Severe Storms

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0221 PM CDT Sat Aug 16 2025 Valid 181200Z - 191200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS IN THE NORTHERN GREAT PLAINS TO THE CORN BELT... ...SUMMARY... Isolated severe thunderstorms are possible across parts of the Corn Belt and northern Great Plains, mainly during the late afternoon and evening on Monday. ...Corn Belt to the northern Great Plains... Large-scale pattern will feature retrogression of the mid/upper anticyclone from the southern Great Plains into the Southwest. An MCV should amplify as a result of D2 MCS development and act as a low-amplitude shortwave impulse drifting across the Upper Great Lakes. Ridging will build north towards the northern High Plains by early Tuesday. This evolution will yield a generally modest zonal mid-level flow regime over the North-Central States on Monday. Extensive but decaying convection should be ongoing at 12Z Monday from the Lake Superior/Upper MS Valley into IA and perhaps the Lower MO Valley. Pockets of stronger boundary-layer heating will be necessary for diurnal intensification with weaker mid-level lapse rates relative to prior days. Confidence is low in just how unstable the airmass will be in WI/IL on Monday afternoon. Still, will maintain a level 1-MRGL with a risk for isolated damaging winds. Farther west, steep mid-level lapse rates will foster moderate to large buoyancy from NE into eastern MT/western ND. Guidance has varying signals for widely scattered convective development, but it appears most probable over the central High Plains and Black Hills during the late afternoon and evening. Coverage is more nebulous in MT/ND as mid/upper ridging gradually builds, but deep-layer shear will be greater compared to farther south. A broad swath of low-probability severe remains appropriate with a mix of wind and hail possible. ..Grams.. 08/16/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1227 PM CDT Sat Aug 16 2025 Valid 171200Z - 181200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS IN PARTS OF THE NORTHERN CONUS... ...SUMMARY... Isolated severe thunderstorms are possible, mainly during the late afternoon and evening Sunday from the Upper Midwest to the northern High Plains. Isolated damaging winds are possible on Sunday afternoon to early evening across the Northeast and New England. ...Upper Midwest... Decaying convective swaths will likely be ongoing at 12Z Sunday, centered on the eastern Dakotas to southern MN. The eastern lobe of this morning activity will aid in strengthening the quasi-stationary baroclinic zone, as differential boundary-layer heating occurs across it through the day. Presence of mid to upper ridging emanating north-northeast from the southern Great Plains anticyclone will remain a limiting factor to more robust severe potential. Still, drifting MCVs across the Dakotas in a modest southwesterly flow regime in conjunction with large buoyancy in the warm-moist sector should aid in scattered late-afternoon thunderstorm development. This appears most probable in the eastern SD to southwest MN vicinity, with isolated coverage trailing into central NE. A mix of isolated severe hail/wind initially should transition to mainly sporadic strong to severe gusts through the evening as slow-moving clusters/MCSs develop. A brief tornado is also possible with any transient supercell structures near the front. ...Northern High Plains... Primary severe potential should emanate out of late afternoon convection initiating off the higher terrain of southern MT and separately in the Black Hills vicinity. A modest combination of deep-layer shear and large-scale ascent suggests mainly a strong to isolated severe threat should be expected as high-based convection spreads northeast across eastern MT. The presence of weak surface/low-level should modulate the eastern extent of severe potential on Sunday evening. ...Northeast/New England... A shortwave trough will progress across the St. Lawrence Valley towards the Canadian Maritimes and northern New England through Sunday afternoon. A cold front will push southeastward through the day with isolated to widely scattered thunderstorms expected along it during the afternoon. Buoyancy appears likely to be weak and will remain a limiting factor to more robust severe potential. More favorable deep-layer shear will exist in New England where localized damaging winds and small hail should be favored. Farther southwest, multicell clustering should be dominant with isolated damaging winds from sporadic strong gusts. ..Grams.. 08/16/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1227 PM CDT Sat Aug 16 2025 Valid 171200Z - 181200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS IN PARTS OF THE NORTHERN CONUS... ...SUMMARY... Isolated severe thunderstorms are possible, mainly during the late afternoon and evening Sunday from the Upper Midwest to the northern High Plains. Isolated damaging winds are possible on Sunday afternoon to early evening across the Northeast and New England. ...Upper Midwest... Decaying convective swaths will likely be ongoing at 12Z Sunday, centered on the eastern Dakotas to southern MN. The eastern lobe of this morning activity will aid in strengthening the quasi-stationary baroclinic zone, as differential boundary-layer heating occurs across it through the day. Presence of mid to upper ridging emanating north-northeast from the southern Great Plains anticyclone will remain a limiting factor to more robust severe potential. Still, drifting MCVs across the Dakotas in a modest southwesterly flow regime in conjunction with large buoyancy in the warm-moist sector should aid in scattered late-afternoon thunderstorm development. This appears most probable in the eastern SD to southwest MN vicinity, with isolated coverage trailing into central NE. A mix of isolated severe hail/wind initially should transition to mainly sporadic strong to severe gusts through the evening as slow-moving clusters/MCSs develop. A brief tornado is also possible with any transient supercell structures near the front. ...Northern High Plains... Primary severe potential should emanate out of late afternoon convection initiating off the higher terrain of southern MT and separately in the Black Hills vicinity. A modest combination of deep-layer shear and large-scale ascent suggests mainly a strong to isolated severe threat should be expected as high-based convection spreads northeast across eastern MT. The presence of weak surface/low-level should modulate the eastern extent of severe potential on Sunday evening. ...Northeast/New England... A shortwave trough will progress across the St. Lawrence Valley towards the Canadian Maritimes and northern New England through Sunday afternoon. A cold front will push southeastward through the day with isolated to widely scattered thunderstorms expected along it during the afternoon. Buoyancy appears likely to be weak and will remain a limiting factor to more robust severe potential. More favorable deep-layer shear will exist in New England where localized damaging winds and small hail should be favored. Farther southwest, multicell clustering should be dominant with isolated damaging winds from sporadic strong gusts. ..Grams.. 08/16/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1227 PM CDT Sat Aug 16 2025 Valid 171200Z - 181200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS IN PARTS OF THE NORTHERN CONUS... ...SUMMARY... Isolated severe thunderstorms are possible, mainly during the late afternoon and evening Sunday from the Upper Midwest to the northern High Plains. Isolated damaging winds are possible on Sunday afternoon to early evening across the Northeast and New England. ...Upper Midwest... Decaying convective swaths will likely be ongoing at 12Z Sunday, centered on the eastern Dakotas to southern MN. The eastern lobe of this morning activity will aid in strengthening the quasi-stationary baroclinic zone, as differential boundary-layer heating occurs across it through the day. Presence of mid to upper ridging emanating north-northeast from the southern Great Plains anticyclone will remain a limiting factor to more robust severe potential. Still, drifting MCVs across the Dakotas in a modest southwesterly flow regime in conjunction with large buoyancy in the warm-moist sector should aid in scattered late-afternoon thunderstorm development. This appears most probable in the eastern SD to southwest MN vicinity, with isolated coverage trailing into central NE. A mix of isolated severe hail/wind initially should transition to mainly sporadic strong to severe gusts through the evening as slow-moving clusters/MCSs develop. A brief tornado is also possible with any transient supercell structures near the front. ...Northern High Plains... Primary severe potential should emanate out of late afternoon convection initiating off the higher terrain of southern MT and separately in the Black Hills vicinity. A modest combination of deep-layer shear and large-scale ascent suggests mainly a strong to isolated severe threat should be expected as high-based convection spreads northeast across eastern MT. The presence of weak surface/low-level should modulate the eastern extent of severe potential on Sunday evening. ...Northeast/New England... A shortwave trough will progress across the St. Lawrence Valley towards the Canadian Maritimes and northern New England through Sunday afternoon. A cold front will push southeastward through the day with isolated to widely scattered thunderstorms expected along it during the afternoon. Buoyancy appears likely to be weak and will remain a limiting factor to more robust severe potential. More favorable deep-layer shear will exist in New England where localized damaging winds and small hail should be favored. Farther southwest, multicell clustering should be dominant with isolated damaging winds from sporadic strong gusts. ..Grams.. 08/16/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1227 PM CDT Sat Aug 16 2025 Valid 171200Z - 181200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS IN PARTS OF THE NORTHERN CONUS... ...SUMMARY... Isolated severe thunderstorms are possible, mainly during the late afternoon and evening Sunday from the Upper Midwest to the northern High Plains. Isolated damaging winds are possible on Sunday afternoon to early evening across the Northeast and New England. ...Upper Midwest... Decaying convective swaths will likely be ongoing at 12Z Sunday, centered on the eastern Dakotas to southern MN. The eastern lobe of this morning activity will aid in strengthening the quasi-stationary baroclinic zone, as differential boundary-layer heating occurs across it through the day. Presence of mid to upper ridging emanating north-northeast from the southern Great Plains anticyclone will remain a limiting factor to more robust severe potential. Still, drifting MCVs across the Dakotas in a modest southwesterly flow regime in conjunction with large buoyancy in the warm-moist sector should aid in scattered late-afternoon thunderstorm development. This appears most probable in the eastern SD to southwest MN vicinity, with isolated coverage trailing into central NE. A mix of isolated severe hail/wind initially should transition to mainly sporadic strong to severe gusts through the evening as slow-moving clusters/MCSs develop. A brief tornado is also possible with any transient supercell structures near the front. ...Northern High Plains... Primary severe potential should emanate out of late afternoon convection initiating off the higher terrain of southern MT and separately in the Black Hills vicinity. A modest combination of deep-layer shear and large-scale ascent suggests mainly a strong to isolated severe threat should be expected as high-based convection spreads northeast across eastern MT. The presence of weak surface/low-level should modulate the eastern extent of severe potential on Sunday evening. ...Northeast/New England... A shortwave trough will progress across the St. Lawrence Valley towards the Canadian Maritimes and northern New England through Sunday afternoon. A cold front will push southeastward through the day with isolated to widely scattered thunderstorms expected along it during the afternoon. Buoyancy appears likely to be weak and will remain a limiting factor to more robust severe potential. More favorable deep-layer shear will exist in New England where localized damaging winds and small hail should be favored. Farther southwest, multicell clustering should be dominant with isolated damaging winds from sporadic strong gusts. ..Grams.. 08/16/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1227 PM CDT Sat Aug 16 2025 Valid 171200Z - 181200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS IN PARTS OF THE NORTHERN CONUS... ...SUMMARY... Isolated severe thunderstorms are possible, mainly during the late afternoon and evening Sunday from the Upper Midwest to the northern High Plains. Isolated damaging winds are possible on Sunday afternoon to early evening across the Northeast and New England. ...Upper Midwest... Decaying convective swaths will likely be ongoing at 12Z Sunday, centered on the eastern Dakotas to southern MN. The eastern lobe of this morning activity will aid in strengthening the quasi-stationary baroclinic zone, as differential boundary-layer heating occurs across it through the day. Presence of mid to upper ridging emanating north-northeast from the southern Great Plains anticyclone will remain a limiting factor to more robust severe potential. Still, drifting MCVs across the Dakotas in a modest southwesterly flow regime in conjunction with large buoyancy in the warm-moist sector should aid in scattered late-afternoon thunderstorm development. This appears most probable in the eastern SD to southwest MN vicinity, with isolated coverage trailing into central NE. A mix of isolated severe hail/wind initially should transition to mainly sporadic strong to severe gusts through the evening as slow-moving clusters/MCSs develop. A brief tornado is also possible with any transient supercell structures near the front. ...Northern High Plains... Primary severe potential should emanate out of late afternoon convection initiating off the higher terrain of southern MT and separately in the Black Hills vicinity. A modest combination of deep-layer shear and large-scale ascent suggests mainly a strong to isolated severe threat should be expected as high-based convection spreads northeast across eastern MT. The presence of weak surface/low-level should modulate the eastern extent of severe potential on Sunday evening. ...Northeast/New England... A shortwave trough will progress across the St. Lawrence Valley towards the Canadian Maritimes and northern New England through Sunday afternoon. A cold front will push southeastward through the day with isolated to widely scattered thunderstorms expected along it during the afternoon. Buoyancy appears likely to be weak and will remain a limiting factor to more robust severe potential. More favorable deep-layer shear will exist in New England where localized damaging winds and small hail should be favored. Farther southwest, multicell clustering should be dominant with isolated damaging winds from sporadic strong gusts. ..Grams.. 08/16/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1227 PM CDT Sat Aug 16 2025 Valid 171200Z - 181200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS IN PARTS OF THE NORTHERN CONUS... ...SUMMARY... Isolated severe thunderstorms are possible, mainly during the late afternoon and evening Sunday from the Upper Midwest to the northern High Plains. Isolated damaging winds are possible on Sunday afternoon to early evening across the Northeast and New England. ...Upper Midwest... Decaying convective swaths will likely be ongoing at 12Z Sunday, centered on the eastern Dakotas to southern MN. The eastern lobe of this morning activity will aid in strengthening the quasi-stationary baroclinic zone, as differential boundary-layer heating occurs across it through the day. Presence of mid to upper ridging emanating north-northeast from the southern Great Plains anticyclone will remain a limiting factor to more robust severe potential. Still, drifting MCVs across the Dakotas in a modest southwesterly flow regime in conjunction with large buoyancy in the warm-moist sector should aid in scattered late-afternoon thunderstorm development. This appears most probable in the eastern SD to southwest MN vicinity, with isolated coverage trailing into central NE. A mix of isolated severe hail/wind initially should transition to mainly sporadic strong to severe gusts through the evening as slow-moving clusters/MCSs develop. A brief tornado is also possible with any transient supercell structures near the front. ...Northern High Plains... Primary severe potential should emanate out of late afternoon convection initiating off the higher terrain of southern MT and separately in the Black Hills vicinity. A modest combination of deep-layer shear and large-scale ascent suggests mainly a strong to isolated severe threat should be expected as high-based convection spreads northeast across eastern MT. The presence of weak surface/low-level should modulate the eastern extent of severe potential on Sunday evening. ...Northeast/New England... A shortwave trough will progress across the St. Lawrence Valley towards the Canadian Maritimes and northern New England through Sunday afternoon. A cold front will push southeastward through the day with isolated to widely scattered thunderstorms expected along it during the afternoon. Buoyancy appears likely to be weak and will remain a limiting factor to more robust severe potential. More favorable deep-layer shear will exist in New England where localized damaging winds and small hail should be favored. Farther southwest, multicell clustering should be dominant with isolated damaging winds from sporadic strong gusts. ..Grams.. 08/16/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1227 PM CDT Sat Aug 16 2025 Valid 171200Z - 181200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS IN PARTS OF THE NORTHERN CONUS... ...SUMMARY... Isolated severe thunderstorms are possible, mainly during the late afternoon and evening Sunday from the Upper Midwest to the northern High Plains. Isolated damaging winds are possible on Sunday afternoon to early evening across the Northeast and New England. ...Upper Midwest... Decaying convective swaths will likely be ongoing at 12Z Sunday, centered on the eastern Dakotas to southern MN. The eastern lobe of this morning activity will aid in strengthening the quasi-stationary baroclinic zone, as differential boundary-layer heating occurs across it through the day. Presence of mid to upper ridging emanating north-northeast from the southern Great Plains anticyclone will remain a limiting factor to more robust severe potential. Still, drifting MCVs across the Dakotas in a modest southwesterly flow regime in conjunction with large buoyancy in the warm-moist sector should aid in scattered late-afternoon thunderstorm development. This appears most probable in the eastern SD to southwest MN vicinity, with isolated coverage trailing into central NE. A mix of isolated severe hail/wind initially should transition to mainly sporadic strong to severe gusts through the evening as slow-moving clusters/MCSs develop. A brief tornado is also possible with any transient supercell structures near the front. ...Northern High Plains... Primary severe potential should emanate out of late afternoon convection initiating off the higher terrain of southern MT and separately in the Black Hills vicinity. A modest combination of deep-layer shear and large-scale ascent suggests mainly a strong to isolated severe threat should be expected as high-based convection spreads northeast across eastern MT. The presence of weak surface/low-level should modulate the eastern extent of severe potential on Sunday evening. ...Northeast/New England... A shortwave trough will progress across the St. Lawrence Valley towards the Canadian Maritimes and northern New England through Sunday afternoon. A cold front will push southeastward through the day with isolated to widely scattered thunderstorms expected along it during the afternoon. Buoyancy appears likely to be weak and will remain a limiting factor to more robust severe potential. More favorable deep-layer shear will exist in New England where localized damaging winds and small hail should be favored. Farther southwest, multicell clustering should be dominant with isolated damaging winds from sporadic strong gusts. ..Grams.. 08/16/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1227 PM CDT Sat Aug 16 2025 Valid 171200Z - 181200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS IN PARTS OF THE NORTHERN CONUS... ...SUMMARY... Isolated severe thunderstorms are possible, mainly during the late afternoon and evening Sunday from the Upper Midwest to the northern High Plains. Isolated damaging winds are possible on Sunday afternoon to early evening across the Northeast and New England. ...Upper Midwest... Decaying convective swaths will likely be ongoing at 12Z Sunday, centered on the eastern Dakotas to southern MN. The eastern lobe of this morning activity will aid in strengthening the quasi-stationary baroclinic zone, as differential boundary-layer heating occurs across it through the day. Presence of mid to upper ridging emanating north-northeast from the southern Great Plains anticyclone will remain a limiting factor to more robust severe potential. Still, drifting MCVs across the Dakotas in a modest southwesterly flow regime in conjunction with large buoyancy in the warm-moist sector should aid in scattered late-afternoon thunderstorm development. This appears most probable in the eastern SD to southwest MN vicinity, with isolated coverage trailing into central NE. A mix of isolated severe hail/wind initially should transition to mainly sporadic strong to severe gusts through the evening as slow-moving clusters/MCSs develop. A brief tornado is also possible with any transient supercell structures near the front. ...Northern High Plains... Primary severe potential should emanate out of late afternoon convection initiating off the higher terrain of southern MT and separately in the Black Hills vicinity. A modest combination of deep-layer shear and large-scale ascent suggests mainly a strong to isolated severe threat should be expected as high-based convection spreads northeast across eastern MT. The presence of weak surface/low-level should modulate the eastern extent of severe potential on Sunday evening. ...Northeast/New England... A shortwave trough will progress across the St. Lawrence Valley towards the Canadian Maritimes and northern New England through Sunday afternoon. A cold front will push southeastward through the day with isolated to widely scattered thunderstorms expected along it during the afternoon. Buoyancy appears likely to be weak and will remain a limiting factor to more robust severe potential. More favorable deep-layer shear will exist in New England where localized damaging winds and small hail should be favored. Farther southwest, multicell clustering should be dominant with isolated damaging winds from sporadic strong gusts. ..Grams.. 08/16/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1227 PM CDT Sat Aug 16 2025 Valid 171200Z - 181200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS IN PARTS OF THE NORTHERN CONUS... ...SUMMARY... Isolated severe thunderstorms are possible, mainly during the late afternoon and evening Sunday from the Upper Midwest to the northern High Plains. Isolated damaging winds are possible on Sunday afternoon to early evening across the Northeast and New England. ...Upper Midwest... Decaying convective swaths will likely be ongoing at 12Z Sunday, centered on the eastern Dakotas to southern MN. The eastern lobe of this morning activity will aid in strengthening the quasi-stationary baroclinic zone, as differential boundary-layer heating occurs across it through the day. Presence of mid to upper ridging emanating north-northeast from the southern Great Plains anticyclone will remain a limiting factor to more robust severe potential. Still, drifting MCVs across the Dakotas in a modest southwesterly flow regime in conjunction with large buoyancy in the warm-moist sector should aid in scattered late-afternoon thunderstorm development. This appears most probable in the eastern SD to southwest MN vicinity, with isolated coverage trailing into central NE. A mix of isolated severe hail/wind initially should transition to mainly sporadic strong to severe gusts through the evening as slow-moving clusters/MCSs develop. A brief tornado is also possible with any transient supercell structures near the front. ...Northern High Plains... Primary severe potential should emanate out of late afternoon convection initiating off the higher terrain of southern MT and separately in the Black Hills vicinity. A modest combination of deep-layer shear and large-scale ascent suggests mainly a strong to isolated severe threat should be expected as high-based convection spreads northeast across eastern MT. The presence of weak surface/low-level should modulate the eastern extent of severe potential on Sunday evening. ...Northeast/New England... A shortwave trough will progress across the St. Lawrence Valley towards the Canadian Maritimes and northern New England through Sunday afternoon. A cold front will push southeastward through the day with isolated to widely scattered thunderstorms expected along it during the afternoon. Buoyancy appears likely to be weak and will remain a limiting factor to more robust severe potential. More favorable deep-layer shear will exist in New England where localized damaging winds and small hail should be favored. Farther southwest, multicell clustering should be dominant with isolated damaging winds from sporadic strong gusts. ..Grams.. 08/16/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1227 PM CDT Sat Aug 16 2025 Valid 171200Z - 181200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS IN PARTS OF THE NORTHERN CONUS... ...SUMMARY... Isolated severe thunderstorms are possible, mainly during the late afternoon and evening Sunday from the Upper Midwest to the northern High Plains. Isolated damaging winds are possible on Sunday afternoon to early evening across the Northeast and New England. ...Upper Midwest... Decaying convective swaths will likely be ongoing at 12Z Sunday, centered on the eastern Dakotas to southern MN. The eastern lobe of this morning activity will aid in strengthening the quasi-stationary baroclinic zone, as differential boundary-layer heating occurs across it through the day. Presence of mid to upper ridging emanating north-northeast from the southern Great Plains anticyclone will remain a limiting factor to more robust severe potential. Still, drifting MCVs across the Dakotas in a modest southwesterly flow regime in conjunction with large buoyancy in the warm-moist sector should aid in scattered late-afternoon thunderstorm development. This appears most probable in the eastern SD to southwest MN vicinity, with isolated coverage trailing into central NE. A mix of isolated severe hail/wind initially should transition to mainly sporadic strong to severe gusts through the evening as slow-moving clusters/MCSs develop. A brief tornado is also possible with any transient supercell structures near the front. ...Northern High Plains... Primary severe potential should emanate out of late afternoon convection initiating off the higher terrain of southern MT and separately in the Black Hills vicinity. A modest combination of deep-layer shear and large-scale ascent suggests mainly a strong to isolated severe threat should be expected as high-based convection spreads northeast across eastern MT. The presence of weak surface/low-level should modulate the eastern extent of severe potential on Sunday evening. ...Northeast/New England... A shortwave trough will progress across the St. Lawrence Valley towards the Canadian Maritimes and northern New England through Sunday afternoon. A cold front will push southeastward through the day with isolated to widely scattered thunderstorms expected along it during the afternoon. Buoyancy appears likely to be weak and will remain a limiting factor to more robust severe potential. More favorable deep-layer shear will exist in New England where localized damaging winds and small hail should be favored. Farther southwest, multicell clustering should be dominant with isolated damaging winds from sporadic strong gusts. ..Grams.. 08/16/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1227 PM CDT Sat Aug 16 2025 Valid 171200Z - 181200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS IN PARTS OF THE NORTHERN CONUS... ...SUMMARY... Isolated severe thunderstorms are possible, mainly during the late afternoon and evening Sunday from the Upper Midwest to the northern High Plains. Isolated damaging winds are possible on Sunday afternoon to early evening across the Northeast and New England. ...Upper Midwest... Decaying convective swaths will likely be ongoing at 12Z Sunday, centered on the eastern Dakotas to southern MN. The eastern lobe of this morning activity will aid in strengthening the quasi-stationary baroclinic zone, as differential boundary-layer heating occurs across it through the day. Presence of mid to upper ridging emanating north-northeast from the southern Great Plains anticyclone will remain a limiting factor to more robust severe potential. Still, drifting MCVs across the Dakotas in a modest southwesterly flow regime in conjunction with large buoyancy in the warm-moist sector should aid in scattered late-afternoon thunderstorm development. This appears most probable in the eastern SD to southwest MN vicinity, with isolated coverage trailing into central NE. A mix of isolated severe hail/wind initially should transition to mainly sporadic strong to severe gusts through the evening as slow-moving clusters/MCSs develop. A brief tornado is also possible with any transient supercell structures near the front. ...Northern High Plains... Primary severe potential should emanate out of late afternoon convection initiating off the higher terrain of southern MT and separately in the Black Hills vicinity. A modest combination of deep-layer shear and large-scale ascent suggests mainly a strong to isolated severe threat should be expected as high-based convection spreads northeast across eastern MT. The presence of weak surface/low-level should modulate the eastern extent of severe potential on Sunday evening. ...Northeast/New England... A shortwave trough will progress across the St. Lawrence Valley towards the Canadian Maritimes and northern New England through Sunday afternoon. A cold front will push southeastward through the day with isolated to widely scattered thunderstorms expected along it during the afternoon. Buoyancy appears likely to be weak and will remain a limiting factor to more robust severe potential. More favorable deep-layer shear will exist in New England where localized damaging winds and small hail should be favored. Farther southwest, multicell clustering should be dominant with isolated damaging winds from sporadic strong gusts. ..Grams.. 08/16/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1227 PM CDT Sat Aug 16 2025 Valid 171200Z - 181200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS IN PARTS OF THE NORTHERN CONUS... ...SUMMARY... Isolated severe thunderstorms are possible, mainly during the late afternoon and evening Sunday from the Upper Midwest to the northern High Plains. Isolated damaging winds are possible on Sunday afternoon to early evening across the Northeast and New England. ...Upper Midwest... Decaying convective swaths will likely be ongoing at 12Z Sunday, centered on the eastern Dakotas to southern MN. The eastern lobe of this morning activity will aid in strengthening the quasi-stationary baroclinic zone, as differential boundary-layer heating occurs across it through the day. Presence of mid to upper ridging emanating north-northeast from the southern Great Plains anticyclone will remain a limiting factor to more robust severe potential. Still, drifting MCVs across the Dakotas in a modest southwesterly flow regime in conjunction with large buoyancy in the warm-moist sector should aid in scattered late-afternoon thunderstorm development. This appears most probable in the eastern SD to southwest MN vicinity, with isolated coverage trailing into central NE. A mix of isolated severe hail/wind initially should transition to mainly sporadic strong to severe gusts through the evening as slow-moving clusters/MCSs develop. A brief tornado is also possible with any transient supercell structures near the front. ...Northern High Plains... Primary severe potential should emanate out of late afternoon convection initiating off the higher terrain of southern MT and separately in the Black Hills vicinity. A modest combination of deep-layer shear and large-scale ascent suggests mainly a strong to isolated severe threat should be expected as high-based convection spreads northeast across eastern MT. The presence of weak surface/low-level should modulate the eastern extent of severe potential on Sunday evening. ...Northeast/New England... A shortwave trough will progress across the St. Lawrence Valley towards the Canadian Maritimes and northern New England through Sunday afternoon. A cold front will push southeastward through the day with isolated to widely scattered thunderstorms expected along it during the afternoon. Buoyancy appears likely to be weak and will remain a limiting factor to more robust severe potential. More favorable deep-layer shear will exist in New England where localized damaging winds and small hail should be favored. Farther southwest, multicell clustering should be dominant with isolated damaging winds from sporadic strong gusts. ..Grams.. 08/16/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1227 PM CDT Sat Aug 16 2025 Valid 171200Z - 181200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS IN PARTS OF THE NORTHERN CONUS... ...SUMMARY... Isolated severe thunderstorms are possible, mainly during the late afternoon and evening Sunday from the Upper Midwest to the northern High Plains. Isolated damaging winds are possible on Sunday afternoon to early evening across the Northeast and New England. ...Upper Midwest... Decaying convective swaths will likely be ongoing at 12Z Sunday, centered on the eastern Dakotas to southern MN. The eastern lobe of this morning activity will aid in strengthening the quasi-stationary baroclinic zone, as differential boundary-layer heating occurs across it through the day. Presence of mid to upper ridging emanating north-northeast from the southern Great Plains anticyclone will remain a limiting factor to more robust severe potential. Still, drifting MCVs across the Dakotas in a modest southwesterly flow regime in conjunction with large buoyancy in the warm-moist sector should aid in scattered late-afternoon thunderstorm development. This appears most probable in the eastern SD to southwest MN vicinity, with isolated coverage trailing into central NE. A mix of isolated severe hail/wind initially should transition to mainly sporadic strong to severe gusts through the evening as slow-moving clusters/MCSs develop. A brief tornado is also possible with any transient supercell structures near the front. ...Northern High Plains... Primary severe potential should emanate out of late afternoon convection initiating off the higher terrain of southern MT and separately in the Black Hills vicinity. A modest combination of deep-layer shear and large-scale ascent suggests mainly a strong to isolated severe threat should be expected as high-based convection spreads northeast across eastern MT. The presence of weak surface/low-level should modulate the eastern extent of severe potential on Sunday evening. ...Northeast/New England... A shortwave trough will progress across the St. Lawrence Valley towards the Canadian Maritimes and northern New England through Sunday afternoon. A cold front will push southeastward through the day with isolated to widely scattered thunderstorms expected along it during the afternoon. Buoyancy appears likely to be weak and will remain a limiting factor to more robust severe potential. More favorable deep-layer shear will exist in New England where localized damaging winds and small hail should be favored. Farther southwest, multicell clustering should be dominant with isolated damaging winds from sporadic strong gusts. ..Grams.. 08/16/2025 Read more

No watches are valid as of Sat Aug 16 17:31:02 UTC 2025.

MD 1964 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR SOUTHERN/SOUTHEAST WISCONSIN AND FAR NORTHERN ILLINOIS
Mesoscale Discussion 1964 NWS Storm Prediction Center Norman OK 1156 AM CDT Sat Aug 16 2025 Areas affected...southern/southeast Wisconsin and far northern Illinois Concerning...Severe potential...Watch possible Valid 161656Z - 161900Z Probability of Watch Issuance...60 percent SUMMARY...Thunderstorms across southern Wisconsin are being monitored. A severe thunderstorm watch is possible. DISCUSSION...The overnight MCS has persisted across Wisconsin this morning with wind gusts of 30 to 35 knots and isolated tree damage reported. A slight increase in lightning over the past 30 minutes suggests this cluster may be trying to re-intensify. However, SPC mesoanalysis suggests significant inhibition is in place and should not erode for another 1 to 2 hours. The evolution of these storms over the next 1 to 2 hours should provide more clarity on the overall evolution this afternoon. If these elevated storms can persist as the boundary layer destabilizes to the south and eventually become surface-based, a forward-propagating MCS capable of damaging winds may develop and move across northeast Illinois, southern Lake Michigan, and eventually into southwest Michigan and northern Indiana. However, if this cluster weakens in the next 1 to 2 hours, the greater severe storm focus may be along the remnant outflow boundary later this afternoon. This threat may be more supercellular initially with a threat for hail and wind before transitioning into a southward moving MCS. Convective trends will be monitored and if the ongoing storms show signs of intensifying/becoming surface-based, a watch may be needed soon. ..Bentley.. 08/16/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...IWX...GRR...GRB...LOT...MKX...DVN...ARX... LAT...LON 43869015 44028934 44348846 44488805 44028756 43298677 42538638 42288630 41868660 41728683 41578732 41618782 41828864 42148923 42578996 43069033 43869015 MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 95 MPH MOST PROBABLE PEAK WIND GUST...55-70 MPH MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1153 AM CDT Sat Aug 16 2025 Valid 161700Z - 171200Z Current satellite imagery shows a broad cloud shield associated with an influx of Pacific moisture along a cold front draped from northwestern CA into the ID Panhandle. PWAT values of around 1.00 inch along with higher surface dewpoints and relative humidity near and behind the frontal boundary will promote more wetting rainfall within heavier shower and thunderstorm cores. This has shifted the dry thunderstorm threat slightly southeastward where diurnal heating is more accessible in conjunction with a drier sub-cloud layer, supporting more limited rainfall within northeastward thunderstorm motions of up to 30 knots expected this afternoon and evening. A mid-level wind maxima of 30-40 knots and associated increased shear stretching from eastern OR into western MT could aid in sustained convection through tonight across eastern OR, central ID mountains and western MT. ..Williams.. 08/16/2025 .PREV DISCUSSION... /ISSUED 0202 AM CDT Sat Aug 16 2025/ ...Synopsis... A broad mid-level trough over the Northwestern US is forecast to consolidate and intensify today/tonight as it impinges on the northwestern edge of a ridge of high pressure over the central US. The tightening height gradient will bolster flow aloft, while at the same time, a surface cold front will move in from the Northwest. Monsoon moisture will support showers and thunderstorms along/ahead of the front, while localized dry and breezy conditions are possible over the Southwestern US. ...Northwest and Rockies Dry Thunder... Across the Northwest and central Rockies, persistent monsoon moisture will be in palace ahead of the upper trough and attendant cold front. Increasing PWATs (0.8-1 inch) will favor a mix of wet and dry storms across far northern CA into eastern OR and ID/MT from the afternoon into the evening hours. While the air mass in the low-levels will not be as dry as recent days, with increasing RH ahead of the front, 30-40 kt of mid-level flow should support faster northeastward storm motions of 25-30 kt. This will allow for less wetting rainfall as storms track eastward over areas of very receptive fuels supportive of lightning ignitions. Additionally, gusty outflow winds are expected, potentially impacting existing active fires across the area. The risk for lightning may continue overnight as the upper trough and front shift eastward towards ID and MT. IsoDryT highlights will remain, and have been expanded over areas of the expected driest fuels and storms. ...Southern Great Basin... As the mid-level trough continues eastward across the Northwest, southwesterly flow aloft should continue to promote locally breezy and dry conditions across portions of southern NV and western UT. South-southwest winds of up to 15 mph, along with daytime relative humidity as low as 15%, are expected in some valleys in the southern Great Basin. Amidst dry fuels, some locally elevated fire-weather conditions are possible. The lack of stronger winds for now precludes elevated highlights. ...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 1153 AM CDT Sat Aug 16 2025 Valid 161700Z - 171200Z Current satellite imagery shows a broad cloud shield associated with an influx of Pacific moisture along a cold front draped from northwestern CA into the ID Panhandle. PWAT values of around 1.00 inch along with higher surface dewpoints and relative humidity near and behind the frontal boundary will promote more wetting rainfall within heavier shower and thunderstorm cores. This has shifted the dry thunderstorm threat slightly southeastward where diurnal heating is more accessible in conjunction with a drier sub-cloud layer, supporting more limited rainfall within northeastward thunderstorm motions of up to 30 knots expected this afternoon and evening. A mid-level wind maxima of 30-40 knots and associated increased shear stretching from eastern OR into western MT could aid in sustained convection through tonight across eastern OR, central ID mountains and western MT. ..Williams.. 08/16/2025 .PREV DISCUSSION... /ISSUED 0202 AM CDT Sat Aug 16 2025/ ...Synopsis... A broad mid-level trough over the Northwestern US is forecast to consolidate and intensify today/tonight as it impinges on the northwestern edge of a ridge of high pressure over the central US. The tightening height gradient will bolster flow aloft, while at the same time, a surface cold front will move in from the Northwest. Monsoon moisture will support showers and thunderstorms along/ahead of the front, while localized dry and breezy conditions are possible over the Southwestern US. ...Northwest and Rockies Dry Thunder... Across the Northwest and central Rockies, persistent monsoon moisture will be in palace ahead of the upper trough and attendant cold front. Increasing PWATs (0.8-1 inch) will favor a mix of wet and dry storms across far northern CA into eastern OR and ID/MT from the afternoon into the evening hours. While the air mass in the low-levels will not be as dry as recent days, with increasing RH ahead of the front, 30-40 kt of mid-level flow should support faster northeastward storm motions of 25-30 kt. This will allow for less wetting rainfall as storms track eastward over areas of very receptive fuels supportive of lightning ignitions. Additionally, gusty outflow winds are expected, potentially impacting existing active fires across the area. The risk for lightning may continue overnight as the upper trough and front shift eastward towards ID and MT. IsoDryT highlights will remain, and have been expanded over areas of the expected driest fuels and storms. ...Southern Great Basin... As the mid-level trough continues eastward across the Northwest, southwesterly flow aloft should continue to promote locally breezy and dry conditions across portions of southern NV and western UT. South-southwest winds of up to 15 mph, along with daytime relative humidity as low as 15%, are expected in some valleys in the southern Great Basin. Amidst dry fuels, some locally elevated fire-weather conditions are possible. The lack of stronger winds for now precludes elevated highlights. ...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 1153 AM CDT Sat Aug 16 2025 Valid 161700Z - 171200Z Current satellite imagery shows a broad cloud shield associated with an influx of Pacific moisture along a cold front draped from northwestern CA into the ID Panhandle. PWAT values of around 1.00 inch along with higher surface dewpoints and relative humidity near and behind the frontal boundary will promote more wetting rainfall within heavier shower and thunderstorm cores. This has shifted the dry thunderstorm threat slightly southeastward where diurnal heating is more accessible in conjunction with a drier sub-cloud layer, supporting more limited rainfall within northeastward thunderstorm motions of up to 30 knots expected this afternoon and evening. A mid-level wind maxima of 30-40 knots and associated increased shear stretching from eastern OR into western MT could aid in sustained convection through tonight across eastern OR, central ID mountains and western MT. ..Williams.. 08/16/2025 .PREV DISCUSSION... /ISSUED 0202 AM CDT Sat Aug 16 2025/ ...Synopsis... A broad mid-level trough over the Northwestern US is forecast to consolidate and intensify today/tonight as it impinges on the northwestern edge of a ridge of high pressure over the central US. The tightening height gradient will bolster flow aloft, while at the same time, a surface cold front will move in from the Northwest. Monsoon moisture will support showers and thunderstorms along/ahead of the front, while localized dry and breezy conditions are possible over the Southwestern US. ...Northwest and Rockies Dry Thunder... Across the Northwest and central Rockies, persistent monsoon moisture will be in palace ahead of the upper trough and attendant cold front. Increasing PWATs (0.8-1 inch) will favor a mix of wet and dry storms across far northern CA into eastern OR and ID/MT from the afternoon into the evening hours. While the air mass in the low-levels will not be as dry as recent days, with increasing RH ahead of the front, 30-40 kt of mid-level flow should support faster northeastward storm motions of 25-30 kt. This will allow for less wetting rainfall as storms track eastward over areas of very receptive fuels supportive of lightning ignitions. Additionally, gusty outflow winds are expected, potentially impacting existing active fires across the area. The risk for lightning may continue overnight as the upper trough and front shift eastward towards ID and MT. IsoDryT highlights will remain, and have been expanded over areas of the expected driest fuels and storms. ...Southern Great Basin... As the mid-level trough continues eastward across the Northwest, southwesterly flow aloft should continue to promote locally breezy and dry conditions across portions of southern NV and western UT. South-southwest winds of up to 15 mph, along with daytime relative humidity as low as 15%, are expected in some valleys in the southern Great Basin. Amidst dry fuels, some locally elevated fire-weather conditions are possible. The lack of stronger winds for now precludes elevated highlights. ...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 1153 AM CDT Sat Aug 16 2025 Valid 161700Z - 171200Z Current satellite imagery shows a broad cloud shield associated with an influx of Pacific moisture along a cold front draped from northwestern CA into the ID Panhandle. PWAT values of around 1.00 inch along with higher surface dewpoints and relative humidity near and behind the frontal boundary will promote more wetting rainfall within heavier shower and thunderstorm cores. This has shifted the dry thunderstorm threat slightly southeastward where diurnal heating is more accessible in conjunction with a drier sub-cloud layer, supporting more limited rainfall within northeastward thunderstorm motions of up to 30 knots expected this afternoon and evening. A mid-level wind maxima of 30-40 knots and associated increased shear stretching from eastern OR into western MT could aid in sustained convection through tonight across eastern OR, central ID mountains and western MT. ..Williams.. 08/16/2025 .PREV DISCUSSION... /ISSUED 0202 AM CDT Sat Aug 16 2025/ ...Synopsis... A broad mid-level trough over the Northwestern US is forecast to consolidate and intensify today/tonight as it impinges on the northwestern edge of a ridge of high pressure over the central US. The tightening height gradient will bolster flow aloft, while at the same time, a surface cold front will move in from the Northwest. Monsoon moisture will support showers and thunderstorms along/ahead of the front, while localized dry and breezy conditions are possible over the Southwestern US. ...Northwest and Rockies Dry Thunder... Across the Northwest and central Rockies, persistent monsoon moisture will be in palace ahead of the upper trough and attendant cold front. Increasing PWATs (0.8-1 inch) will favor a mix of wet and dry storms across far northern CA into eastern OR and ID/MT from the afternoon into the evening hours. While the air mass in the low-levels will not be as dry as recent days, with increasing RH ahead of the front, 30-40 kt of mid-level flow should support faster northeastward storm motions of 25-30 kt. This will allow for less wetting rainfall as storms track eastward over areas of very receptive fuels supportive of lightning ignitions. Additionally, gusty outflow winds are expected, potentially impacting existing active fires across the area. The risk for lightning may continue overnight as the upper trough and front shift eastward towards ID and MT. IsoDryT highlights will remain, and have been expanded over areas of the expected driest fuels and storms. ...Southern Great Basin... As the mid-level trough continues eastward across the Northwest, southwesterly flow aloft should continue to promote locally breezy and dry conditions across portions of southern NV and western UT. South-southwest winds of up to 15 mph, along with daytime relative humidity as low as 15%, are expected in some valleys in the southern Great Basin. Amidst dry fuels, some locally elevated fire-weather conditions are possible. The lack of stronger winds for now precludes elevated highlights. ...Please see www.spc.noaa.gov/fire for graphic product... Read more