Severe Storms

SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1241 AM CST Sun Dec 10 2023 Valid 111200Z - 121200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorm probabilities are less than 10 percent on Monday. ...Discussion... Substantial cyclogenesis tonight will persist into Monday with the surface low tracking across southern and eastern New England to the Canadian Maritimes. An extremely strong low-level jet ahead of the cyclone, increasing to around 100 kts at 850 mb, should advect adequate western Atlantic moisture to yield minimal elevated buoyancy towards coastal New England. The bulk of guidance outside of the 00Z NAM indicates this may be inadequate for charge separation amid weak lapse rates above 500 mb. But given the very strong forcing for ascent, there may be a short-duration period from 12-15Z across southeast MA to coastal ME where heavier convective elements within the broader warm conveyor rain band could produce a few lightning flashes. Elsewhere across the CONUS, with the surface cold front expected to clear the rest of the Atlantic Seaboard prior to 12Z Monday, thunderstorm potential will be negligible. ..Grams.. 12/10/2023 Read more

SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1241 AM CST Sun Dec 10 2023 Valid 111200Z - 121200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorm probabilities are less than 10 percent on Monday. ...Discussion... Substantial cyclogenesis tonight will persist into Monday with the surface low tracking across southern and eastern New England to the Canadian Maritimes. An extremely strong low-level jet ahead of the cyclone, increasing to around 100 kts at 850 mb, should advect adequate western Atlantic moisture to yield minimal elevated buoyancy towards coastal New England. The bulk of guidance outside of the 00Z NAM indicates this may be inadequate for charge separation amid weak lapse rates above 500 mb. But given the very strong forcing for ascent, there may be a short-duration period from 12-15Z across southeast MA to coastal ME where heavier convective elements within the broader warm conveyor rain band could produce a few lightning flashes. Elsewhere across the CONUS, with the surface cold front expected to clear the rest of the Atlantic Seaboard prior to 12Z Monday, thunderstorm potential will be negligible. ..Grams.. 12/10/2023 Read more

SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1241 AM CST Sun Dec 10 2023 Valid 111200Z - 121200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorm probabilities are less than 10 percent on Monday. ...Discussion... Substantial cyclogenesis tonight will persist into Monday with the surface low tracking across southern and eastern New England to the Canadian Maritimes. An extremely strong low-level jet ahead of the cyclone, increasing to around 100 kts at 850 mb, should advect adequate western Atlantic moisture to yield minimal elevated buoyancy towards coastal New England. The bulk of guidance outside of the 00Z NAM indicates this may be inadequate for charge separation amid weak lapse rates above 500 mb. But given the very strong forcing for ascent, there may be a short-duration period from 12-15Z across southeast MA to coastal ME where heavier convective elements within the broader warm conveyor rain band could produce a few lightning flashes. Elsewhere across the CONUS, with the surface cold front expected to clear the rest of the Atlantic Seaboard prior to 12Z Monday, thunderstorm potential will be negligible. ..Grams.. 12/10/2023 Read more

SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1241 AM CST Sun Dec 10 2023 Valid 111200Z - 121200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorm probabilities are less than 10 percent on Monday. ...Discussion... Substantial cyclogenesis tonight will persist into Monday with the surface low tracking across southern and eastern New England to the Canadian Maritimes. An extremely strong low-level jet ahead of the cyclone, increasing to around 100 kts at 850 mb, should advect adequate western Atlantic moisture to yield minimal elevated buoyancy towards coastal New England. The bulk of guidance outside of the 00Z NAM indicates this may be inadequate for charge separation amid weak lapse rates above 500 mb. But given the very strong forcing for ascent, there may be a short-duration period from 12-15Z across southeast MA to coastal ME where heavier convective elements within the broader warm conveyor rain band could produce a few lightning flashes. Elsewhere across the CONUS, with the surface cold front expected to clear the rest of the Atlantic Seaboard prior to 12Z Monday, thunderstorm potential will be negligible. ..Grams.. 12/10/2023 Read more

SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1241 AM CST Sun Dec 10 2023 Valid 111200Z - 121200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorm probabilities are less than 10 percent on Monday. ...Discussion... Substantial cyclogenesis tonight will persist into Monday with the surface low tracking across southern and eastern New England to the Canadian Maritimes. An extremely strong low-level jet ahead of the cyclone, increasing to around 100 kts at 850 mb, should advect adequate western Atlantic moisture to yield minimal elevated buoyancy towards coastal New England. The bulk of guidance outside of the 00Z NAM indicates this may be inadequate for charge separation amid weak lapse rates above 500 mb. But given the very strong forcing for ascent, there may be a short-duration period from 12-15Z across southeast MA to coastal ME where heavier convective elements within the broader warm conveyor rain band could produce a few lightning flashes. Elsewhere across the CONUS, with the surface cold front expected to clear the rest of the Atlantic Seaboard prior to 12Z Monday, thunderstorm potential will be negligible. ..Grams.. 12/10/2023 Read more

SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1241 AM CST Sun Dec 10 2023 Valid 111200Z - 121200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorm probabilities are less than 10 percent on Monday. ...Discussion... Substantial cyclogenesis tonight will persist into Monday with the surface low tracking across southern and eastern New England to the Canadian Maritimes. An extremely strong low-level jet ahead of the cyclone, increasing to around 100 kts at 850 mb, should advect adequate western Atlantic moisture to yield minimal elevated buoyancy towards coastal New England. The bulk of guidance outside of the 00Z NAM indicates this may be inadequate for charge separation amid weak lapse rates above 500 mb. But given the very strong forcing for ascent, there may be a short-duration period from 12-15Z across southeast MA to coastal ME where heavier convective elements within the broader warm conveyor rain band could produce a few lightning flashes. Elsewhere across the CONUS, with the surface cold front expected to clear the rest of the Atlantic Seaboard prior to 12Z Monday, thunderstorm potential will be negligible. ..Grams.. 12/10/2023 Read more

SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1241 AM CST Sun Dec 10 2023 Valid 111200Z - 121200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorm probabilities are less than 10 percent on Monday. ...Discussion... Substantial cyclogenesis tonight will persist into Monday with the surface low tracking across southern and eastern New England to the Canadian Maritimes. An extremely strong low-level jet ahead of the cyclone, increasing to around 100 kts at 850 mb, should advect adequate western Atlantic moisture to yield minimal elevated buoyancy towards coastal New England. The bulk of guidance outside of the 00Z NAM indicates this may be inadequate for charge separation amid weak lapse rates above 500 mb. But given the very strong forcing for ascent, there may be a short-duration period from 12-15Z across southeast MA to coastal ME where heavier convective elements within the broader warm conveyor rain band could produce a few lightning flashes. Elsewhere across the CONUS, with the surface cold front expected to clear the rest of the Atlantic Seaboard prior to 12Z Monday, thunderstorm potential will be negligible. ..Grams.. 12/10/2023 Read more

SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1241 AM CST Sun Dec 10 2023 Valid 111200Z - 121200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorm probabilities are less than 10 percent on Monday. ...Discussion... Substantial cyclogenesis tonight will persist into Monday with the surface low tracking across southern and eastern New England to the Canadian Maritimes. An extremely strong low-level jet ahead of the cyclone, increasing to around 100 kts at 850 mb, should advect adequate western Atlantic moisture to yield minimal elevated buoyancy towards coastal New England. The bulk of guidance outside of the 00Z NAM indicates this may be inadequate for charge separation amid weak lapse rates above 500 mb. But given the very strong forcing for ascent, there may be a short-duration period from 12-15Z across southeast MA to coastal ME where heavier convective elements within the broader warm conveyor rain band could produce a few lightning flashes. Elsewhere across the CONUS, with the surface cold front expected to clear the rest of the Atlantic Seaboard prior to 12Z Monday, thunderstorm potential will be negligible. ..Grams.. 12/10/2023 Read more

SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1241 AM CST Sun Dec 10 2023 Valid 111200Z - 121200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorm probabilities are less than 10 percent on Monday. ...Discussion... Substantial cyclogenesis tonight will persist into Monday with the surface low tracking across southern and eastern New England to the Canadian Maritimes. An extremely strong low-level jet ahead of the cyclone, increasing to around 100 kts at 850 mb, should advect adequate western Atlantic moisture to yield minimal elevated buoyancy towards coastal New England. The bulk of guidance outside of the 00Z NAM indicates this may be inadequate for charge separation amid weak lapse rates above 500 mb. But given the very strong forcing for ascent, there may be a short-duration period from 12-15Z across southeast MA to coastal ME where heavier convective elements within the broader warm conveyor rain band could produce a few lightning flashes. Elsewhere across the CONUS, with the surface cold front expected to clear the rest of the Atlantic Seaboard prior to 12Z Monday, thunderstorm potential will be negligible. ..Grams.. 12/10/2023 Read more

SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1241 AM CST Sun Dec 10 2023 Valid 111200Z - 121200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorm probabilities are less than 10 percent on Monday. ...Discussion... Substantial cyclogenesis tonight will persist into Monday with the surface low tracking across southern and eastern New England to the Canadian Maritimes. An extremely strong low-level jet ahead of the cyclone, increasing to around 100 kts at 850 mb, should advect adequate western Atlantic moisture to yield minimal elevated buoyancy towards coastal New England. The bulk of guidance outside of the 00Z NAM indicates this may be inadequate for charge separation amid weak lapse rates above 500 mb. But given the very strong forcing for ascent, there may be a short-duration period from 12-15Z across southeast MA to coastal ME where heavier convective elements within the broader warm conveyor rain band could produce a few lightning flashes. Elsewhere across the CONUS, with the surface cold front expected to clear the rest of the Atlantic Seaboard prior to 12Z Monday, thunderstorm potential will be negligible. ..Grams.. 12/10/2023 Read more

SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1241 AM CST Sun Dec 10 2023 Valid 111200Z - 121200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorm probabilities are less than 10 percent on Monday. ...Discussion... Substantial cyclogenesis tonight will persist into Monday with the surface low tracking across southern and eastern New England to the Canadian Maritimes. An extremely strong low-level jet ahead of the cyclone, increasing to around 100 kts at 850 mb, should advect adequate western Atlantic moisture to yield minimal elevated buoyancy towards coastal New England. The bulk of guidance outside of the 00Z NAM indicates this may be inadequate for charge separation amid weak lapse rates above 500 mb. But given the very strong forcing for ascent, there may be a short-duration period from 12-15Z across southeast MA to coastal ME where heavier convective elements within the broader warm conveyor rain band could produce a few lightning flashes. Elsewhere across the CONUS, with the surface cold front expected to clear the rest of the Atlantic Seaboard prior to 12Z Monday, thunderstorm potential will be negligible. ..Grams.. 12/10/2023 Read more

SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1241 AM CST Sun Dec 10 2023 Valid 111200Z - 121200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorm probabilities are less than 10 percent on Monday. ...Discussion... Substantial cyclogenesis tonight will persist into Monday with the surface low tracking across southern and eastern New England to the Canadian Maritimes. An extremely strong low-level jet ahead of the cyclone, increasing to around 100 kts at 850 mb, should advect adequate western Atlantic moisture to yield minimal elevated buoyancy towards coastal New England. The bulk of guidance outside of the 00Z NAM indicates this may be inadequate for charge separation amid weak lapse rates above 500 mb. But given the very strong forcing for ascent, there may be a short-duration period from 12-15Z across southeast MA to coastal ME where heavier convective elements within the broader warm conveyor rain band could produce a few lightning flashes. Elsewhere across the CONUS, with the surface cold front expected to clear the rest of the Atlantic Seaboard prior to 12Z Monday, thunderstorm potential will be negligible. ..Grams.. 12/10/2023 Read more

MD 2318 CONCERNING TORNADO WATCH 717... FOR PORTIONS OF NORTHERN GEORGIA INTO FAR SOUTHEASTERN TENNESSEE
Mesoscale Discussion 2318 NWS Storm Prediction Center Norman OK 1140 PM CST Sat Dec 09 2023 Areas affected...portions of northern Georgia into far southeastern Tennessee Concerning...Tornado Watch 717... Valid 100540Z - 100645Z The severe weather threat for Tornado Watch 717 continues. SUMMARY...The severe threat continues across Tornado Watch 717. A couple of damaging gusts are the main threat, though a tornado cannot be ruled out. DISCUSSION...Linear convection is progressing across Tornado Watch 717, with a history of producing isolated bouts of sub-severe hail and scattered damaging gusts. These storms persist in a low-CAPE/high shear regime, which continues to support some organization. What little buoyancy remains continues to diminish in northern GA and points north and east, casting doubt on a more organized severe threat. However, low-level shear remains quite strong, so an additional damaging gust or even a tornado cannot be ruled out over the next few hours. Given the diminishing downstream buoyancy, convective trends will need to be closely monitored for the need of a downstream WW issuance or local extension. ..Squitieri.. 12/10/2023 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...GSP...MRX...FFC...BMX...HUN... LAT...LON 33948603 35308477 35568416 35378383 34798386 34348440 33938487 33808519 33948603 Read more

WW 0718 Status Updates
STATUS REPORT ON WW 718 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 25 E MEI TO 35 W SEM TO 15 ESE BHM TO 25 W GAD. FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 2319 ..GLEASON..12/10/23 ATTN...WFO...BMX...MOB...FFC... STATUS REPORT FOR WT 718 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS ALC001-007-015-021-023-025-027-029-037-047-091-099-105-115-117- 121-129-131-100740- AL . ALABAMA COUNTIES INCLUDED ARE AUTAUGA BIBB CALHOUN CHILTON CHOCTAW CLARKE CLAY CLEBURNE COOSA DALLAS MARENGO MONROE PERRY ST. CLAIR SHELBY TALLADEGA WASHINGTON WILCOX GAC143-233-100740- GA . GEORGIA COUNTIES INCLUDED ARE HARALSON POLK MSC153-100740- Read more

WW 0717 Status Updates
STATUS REPORT ON WW 717 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 5 WSW GAD TO 15 NNE RMG TO 40 E CHA TO 60 S TYS. FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 2318 ..GLEASON..12/10/23 ATTN...WFO...BMX...HUN...FFC...MRX... STATUS REPORT FOR WT 717 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS ALC019-055-100740- AL . ALABAMA COUNTIES INCLUDED ARE CHEROKEE ETOWAH GAC111-115-123-129-213-100740- GA . GEORGIA COUNTIES INCLUDED ARE FANNIN FLOYD GILMER GORDON MURRAY THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE REFER TO WATCH COUNTY NOTIFICATION STATEMENTS FOR OFFICIAL INFORMATION ON COUNTIES...INDEPENDENT CITIES AND MARINE ZONES CLEARED FROM SEVERE THUNDERSTORM AND TORNADO WATCHES. Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1159 PM CST Sat Dec 09 2023 Valid 101200Z - 111200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF FAR EASTERN SOUTH CAROLINA AND EASTERN NORTH CAROLINA... ...SUMMARY... Severe thunderstorms associated with wind damage and a few tornadoes are expected across parts of far eastern South Carolina and eastern North Carolina today. Marginally severe wind gusts will also be possible over much of the Atlantic Coastal region from Florida to the Mid-Atlantic. ...Atlantic Coastal States... An upper-level trough will move eastward across the Ohio and Tennessee Valleys today, as an associated belt of strong mid-level flow translates eastward into the Appalachians and Atlantic coastal states. At the surface, a cold front will advance eastward through the southern and central Appalachians. Ahead of the front, moisture advection will take place from the eastern Gulf Coast States northward to the Mid-Atlantic, maintaining or increasing surface dewpoints into the lower to mid 60s F in most areas. Thunderstorms are expected to continue throughout the morning as the front progresses eastward. Strengthening low-level flow ahead of the system will result in a gradual increase in convective coverage throughout the day over the moist sector. In spite of abundant cloud cover and weak instability, an isolated severe threat is expected to develop ahead of the front. Marginally severe wind gusts will be the primary threat from northern Florida northward into the western and central Carolinas and into the Mid-Atlantic. Over the eastern Carolinas, the severe threat is expected to be greater due to a number of factors. First, model forecasts suggest that a corridor of stronger instability will develop by afternoon from far eastern South Carolina into east-central North Carolina, where MLCAPE is expected to peak around 1000 J/kg. Second, a low-level jet is forecast to move through the central Carolinas during the early afternoon. The combination of stronger instability, moderate to strong deep-layer shear and increasing low-level flow will be favorable for rotating storms. As the low-level jet moves through during the early afternoon, 0-3 km storm-relative helicity is forecast to increase to around 200 m2/s2 over parts of far eastern South Carolina and eastern North Carolina, suggesting that some of the storms could develop a tornado threat. The tornado threat will likely be greatest with storms that remain discrete and develop near the moist axis. A gradual increase in storm coverage is expected during afternoon, with a mixed mode likely. Supercells and organized line segments will likely be capable of wind-damage, with the threat peaking during the early to mid afternoon. ..Broyles/Wendt.. 12/10/2023 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1159 PM CST Sat Dec 09 2023 Valid 101200Z - 111200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF FAR EASTERN SOUTH CAROLINA AND EASTERN NORTH CAROLINA... ...SUMMARY... Severe thunderstorms associated with wind damage and a few tornadoes are expected across parts of far eastern South Carolina and eastern North Carolina today. Marginally severe wind gusts will also be possible over much of the Atlantic Coastal region from Florida to the Mid-Atlantic. ...Atlantic Coastal States... An upper-level trough will move eastward across the Ohio and Tennessee Valleys today, as an associated belt of strong mid-level flow translates eastward into the Appalachians and Atlantic coastal states. At the surface, a cold front will advance eastward through the southern and central Appalachians. Ahead of the front, moisture advection will take place from the eastern Gulf Coast States northward to the Mid-Atlantic, maintaining or increasing surface dewpoints into the lower to mid 60s F in most areas. Thunderstorms are expected to continue throughout the morning as the front progresses eastward. Strengthening low-level flow ahead of the system will result in a gradual increase in convective coverage throughout the day over the moist sector. In spite of abundant cloud cover and weak instability, an isolated severe threat is expected to develop ahead of the front. Marginally severe wind gusts will be the primary threat from northern Florida northward into the western and central Carolinas and into the Mid-Atlantic. Over the eastern Carolinas, the severe threat is expected to be greater due to a number of factors. First, model forecasts suggest that a corridor of stronger instability will develop by afternoon from far eastern South Carolina into east-central North Carolina, where MLCAPE is expected to peak around 1000 J/kg. Second, a low-level jet is forecast to move through the central Carolinas during the early afternoon. The combination of stronger instability, moderate to strong deep-layer shear and increasing low-level flow will be favorable for rotating storms. As the low-level jet moves through during the early afternoon, 0-3 km storm-relative helicity is forecast to increase to around 200 m2/s2 over parts of far eastern South Carolina and eastern North Carolina, suggesting that some of the storms could develop a tornado threat. The tornado threat will likely be greatest with storms that remain discrete and develop near the moist axis. A gradual increase in storm coverage is expected during afternoon, with a mixed mode likely. Supercells and organized line segments will likely be capable of wind-damage, with the threat peaking during the early to mid afternoon. ..Broyles/Wendt.. 12/10/2023 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1159 PM CST Sat Dec 09 2023 Valid 101200Z - 111200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF FAR EASTERN SOUTH CAROLINA AND EASTERN NORTH CAROLINA... ...SUMMARY... Severe thunderstorms associated with wind damage and a few tornadoes are expected across parts of far eastern South Carolina and eastern North Carolina today. Marginally severe wind gusts will also be possible over much of the Atlantic Coastal region from Florida to the Mid-Atlantic. ...Atlantic Coastal States... An upper-level trough will move eastward across the Ohio and Tennessee Valleys today, as an associated belt of strong mid-level flow translates eastward into the Appalachians and Atlantic coastal states. At the surface, a cold front will advance eastward through the southern and central Appalachians. Ahead of the front, moisture advection will take place from the eastern Gulf Coast States northward to the Mid-Atlantic, maintaining or increasing surface dewpoints into the lower to mid 60s F in most areas. Thunderstorms are expected to continue throughout the morning as the front progresses eastward. Strengthening low-level flow ahead of the system will result in a gradual increase in convective coverage throughout the day over the moist sector. In spite of abundant cloud cover and weak instability, an isolated severe threat is expected to develop ahead of the front. Marginally severe wind gusts will be the primary threat from northern Florida northward into the western and central Carolinas and into the Mid-Atlantic. Over the eastern Carolinas, the severe threat is expected to be greater due to a number of factors. First, model forecasts suggest that a corridor of stronger instability will develop by afternoon from far eastern South Carolina into east-central North Carolina, where MLCAPE is expected to peak around 1000 J/kg. Second, a low-level jet is forecast to move through the central Carolinas during the early afternoon. The combination of stronger instability, moderate to strong deep-layer shear and increasing low-level flow will be favorable for rotating storms. As the low-level jet moves through during the early afternoon, 0-3 km storm-relative helicity is forecast to increase to around 200 m2/s2 over parts of far eastern South Carolina and eastern North Carolina, suggesting that some of the storms could develop a tornado threat. The tornado threat will likely be greatest with storms that remain discrete and develop near the moist axis. A gradual increase in storm coverage is expected during afternoon, with a mixed mode likely. Supercells and organized line segments will likely be capable of wind-damage, with the threat peaking during the early to mid afternoon. ..Broyles/Wendt.. 12/10/2023 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1159 PM CST Sat Dec 09 2023 Valid 101200Z - 111200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF FAR EASTERN SOUTH CAROLINA AND EASTERN NORTH CAROLINA... ...SUMMARY... Severe thunderstorms associated with wind damage and a few tornadoes are expected across parts of far eastern South Carolina and eastern North Carolina today. Marginally severe wind gusts will also be possible over much of the Atlantic Coastal region from Florida to the Mid-Atlantic. ...Atlantic Coastal States... An upper-level trough will move eastward across the Ohio and Tennessee Valleys today, as an associated belt of strong mid-level flow translates eastward into the Appalachians and Atlantic coastal states. At the surface, a cold front will advance eastward through the southern and central Appalachians. Ahead of the front, moisture advection will take place from the eastern Gulf Coast States northward to the Mid-Atlantic, maintaining or increasing surface dewpoints into the lower to mid 60s F in most areas. Thunderstorms are expected to continue throughout the morning as the front progresses eastward. Strengthening low-level flow ahead of the system will result in a gradual increase in convective coverage throughout the day over the moist sector. In spite of abundant cloud cover and weak instability, an isolated severe threat is expected to develop ahead of the front. Marginally severe wind gusts will be the primary threat from northern Florida northward into the western and central Carolinas and into the Mid-Atlantic. Over the eastern Carolinas, the severe threat is expected to be greater due to a number of factors. First, model forecasts suggest that a corridor of stronger instability will develop by afternoon from far eastern South Carolina into east-central North Carolina, where MLCAPE is expected to peak around 1000 J/kg. Second, a low-level jet is forecast to move through the central Carolinas during the early afternoon. The combination of stronger instability, moderate to strong deep-layer shear and increasing low-level flow will be favorable for rotating storms. As the low-level jet moves through during the early afternoon, 0-3 km storm-relative helicity is forecast to increase to around 200 m2/s2 over parts of far eastern South Carolina and eastern North Carolina, suggesting that some of the storms could develop a tornado threat. The tornado threat will likely be greatest with storms that remain discrete and develop near the moist axis. A gradual increase in storm coverage is expected during afternoon, with a mixed mode likely. Supercells and organized line segments will likely be capable of wind-damage, with the threat peaking during the early to mid afternoon. ..Broyles/Wendt.. 12/10/2023 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1159 PM CST Sat Dec 09 2023 Valid 101200Z - 111200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF FAR EASTERN SOUTH CAROLINA AND EASTERN NORTH CAROLINA... ...SUMMARY... Severe thunderstorms associated with wind damage and a few tornadoes are expected across parts of far eastern South Carolina and eastern North Carolina today. Marginally severe wind gusts will also be possible over much of the Atlantic Coastal region from Florida to the Mid-Atlantic. ...Atlantic Coastal States... An upper-level trough will move eastward across the Ohio and Tennessee Valleys today, as an associated belt of strong mid-level flow translates eastward into the Appalachians and Atlantic coastal states. At the surface, a cold front will advance eastward through the southern and central Appalachians. Ahead of the front, moisture advection will take place from the eastern Gulf Coast States northward to the Mid-Atlantic, maintaining or increasing surface dewpoints into the lower to mid 60s F in most areas. Thunderstorms are expected to continue throughout the morning as the front progresses eastward. Strengthening low-level flow ahead of the system will result in a gradual increase in convective coverage throughout the day over the moist sector. In spite of abundant cloud cover and weak instability, an isolated severe threat is expected to develop ahead of the front. Marginally severe wind gusts will be the primary threat from northern Florida northward into the western and central Carolinas and into the Mid-Atlantic. Over the eastern Carolinas, the severe threat is expected to be greater due to a number of factors. First, model forecasts suggest that a corridor of stronger instability will develop by afternoon from far eastern South Carolina into east-central North Carolina, where MLCAPE is expected to peak around 1000 J/kg. Second, a low-level jet is forecast to move through the central Carolinas during the early afternoon. The combination of stronger instability, moderate to strong deep-layer shear and increasing low-level flow will be favorable for rotating storms. As the low-level jet moves through during the early afternoon, 0-3 km storm-relative helicity is forecast to increase to around 200 m2/s2 over parts of far eastern South Carolina and eastern North Carolina, suggesting that some of the storms could develop a tornado threat. The tornado threat will likely be greatest with storms that remain discrete and develop near the moist axis. A gradual increase in storm coverage is expected during afternoon, with a mixed mode likely. Supercells and organized line segments will likely be capable of wind-damage, with the threat peaking during the early to mid afternoon. ..Broyles/Wendt.. 12/10/2023 Read more