Severe Storms

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0129 PM CST Tue Dec 10 2024 Valid 111200Z - 121200Z Minor changes were made to the D2 Elevated area to extend areas to the coastline in Ventura/Los Angeles county. Otherwise, the outlook remains on track. See previous discussion below for more information. ..Thornton.. 12/10/2024 .PREV DISCUSSION... /ISSUED 0132 AM CST Tue Dec 10 2024/ ...Synopsis... Elevated to locally critical fire weather conditions are anticipated Wednesday along the southern CA coast as an ongoing offshore wind event begins to wane. This event is expected to peak in intensity this morning (Tuesday) before gradually abating through the late afternoon and overnight hours. Critical (20+ mph) wind speeds will likely be ongoing within the coastal mountains by 12 UTC Wednesday, but winds are expected to weaken steadily through the day as the surface high over the Great Basin shifts southeast into the Four Corners/southern High Plains. Regardless, overnight RH recovery will be minimal due to the long-duration nature of the offshore wind event heading into Wednesday morning, which will promote several hours of elevated to locally critical fire weather conditions (most likely through 18 UTC). By late Wednesday afternoon, 15-25 mph winds should be confined to typically breezy locations within the higher terrain, though widespread 5-15% RH values should persist, given increasing subsidence and diurnal heating. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0129 PM CST Tue Dec 10 2024 Valid 111200Z - 121200Z Minor changes were made to the D2 Elevated area to extend areas to the coastline in Ventura/Los Angeles county. Otherwise, the outlook remains on track. See previous discussion below for more information. ..Thornton.. 12/10/2024 .PREV DISCUSSION... /ISSUED 0132 AM CST Tue Dec 10 2024/ ...Synopsis... Elevated to locally critical fire weather conditions are anticipated Wednesday along the southern CA coast as an ongoing offshore wind event begins to wane. This event is expected to peak in intensity this morning (Tuesday) before gradually abating through the late afternoon and overnight hours. Critical (20+ mph) wind speeds will likely be ongoing within the coastal mountains by 12 UTC Wednesday, but winds are expected to weaken steadily through the day as the surface high over the Great Basin shifts southeast into the Four Corners/southern High Plains. Regardless, overnight RH recovery will be minimal due to the long-duration nature of the offshore wind event heading into Wednesday morning, which will promote several hours of elevated to locally critical fire weather conditions (most likely through 18 UTC). By late Wednesday afternoon, 15-25 mph winds should be confined to typically breezy locations within the higher terrain, though widespread 5-15% RH values should persist, given increasing subsidence and diurnal heating. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0129 PM CST Tue Dec 10 2024 Valid 111200Z - 121200Z Minor changes were made to the D2 Elevated area to extend areas to the coastline in Ventura/Los Angeles county. Otherwise, the outlook remains on track. See previous discussion below for more information. ..Thornton.. 12/10/2024 .PREV DISCUSSION... /ISSUED 0132 AM CST Tue Dec 10 2024/ ...Synopsis... Elevated to locally critical fire weather conditions are anticipated Wednesday along the southern CA coast as an ongoing offshore wind event begins to wane. This event is expected to peak in intensity this morning (Tuesday) before gradually abating through the late afternoon and overnight hours. Critical (20+ mph) wind speeds will likely be ongoing within the coastal mountains by 12 UTC Wednesday, but winds are expected to weaken steadily through the day as the surface high over the Great Basin shifts southeast into the Four Corners/southern High Plains. Regardless, overnight RH recovery will be minimal due to the long-duration nature of the offshore wind event heading into Wednesday morning, which will promote several hours of elevated to locally critical fire weather conditions (most likely through 18 UTC). By late Wednesday afternoon, 15-25 mph winds should be confined to typically breezy locations within the higher terrain, though widespread 5-15% RH values should persist, given increasing subsidence and diurnal heating. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 1250 PM CST Tue Dec 10 2024 Valid 121200Z - 131200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorms are not expected on Thursday. ...Discussion... A quiescent synoptic pattern for thunderstorm activity is expected on Thursday. In the wake of a cold front pushing offshore of the entire East Coast on D2, an Arctic air mass will settle into the Upper Great Lakes. A couple lightning flashes are possible in the heaviest lake-effect snow bands immediately downstream of the Lower Great Lakes, but probabilities appear to be less than 10 percent. Otherwise, modified moisture return will commence across the western Gulf Coast, well downstream of the next shortwave trough progressing into the Great Basin vicinity. Conditions appear too stable for thunderstorms with this wave through 12Z Friday. ..Grams.. 12/10/2024 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 1250 PM CST Tue Dec 10 2024 Valid 121200Z - 131200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorms are not expected on Thursday. ...Discussion... A quiescent synoptic pattern for thunderstorm activity is expected on Thursday. In the wake of a cold front pushing offshore of the entire East Coast on D2, an Arctic air mass will settle into the Upper Great Lakes. A couple lightning flashes are possible in the heaviest lake-effect snow bands immediately downstream of the Lower Great Lakes, but probabilities appear to be less than 10 percent. Otherwise, modified moisture return will commence across the western Gulf Coast, well downstream of the next shortwave trough progressing into the Great Basin vicinity. Conditions appear too stable for thunderstorms with this wave through 12Z Friday. ..Grams.. 12/10/2024 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 1250 PM CST Tue Dec 10 2024 Valid 121200Z - 131200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorms are not expected on Thursday. ...Discussion... A quiescent synoptic pattern for thunderstorm activity is expected on Thursday. In the wake of a cold front pushing offshore of the entire East Coast on D2, an Arctic air mass will settle into the Upper Great Lakes. A couple lightning flashes are possible in the heaviest lake-effect snow bands immediately downstream of the Lower Great Lakes, but probabilities appear to be less than 10 percent. Otherwise, modified moisture return will commence across the western Gulf Coast, well downstream of the next shortwave trough progressing into the Great Basin vicinity. Conditions appear too stable for thunderstorms with this wave through 12Z Friday. ..Grams.. 12/10/2024 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 1250 PM CST Tue Dec 10 2024 Valid 121200Z - 131200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorms are not expected on Thursday. ...Discussion... A quiescent synoptic pattern for thunderstorm activity is expected on Thursday. In the wake of a cold front pushing offshore of the entire East Coast on D2, an Arctic air mass will settle into the Upper Great Lakes. A couple lightning flashes are possible in the heaviest lake-effect snow bands immediately downstream of the Lower Great Lakes, but probabilities appear to be less than 10 percent. Otherwise, modified moisture return will commence across the western Gulf Coast, well downstream of the next shortwave trough progressing into the Great Basin vicinity. Conditions appear too stable for thunderstorms with this wave through 12Z Friday. ..Grams.. 12/10/2024 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 1250 PM CST Tue Dec 10 2024 Valid 121200Z - 131200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorms are not expected on Thursday. ...Discussion... A quiescent synoptic pattern for thunderstorm activity is expected on Thursday. In the wake of a cold front pushing offshore of the entire East Coast on D2, an Arctic air mass will settle into the Upper Great Lakes. A couple lightning flashes are possible in the heaviest lake-effect snow bands immediately downstream of the Lower Great Lakes, but probabilities appear to be less than 10 percent. Otherwise, modified moisture return will commence across the western Gulf Coast, well downstream of the next shortwave trough progressing into the Great Basin vicinity. Conditions appear too stable for thunderstorms with this wave through 12Z Friday. ..Grams.. 12/10/2024 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 1250 PM CST Tue Dec 10 2024 Valid 121200Z - 131200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorms are not expected on Thursday. ...Discussion... A quiescent synoptic pattern for thunderstorm activity is expected on Thursday. In the wake of a cold front pushing offshore of the entire East Coast on D2, an Arctic air mass will settle into the Upper Great Lakes. A couple lightning flashes are possible in the heaviest lake-effect snow bands immediately downstream of the Lower Great Lakes, but probabilities appear to be less than 10 percent. Otherwise, modified moisture return will commence across the western Gulf Coast, well downstream of the next shortwave trough progressing into the Great Basin vicinity. Conditions appear too stable for thunderstorms with this wave through 12Z Friday. ..Grams.. 12/10/2024 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 1250 PM CST Tue Dec 10 2024 Valid 121200Z - 131200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorms are not expected on Thursday. ...Discussion... A quiescent synoptic pattern for thunderstorm activity is expected on Thursday. In the wake of a cold front pushing offshore of the entire East Coast on D2, an Arctic air mass will settle into the Upper Great Lakes. A couple lightning flashes are possible in the heaviest lake-effect snow bands immediately downstream of the Lower Great Lakes, but probabilities appear to be less than 10 percent. Otherwise, modified moisture return will commence across the western Gulf Coast, well downstream of the next shortwave trough progressing into the Great Basin vicinity. Conditions appear too stable for thunderstorms with this wave through 12Z Friday. ..Grams.. 12/10/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1122 AM CST Tue Dec 10 2024 Valid 111200Z - 121200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS IN THE EASTERN NC VICINITY... ...SUMMARY... Isolated severe thunderstorms are possible across many of the East Coast States. The most probable area for a few tornadoes and damaging winds is centered on eastern North Carolina during Wednesday afternoon. ...Synopsis... A longwave trough will extend from south-central Canada to the northern Gulf Coast on Wednesday morning. A vigorous shortwave impulse embedded within the basal portion of the trough will rapidly advance into the Mid-Atlantic States by early evening and pivot north to the St. Lawrence Valley Wednesday night. This will yield an increasingly negative tilt to the broad trough, with associated intensification of deep-layer flow fields and surface cyclogenesis. ...Eastern NC vicinity... A plume of mid 60s surface dew points are expected to advect north across parts of the eastern Carolinas into southeast VA by Wednesday afternoon. Boundary-layer destabilization should be tempered by preceding weak convection within the warm conveyor and pervasive cloudiness limiting insolation. Still, consensus of guidance suggests the relatively warmest surface temperatures should occur across eastern NC. Amid weak lapse rates, buoyancy should remain meager to around 500 J/kg along the coast. Even so, favorable timing of the synoptic evolution with respect to the diurnal heating cycle should yield a strongly forced convective line along the progressive cold front. Some guidance suggests a pre-frontal band of surface-based storms might separately develop in low-level confluence over coastal NC and the Outer Banks. At least a few embedded supercells are plausible, yielding a tornado and wind threat. The progressive nature of the front suggests the tornado threat may be more sporadic with shorter-lived circulations embedded in the line until it shifts offshore. ...Eastern Gulf/South Atlantic Coasts... Deep convection should be ongoing across parts of the FL Panhandle into south GA at 12Z Wednesday. Despite the time of day, the northern periphery of rich eastern Gulf moisture in conjunction with enhanced low-level hodograph curvature will support a localized tornado/wind threat through midday. Some potential may persist into the afternoon over parts of the north/central FL Peninsula but low-level winds will become more veered with time as the shortwave trough rapidly advances away from this region. The northern extent of the threat into GA/SC will be predicated on the degree of surface-based destabilization, which appears to be a relative min in the Southeast. ...Northeast... Primary thunderstorm activity should be in the form of sporadic lightning flashes amid scant elevated buoyancy within the low-level warm conveyor. Some CAM guidance does suggest a low-topped convective line may develop along the eastward-surging cold front during the afternoon/evening. Surface-based instability may remain negligible and lightning production appears unlikely. But with intensifying wind fields, potential remains for strong surface gusts capable of tree damage. ..Grams.. 12/10/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1122 AM CST Tue Dec 10 2024 Valid 111200Z - 121200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS IN THE EASTERN NC VICINITY... ...SUMMARY... Isolated severe thunderstorms are possible across many of the East Coast States. The most probable area for a few tornadoes and damaging winds is centered on eastern North Carolina during Wednesday afternoon. ...Synopsis... A longwave trough will extend from south-central Canada to the northern Gulf Coast on Wednesday morning. A vigorous shortwave impulse embedded within the basal portion of the trough will rapidly advance into the Mid-Atlantic States by early evening and pivot north to the St. Lawrence Valley Wednesday night. This will yield an increasingly negative tilt to the broad trough, with associated intensification of deep-layer flow fields and surface cyclogenesis. ...Eastern NC vicinity... A plume of mid 60s surface dew points are expected to advect north across parts of the eastern Carolinas into southeast VA by Wednesday afternoon. Boundary-layer destabilization should be tempered by preceding weak convection within the warm conveyor and pervasive cloudiness limiting insolation. Still, consensus of guidance suggests the relatively warmest surface temperatures should occur across eastern NC. Amid weak lapse rates, buoyancy should remain meager to around 500 J/kg along the coast. Even so, favorable timing of the synoptic evolution with respect to the diurnal heating cycle should yield a strongly forced convective line along the progressive cold front. Some guidance suggests a pre-frontal band of surface-based storms might separately develop in low-level confluence over coastal NC and the Outer Banks. At least a few embedded supercells are plausible, yielding a tornado and wind threat. The progressive nature of the front suggests the tornado threat may be more sporadic with shorter-lived circulations embedded in the line until it shifts offshore. ...Eastern Gulf/South Atlantic Coasts... Deep convection should be ongoing across parts of the FL Panhandle into south GA at 12Z Wednesday. Despite the time of day, the northern periphery of rich eastern Gulf moisture in conjunction with enhanced low-level hodograph curvature will support a localized tornado/wind threat through midday. Some potential may persist into the afternoon over parts of the north/central FL Peninsula but low-level winds will become more veered with time as the shortwave trough rapidly advances away from this region. The northern extent of the threat into GA/SC will be predicated on the degree of surface-based destabilization, which appears to be a relative min in the Southeast. ...Northeast... Primary thunderstorm activity should be in the form of sporadic lightning flashes amid scant elevated buoyancy within the low-level warm conveyor. Some CAM guidance does suggest a low-topped convective line may develop along the eastward-surging cold front during the afternoon/evening. Surface-based instability may remain negligible and lightning production appears unlikely. But with intensifying wind fields, potential remains for strong surface gusts capable of tree damage. ..Grams.. 12/10/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1122 AM CST Tue Dec 10 2024 Valid 111200Z - 121200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS IN THE EASTERN NC VICINITY... ...SUMMARY... Isolated severe thunderstorms are possible across many of the East Coast States. The most probable area for a few tornadoes and damaging winds is centered on eastern North Carolina during Wednesday afternoon. ...Synopsis... A longwave trough will extend from south-central Canada to the northern Gulf Coast on Wednesday morning. A vigorous shortwave impulse embedded within the basal portion of the trough will rapidly advance into the Mid-Atlantic States by early evening and pivot north to the St. Lawrence Valley Wednesday night. This will yield an increasingly negative tilt to the broad trough, with associated intensification of deep-layer flow fields and surface cyclogenesis. ...Eastern NC vicinity... A plume of mid 60s surface dew points are expected to advect north across parts of the eastern Carolinas into southeast VA by Wednesday afternoon. Boundary-layer destabilization should be tempered by preceding weak convection within the warm conveyor and pervasive cloudiness limiting insolation. Still, consensus of guidance suggests the relatively warmest surface temperatures should occur across eastern NC. Amid weak lapse rates, buoyancy should remain meager to around 500 J/kg along the coast. Even so, favorable timing of the synoptic evolution with respect to the diurnal heating cycle should yield a strongly forced convective line along the progressive cold front. Some guidance suggests a pre-frontal band of surface-based storms might separately develop in low-level confluence over coastal NC and the Outer Banks. At least a few embedded supercells are plausible, yielding a tornado and wind threat. The progressive nature of the front suggests the tornado threat may be more sporadic with shorter-lived circulations embedded in the line until it shifts offshore. ...Eastern Gulf/South Atlantic Coasts... Deep convection should be ongoing across parts of the FL Panhandle into south GA at 12Z Wednesday. Despite the time of day, the northern periphery of rich eastern Gulf moisture in conjunction with enhanced low-level hodograph curvature will support a localized tornado/wind threat through midday. Some potential may persist into the afternoon over parts of the north/central FL Peninsula but low-level winds will become more veered with time as the shortwave trough rapidly advances away from this region. The northern extent of the threat into GA/SC will be predicated on the degree of surface-based destabilization, which appears to be a relative min in the Southeast. ...Northeast... Primary thunderstorm activity should be in the form of sporadic lightning flashes amid scant elevated buoyancy within the low-level warm conveyor. Some CAM guidance does suggest a low-topped convective line may develop along the eastward-surging cold front during the afternoon/evening. Surface-based instability may remain negligible and lightning production appears unlikely. But with intensifying wind fields, potential remains for strong surface gusts capable of tree damage. ..Grams.. 12/10/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1122 AM CST Tue Dec 10 2024 Valid 111200Z - 121200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS IN THE EASTERN NC VICINITY... ...SUMMARY... Isolated severe thunderstorms are possible across many of the East Coast States. The most probable area for a few tornadoes and damaging winds is centered on eastern North Carolina during Wednesday afternoon. ...Synopsis... A longwave trough will extend from south-central Canada to the northern Gulf Coast on Wednesday morning. A vigorous shortwave impulse embedded within the basal portion of the trough will rapidly advance into the Mid-Atlantic States by early evening and pivot north to the St. Lawrence Valley Wednesday night. This will yield an increasingly negative tilt to the broad trough, with associated intensification of deep-layer flow fields and surface cyclogenesis. ...Eastern NC vicinity... A plume of mid 60s surface dew points are expected to advect north across parts of the eastern Carolinas into southeast VA by Wednesday afternoon. Boundary-layer destabilization should be tempered by preceding weak convection within the warm conveyor and pervasive cloudiness limiting insolation. Still, consensus of guidance suggests the relatively warmest surface temperatures should occur across eastern NC. Amid weak lapse rates, buoyancy should remain meager to around 500 J/kg along the coast. Even so, favorable timing of the synoptic evolution with respect to the diurnal heating cycle should yield a strongly forced convective line along the progressive cold front. Some guidance suggests a pre-frontal band of surface-based storms might separately develop in low-level confluence over coastal NC and the Outer Banks. At least a few embedded supercells are plausible, yielding a tornado and wind threat. The progressive nature of the front suggests the tornado threat may be more sporadic with shorter-lived circulations embedded in the line until it shifts offshore. ...Eastern Gulf/South Atlantic Coasts... Deep convection should be ongoing across parts of the FL Panhandle into south GA at 12Z Wednesday. Despite the time of day, the northern periphery of rich eastern Gulf moisture in conjunction with enhanced low-level hodograph curvature will support a localized tornado/wind threat through midday. Some potential may persist into the afternoon over parts of the north/central FL Peninsula but low-level winds will become more veered with time as the shortwave trough rapidly advances away from this region. The northern extent of the threat into GA/SC will be predicated on the degree of surface-based destabilization, which appears to be a relative min in the Southeast. ...Northeast... Primary thunderstorm activity should be in the form of sporadic lightning flashes amid scant elevated buoyancy within the low-level warm conveyor. Some CAM guidance does suggest a low-topped convective line may develop along the eastward-surging cold front during the afternoon/evening. Surface-based instability may remain negligible and lightning production appears unlikely. But with intensifying wind fields, potential remains for strong surface gusts capable of tree damage. ..Grams.. 12/10/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1122 AM CST Tue Dec 10 2024 Valid 111200Z - 121200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS IN THE EASTERN NC VICINITY... ...SUMMARY... Isolated severe thunderstorms are possible across many of the East Coast States. The most probable area for a few tornadoes and damaging winds is centered on eastern North Carolina during Wednesday afternoon. ...Synopsis... A longwave trough will extend from south-central Canada to the northern Gulf Coast on Wednesday morning. A vigorous shortwave impulse embedded within the basal portion of the trough will rapidly advance into the Mid-Atlantic States by early evening and pivot north to the St. Lawrence Valley Wednesday night. This will yield an increasingly negative tilt to the broad trough, with associated intensification of deep-layer flow fields and surface cyclogenesis. ...Eastern NC vicinity... A plume of mid 60s surface dew points are expected to advect north across parts of the eastern Carolinas into southeast VA by Wednesday afternoon. Boundary-layer destabilization should be tempered by preceding weak convection within the warm conveyor and pervasive cloudiness limiting insolation. Still, consensus of guidance suggests the relatively warmest surface temperatures should occur across eastern NC. Amid weak lapse rates, buoyancy should remain meager to around 500 J/kg along the coast. Even so, favorable timing of the synoptic evolution with respect to the diurnal heating cycle should yield a strongly forced convective line along the progressive cold front. Some guidance suggests a pre-frontal band of surface-based storms might separately develop in low-level confluence over coastal NC and the Outer Banks. At least a few embedded supercells are plausible, yielding a tornado and wind threat. The progressive nature of the front suggests the tornado threat may be more sporadic with shorter-lived circulations embedded in the line until it shifts offshore. ...Eastern Gulf/South Atlantic Coasts... Deep convection should be ongoing across parts of the FL Panhandle into south GA at 12Z Wednesday. Despite the time of day, the northern periphery of rich eastern Gulf moisture in conjunction with enhanced low-level hodograph curvature will support a localized tornado/wind threat through midday. Some potential may persist into the afternoon over parts of the north/central FL Peninsula but low-level winds will become more veered with time as the shortwave trough rapidly advances away from this region. The northern extent of the threat into GA/SC will be predicated on the degree of surface-based destabilization, which appears to be a relative min in the Southeast. ...Northeast... Primary thunderstorm activity should be in the form of sporadic lightning flashes amid scant elevated buoyancy within the low-level warm conveyor. Some CAM guidance does suggest a low-topped convective line may develop along the eastward-surging cold front during the afternoon/evening. Surface-based instability may remain negligible and lightning production appears unlikely. But with intensifying wind fields, potential remains for strong surface gusts capable of tree damage. ..Grams.. 12/10/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1122 AM CST Tue Dec 10 2024 Valid 111200Z - 121200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS IN THE EASTERN NC VICINITY... ...SUMMARY... Isolated severe thunderstorms are possible across many of the East Coast States. The most probable area for a few tornadoes and damaging winds is centered on eastern North Carolina during Wednesday afternoon. ...Synopsis... A longwave trough will extend from south-central Canada to the northern Gulf Coast on Wednesday morning. A vigorous shortwave impulse embedded within the basal portion of the trough will rapidly advance into the Mid-Atlantic States by early evening and pivot north to the St. Lawrence Valley Wednesday night. This will yield an increasingly negative tilt to the broad trough, with associated intensification of deep-layer flow fields and surface cyclogenesis. ...Eastern NC vicinity... A plume of mid 60s surface dew points are expected to advect north across parts of the eastern Carolinas into southeast VA by Wednesday afternoon. Boundary-layer destabilization should be tempered by preceding weak convection within the warm conveyor and pervasive cloudiness limiting insolation. Still, consensus of guidance suggests the relatively warmest surface temperatures should occur across eastern NC. Amid weak lapse rates, buoyancy should remain meager to around 500 J/kg along the coast. Even so, favorable timing of the synoptic evolution with respect to the diurnal heating cycle should yield a strongly forced convective line along the progressive cold front. Some guidance suggests a pre-frontal band of surface-based storms might separately develop in low-level confluence over coastal NC and the Outer Banks. At least a few embedded supercells are plausible, yielding a tornado and wind threat. The progressive nature of the front suggests the tornado threat may be more sporadic with shorter-lived circulations embedded in the line until it shifts offshore. ...Eastern Gulf/South Atlantic Coasts... Deep convection should be ongoing across parts of the FL Panhandle into south GA at 12Z Wednesday. Despite the time of day, the northern periphery of rich eastern Gulf moisture in conjunction with enhanced low-level hodograph curvature will support a localized tornado/wind threat through midday. Some potential may persist into the afternoon over parts of the north/central FL Peninsula but low-level winds will become more veered with time as the shortwave trough rapidly advances away from this region. The northern extent of the threat into GA/SC will be predicated on the degree of surface-based destabilization, which appears to be a relative min in the Southeast. ...Northeast... Primary thunderstorm activity should be in the form of sporadic lightning flashes amid scant elevated buoyancy within the low-level warm conveyor. Some CAM guidance does suggest a low-topped convective line may develop along the eastward-surging cold front during the afternoon/evening. Surface-based instability may remain negligible and lightning production appears unlikely. But with intensifying wind fields, potential remains for strong surface gusts capable of tree damage. ..Grams.. 12/10/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1122 AM CST Tue Dec 10 2024 Valid 111200Z - 121200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS IN THE EASTERN NC VICINITY... ...SUMMARY... Isolated severe thunderstorms are possible across many of the East Coast States. The most probable area for a few tornadoes and damaging winds is centered on eastern North Carolina during Wednesday afternoon. ...Synopsis... A longwave trough will extend from south-central Canada to the northern Gulf Coast on Wednesday morning. A vigorous shortwave impulse embedded within the basal portion of the trough will rapidly advance into the Mid-Atlantic States by early evening and pivot north to the St. Lawrence Valley Wednesday night. This will yield an increasingly negative tilt to the broad trough, with associated intensification of deep-layer flow fields and surface cyclogenesis. ...Eastern NC vicinity... A plume of mid 60s surface dew points are expected to advect north across parts of the eastern Carolinas into southeast VA by Wednesday afternoon. Boundary-layer destabilization should be tempered by preceding weak convection within the warm conveyor and pervasive cloudiness limiting insolation. Still, consensus of guidance suggests the relatively warmest surface temperatures should occur across eastern NC. Amid weak lapse rates, buoyancy should remain meager to around 500 J/kg along the coast. Even so, favorable timing of the synoptic evolution with respect to the diurnal heating cycle should yield a strongly forced convective line along the progressive cold front. Some guidance suggests a pre-frontal band of surface-based storms might separately develop in low-level confluence over coastal NC and the Outer Banks. At least a few embedded supercells are plausible, yielding a tornado and wind threat. The progressive nature of the front suggests the tornado threat may be more sporadic with shorter-lived circulations embedded in the line until it shifts offshore. ...Eastern Gulf/South Atlantic Coasts... Deep convection should be ongoing across parts of the FL Panhandle into south GA at 12Z Wednesday. Despite the time of day, the northern periphery of rich eastern Gulf moisture in conjunction with enhanced low-level hodograph curvature will support a localized tornado/wind threat through midday. Some potential may persist into the afternoon over parts of the north/central FL Peninsula but low-level winds will become more veered with time as the shortwave trough rapidly advances away from this region. The northern extent of the threat into GA/SC will be predicated on the degree of surface-based destabilization, which appears to be a relative min in the Southeast. ...Northeast... Primary thunderstorm activity should be in the form of sporadic lightning flashes amid scant elevated buoyancy within the low-level warm conveyor. Some CAM guidance does suggest a low-topped convective line may develop along the eastward-surging cold front during the afternoon/evening. Surface-based instability may remain negligible and lightning production appears unlikely. But with intensifying wind fields, potential remains for strong surface gusts capable of tree damage. ..Grams.. 12/10/2024 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1044 AM CST Tue Dec 10 2024 Valid 101700Z - 111200Z ...EXTREMELY CRITICAL FIRE WEATHER AREA FOR PORTIONS OF THE SOUTHERN CALIFORNIA COAST... ...CRITICAL FIRE WEATHER AREA FOR THE SOUTHERN CALIFORNIA COAST... Critical to Extremely Critical fire weather conditions continue across southern California this morning. Peak wind gusts of 50-70 mph (localized 80-90 mph) with a fire ongoing in Malibu. Guidance suggests that the peak winds have occurred this morning, with gradual weakening through the afternoon. However, Critical to locally Extremely Critical conditions will continue across the mountains and foothills through the rest of the afternoon and into the evening. Some lingering Elevated to Critical conditions will continue into Wednesday morning. Minor changes were made to bring the Critical to the coast in Ventura and Los Angeles county in alignment with ongoing surface observations. ..Thornton.. 12/10/2024 .PREV DISCUSSION... /ISSUED 0102 AM CST Tue Dec 10 2024/ ...Synopsis... Critical to extremely critical fire weather conditions are expected today along the southern CA coast, posing a high-end fire weather threat. 06 UTC surface observations within the southern CA coastal mountains are showing widespread RH reductions into the low to mid teens with sustained winds between 25-35 mph and frequent gusts upwards of 40-50 mph (occasionally gusting to 60-75 mph in a few locations). Other observed trends across the region suggest that winds will increase through the early to mid-morning hours (most likely peaking during the 12-17 UTC period). Surface pressure obs across northeast NV are reporting a 1036 mb surface high with further pressure rises to around 1037-1039 mb expected through 15 UTC. Additionally, latest upper-air analyses show a low to mid-level cold front pushing south into southern CA. The arrival of the cooler/more dense air mass and stronger mid-level flow, accompanied by further surface pressure rises, should result in strengthening winds through the morning hours. The observed LAX-DAG pressure gradient has also been trending lower (i.e. stronger) than depicted by most deterministic solutions, but guidance that has captured recent trends well shows increasingly widespread 60+ mph wind gusts within the Sierra Madre, San Gabriel, and San Jacinto mountains by mid-morning. Single-digit RH values will also become more common by the afternoon hours, given the duration of the downslope wind event coupled with the diurnal heating cycle. The prolonged nature of the event is also promoting rapid drying of 1- and 10-hour fuels, which will increase the fire weather threat through the day. Extremely critical wind speeds will gradually begin to abate after roughly 20 UTC, as the surface high over the Great Basin begins to weaken. However, widespread critical fire weather conditions should still persist well into early Wednesday morning. ...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 1044 AM CST Tue Dec 10 2024 Valid 101700Z - 111200Z ...EXTREMELY CRITICAL FIRE WEATHER AREA FOR PORTIONS OF THE SOUTHERN CALIFORNIA COAST... ...CRITICAL FIRE WEATHER AREA FOR THE SOUTHERN CALIFORNIA COAST... Critical to Extremely Critical fire weather conditions continue across southern California this morning. Peak wind gusts of 50-70 mph (localized 80-90 mph) with a fire ongoing in Malibu. Guidance suggests that the peak winds have occurred this morning, with gradual weakening through the afternoon. However, Critical to locally Extremely Critical conditions will continue across the mountains and foothills through the rest of the afternoon and into the evening. Some lingering Elevated to Critical conditions will continue into Wednesday morning. Minor changes were made to bring the Critical to the coast in Ventura and Los Angeles county in alignment with ongoing surface observations. ..Thornton.. 12/10/2024 .PREV DISCUSSION... /ISSUED 0102 AM CST Tue Dec 10 2024/ ...Synopsis... Critical to extremely critical fire weather conditions are expected today along the southern CA coast, posing a high-end fire weather threat. 06 UTC surface observations within the southern CA coastal mountains are showing widespread RH reductions into the low to mid teens with sustained winds between 25-35 mph and frequent gusts upwards of 40-50 mph (occasionally gusting to 60-75 mph in a few locations). Other observed trends across the region suggest that winds will increase through the early to mid-morning hours (most likely peaking during the 12-17 UTC period). Surface pressure obs across northeast NV are reporting a 1036 mb surface high with further pressure rises to around 1037-1039 mb expected through 15 UTC. Additionally, latest upper-air analyses show a low to mid-level cold front pushing south into southern CA. The arrival of the cooler/more dense air mass and stronger mid-level flow, accompanied by further surface pressure rises, should result in strengthening winds through the morning hours. The observed LAX-DAG pressure gradient has also been trending lower (i.e. stronger) than depicted by most deterministic solutions, but guidance that has captured recent trends well shows increasingly widespread 60+ mph wind gusts within the Sierra Madre, San Gabriel, and San Jacinto mountains by mid-morning. Single-digit RH values will also become more common by the afternoon hours, given the duration of the downslope wind event coupled with the diurnal heating cycle. The prolonged nature of the event is also promoting rapid drying of 1- and 10-hour fuels, which will increase the fire weather threat through the day. Extremely critical wind speeds will gradually begin to abate after roughly 20 UTC, as the surface high over the Great Basin begins to weaken. However, widespread critical fire weather conditions should still persist well into early Wednesday morning. ...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 1044 AM CST Tue Dec 10 2024 Valid 101700Z - 111200Z ...EXTREMELY CRITICAL FIRE WEATHER AREA FOR PORTIONS OF THE SOUTHERN CALIFORNIA COAST... ...CRITICAL FIRE WEATHER AREA FOR THE SOUTHERN CALIFORNIA COAST... Critical to Extremely Critical fire weather conditions continue across southern California this morning. Peak wind gusts of 50-70 mph (localized 80-90 mph) with a fire ongoing in Malibu. Guidance suggests that the peak winds have occurred this morning, with gradual weakening through the afternoon. However, Critical to locally Extremely Critical conditions will continue across the mountains and foothills through the rest of the afternoon and into the evening. Some lingering Elevated to Critical conditions will continue into Wednesday morning. Minor changes were made to bring the Critical to the coast in Ventura and Los Angeles county in alignment with ongoing surface observations. ..Thornton.. 12/10/2024 .PREV DISCUSSION... /ISSUED 0102 AM CST Tue Dec 10 2024/ ...Synopsis... Critical to extremely critical fire weather conditions are expected today along the southern CA coast, posing a high-end fire weather threat. 06 UTC surface observations within the southern CA coastal mountains are showing widespread RH reductions into the low to mid teens with sustained winds between 25-35 mph and frequent gusts upwards of 40-50 mph (occasionally gusting to 60-75 mph in a few locations). Other observed trends across the region suggest that winds will increase through the early to mid-morning hours (most likely peaking during the 12-17 UTC period). Surface pressure obs across northeast NV are reporting a 1036 mb surface high with further pressure rises to around 1037-1039 mb expected through 15 UTC. Additionally, latest upper-air analyses show a low to mid-level cold front pushing south into southern CA. The arrival of the cooler/more dense air mass and stronger mid-level flow, accompanied by further surface pressure rises, should result in strengthening winds through the morning hours. The observed LAX-DAG pressure gradient has also been trending lower (i.e. stronger) than depicted by most deterministic solutions, but guidance that has captured recent trends well shows increasingly widespread 60+ mph wind gusts within the Sierra Madre, San Gabriel, and San Jacinto mountains by mid-morning. Single-digit RH values will also become more common by the afternoon hours, given the duration of the downslope wind event coupled with the diurnal heating cycle. The prolonged nature of the event is also promoting rapid drying of 1- and 10-hour fuels, which will increase the fire weather threat through the day. Extremely critical wind speeds will gradually begin to abate after roughly 20 UTC, as the surface high over the Great Basin begins to weaken. However, widespread critical fire weather conditions should still persist well into early Wednesday morning. ...Please see www.spc.noaa.gov/fire for graphic product... Read more