valid 271200Z - 281200Z ...Synopsis... Monsoonal moisture will continue spreading northward across parts of the Northwest and northern Rockies, while a pair of convectively augmented midlevel lows overspread the region. The associated forcing for ascent and weak buoyancy will support some potential for isolated/embedded lightning within high-based showers. Given dry/receptive fuels, any lightning that does occur will pose a risk of new ignitions along the leading edge of the deeper monsoonal moisture plume. Additionally, another day of mixed wet/dry thunderstorms are expected across parts of northern CA into southern OR. Similar to Day 1/Tuesday, several days of rainfall limits confidence in the overall fire-weather threat, though isolated lightning-induced ignitions will still be possible where fuels remain dry. ..Weinman.. 08/26/2025 ...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 0159 AM CDT Tue Aug 26 2025 Valid 261200Z - 271200Z ...Synopsis... One or more subtle midlevel disturbances will overspread the Northwest today, where well-established monsoonal moisture is in place. The associated forcing for ascent and sufficient buoyancy should support a mix of wet/dry high-based thunderstorms over the Cascades during afternoon into the evening. While thunderstorm coverage may remain somewhat limited (potentially 5-10 percent), any storms that form may pose a risk of new ignitions and gusty/erratic outflow winds. A continuation of mixed wet/dry thunderstorms is expected farther south into northern CA, though several days of rain casts uncertainty on fuel receptiveness -- precluding highlights at this time. ..Weinman.. 08/26/2025 ...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 0159 AM CDT Tue Aug 26 2025 Valid 261200Z - 271200Z ...Synopsis... One or more subtle midlevel disturbances will overspread the Northwest today, where well-established monsoonal moisture is in place. The associated forcing for ascent and sufficient buoyancy should support a mix of wet/dry high-based thunderstorms over the Cascades during afternoon into the evening. While thunderstorm coverage may remain somewhat limited (potentially 5-10 percent), any storms that form may pose a risk of new ignitions and gusty/erratic outflow winds. A continuation of mixed wet/dry thunderstorms is expected farther south into northern CA, though several days of rain casts uncertainty on fuel receptiveness -- precluding highlights at this time. ..Weinman.. 08/26/2025 ...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 0159 AM CDT Tue Aug 26 2025 Valid 261200Z - 271200Z ...Synopsis... One or more subtle midlevel disturbances will overspread the Northwest today, where well-established monsoonal moisture is in place. The associated forcing for ascent and sufficient buoyancy should support a mix of wet/dry high-based thunderstorms over the Cascades during afternoon into the evening. While thunderstorm coverage may remain somewhat limited (potentially 5-10 percent), any storms that form may pose a risk of new ignitions and gusty/erratic outflow winds. A continuation of mixed wet/dry thunderstorms is expected farther south into northern CA, though several days of rain casts uncertainty on fuel receptiveness -- precluding highlights at this time. ..Weinman.. 08/26/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more