Severe Storms

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0132 AM CST Tue Dec 10 2024 Valid 111200Z - 121200Z ...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. ..Moore.. 12/10/2024 ...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 0132 AM CST Tue Dec 10 2024 Valid 111200Z - 121200Z ...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. ..Moore.. 12/10/2024 ...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 0102 AM CST Tue Dec 10 2024 Valid 101200Z - 111200Z ...EXTREMELY CRITICAL FIRE WEATHER AREA FOR PORTIONS OF THE SOUTHERN CALIFORNIA COAST... ...CRITICAL FIRE WEATHER AREA FOR THE SOUTHERN CALIFORNIA COAST... ...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. ..Moore.. 12/10/2024 ...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 0102 AM CST Tue Dec 10 2024 Valid 101200Z - 111200Z ...EXTREMELY CRITICAL FIRE WEATHER AREA FOR PORTIONS OF THE SOUTHERN CALIFORNIA COAST... ...CRITICAL FIRE WEATHER AREA FOR THE SOUTHERN CALIFORNIA COAST... ...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. ..Moore.. 12/10/2024 ...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 0102 AM CST Tue Dec 10 2024 Valid 101200Z - 111200Z ...EXTREMELY CRITICAL FIRE WEATHER AREA FOR PORTIONS OF THE SOUTHERN CALIFORNIA COAST... ...CRITICAL FIRE WEATHER AREA FOR THE SOUTHERN CALIFORNIA COAST... ...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. ..Moore.. 12/10/2024 ...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 0102 AM CST Tue Dec 10 2024 Valid 101200Z - 111200Z ...EXTREMELY CRITICAL FIRE WEATHER AREA FOR PORTIONS OF THE SOUTHERN CALIFORNIA COAST... ...CRITICAL FIRE WEATHER AREA FOR THE SOUTHERN CALIFORNIA COAST... ...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. ..Moore.. 12/10/2024 ...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 0102 AM CST Tue Dec 10 2024 Valid 101200Z - 111200Z ...EXTREMELY CRITICAL FIRE WEATHER AREA FOR PORTIONS OF THE SOUTHERN CALIFORNIA COAST... ...CRITICAL FIRE WEATHER AREA FOR THE SOUTHERN CALIFORNIA COAST... ...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. ..Moore.. 12/10/2024 ...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 0102 AM CST Tue Dec 10 2024 Valid 101200Z - 111200Z ...EXTREMELY CRITICAL FIRE WEATHER AREA FOR PORTIONS OF THE SOUTHERN CALIFORNIA COAST... ...CRITICAL FIRE WEATHER AREA FOR THE SOUTHERN CALIFORNIA COAST... ...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. ..Moore.. 12/10/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1256 AM CST Tue Dec 10 2024 Valid 111200Z - 121200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM EASTERN NC INTO SOUTHERN NEW ENGLAND... ...SUMMARY... Strong to isolated severe thunderstorms are possible along and ahead of a cold front from eastern North Carolina into southern New England on Wednesday. ...Synopsis... A deep upper trough is expected to extend from central Canada southward along the length of the MS Valley into the western Gulf early Wednesday morning. A shortwave trough embedded within the base of this larger troughing is forecast to move quickly northeastward from the Lower MS Valley into the Mid-Atlantic. In response, the parent upper troughing will shift eastward while also deamplifying. Strong mid/upper flow is anticipated throughout the eastern periphery of this troughing, with a 100-110 kt 500 mb jet shifting northeastward from the Southeast into the Mid-Atlantic throughout the day. An associated surface low will deepen as it moves northeastward from northern VA through the Hudson Valley into NH/VT. An attendant cold front is forecast to sharpens as it moves quickly eastward, moving off the East Coast by Wednesday evening. ...Eastern North Carolina to southern New England... Low to mid 60s dewpoints are expected to advect northward into the Carolinas and northern Mid-Atlantic States ahead of the approaching cold front, with mid to upper 50s possible farther north into southern New England. These dewpoints will support modest buoyancy, with the overall buoyancy tempered by poor mid-level lapse rates and widespread precipitation. Even so, a strongly forced convective line is still expected to develop along the front as it moves quickly eastward across the region during the afternoon. Deeper convection is anticipated in this line when increasing large-scale ascent aligns with the low-level forcing along the front. Guidance differs on when and where this occurs, with some guidance suggesting it occurs primarily offshore. Even so, there is still enough potential for this occur onshore to maintain probabilities for strong gusts. Expectation is for this deeper convection to combine with the robust kinematic fields to provide a large reservoir of high-momentum air capable of mixing down to the surface. Given the strength of the forcing, this potential exists as far north across southern New England where buoyancy is expected to be very low. Additionally, some potential exists for surface-based storms within the warm sector ahead of the front, provided that antecedent precipitation does not entirely stabilize the low levels. Some guidance suggests a pre-frontal band of surface-based storms develops with low-level confluence within the warm sector over coastal NC and the Outer Banks. ..Mosier.. 12/10/2024 Read more

SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1256 AM CST Tue Dec 10 2024 Valid 111200Z - 121200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM EASTERN NC INTO SOUTHERN NEW ENGLAND... ...SUMMARY... Strong to isolated severe thunderstorms are possible along and ahead of a cold front from eastern North Carolina into southern New England on Wednesday. ...Synopsis... A deep upper trough is expected to extend from central Canada southward along the length of the MS Valley into the western Gulf early Wednesday morning. A shortwave trough embedded within the base of this larger troughing is forecast to move quickly northeastward from the Lower MS Valley into the Mid-Atlantic. In response, the parent upper troughing will shift eastward while also deamplifying. Strong mid/upper flow is anticipated throughout the eastern periphery of this troughing, with a 100-110 kt 500 mb jet shifting northeastward from the Southeast into the Mid-Atlantic throughout the day. An associated surface low will deepen as it moves northeastward from northern VA through the Hudson Valley into NH/VT. An attendant cold front is forecast to sharpens as it moves quickly eastward, moving off the East Coast by Wednesday evening. ...Eastern North Carolina to southern New England... Low to mid 60s dewpoints are expected to advect northward into the Carolinas and northern Mid-Atlantic States ahead of the approaching cold front, with mid to upper 50s possible farther north into southern New England. These dewpoints will support modest buoyancy, with the overall buoyancy tempered by poor mid-level lapse rates and widespread precipitation. Even so, a strongly forced convective line is still expected to develop along the front as it moves quickly eastward across the region during the afternoon. Deeper convection is anticipated in this line when increasing large-scale ascent aligns with the low-level forcing along the front. Guidance differs on when and where this occurs, with some guidance suggesting it occurs primarily offshore. Even so, there is still enough potential for this occur onshore to maintain probabilities for strong gusts. Expectation is for this deeper convection to combine with the robust kinematic fields to provide a large reservoir of high-momentum air capable of mixing down to the surface. Given the strength of the forcing, this potential exists as far north across southern New England where buoyancy is expected to be very low. Additionally, some potential exists for surface-based storms within the warm sector ahead of the front, provided that antecedent precipitation does not entirely stabilize the low levels. Some guidance suggests a pre-frontal band of surface-based storms develops with low-level confluence within the warm sector over coastal NC and the Outer Banks. ..Mosier.. 12/10/2024 Read more

SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1256 AM CST Tue Dec 10 2024 Valid 111200Z - 121200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM EASTERN NC INTO SOUTHERN NEW ENGLAND... ...SUMMARY... Strong to isolated severe thunderstorms are possible along and ahead of a cold front from eastern North Carolina into southern New England on Wednesday. ...Synopsis... A deep upper trough is expected to extend from central Canada southward along the length of the MS Valley into the western Gulf early Wednesday morning. A shortwave trough embedded within the base of this larger troughing is forecast to move quickly northeastward from the Lower MS Valley into the Mid-Atlantic. In response, the parent upper troughing will shift eastward while also deamplifying. Strong mid/upper flow is anticipated throughout the eastern periphery of this troughing, with a 100-110 kt 500 mb jet shifting northeastward from the Southeast into the Mid-Atlantic throughout the day. An associated surface low will deepen as it moves northeastward from northern VA through the Hudson Valley into NH/VT. An attendant cold front is forecast to sharpens as it moves quickly eastward, moving off the East Coast by Wednesday evening. ...Eastern North Carolina to southern New England... Low to mid 60s dewpoints are expected to advect northward into the Carolinas and northern Mid-Atlantic States ahead of the approaching cold front, with mid to upper 50s possible farther north into southern New England. These dewpoints will support modest buoyancy, with the overall buoyancy tempered by poor mid-level lapse rates and widespread precipitation. Even so, a strongly forced convective line is still expected to develop along the front as it moves quickly eastward across the region during the afternoon. Deeper convection is anticipated in this line when increasing large-scale ascent aligns with the low-level forcing along the front. Guidance differs on when and where this occurs, with some guidance suggesting it occurs primarily offshore. Even so, there is still enough potential for this occur onshore to maintain probabilities for strong gusts. Expectation is for this deeper convection to combine with the robust kinematic fields to provide a large reservoir of high-momentum air capable of mixing down to the surface. Given the strength of the forcing, this potential exists as far north across southern New England where buoyancy is expected to be very low. Additionally, some potential exists for surface-based storms within the warm sector ahead of the front, provided that antecedent precipitation does not entirely stabilize the low levels. Some guidance suggests a pre-frontal band of surface-based storms develops with low-level confluence within the warm sector over coastal NC and the Outer Banks. ..Mosier.. 12/10/2024 Read more

SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1256 AM CST Tue Dec 10 2024 Valid 111200Z - 121200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM EASTERN NC INTO SOUTHERN NEW ENGLAND... ...SUMMARY... Strong to isolated severe thunderstorms are possible along and ahead of a cold front from eastern North Carolina into southern New England on Wednesday. ...Synopsis... A deep upper trough is expected to extend from central Canada southward along the length of the MS Valley into the western Gulf early Wednesday morning. A shortwave trough embedded within the base of this larger troughing is forecast to move quickly northeastward from the Lower MS Valley into the Mid-Atlantic. In response, the parent upper troughing will shift eastward while also deamplifying. Strong mid/upper flow is anticipated throughout the eastern periphery of this troughing, with a 100-110 kt 500 mb jet shifting northeastward from the Southeast into the Mid-Atlantic throughout the day. An associated surface low will deepen as it moves northeastward from northern VA through the Hudson Valley into NH/VT. An attendant cold front is forecast to sharpens as it moves quickly eastward, moving off the East Coast by Wednesday evening. ...Eastern North Carolina to southern New England... Low to mid 60s dewpoints are expected to advect northward into the Carolinas and northern Mid-Atlantic States ahead of the approaching cold front, with mid to upper 50s possible farther north into southern New England. These dewpoints will support modest buoyancy, with the overall buoyancy tempered by poor mid-level lapse rates and widespread precipitation. Even so, a strongly forced convective line is still expected to develop along the front as it moves quickly eastward across the region during the afternoon. Deeper convection is anticipated in this line when increasing large-scale ascent aligns with the low-level forcing along the front. Guidance differs on when and where this occurs, with some guidance suggesting it occurs primarily offshore. Even so, there is still enough potential for this occur onshore to maintain probabilities for strong gusts. Expectation is for this deeper convection to combine with the robust kinematic fields to provide a large reservoir of high-momentum air capable of mixing down to the surface. Given the strength of the forcing, this potential exists as far north across southern New England where buoyancy is expected to be very low. Additionally, some potential exists for surface-based storms within the warm sector ahead of the front, provided that antecedent precipitation does not entirely stabilize the low levels. Some guidance suggests a pre-frontal band of surface-based storms develops with low-level confluence within the warm sector over coastal NC and the Outer Banks. ..Mosier.. 12/10/2024 Read more

SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1256 AM CST Tue Dec 10 2024 Valid 111200Z - 121200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM EASTERN NC INTO SOUTHERN NEW ENGLAND... ...SUMMARY... Strong to isolated severe thunderstorms are possible along and ahead of a cold front from eastern North Carolina into southern New England on Wednesday. ...Synopsis... A deep upper trough is expected to extend from central Canada southward along the length of the MS Valley into the western Gulf early Wednesday morning. A shortwave trough embedded within the base of this larger troughing is forecast to move quickly northeastward from the Lower MS Valley into the Mid-Atlantic. In response, the parent upper troughing will shift eastward while also deamplifying. Strong mid/upper flow is anticipated throughout the eastern periphery of this troughing, with a 100-110 kt 500 mb jet shifting northeastward from the Southeast into the Mid-Atlantic throughout the day. An associated surface low will deepen as it moves northeastward from northern VA through the Hudson Valley into NH/VT. An attendant cold front is forecast to sharpens as it moves quickly eastward, moving off the East Coast by Wednesday evening. ...Eastern North Carolina to southern New England... Low to mid 60s dewpoints are expected to advect northward into the Carolinas and northern Mid-Atlantic States ahead of the approaching cold front, with mid to upper 50s possible farther north into southern New England. These dewpoints will support modest buoyancy, with the overall buoyancy tempered by poor mid-level lapse rates and widespread precipitation. Even so, a strongly forced convective line is still expected to develop along the front as it moves quickly eastward across the region during the afternoon. Deeper convection is anticipated in this line when increasing large-scale ascent aligns with the low-level forcing along the front. Guidance differs on when and where this occurs, with some guidance suggesting it occurs primarily offshore. Even so, there is still enough potential for this occur onshore to maintain probabilities for strong gusts. Expectation is for this deeper convection to combine with the robust kinematic fields to provide a large reservoir of high-momentum air capable of mixing down to the surface. Given the strength of the forcing, this potential exists as far north across southern New England where buoyancy is expected to be very low. Additionally, some potential exists for surface-based storms within the warm sector ahead of the front, provided that antecedent precipitation does not entirely stabilize the low levels. Some guidance suggests a pre-frontal band of surface-based storms develops with low-level confluence within the warm sector over coastal NC and the Outer Banks. ..Mosier.. 12/10/2024 Read more

SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1256 AM CST Tue Dec 10 2024 Valid 111200Z - 121200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM EASTERN NC INTO SOUTHERN NEW ENGLAND... ...SUMMARY... Strong to isolated severe thunderstorms are possible along and ahead of a cold front from eastern North Carolina into southern New England on Wednesday. ...Synopsis... A deep upper trough is expected to extend from central Canada southward along the length of the MS Valley into the western Gulf early Wednesday morning. A shortwave trough embedded within the base of this larger troughing is forecast to move quickly northeastward from the Lower MS Valley into the Mid-Atlantic. In response, the parent upper troughing will shift eastward while also deamplifying. Strong mid/upper flow is anticipated throughout the eastern periphery of this troughing, with a 100-110 kt 500 mb jet shifting northeastward from the Southeast into the Mid-Atlantic throughout the day. An associated surface low will deepen as it moves northeastward from northern VA through the Hudson Valley into NH/VT. An attendant cold front is forecast to sharpens as it moves quickly eastward, moving off the East Coast by Wednesday evening. ...Eastern North Carolina to southern New England... Low to mid 60s dewpoints are expected to advect northward into the Carolinas and northern Mid-Atlantic States ahead of the approaching cold front, with mid to upper 50s possible farther north into southern New England. These dewpoints will support modest buoyancy, with the overall buoyancy tempered by poor mid-level lapse rates and widespread precipitation. Even so, a strongly forced convective line is still expected to develop along the front as it moves quickly eastward across the region during the afternoon. Deeper convection is anticipated in this line when increasing large-scale ascent aligns with the low-level forcing along the front. Guidance differs on when and where this occurs, with some guidance suggesting it occurs primarily offshore. Even so, there is still enough potential for this occur onshore to maintain probabilities for strong gusts. Expectation is for this deeper convection to combine with the robust kinematic fields to provide a large reservoir of high-momentum air capable of mixing down to the surface. Given the strength of the forcing, this potential exists as far north across southern New England where buoyancy is expected to be very low. Additionally, some potential exists for surface-based storms within the warm sector ahead of the front, provided that antecedent precipitation does not entirely stabilize the low levels. Some guidance suggests a pre-frontal band of surface-based storms develops with low-level confluence within the warm sector over coastal NC and the Outer Banks. ..Mosier.. 12/10/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1147 PM CST Mon Dec 09 2024 Valid 101200Z - 111200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE CENTRAL GULF COAST REGION AND INTO SOUTHWESTERN GEORGIA AND THE FLORIDA PANHANDLE... ...SUMMARY... A few strong to severe thunderstorms are possible across portions of the central Gulf Coast region into southwestern Georgia and the Florida Panhandle today. ...Synopsis... An amplifying upper trough will cross the central third of the U.S. today, taking on weak negative tilt by late in the period as it reaches the Mississippi Valley vicinity. Accompanying the upper system, a gradually sharpening cold front -- lying across the Tennessee and Lower Mississippi Valleys early -- will make steady eastward progress. By Wednesday morning, the front should extend from the Lower Great Lakes southward to the southern Appalachians, and then southwestward into the central and western Gulf of Mexico. ...Southeastern Louisiana to southwestern Georgia and the Florida Panhandle... Widespread showers and embedded thunderstorms are forecast across the central Gulf Coast region and Southeast, ahead of the advancing upper trough, and accompanying cold front. A broad/moist boundary layer will continue spreading across this region ahead of the front, but weak lapse rates aloft -- in part due to widespread clouds and precipitation anticipated across the warm sector -- should limit destabilization potential. This lack of CAPE is expected to substantially temper storm intensity/organization, despite a strong flow field favorably increasing and veering with height across the region. With that said, transient/occasionally more-organized convective structures seem likely -- through much of the period, but particularly from afternoon onward. Presuming that a few stronger bowing and/or weakly rotating segments will sporadically manifest, accompanying/local risk for gusty/damaging winds and/or a tornado or two would likely evolve as well -- primarily from the central Gulf Coast region into parts of western Georgia and the Florida Panhandle. ..Goss/Moore.. 12/10/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1147 PM CST Mon Dec 09 2024 Valid 101200Z - 111200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE CENTRAL GULF COAST REGION AND INTO SOUTHWESTERN GEORGIA AND THE FLORIDA PANHANDLE... ...SUMMARY... A few strong to severe thunderstorms are possible across portions of the central Gulf Coast region into southwestern Georgia and the Florida Panhandle today. ...Synopsis... An amplifying upper trough will cross the central third of the U.S. today, taking on weak negative tilt by late in the period as it reaches the Mississippi Valley vicinity. Accompanying the upper system, a gradually sharpening cold front -- lying across the Tennessee and Lower Mississippi Valleys early -- will make steady eastward progress. By Wednesday morning, the front should extend from the Lower Great Lakes southward to the southern Appalachians, and then southwestward into the central and western Gulf of Mexico. ...Southeastern Louisiana to southwestern Georgia and the Florida Panhandle... Widespread showers and embedded thunderstorms are forecast across the central Gulf Coast region and Southeast, ahead of the advancing upper trough, and accompanying cold front. A broad/moist boundary layer will continue spreading across this region ahead of the front, but weak lapse rates aloft -- in part due to widespread clouds and precipitation anticipated across the warm sector -- should limit destabilization potential. This lack of CAPE is expected to substantially temper storm intensity/organization, despite a strong flow field favorably increasing and veering with height across the region. With that said, transient/occasionally more-organized convective structures seem likely -- through much of the period, but particularly from afternoon onward. Presuming that a few stronger bowing and/or weakly rotating segments will sporadically manifest, accompanying/local risk for gusty/damaging winds and/or a tornado or two would likely evolve as well -- primarily from the central Gulf Coast region into parts of western Georgia and the Florida Panhandle. ..Goss/Moore.. 12/10/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1147 PM CST Mon Dec 09 2024 Valid 101200Z - 111200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE CENTRAL GULF COAST REGION AND INTO SOUTHWESTERN GEORGIA AND THE FLORIDA PANHANDLE... ...SUMMARY... A few strong to severe thunderstorms are possible across portions of the central Gulf Coast region into southwestern Georgia and the Florida Panhandle today. ...Synopsis... An amplifying upper trough will cross the central third of the U.S. today, taking on weak negative tilt by late in the period as it reaches the Mississippi Valley vicinity. Accompanying the upper system, a gradually sharpening cold front -- lying across the Tennessee and Lower Mississippi Valleys early -- will make steady eastward progress. By Wednesday morning, the front should extend from the Lower Great Lakes southward to the southern Appalachians, and then southwestward into the central and western Gulf of Mexico. ...Southeastern Louisiana to southwestern Georgia and the Florida Panhandle... Widespread showers and embedded thunderstorms are forecast across the central Gulf Coast region and Southeast, ahead of the advancing upper trough, and accompanying cold front. A broad/moist boundary layer will continue spreading across this region ahead of the front, but weak lapse rates aloft -- in part due to widespread clouds and precipitation anticipated across the warm sector -- should limit destabilization potential. This lack of CAPE is expected to substantially temper storm intensity/organization, despite a strong flow field favorably increasing and veering with height across the region. With that said, transient/occasionally more-organized convective structures seem likely -- through much of the period, but particularly from afternoon onward. Presuming that a few stronger bowing and/or weakly rotating segments will sporadically manifest, accompanying/local risk for gusty/damaging winds and/or a tornado or two would likely evolve as well -- primarily from the central Gulf Coast region into parts of western Georgia and the Florida Panhandle. ..Goss/Moore.. 12/10/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1147 PM CST Mon Dec 09 2024 Valid 101200Z - 111200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE CENTRAL GULF COAST REGION AND INTO SOUTHWESTERN GEORGIA AND THE FLORIDA PANHANDLE... ...SUMMARY... A few strong to severe thunderstorms are possible across portions of the central Gulf Coast region into southwestern Georgia and the Florida Panhandle today. ...Synopsis... An amplifying upper trough will cross the central third of the U.S. today, taking on weak negative tilt by late in the period as it reaches the Mississippi Valley vicinity. Accompanying the upper system, a gradually sharpening cold front -- lying across the Tennessee and Lower Mississippi Valleys early -- will make steady eastward progress. By Wednesday morning, the front should extend from the Lower Great Lakes southward to the southern Appalachians, and then southwestward into the central and western Gulf of Mexico. ...Southeastern Louisiana to southwestern Georgia and the Florida Panhandle... Widespread showers and embedded thunderstorms are forecast across the central Gulf Coast region and Southeast, ahead of the advancing upper trough, and accompanying cold front. A broad/moist boundary layer will continue spreading across this region ahead of the front, but weak lapse rates aloft -- in part due to widespread clouds and precipitation anticipated across the warm sector -- should limit destabilization potential. This lack of CAPE is expected to substantially temper storm intensity/organization, despite a strong flow field favorably increasing and veering with height across the region. With that said, transient/occasionally more-organized convective structures seem likely -- through much of the period, but particularly from afternoon onward. Presuming that a few stronger bowing and/or weakly rotating segments will sporadically manifest, accompanying/local risk for gusty/damaging winds and/or a tornado or two would likely evolve as well -- primarily from the central Gulf Coast region into parts of western Georgia and the Florida Panhandle. ..Goss/Moore.. 12/10/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1147 PM CST Mon Dec 09 2024 Valid 101200Z - 111200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE CENTRAL GULF COAST REGION AND INTO SOUTHWESTERN GEORGIA AND THE FLORIDA PANHANDLE... ...SUMMARY... A few strong to severe thunderstorms are possible across portions of the central Gulf Coast region into southwestern Georgia and the Florida Panhandle today. ...Synopsis... An amplifying upper trough will cross the central third of the U.S. today, taking on weak negative tilt by late in the period as it reaches the Mississippi Valley vicinity. Accompanying the upper system, a gradually sharpening cold front -- lying across the Tennessee and Lower Mississippi Valleys early -- will make steady eastward progress. By Wednesday morning, the front should extend from the Lower Great Lakes southward to the southern Appalachians, and then southwestward into the central and western Gulf of Mexico. ...Southeastern Louisiana to southwestern Georgia and the Florida Panhandle... Widespread showers and embedded thunderstorms are forecast across the central Gulf Coast region and Southeast, ahead of the advancing upper trough, and accompanying cold front. A broad/moist boundary layer will continue spreading across this region ahead of the front, but weak lapse rates aloft -- in part due to widespread clouds and precipitation anticipated across the warm sector -- should limit destabilization potential. This lack of CAPE is expected to substantially temper storm intensity/organization, despite a strong flow field favorably increasing and veering with height across the region. With that said, transient/occasionally more-organized convective structures seem likely -- through much of the period, but particularly from afternoon onward. Presuming that a few stronger bowing and/or weakly rotating segments will sporadically manifest, accompanying/local risk for gusty/damaging winds and/or a tornado or two would likely evolve as well -- primarily from the central Gulf Coast region into parts of western Georgia and the Florida Panhandle. ..Goss/Moore.. 12/10/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1147 PM CST Mon Dec 09 2024 Valid 101200Z - 111200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE CENTRAL GULF COAST REGION AND INTO SOUTHWESTERN GEORGIA AND THE FLORIDA PANHANDLE... ...SUMMARY... A few strong to severe thunderstorms are possible across portions of the central Gulf Coast region into southwestern Georgia and the Florida Panhandle today. ...Synopsis... An amplifying upper trough will cross the central third of the U.S. today, taking on weak negative tilt by late in the period as it reaches the Mississippi Valley vicinity. Accompanying the upper system, a gradually sharpening cold front -- lying across the Tennessee and Lower Mississippi Valleys early -- will make steady eastward progress. By Wednesday morning, the front should extend from the Lower Great Lakes southward to the southern Appalachians, and then southwestward into the central and western Gulf of Mexico. ...Southeastern Louisiana to southwestern Georgia and the Florida Panhandle... Widespread showers and embedded thunderstorms are forecast across the central Gulf Coast region and Southeast, ahead of the advancing upper trough, and accompanying cold front. A broad/moist boundary layer will continue spreading across this region ahead of the front, but weak lapse rates aloft -- in part due to widespread clouds and precipitation anticipated across the warm sector -- should limit destabilization potential. This lack of CAPE is expected to substantially temper storm intensity/organization, despite a strong flow field favorably increasing and veering with height across the region. With that said, transient/occasionally more-organized convective structures seem likely -- through much of the period, but particularly from afternoon onward. Presuming that a few stronger bowing and/or weakly rotating segments will sporadically manifest, accompanying/local risk for gusty/damaging winds and/or a tornado or two would likely evolve as well -- primarily from the central Gulf Coast region into parts of western Georgia and the Florida Panhandle. ..Goss/Moore.. 12/10/2024 Read more