Severe Storms

SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1229 AM CST Tue Dec 26 2023 Valid 271200Z - 281200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected on Wednesday. ...Synopsis... A large upper cyclone will be centered over the Mid-MS Valley on Wednesday. This system and associated upper trough will move only modestly eastward through the period. Deep-layer southwesterly flow ahead of the upper low/trough will be maintained over the eastern third of the CONUS. At the surface, low pressure off the SC coast will lift north/northeast. The center of the low will pass near or just offshore from the NC Outer Banks. Showers will be ongoing across the Mid-Atlantic Wednesday morning. While generally poor lower-level lapse rates and little heating will limited instability, some modest midlevel lapse rates will support modest elevated instability, and isolated thunderstorms are possible across coastal NC. A surface cold front will move offshore the Mid-Atlantic during the evening/overnight hours. Severe thunderstorms are not expected. Across the West, a weak upper shortwave trough will quickly move across the Pacific Northwest. A few lightning flashes are possible offshore from the northern CA/OR/WA coasts, but overall chances for inland lightning appear lower than previously indicated given meager elevated instability. ..Leitman.. 12/26/2023 Read more

SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1229 AM CST Tue Dec 26 2023 Valid 271200Z - 281200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected on Wednesday. ...Synopsis... A large upper cyclone will be centered over the Mid-MS Valley on Wednesday. This system and associated upper trough will move only modestly eastward through the period. Deep-layer southwesterly flow ahead of the upper low/trough will be maintained over the eastern third of the CONUS. At the surface, low pressure off the SC coast will lift north/northeast. The center of the low will pass near or just offshore from the NC Outer Banks. Showers will be ongoing across the Mid-Atlantic Wednesday morning. While generally poor lower-level lapse rates and little heating will limited instability, some modest midlevel lapse rates will support modest elevated instability, and isolated thunderstorms are possible across coastal NC. A surface cold front will move offshore the Mid-Atlantic during the evening/overnight hours. Severe thunderstorms are not expected. Across the West, a weak upper shortwave trough will quickly move across the Pacific Northwest. A few lightning flashes are possible offshore from the northern CA/OR/WA coasts, but overall chances for inland lightning appear lower than previously indicated given meager elevated instability. ..Leitman.. 12/26/2023 Read more

MD 2347 CONCERNING BLIZZARD FOR SOUTHEAST NORTH DAKOTA...MUCH OF SOUTH DAKOTA...FAR WESTERN MINNESOTA...AND CENTRAL NEBRASKA
Mesoscale Discussion 2347 NWS Storm Prediction Center Norman OK 0756 PM CST Mon Dec 25 2023 Areas affected...Southeast North Dakota...much of South Dakota...far western Minnesota...and central Nebraska Concerning...Blizzard Valid 260156Z - 260630Z SUMMARY...Heavy snow, freezing rain and blizzard conditions will continue into the overnight hours across portions of the central and northern Plains. DISCUSSION...A surface low has drifted northwest across Iowa through the day today and the 01Z surface analysis shows the surface low southeast of Sioux Falls, SD with a central pressure around 1001mb as it continues to occlude. Strong easterly warm air advection to the north of this surface low continues, and has somewhat overperformed from what most model guidance has shown. Therefore, most areas which were seeing freezing rain earlier have now warmed above freezing. The only exceptions is a confined area across eastern South Dakota and far southeast North Dakota where some freezing rain continues. Elsewhere, a broad region of light to moderate snow continues within a broad deformation zone from far western Minnesota to northern Kansas. Within this, some heavier snow is occurring. Especially across South Dakota and southern North Dakota. Winds are quite strong in most of the deformation zone (20 to 30 knot sustained winds with gusts to 30-45 knots). However, observations show greater visibility restriction farther west where temperatures are in the low 20s and snow ratios are likely higher. This entire region of wintry precipitation will drift slowly east into the overnight hours as the surface low continues to move northwest. ..Bentley.. 12/26/2023 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...FGF...FSD...ABR...GID...BIS...LBF...UNR...BOU... CYS... LAT...LON 40879898 40609958 40530048 40650127 40800181 41090236 42470302 44100338 44970303 46270101 47679779 47739624 47159611 46399671 44539725 42799855 41829875 40879898 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1118 PM CST Mon Dec 25 2023 Valid 261200Z - 271200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not forecast through tonight across the contiguous United States. ...Synopsis... A large, vertically stacked cyclone over the lower MO Valley will slowly move east during the period. An occluded front will slowly move across the Great Lakes and OH Valley. The southern portion of the boundary will undergo frontolysis across the Southeast. Ahead of the cold front, showers and thunderstorms will primarily be relegated to be over the Gulf Stream waters east of FL and the GA coast. Weak instability developing during the day over the Carolinas northward into the central Appalachians may yield sporadic general thunderstorms within a moist conveyor. The limited instability will likely preclude a severe risk with the stronger storms. ..Smith/Bentley.. 12/26/2023 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1118 PM CST Mon Dec 25 2023 Valid 261200Z - 271200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not forecast through tonight across the contiguous United States. ...Synopsis... A large, vertically stacked cyclone over the lower MO Valley will slowly move east during the period. An occluded front will slowly move across the Great Lakes and OH Valley. The southern portion of the boundary will undergo frontolysis across the Southeast. Ahead of the cold front, showers and thunderstorms will primarily be relegated to be over the Gulf Stream waters east of FL and the GA coast. Weak instability developing during the day over the Carolinas northward into the central Appalachians may yield sporadic general thunderstorms within a moist conveyor. The limited instability will likely preclude a severe risk with the stronger storms. ..Smith/Bentley.. 12/26/2023 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1118 PM CST Mon Dec 25 2023 Valid 261200Z - 271200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not forecast through tonight across the contiguous United States. ...Synopsis... A large, vertically stacked cyclone over the lower MO Valley will slowly move east during the period. An occluded front will slowly move across the Great Lakes and OH Valley. The southern portion of the boundary will undergo frontolysis across the Southeast. Ahead of the cold front, showers and thunderstorms will primarily be relegated to be over the Gulf Stream waters east of FL and the GA coast. Weak instability developing during the day over the Carolinas northward into the central Appalachians may yield sporadic general thunderstorms within a moist conveyor. The limited instability will likely preclude a severe risk with the stronger storms. ..Smith/Bentley.. 12/26/2023 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1118 PM CST Mon Dec 25 2023 Valid 261200Z - 271200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not forecast through tonight across the contiguous United States. ...Synopsis... A large, vertically stacked cyclone over the lower MO Valley will slowly move east during the period. An occluded front will slowly move across the Great Lakes and OH Valley. The southern portion of the boundary will undergo frontolysis across the Southeast. Ahead of the cold front, showers and thunderstorms will primarily be relegated to be over the Gulf Stream waters east of FL and the GA coast. Weak instability developing during the day over the Carolinas northward into the central Appalachians may yield sporadic general thunderstorms within a moist conveyor. The limited instability will likely preclude a severe risk with the stronger storms. ..Smith/Bentley.. 12/26/2023 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1118 PM CST Mon Dec 25 2023 Valid 261200Z - 271200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not forecast through tonight across the contiguous United States. ...Synopsis... A large, vertically stacked cyclone over the lower MO Valley will slowly move east during the period. An occluded front will slowly move across the Great Lakes and OH Valley. The southern portion of the boundary will undergo frontolysis across the Southeast. Ahead of the cold front, showers and thunderstorms will primarily be relegated to be over the Gulf Stream waters east of FL and the GA coast. Weak instability developing during the day over the Carolinas northward into the central Appalachians may yield sporadic general thunderstorms within a moist conveyor. The limited instability will likely preclude a severe risk with the stronger storms. ..Smith/Bentley.. 12/26/2023 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1118 PM CST Mon Dec 25 2023 Valid 261200Z - 271200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not forecast through tonight across the contiguous United States. ...Synopsis... A large, vertically stacked cyclone over the lower MO Valley will slowly move east during the period. An occluded front will slowly move across the Great Lakes and OH Valley. The southern portion of the boundary will undergo frontolysis across the Southeast. Ahead of the cold front, showers and thunderstorms will primarily be relegated to be over the Gulf Stream waters east of FL and the GA coast. Weak instability developing during the day over the Carolinas northward into the central Appalachians may yield sporadic general thunderstorms within a moist conveyor. The limited instability will likely preclude a severe risk with the stronger storms. ..Smith/Bentley.. 12/26/2023 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1118 PM CST Mon Dec 25 2023 Valid 261200Z - 271200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not forecast through tonight across the contiguous United States. ...Synopsis... A large, vertically stacked cyclone over the lower MO Valley will slowly move east during the period. An occluded front will slowly move across the Great Lakes and OH Valley. The southern portion of the boundary will undergo frontolysis across the Southeast. Ahead of the cold front, showers and thunderstorms will primarily be relegated to be over the Gulf Stream waters east of FL and the GA coast. Weak instability developing during the day over the Carolinas northward into the central Appalachians may yield sporadic general thunderstorms within a moist conveyor. The limited instability will likely preclude a severe risk with the stronger storms. ..Smith/Bentley.. 12/26/2023 Read more

MD 2346 CONCERNING HEAVY SNOW FOR PORTIONS OF SOUTH-CENTRAL NORTH DAKOTA...CENTRAL AND EASTERN SOUTH DAKOTA...AND NORTH CENTRAL NEBRASKA
Mesoscale Discussion 2346 NWS Storm Prediction Center Norman OK 0331 PM CST Mon Dec 25 2023 Areas affected...Portions of South-Central North Dakota...central and eastern South Dakota...and North Central Nebraska Concerning...Heavy snow Valid 252131Z - 260130Z SUMMARY...Moderate to heavy snow possible this evening, with blizzard conditions at times from south-central North Dakota southward into central South Dakota and north-central Nebraska. DISCUSSION...A deep surface low located across western Iowa has begun to occlude this afternoon while bringing warm and moist air across Iowa and Minnesota into the Dakotas. Aloft, a mid-level low is stacked back to the southwest with very cold air being funneled in by strong northwesterly flow across the High Plains into the Central Plains. Areas of moderate to heavy snow have been ongoing across eastern Nebraska and eastern South Dakota, with a transition to accumulating ice/freezing rain to the northeast. Due to the strength of the surface low, background flow has increased with the strong mass response with surface winds sustained at 25-30 mph gusting as high as 40-50 mph. Blizzard conditions have been observed across central South Dakota with visibility around 1/4 mi and sustained winds at 20-30 mph gusting up to 50 mph. As the surface low shifts back westward through the evening, strengthening mid-level flow around 40-50 kts will overspread portions of the Dakotas into western Nebraska. Warm air overspreading eastern North Dakota into northeastern South Dakota will lead to a transition from snow to freezing rain with potential for ice accumulations. The increased upper-level support across the Dakotas into far northern Nebraska will aid in formation of snow bands capable of 1"+/hr rates along with potential for blowing snow and reduced visibility below 1/4 mi with continued strong surface winds. These conditions will continue to spread westward as the low shifts west through the late evening and overnight. ..Thornton/Hart.. 12/25/2023 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...FGF...FSD...ABR...BIS...LBF...UNR... LAT...LON 42480106 43430210 43880217 44520205 45310195 45890125 46919946 47049925 47499717 46689638 46029630 44159761 43679792 43159838 42649882 42239942 42209951 42160028 42480106 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0643 PM CST Mon Dec 25 2023 Valid 260100Z - 261200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected through tonight. ...Synopsis... A large deep-layer cyclone will become vertically stacked and be centered over the north-central Great Plains through tonight. An occluded cyclone near the IA/MN/NE border will feature a boundary arcing from the Upper Midwest southeastward into OH Valley, with the southern portion of the boundary continuing to progress east as a cold front across the northeast Gulf Coast states tonight. A few widely spaced showers/thunderstorms are possible from GA/SC into the southern Appalachians this evening as well as a low risk for thunderstorm activity across the southern FL Peninsula into the FL Straits. Scant to weak buoyancy sampled by the 00z southeastern U.S. raobs indicates thunderstorms will likely remain weak through tonight. Elsewhere, quiescent conditions will occur in areas displaced from precipitation associated with the deep-layer cyclone over the central U.S., and an approaching shortwave trough over the Pacific Northwest. ..Smith.. 12/26/2023 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0643 PM CST Mon Dec 25 2023 Valid 260100Z - 261200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected through tonight. ...Synopsis... A large deep-layer cyclone will become vertically stacked and be centered over the north-central Great Plains through tonight. An occluded cyclone near the IA/MN/NE border will feature a boundary arcing from the Upper Midwest southeastward into OH Valley, with the southern portion of the boundary continuing to progress east as a cold front across the northeast Gulf Coast states tonight. A few widely spaced showers/thunderstorms are possible from GA/SC into the southern Appalachians this evening as well as a low risk for thunderstorm activity across the southern FL Peninsula into the FL Straits. Scant to weak buoyancy sampled by the 00z southeastern U.S. raobs indicates thunderstorms will likely remain weak through tonight. Elsewhere, quiescent conditions will occur in areas displaced from precipitation associated with the deep-layer cyclone over the central U.S., and an approaching shortwave trough over the Pacific Northwest. ..Smith.. 12/26/2023 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0643 PM CST Mon Dec 25 2023 Valid 260100Z - 261200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected through tonight. ...Synopsis... A large deep-layer cyclone will become vertically stacked and be centered over the north-central Great Plains through tonight. An occluded cyclone near the IA/MN/NE border will feature a boundary arcing from the Upper Midwest southeastward into OH Valley, with the southern portion of the boundary continuing to progress east as a cold front across the northeast Gulf Coast states tonight. A few widely spaced showers/thunderstorms are possible from GA/SC into the southern Appalachians this evening as well as a low risk for thunderstorm activity across the southern FL Peninsula into the FL Straits. Scant to weak buoyancy sampled by the 00z southeastern U.S. raobs indicates thunderstorms will likely remain weak through tonight. Elsewhere, quiescent conditions will occur in areas displaced from precipitation associated with the deep-layer cyclone over the central U.S., and an approaching shortwave trough over the Pacific Northwest. ..Smith.. 12/26/2023 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0643 PM CST Mon Dec 25 2023 Valid 260100Z - 261200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected through tonight. ...Synopsis... A large deep-layer cyclone will become vertically stacked and be centered over the north-central Great Plains through tonight. An occluded cyclone near the IA/MN/NE border will feature a boundary arcing from the Upper Midwest southeastward into OH Valley, with the southern portion of the boundary continuing to progress east as a cold front across the northeast Gulf Coast states tonight. A few widely spaced showers/thunderstorms are possible from GA/SC into the southern Appalachians this evening as well as a low risk for thunderstorm activity across the southern FL Peninsula into the FL Straits. Scant to weak buoyancy sampled by the 00z southeastern U.S. raobs indicates thunderstorms will likely remain weak through tonight. Elsewhere, quiescent conditions will occur in areas displaced from precipitation associated with the deep-layer cyclone over the central U.S., and an approaching shortwave trough over the Pacific Northwest. ..Smith.. 12/26/2023 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0643 PM CST Mon Dec 25 2023 Valid 260100Z - 261200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected through tonight. ...Synopsis... A large deep-layer cyclone will become vertically stacked and be centered over the north-central Great Plains through tonight. An occluded cyclone near the IA/MN/NE border will feature a boundary arcing from the Upper Midwest southeastward into OH Valley, with the southern portion of the boundary continuing to progress east as a cold front across the northeast Gulf Coast states tonight. A few widely spaced showers/thunderstorms are possible from GA/SC into the southern Appalachians this evening as well as a low risk for thunderstorm activity across the southern FL Peninsula into the FL Straits. Scant to weak buoyancy sampled by the 00z southeastern U.S. raobs indicates thunderstorms will likely remain weak through tonight. Elsewhere, quiescent conditions will occur in areas displaced from precipitation associated with the deep-layer cyclone over the central U.S., and an approaching shortwave trough over the Pacific Northwest. ..Smith.. 12/26/2023 Read more

No watches are valid as of Mon Dec 25 22:30:02 UTC 2023.

MD 2346 CONCERNING HEAVY SNOW FOR PORTIONS OF SOUTH-CENTRAL NORTH DAKOTA...CENTRAL AND EASTERN SOUTH DAKOTA...AND NORTH CENTRAL NEBRASKA
Mesoscale Discussion 2346 NWS Storm Prediction Center Norman OK 0331 PM CST Mon Dec 25 2023 Areas affected...Portions of South-Central North Dakota...central and eastern South Dakota...and North Central Nebraska Concerning...Heavy snow Valid 252131Z - 260130Z SUMMARY...Moderate to heavy snow possible this evening, with blizzard conditions at times from south-central North Dakota southward into central South Dakota and north-central Nebraska. DISCUSSION...A deep surface low located across western Iowa has begun to occlude this afternoon while bringing warm and moist air across Iowa and Minnesota into the Dakotas. Aloft, a mid-level low is stacked back to the southwest with very cold air being funneled in by strong northwesterly flow across the High Plains into the Central Plains. Areas of moderate to heavy snow have been ongoing across eastern Nebraska and eastern South Dakota, with a transition to accumulating ice/freezing rain to the northeast. Due to the strength of the surface low, background flow has increased with the strong mass response with surface winds sustained at 25-30 mph gusting as high as 40-50 mph. Blizzard conditions have been observed across central South Dakota with visibility around 1/4 mi and sustained winds at 20-30 mph gusting up to 50 mph. As the surface low shifts back westward through the evening, strengthening mid-level flow around 40-50 kts will overspread portions of the Dakotas into western Nebraska. Warm air overspreading eastern North Dakota into northeastern South Dakota will lead to a transition from snow to freezing rain with potential for ice accumulations. The increased upper-level support across the Dakotas into far northern Nebraska will aid in formation of snow bands capable of 1"+/hr rates along with potential for blowing snow and reduced visibility below 1/4 mi with continued strong surface winds. These conditions will continue to spread westward as the low shifts west through the late evening and overnight. ..Thornton/Hart.. 12/25/2023 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...FGF...FSD...ABR...BIS...LBF...UNR... LAT...LON 42480106 43430210 43880217 44520205 45310195 45890125 46919946 47049925 47499717 46689638 46029630 44159761 43679792 43159838 42649882 42239942 42209951 42160028 42480106 Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0300 PM CST Mon Dec 25 2023 Valid 271200Z - 021200Z The potential for critical fire-weather conditions is low through the extended forecast period. An expansive midlevel low will move gradually eastward from the Middle MS Valley to the central/southern Appalachians from D3/Wednesday through D5/Friday. Along the southern periphery of this feature, strong deep-layer flow will overspread the Lower MS Valley, Gulf Coast, and Southeast. This will promote locally breezy/gusty offshore flow across these areas, though generally cool surface temperatures will limit RH reductions. While ongoing extreme/exceptional drought suggests fuels may be locally receptive to carrying fires across the region, recent rainfall and the marginal wind/RH combination should limit most fire-weather concerns. Elsewhere across the CONUS, a limited overlap of warm/dry/breezy conditions will mitigate fire-weather potential. ..Weinman.. 12/25/2023 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0300 PM CST Mon Dec 25 2023 Valid 271200Z - 021200Z The potential for critical fire-weather conditions is low through the extended forecast period. An expansive midlevel low will move gradually eastward from the Middle MS Valley to the central/southern Appalachians from D3/Wednesday through D5/Friday. Along the southern periphery of this feature, strong deep-layer flow will overspread the Lower MS Valley, Gulf Coast, and Southeast. This will promote locally breezy/gusty offshore flow across these areas, though generally cool surface temperatures will limit RH reductions. While ongoing extreme/exceptional drought suggests fuels may be locally receptive to carrying fires across the region, recent rainfall and the marginal wind/RH combination should limit most fire-weather concerns. Elsewhere across the CONUS, a limited overlap of warm/dry/breezy conditions will mitigate fire-weather potential. ..Weinman.. 12/25/2023 ...Please see www.spc.noaa.gov/fire for graphic product... Read more