Severe Storms

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0334 AM CDT Tue Sep 02 2025 Valid 051200Z - 101200Z ...DISCUSSION... A pronounced mid-level trough will progress across the Northeast late this week, ejecting into the Atlantic by the end of the weekend. Thereafter, a more progressive pattern will ensue, with multiple mid-level shortwave troughs poised to traverse the CONUS early into the middle of next week. Despite differences among medium-range guidance members, there is general agreement that a surface cold front will encounter seasonal low-level moisture across the eastern U.S. Days 4-5 (Friday-Saturday), promoting thunderstorm potential (some of which may be strong). However, any severe threat accompanying these storms is expected to be localized and isolated. Surface high pressure will then become established from the MS River Valley eastward, allowing for moisture return across the Plains states by next week. Nonetheless, overall forcing for ascent, along with buoyancy, are expected to be weak over the Plains next week, with severe potential currently appearing low. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0334 AM CDT Tue Sep 02 2025 Valid 051200Z - 101200Z ...DISCUSSION... A pronounced mid-level trough will progress across the Northeast late this week, ejecting into the Atlantic by the end of the weekend. Thereafter, a more progressive pattern will ensue, with multiple mid-level shortwave troughs poised to traverse the CONUS early into the middle of next week. Despite differences among medium-range guidance members, there is general agreement that a surface cold front will encounter seasonal low-level moisture across the eastern U.S. Days 4-5 (Friday-Saturday), promoting thunderstorm potential (some of which may be strong). However, any severe threat accompanying these storms is expected to be localized and isolated. Surface high pressure will then become established from the MS River Valley eastward, allowing for moisture return across the Plains states by next week. Nonetheless, overall forcing for ascent, along with buoyancy, are expected to be weak over the Plains next week, with severe potential currently appearing low. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0334 AM CDT Tue Sep 02 2025 Valid 051200Z - 101200Z ...DISCUSSION... A pronounced mid-level trough will progress across the Northeast late this week, ejecting into the Atlantic by the end of the weekend. Thereafter, a more progressive pattern will ensue, with multiple mid-level shortwave troughs poised to traverse the CONUS early into the middle of next week. Despite differences among medium-range guidance members, there is general agreement that a surface cold front will encounter seasonal low-level moisture across the eastern U.S. Days 4-5 (Friday-Saturday), promoting thunderstorm potential (some of which may be strong). However, any severe threat accompanying these storms is expected to be localized and isolated. Surface high pressure will then become established from the MS River Valley eastward, allowing for moisture return across the Plains states by next week. Nonetheless, overall forcing for ascent, along with buoyancy, are expected to be weak over the Plains next week, with severe potential currently appearing low. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0334 AM CDT Tue Sep 02 2025 Valid 051200Z - 101200Z ...DISCUSSION... A pronounced mid-level trough will progress across the Northeast late this week, ejecting into the Atlantic by the end of the weekend. Thereafter, a more progressive pattern will ensue, with multiple mid-level shortwave troughs poised to traverse the CONUS early into the middle of next week. Despite differences among medium-range guidance members, there is general agreement that a surface cold front will encounter seasonal low-level moisture across the eastern U.S. Days 4-5 (Friday-Saturday), promoting thunderstorm potential (some of which may be strong). However, any severe threat accompanying these storms is expected to be localized and isolated. Surface high pressure will then become established from the MS River Valley eastward, allowing for moisture return across the Plains states by next week. Nonetheless, overall forcing for ascent, along with buoyancy, are expected to be weak over the Plains next week, with severe potential currently appearing low. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0334 AM CDT Tue Sep 02 2025 Valid 051200Z - 101200Z ...DISCUSSION... A pronounced mid-level trough will progress across the Northeast late this week, ejecting into the Atlantic by the end of the weekend. Thereafter, a more progressive pattern will ensue, with multiple mid-level shortwave troughs poised to traverse the CONUS early into the middle of next week. Despite differences among medium-range guidance members, there is general agreement that a surface cold front will encounter seasonal low-level moisture across the eastern U.S. Days 4-5 (Friday-Saturday), promoting thunderstorm potential (some of which may be strong). However, any severe threat accompanying these storms is expected to be localized and isolated. Surface high pressure will then become established from the MS River Valley eastward, allowing for moisture return across the Plains states by next week. Nonetheless, overall forcing for ascent, along with buoyancy, are expected to be weak over the Plains next week, with severe potential currently appearing low. Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0224 AM CDT Tue Sep 02 2025 Valid 041200Z - 051200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE CENTRAL APPALACHIANS... ...SUMMARY... A few strong to potentially severe gusts may accompany a band of thunderstorms across parts of the central Appalachians on Thursday. ...Synopsis... Broad cyclonic flow will overspread much of the central and eastern CONUS on Thursday. Through the period, a mid-level impulse will pivot around the broader cyclonic flow into Quebec while an even more potent embedded mid-level trough rapidly amplifies over the Midwest. As a result, a surface cold front will rapidly surge eastward over the Appalachians and impinge on the East Coast, where seasonal low-level moisture will be in place to support an extensive band of thunderstorms. Given overlapping buoyancy and vertical wind shear, a few storms may be strong to severe. ...Central Appalachians... The cold front will surge to the east during the late morning into early afternoon hours, encountering low 60s F dewpoints over the central Appalachians. Tropospheric lapse rates should be poor, yielding thin MLCAPE profiles in the 500-1000 J/kg range. The lack of stronger buoyancy should limit the severe threat to a degree. Nonetheless, strengthening and veering of the 850-500 mb flow with height will encourage curved/elongated hodographs with 40-50 kts of effective bulk shear. A broken squall line should develop ahead of the cold front, perhaps with transient rotating cells, capable of mainly damaging gusts, warranting the introduction of Category 1/Marginal risk probabilities. ..Squitieri.. 09/02/2025 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0224 AM CDT Tue Sep 02 2025 Valid 041200Z - 051200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE CENTRAL APPALACHIANS... ...SUMMARY... A few strong to potentially severe gusts may accompany a band of thunderstorms across parts of the central Appalachians on Thursday. ...Synopsis... Broad cyclonic flow will overspread much of the central and eastern CONUS on Thursday. Through the period, a mid-level impulse will pivot around the broader cyclonic flow into Quebec while an even more potent embedded mid-level trough rapidly amplifies over the Midwest. As a result, a surface cold front will rapidly surge eastward over the Appalachians and impinge on the East Coast, where seasonal low-level moisture will be in place to support an extensive band of thunderstorms. Given overlapping buoyancy and vertical wind shear, a few storms may be strong to severe. ...Central Appalachians... The cold front will surge to the east during the late morning into early afternoon hours, encountering low 60s F dewpoints over the central Appalachians. Tropospheric lapse rates should be poor, yielding thin MLCAPE profiles in the 500-1000 J/kg range. The lack of stronger buoyancy should limit the severe threat to a degree. Nonetheless, strengthening and veering of the 850-500 mb flow with height will encourage curved/elongated hodographs with 40-50 kts of effective bulk shear. A broken squall line should develop ahead of the cold front, perhaps with transient rotating cells, capable of mainly damaging gusts, warranting the introduction of Category 1/Marginal risk probabilities. ..Squitieri.. 09/02/2025 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0224 AM CDT Tue Sep 02 2025 Valid 041200Z - 051200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE CENTRAL APPALACHIANS... ...SUMMARY... A few strong to potentially severe gusts may accompany a band of thunderstorms across parts of the central Appalachians on Thursday. ...Synopsis... Broad cyclonic flow will overspread much of the central and eastern CONUS on Thursday. Through the period, a mid-level impulse will pivot around the broader cyclonic flow into Quebec while an even more potent embedded mid-level trough rapidly amplifies over the Midwest. As a result, a surface cold front will rapidly surge eastward over the Appalachians and impinge on the East Coast, where seasonal low-level moisture will be in place to support an extensive band of thunderstorms. Given overlapping buoyancy and vertical wind shear, a few storms may be strong to severe. ...Central Appalachians... The cold front will surge to the east during the late morning into early afternoon hours, encountering low 60s F dewpoints over the central Appalachians. Tropospheric lapse rates should be poor, yielding thin MLCAPE profiles in the 500-1000 J/kg range. The lack of stronger buoyancy should limit the severe threat to a degree. Nonetheless, strengthening and veering of the 850-500 mb flow with height will encourage curved/elongated hodographs with 40-50 kts of effective bulk shear. A broken squall line should develop ahead of the cold front, perhaps with transient rotating cells, capable of mainly damaging gusts, warranting the introduction of Category 1/Marginal risk probabilities. ..Squitieri.. 09/02/2025 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0224 AM CDT Tue Sep 02 2025 Valid 041200Z - 051200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE CENTRAL APPALACHIANS... ...SUMMARY... A few strong to potentially severe gusts may accompany a band of thunderstorms across parts of the central Appalachians on Thursday. ...Synopsis... Broad cyclonic flow will overspread much of the central and eastern CONUS on Thursday. Through the period, a mid-level impulse will pivot around the broader cyclonic flow into Quebec while an even more potent embedded mid-level trough rapidly amplifies over the Midwest. As a result, a surface cold front will rapidly surge eastward over the Appalachians and impinge on the East Coast, where seasonal low-level moisture will be in place to support an extensive band of thunderstorms. Given overlapping buoyancy and vertical wind shear, a few storms may be strong to severe. ...Central Appalachians... The cold front will surge to the east during the late morning into early afternoon hours, encountering low 60s F dewpoints over the central Appalachians. Tropospheric lapse rates should be poor, yielding thin MLCAPE profiles in the 500-1000 J/kg range. The lack of stronger buoyancy should limit the severe threat to a degree. Nonetheless, strengthening and veering of the 850-500 mb flow with height will encourage curved/elongated hodographs with 40-50 kts of effective bulk shear. A broken squall line should develop ahead of the cold front, perhaps with transient rotating cells, capable of mainly damaging gusts, warranting the introduction of Category 1/Marginal risk probabilities. ..Squitieri.. 09/02/2025 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0224 AM CDT Tue Sep 02 2025 Valid 041200Z - 051200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE CENTRAL APPALACHIANS... ...SUMMARY... A few strong to potentially severe gusts may accompany a band of thunderstorms across parts of the central Appalachians on Thursday. ...Synopsis... Broad cyclonic flow will overspread much of the central and eastern CONUS on Thursday. Through the period, a mid-level impulse will pivot around the broader cyclonic flow into Quebec while an even more potent embedded mid-level trough rapidly amplifies over the Midwest. As a result, a surface cold front will rapidly surge eastward over the Appalachians and impinge on the East Coast, where seasonal low-level moisture will be in place to support an extensive band of thunderstorms. Given overlapping buoyancy and vertical wind shear, a few storms may be strong to severe. ...Central Appalachians... The cold front will surge to the east during the late morning into early afternoon hours, encountering low 60s F dewpoints over the central Appalachians. Tropospheric lapse rates should be poor, yielding thin MLCAPE profiles in the 500-1000 J/kg range. The lack of stronger buoyancy should limit the severe threat to a degree. Nonetheless, strengthening and veering of the 850-500 mb flow with height will encourage curved/elongated hodographs with 40-50 kts of effective bulk shear. A broken squall line should develop ahead of the cold front, perhaps with transient rotating cells, capable of mainly damaging gusts, warranting the introduction of Category 1/Marginal risk probabilities. ..Squitieri.. 09/02/2025 Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0156 AM CDT Tue Sep 02 2025 Valid 031200Z - 041200Z ...Synopsis... As the upper-level low continues to shift northward through D2/Wednesday, the isolated dry thunderstorms chances will continue across northern California into central Oregon, southern Washington, and western Idaho. Storm motions will decrease but coverage and moisture may also decrease with more isolated lingering activity expected. An isolated dry thunderstorm area was maintained with this outlook to cover this potential. ..Thornton.. 09/02/2025 ...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 0156 AM CDT Tue Sep 02 2025 Valid 031200Z - 041200Z ...Synopsis... As the upper-level low continues to shift northward through D2/Wednesday, the isolated dry thunderstorms chances will continue across northern California into central Oregon, southern Washington, and western Idaho. Storm motions will decrease but coverage and moisture may also decrease with more isolated lingering activity expected. An isolated dry thunderstorm area was maintained with this outlook to cover this potential. ..Thornton.. 09/02/2025 ...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 0156 AM CDT Tue Sep 02 2025 Valid 031200Z - 041200Z ...Synopsis... As the upper-level low continues to shift northward through D2/Wednesday, the isolated dry thunderstorms chances will continue across northern California into central Oregon, southern Washington, and western Idaho. Storm motions will decrease but coverage and moisture may also decrease with more isolated lingering activity expected. An isolated dry thunderstorm area was maintained with this outlook to cover this potential. ..Thornton.. 09/02/2025 ...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 0156 AM CDT Tue Sep 02 2025 Valid 031200Z - 041200Z ...Synopsis... As the upper-level low continues to shift northward through D2/Wednesday, the isolated dry thunderstorms chances will continue across northern California into central Oregon, southern Washington, and western Idaho. Storm motions will decrease but coverage and moisture may also decrease with more isolated lingering activity expected. An isolated dry thunderstorm area was maintained with this outlook to cover this potential. ..Thornton.. 09/02/2025 ...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 0156 AM CDT Tue Sep 02 2025 Valid 031200Z - 041200Z ...Synopsis... As the upper-level low continues to shift northward through D2/Wednesday, the isolated dry thunderstorms chances will continue across northern California into central Oregon, southern Washington, and western Idaho. Storm motions will decrease but coverage and moisture may also decrease with more isolated lingering activity expected. An isolated dry thunderstorm area was maintained with this outlook to cover this potential. ..Thornton.. 09/02/2025 ...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 0155 AM CDT Tue Sep 02 2025 Valid 021200Z - 031200Z ...Synopsis... A weak upper-level low will move northward across northern California into the Pacific Northwest today through D2/Wednesday, with increases in moisture and forcing leading to thunderstorm development. Precipitable water values will approach 0.60-0.90", decreasing with eastward extent across eastern Oregon/western Nevada. Faster storm motions around 15-20 kts will likely lead to a mix of wet/dry thunderstorms. New starts will be possible where little to no precipitation occurs, with ERCs around the 80th-90th percentile across portions of these regions. An isolated dry thunderstorm area was maintained with this outlook across portions of northern California into western Nevada an northward into central Oregon. ..Thornton.. 09/02/2025 ...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 0155 AM CDT Tue Sep 02 2025 Valid 021200Z - 031200Z ...Synopsis... A weak upper-level low will move northward across northern California into the Pacific Northwest today through D2/Wednesday, with increases in moisture and forcing leading to thunderstorm development. Precipitable water values will approach 0.60-0.90", decreasing with eastward extent across eastern Oregon/western Nevada. Faster storm motions around 15-20 kts will likely lead to a mix of wet/dry thunderstorms. New starts will be possible where little to no precipitation occurs, with ERCs around the 80th-90th percentile across portions of these regions. An isolated dry thunderstorm area was maintained with this outlook across portions of northern California into western Nevada an northward into central Oregon. ..Thornton.. 09/02/2025 ...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 0155 AM CDT Tue Sep 02 2025 Valid 021200Z - 031200Z ...Synopsis... A weak upper-level low will move northward across northern California into the Pacific Northwest today through D2/Wednesday, with increases in moisture and forcing leading to thunderstorm development. Precipitable water values will approach 0.60-0.90", decreasing with eastward extent across eastern Oregon/western Nevada. Faster storm motions around 15-20 kts will likely lead to a mix of wet/dry thunderstorms. New starts will be possible where little to no precipitation occurs, with ERCs around the 80th-90th percentile across portions of these regions. An isolated dry thunderstorm area was maintained with this outlook across portions of northern California into western Nevada an northward into central Oregon. ..Thornton.. 09/02/2025 ...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 0155 AM CDT Tue Sep 02 2025 Valid 021200Z - 031200Z ...Synopsis... A weak upper-level low will move northward across northern California into the Pacific Northwest today through D2/Wednesday, with increases in moisture and forcing leading to thunderstorm development. Precipitable water values will approach 0.60-0.90", decreasing with eastward extent across eastern Oregon/western Nevada. Faster storm motions around 15-20 kts will likely lead to a mix of wet/dry thunderstorms. New starts will be possible where little to no precipitation occurs, with ERCs around the 80th-90th percentile across portions of these regions. An isolated dry thunderstorm area was maintained with this outlook across portions of northern California into western Nevada an northward into central Oregon. ..Thornton.. 09/02/2025 ...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 0155 AM CDT Tue Sep 02 2025 Valid 021200Z - 031200Z ...Synopsis... A weak upper-level low will move northward across northern California into the Pacific Northwest today through D2/Wednesday, with increases in moisture and forcing leading to thunderstorm development. Precipitable water values will approach 0.60-0.90", decreasing with eastward extent across eastern Oregon/western Nevada. Faster storm motions around 15-20 kts will likely lead to a mix of wet/dry thunderstorms. New starts will be possible where little to no precipitation occurs, with ERCs around the 80th-90th percentile across portions of these regions. An isolated dry thunderstorm area was maintained with this outlook across portions of northern California into western Nevada an northward into central Oregon. ..Thornton.. 09/02/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more