Severe Storms

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1104 PM CST Wed Dec 11 2024 Valid 121200Z - 131200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... The risk for thunderstorms appears negligible across the U.S. today through tonight. ...Synopsis... As significant lower/mid-tropospheric cyclogenesis proceeds across northeastern Quebec, models indicate that large-scale mid-level troughing initially encompassing much of the eastern U.S. will begin to lose amplitude later today through tonight. A couple of digging short wave perturbations may maintain broad deep troughing across the Great Lakes and much of the Northeast; however, low amplitude ridging appears likely to overspread the southern Great Plains/lower Mississippi Valley and much of the Gulf States, downstream of weakening mid-level troughing progressing inland of the Pacific coast through much of the Great Basin and Rockies by early Friday. In the wake of the cyclone, and associated trailing cold front stalling to the south of the Florida Peninsula, models indicate that cold surface ridging will maintain a considerable influence while continuing to build across much of the nation to the east of the Rockies. Weak surface troughing may be maintained to the lee of the Rockies, but boundary-layer modification across the western Gulf of Mexico is not expected to yield sufficient moistening within southerly inland return flow to support appreciable destabilization. ...Great Lakes... High resolution model output indicates that the evolving pattern may maintain the development of sustained convective bands across the region, with the most substantive low-level destabilization generally focused across and east of the Lake Huron/Georgian Bay and Lake Ontario vicinities. However, given relatively low (and lowering) equilibrium levels forecast even across these areas, the potential for convection capable of producing lightning appears negligible (i.e., less than 10 percent) today through tonight. ..Kerr.. 12/12/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1104 PM CST Wed Dec 11 2024 Valid 121200Z - 131200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... The risk for thunderstorms appears negligible across the U.S. today through tonight. ...Synopsis... As significant lower/mid-tropospheric cyclogenesis proceeds across northeastern Quebec, models indicate that large-scale mid-level troughing initially encompassing much of the eastern U.S. will begin to lose amplitude later today through tonight. A couple of digging short wave perturbations may maintain broad deep troughing across the Great Lakes and much of the Northeast; however, low amplitude ridging appears likely to overspread the southern Great Plains/lower Mississippi Valley and much of the Gulf States, downstream of weakening mid-level troughing progressing inland of the Pacific coast through much of the Great Basin and Rockies by early Friday. In the wake of the cyclone, and associated trailing cold front stalling to the south of the Florida Peninsula, models indicate that cold surface ridging will maintain a considerable influence while continuing to build across much of the nation to the east of the Rockies. Weak surface troughing may be maintained to the lee of the Rockies, but boundary-layer modification across the western Gulf of Mexico is not expected to yield sufficient moistening within southerly inland return flow to support appreciable destabilization. ...Great Lakes... High resolution model output indicates that the evolving pattern may maintain the development of sustained convective bands across the region, with the most substantive low-level destabilization generally focused across and east of the Lake Huron/Georgian Bay and Lake Ontario vicinities. However, given relatively low (and lowering) equilibrium levels forecast even across these areas, the potential for convection capable of producing lightning appears negligible (i.e., less than 10 percent) today through tonight. ..Kerr.. 12/12/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1104 PM CST Wed Dec 11 2024 Valid 121200Z - 131200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... The risk for thunderstorms appears negligible across the U.S. today through tonight. ...Synopsis... As significant lower/mid-tropospheric cyclogenesis proceeds across northeastern Quebec, models indicate that large-scale mid-level troughing initially encompassing much of the eastern U.S. will begin to lose amplitude later today through tonight. A couple of digging short wave perturbations may maintain broad deep troughing across the Great Lakes and much of the Northeast; however, low amplitude ridging appears likely to overspread the southern Great Plains/lower Mississippi Valley and much of the Gulf States, downstream of weakening mid-level troughing progressing inland of the Pacific coast through much of the Great Basin and Rockies by early Friday. In the wake of the cyclone, and associated trailing cold front stalling to the south of the Florida Peninsula, models indicate that cold surface ridging will maintain a considerable influence while continuing to build across much of the nation to the east of the Rockies. Weak surface troughing may be maintained to the lee of the Rockies, but boundary-layer modification across the western Gulf of Mexico is not expected to yield sufficient moistening within southerly inland return flow to support appreciable destabilization. ...Great Lakes... High resolution model output indicates that the evolving pattern may maintain the development of sustained convective bands across the region, with the most substantive low-level destabilization generally focused across and east of the Lake Huron/Georgian Bay and Lake Ontario vicinities. However, given relatively low (and lowering) equilibrium levels forecast even across these areas, the potential for convection capable of producing lightning appears negligible (i.e., less than 10 percent) today through tonight. ..Kerr.. 12/12/2024 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0648 PM CST Wed Dec 11 2024 Valid 120100Z - 121200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Some lightning remains possible in heavier showers overspreading portions of coastal New England, and offshore of coastal southeastern Florida, this evening. However, the risk for severe weather appears negligible. ...01Z Update... ...Atlantic Seaboard... Thunderstorm development has generally become focused in a narrow pre-frontal line, now mostly offshore near the Gulf Stream. Offshore of northern Mid Atlantic into portions of New England coastal areas, the narrow corridor of pre-frontal destabilization is very weak and based above a stable near-surface layer, but guidance suggests that some lightning remains possible until the cold front clears the Cape Cod and Down East Maine vicinities overnight. ...Lower Great Lakes... Otherwise, to the southwest of the deepening cyclone migrating northward across eastern Quebec, convection allowing model output indicates that at least a couple of longer-lived bands of low-topped convection will develop across the lower Great Lakes beneath cooling, cyclonic lower/mid-tropospheric flow. It appears that this will include one near southeastern Lake Erie coastal areas by late this evening and another across/east of Lake Ontario overnight. However, the potential for sustained convection capable of producing lightning still appears negligible (less than 10 percent). ..Kerr.. 12/12/2024 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0648 PM CST Wed Dec 11 2024 Valid 120100Z - 121200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Some lightning remains possible in heavier showers overspreading portions of coastal New England, and offshore of coastal southeastern Florida, this evening. However, the risk for severe weather appears negligible. ...01Z Update... ...Atlantic Seaboard... Thunderstorm development has generally become focused in a narrow pre-frontal line, now mostly offshore near the Gulf Stream. Offshore of northern Mid Atlantic into portions of New England coastal areas, the narrow corridor of pre-frontal destabilization is very weak and based above a stable near-surface layer, but guidance suggests that some lightning remains possible until the cold front clears the Cape Cod and Down East Maine vicinities overnight. ...Lower Great Lakes... Otherwise, to the southwest of the deepening cyclone migrating northward across eastern Quebec, convection allowing model output indicates that at least a couple of longer-lived bands of low-topped convection will develop across the lower Great Lakes beneath cooling, cyclonic lower/mid-tropospheric flow. It appears that this will include one near southeastern Lake Erie coastal areas by late this evening and another across/east of Lake Ontario overnight. However, the potential for sustained convection capable of producing lightning still appears negligible (less than 10 percent). ..Kerr.. 12/12/2024 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0648 PM CST Wed Dec 11 2024 Valid 120100Z - 121200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Some lightning remains possible in heavier showers overspreading portions of coastal New England, and offshore of coastal southeastern Florida, this evening. However, the risk for severe weather appears negligible. ...01Z Update... ...Atlantic Seaboard... Thunderstorm development has generally become focused in a narrow pre-frontal line, now mostly offshore near the Gulf Stream. Offshore of northern Mid Atlantic into portions of New England coastal areas, the narrow corridor of pre-frontal destabilization is very weak and based above a stable near-surface layer, but guidance suggests that some lightning remains possible until the cold front clears the Cape Cod and Down East Maine vicinities overnight. ...Lower Great Lakes... Otherwise, to the southwest of the deepening cyclone migrating northward across eastern Quebec, convection allowing model output indicates that at least a couple of longer-lived bands of low-topped convection will develop across the lower Great Lakes beneath cooling, cyclonic lower/mid-tropospheric flow. It appears that this will include one near southeastern Lake Erie coastal areas by late this evening and another across/east of Lake Ontario overnight. However, the potential for sustained convection capable of producing lightning still appears negligible (less than 10 percent). ..Kerr.. 12/12/2024 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0648 PM CST Wed Dec 11 2024 Valid 120100Z - 121200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Some lightning remains possible in heavier showers overspreading portions of coastal New England, and offshore of coastal southeastern Florida, this evening. However, the risk for severe weather appears negligible. ...01Z Update... ...Atlantic Seaboard... Thunderstorm development has generally become focused in a narrow pre-frontal line, now mostly offshore near the Gulf Stream. Offshore of northern Mid Atlantic into portions of New England coastal areas, the narrow corridor of pre-frontal destabilization is very weak and based above a stable near-surface layer, but guidance suggests that some lightning remains possible until the cold front clears the Cape Cod and Down East Maine vicinities overnight. ...Lower Great Lakes... Otherwise, to the southwest of the deepening cyclone migrating northward across eastern Quebec, convection allowing model output indicates that at least a couple of longer-lived bands of low-topped convection will develop across the lower Great Lakes beneath cooling, cyclonic lower/mid-tropospheric flow. It appears that this will include one near southeastern Lake Erie coastal areas by late this evening and another across/east of Lake Ontario overnight. However, the potential for sustained convection capable of producing lightning still appears negligible (less than 10 percent). ..Kerr.. 12/12/2024 Read more

No watches are valid as of Wed Dec 11 22:11:01 UTC 2024.

No Mesoscale Discussions are in effect as of Wed Dec 11 22:11:01 UTC 2024.

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0255 PM CST Wed Dec 11 2024 Valid 131200Z - 191200Z Fire weather concerns will remain low in the extended as a progressive pattern brings several storms across the CONUS with potential for cool temperatures and widespread precipitation. Periods of dry/windy conditions are expected across the High/Southern Plains, however, fuels do not appear supportive of large-fire potential at this time. ERC forecasts do indicate fuels will dry, particularly across western Texas into eastern New Mexico, but largely remain below Critical thresholds. ..Thornton.. 12/11/2024 ...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 0255 PM CST Wed Dec 11 2024 Valid 131200Z - 191200Z Fire weather concerns will remain low in the extended as a progressive pattern brings several storms across the CONUS with potential for cool temperatures and widespread precipitation. Periods of dry/windy conditions are expected across the High/Southern Plains, however, fuels do not appear supportive of large-fire potential at this time. ERC forecasts do indicate fuels will dry, particularly across western Texas into eastern New Mexico, but largely remain below Critical thresholds. ..Thornton.. 12/11/2024 ...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 0255 PM CST Wed Dec 11 2024 Valid 131200Z - 191200Z Fire weather concerns will remain low in the extended as a progressive pattern brings several storms across the CONUS with potential for cool temperatures and widespread precipitation. Periods of dry/windy conditions are expected across the High/Southern Plains, however, fuels do not appear supportive of large-fire potential at this time. ERC forecasts do indicate fuels will dry, particularly across western Texas into eastern New Mexico, but largely remain below Critical thresholds. ..Thornton.. 12/11/2024 ...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 0255 PM CST Wed Dec 11 2024 Valid 131200Z - 191200Z Fire weather concerns will remain low in the extended as a progressive pattern brings several storms across the CONUS with potential for cool temperatures and widespread precipitation. Periods of dry/windy conditions are expected across the High/Southern Plains, however, fuels do not appear supportive of large-fire potential at this time. ERC forecasts do indicate fuels will dry, particularly across western Texas into eastern New Mexico, but largely remain below Critical thresholds. ..Thornton.. 12/11/2024 ...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 0255 PM CST Wed Dec 11 2024 Valid 131200Z - 191200Z Fire weather concerns will remain low in the extended as a progressive pattern brings several storms across the CONUS with potential for cool temperatures and widespread precipitation. Periods of dry/windy conditions are expected across the High/Southern Plains, however, fuels do not appear supportive of large-fire potential at this time. ERC forecasts do indicate fuels will dry, particularly across western Texas into eastern New Mexico, but largely remain below Critical thresholds. ..Thornton.. 12/11/2024 ...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 0255 PM CST Wed Dec 11 2024 Valid 131200Z - 191200Z Fire weather concerns will remain low in the extended as a progressive pattern brings several storms across the CONUS with potential for cool temperatures and widespread precipitation. Periods of dry/windy conditions are expected across the High/Southern Plains, however, fuels do not appear supportive of large-fire potential at this time. ERC forecasts do indicate fuels will dry, particularly across western Texas into eastern New Mexico, but largely remain below Critical thresholds. ..Thornton.. 12/11/2024 ...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 0255 PM CST Wed Dec 11 2024 Valid 131200Z - 191200Z Fire weather concerns will remain low in the extended as a progressive pattern brings several storms across the CONUS with potential for cool temperatures and widespread precipitation. Periods of dry/windy conditions are expected across the High/Southern Plains, however, fuels do not appear supportive of large-fire potential at this time. ERC forecasts do indicate fuels will dry, particularly across western Texas into eastern New Mexico, but largely remain below Critical thresholds. ..Thornton.. 12/11/2024 ...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 0255 PM CST Wed Dec 11 2024 Valid 131200Z - 191200Z Fire weather concerns will remain low in the extended as a progressive pattern brings several storms across the CONUS with potential for cool temperatures and widespread precipitation. Periods of dry/windy conditions are expected across the High/Southern Plains, however, fuels do not appear supportive of large-fire potential at this time. ERC forecasts do indicate fuels will dry, particularly across western Texas into eastern New Mexico, but largely remain below Critical thresholds. ..Thornton.. 12/11/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0159 PM CST Wed Dec 11 2024 Valid 112000Z - 121200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS INTO THIS EVENING OVER THE COASTAL MID-ATLANTIC... ...SUMMARY... Severe wind gusts and a tornado or two are possible from the eastern Carolinas to southern New England. ...20Z Update... Severe probabilities have been trimmed along the western portion of the outlook, and reduced along the southern New England coast. For both areas, widespread stratiform rain has limited destabilization and the overall severe threat. Farther south, severe probabilities were removed from the FL peninsula, as convection has decreased in strength and coverage owing to the front lagging south of the large-scale forcing for ascent. The main severe threat through the remainder of the afternoon will be associated with any line segments that can organize along the coastal Mid-Atlantic, posing a risk for severe wind gusts and perhaps a brief tornado. For additional details, reference the latest mesoscale discussion (MCD #2261). ..Weinman.. 12/11/2024 .PREV DISCUSSION... /ISSUED 1026 AM CST Wed Dec 11 2024/ ...Delmarva region into the Carolinas... A large and fast-moving upper trough is tracking across the TN Valley and Gulf Coast region today, with the associated surface cold front sweeping toward the East Coast. Low and mid level wind fields are very strong ahead of the front, with VAD observations and model guidance suggesting 50-70 knot southwesterly flow in the 1-2km layer throughout the area. This will lead to a conditional risk of damaging winds and tornadoes in organized thunderstorms that can develop. However, thermodynamics are quite weak, limiting overall confidence in the extent of severe activity later today. Morning CAM solutions continue to suggest the development of a fine-line of convection this afternoon along the front from the Delmarva region southward into the Carolinas. This appears to be the area of highest confidence in locally gusty/damaging thunderstorm winds and a tornado or two. ...Southern New England... Rapid surface cyclogenesis and intense low-level wind fields will result in some risk of damaging winds in the fast-moving showers that affect Southern New England this afternoon. Forecast soundings show very weak instability, suggesting that frontal activity may struggle to develop robust updrafts/lightning. Will maintain the ongoing SLGT due to the conditional risk, but confidence in the coverage of severe weather is not very high. ...FL... The southern end of the frontal band of convection will sweep across the FL Peninsula this afternoon, with scattered thunderstorms expected to continue. This area will be farthest removed from the synoptic system, but will have better low level moisture/instability. A few strong storms are expected, capable of gusty winds and perhaps a tornado. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0159 PM CST Wed Dec 11 2024 Valid 112000Z - 121200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS INTO THIS EVENING OVER THE COASTAL MID-ATLANTIC... ...SUMMARY... Severe wind gusts and a tornado or two are possible from the eastern Carolinas to southern New England. ...20Z Update... Severe probabilities have been trimmed along the western portion of the outlook, and reduced along the southern New England coast. For both areas, widespread stratiform rain has limited destabilization and the overall severe threat. Farther south, severe probabilities were removed from the FL peninsula, as convection has decreased in strength and coverage owing to the front lagging south of the large-scale forcing for ascent. The main severe threat through the remainder of the afternoon will be associated with any line segments that can organize along the coastal Mid-Atlantic, posing a risk for severe wind gusts and perhaps a brief tornado. For additional details, reference the latest mesoscale discussion (MCD #2261). ..Weinman.. 12/11/2024 .PREV DISCUSSION... /ISSUED 1026 AM CST Wed Dec 11 2024/ ...Delmarva region into the Carolinas... A large and fast-moving upper trough is tracking across the TN Valley and Gulf Coast region today, with the associated surface cold front sweeping toward the East Coast. Low and mid level wind fields are very strong ahead of the front, with VAD observations and model guidance suggesting 50-70 knot southwesterly flow in the 1-2km layer throughout the area. This will lead to a conditional risk of damaging winds and tornadoes in organized thunderstorms that can develop. However, thermodynamics are quite weak, limiting overall confidence in the extent of severe activity later today. Morning CAM solutions continue to suggest the development of a fine-line of convection this afternoon along the front from the Delmarva region southward into the Carolinas. This appears to be the area of highest confidence in locally gusty/damaging thunderstorm winds and a tornado or two. ...Southern New England... Rapid surface cyclogenesis and intense low-level wind fields will result in some risk of damaging winds in the fast-moving showers that affect Southern New England this afternoon. Forecast soundings show very weak instability, suggesting that frontal activity may struggle to develop robust updrafts/lightning. Will maintain the ongoing SLGT due to the conditional risk, but confidence in the coverage of severe weather is not very high. ...FL... The southern end of the frontal band of convection will sweep across the FL Peninsula this afternoon, with scattered thunderstorms expected to continue. This area will be farthest removed from the synoptic system, but will have better low level moisture/instability. A few strong storms are expected, capable of gusty winds and perhaps a tornado. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0159 PM CST Wed Dec 11 2024 Valid 112000Z - 121200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS INTO THIS EVENING OVER THE COASTAL MID-ATLANTIC... ...SUMMARY... Severe wind gusts and a tornado or two are possible from the eastern Carolinas to southern New England. ...20Z Update... Severe probabilities have been trimmed along the western portion of the outlook, and reduced along the southern New England coast. For both areas, widespread stratiform rain has limited destabilization and the overall severe threat. Farther south, severe probabilities were removed from the FL peninsula, as convection has decreased in strength and coverage owing to the front lagging south of the large-scale forcing for ascent. The main severe threat through the remainder of the afternoon will be associated with any line segments that can organize along the coastal Mid-Atlantic, posing a risk for severe wind gusts and perhaps a brief tornado. For additional details, reference the latest mesoscale discussion (MCD #2261). ..Weinman.. 12/11/2024 .PREV DISCUSSION... /ISSUED 1026 AM CST Wed Dec 11 2024/ ...Delmarva region into the Carolinas... A large and fast-moving upper trough is tracking across the TN Valley and Gulf Coast region today, with the associated surface cold front sweeping toward the East Coast. Low and mid level wind fields are very strong ahead of the front, with VAD observations and model guidance suggesting 50-70 knot southwesterly flow in the 1-2km layer throughout the area. This will lead to a conditional risk of damaging winds and tornadoes in organized thunderstorms that can develop. However, thermodynamics are quite weak, limiting overall confidence in the extent of severe activity later today. Morning CAM solutions continue to suggest the development of a fine-line of convection this afternoon along the front from the Delmarva region southward into the Carolinas. This appears to be the area of highest confidence in locally gusty/damaging thunderstorm winds and a tornado or two. ...Southern New England... Rapid surface cyclogenesis and intense low-level wind fields will result in some risk of damaging winds in the fast-moving showers that affect Southern New England this afternoon. Forecast soundings show very weak instability, suggesting that frontal activity may struggle to develop robust updrafts/lightning. Will maintain the ongoing SLGT due to the conditional risk, but confidence in the coverage of severe weather is not very high. ...FL... The southern end of the frontal band of convection will sweep across the FL Peninsula this afternoon, with scattered thunderstorms expected to continue. This area will be farthest removed from the synoptic system, but will have better low level moisture/instability. A few strong storms are expected, capable of gusty winds and perhaps a tornado. Read more