Aggregator

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0337 PM CST Tue Nov 21 2023 Valid 231200Z - 291200Z Brief quasi-zonal flow aloft during the middle of the week will quickly give way to a large trough digging into the West. By the weekend, broad troughing aloft will envelop most of the CONUS. Models are coming into better agreement about a cutoff low developing in the southern California vicinity around the start of next week. At the surface, cold air will move into the northern/central Plains late this week and make some progress into the southern Plains Friday/Saturday. A secondary push of cold air will occur on Sunday/Monday and bring colder air all the way to the Gulf Coast. Overall, fire weather concerns will remain limited in most areas due to cool/cold temperatures, light winds, or precipitation. ...Southern California... Models continue to suggest weak to possibly moderate offshore winds Sunday into Monday. Fuels will be drier than the previous offshore wind event. However, it is not clear that dry fuels will be widespread enough for a greater fire weather risk. Further, as the cutoff low develops, there may be potential for light precipitation in some areas within the region. When coupled with upper-level wind support that is not expected to be overly strong, the potential for critical fire weather appears too low for highlights. ..Wendt.. 11/21/2023 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0203 PM CST Tue Nov 21 2023 Valid 212000Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS PARTS OF SOUTHEAST AL...WEST-CENTRAL/SOUTHWEST GA AND THE FL PANHANDLE... ...SUMMARY... A few brief tornadoes and isolated damaging gusts may occur across parts of the Southeast States through tonight. ...Southeast... A generally low probability but broad severe threat area will likely continue through tonight where strong low-level shear can persist amid weak instability. Through early evening, the primary corridor for a brief tornado or two appears to be focused near the GA/AL/FL border areas. Low-topped convection along/just ahead of the cold front might deepen sufficiently to acquire low-level updraft rotation, a scenario still supported by 18-19Z WoFS runs. Large low-level hodographs will generally be confined to the minimal/scant instability on the northern periphery of the surface-based buoyancy plume. Farther south, low-level hodographs will gradually shrink as flow becomes more veered where somewhat greater instability and richer low-level moisture are present into the FL Panhandle. See MCD 2282 for additional near-term forecast information. Elsewhere, the forecast appears reasonably on-track with no changes necessary. ..Grams.. 11/21/2023 .PREV DISCUSSION... /ISSUED 1028 AM CST Tue Nov 21 2023/ ...Synopsis... A large mid/upper-level cyclone over the Great Lakes this morning will continue to move eastward today. A trailing, positively tilted upper trough extends across the Midwest into the mid/lower MS Valley and southern Plains. The primary surface low over the Midwest is also forecast to develop slowly east-northeastward toward the Lower Great Lakes through tonight. A trailing cold front will progress eastward today and tonight across the Southeast and Mid-Atlantic states as a secondary surface low eventually forms over VA/MD and develops quickly northeastward across the coastal Mid-Atlantic. ...Central to Northeast Gulf Coast States... Swaths of warm-advection-related precipitation and widespread cloud cover have hindered daytime heating so far this morning across southern AL, the FL Panhandle, and GA. Still, some clearing has recently been noted between the cold front ongoing precipitation. Most guidance suggests that surface temperatures reaching into the low 70s will be needed for sufficient boundary-layer destabilization to support surface-based thunderstorms. Even with this modest heating, poor lapse rates aloft will likely hinder the degree of MLCAPE across the warm sector this afternoon. This should temper updraft intensities to some extent. But, latest VWPs from area radars show rather strong low-level and deep-layer shear are still present across this region. Any robust convection that can develop along/near the cold front this afternoon could become supercellular, with an associated threat for a few tornadoes and isolated damaging winds. But, confidence remains low that enough instability will develop to support intense thunderstorms. Have therefore maintained the low-confidence Slight Risk across this region with minimal changes. ...Georgia into the Carolinas and Southeastern Virginia... Widespread cloud cover and areas of precipitation remain prevalent from GA into the NC/SC and VA, with a warm front/retreating wedge front delineating the northern extent of low-level moisture return. Instability should remain fairly weak through the period with northeastward extent from central/northern GA into the Carolinas. This limits confidence in thunderstorm intensities this afternoon. Still, a conditional threat for damaging wind gusts and perhaps a tornado or two exists with mainly linear convection that can develop/strengthen along the eastward-moving cold front this afternoon and evening. Late tonight, a low-topped line of convection may develop along the front from NC into southeastern VA and vicinity. While instability is forecast to remain minimal, strong flow at low/mid levels may still reach the surface through convective downdrafts. Have expanded the Marginal Risk for isolated damaging winds northward a bit based on this potential. Confidence in supercells developing across coastal/eastern NC in the last few hours of the period remains low. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0203 PM CST Tue Nov 21 2023 Valid 212000Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS PARTS OF SOUTHEAST AL...WEST-CENTRAL/SOUTHWEST GA AND THE FL PANHANDLE... ...SUMMARY... A few brief tornadoes and isolated damaging gusts may occur across parts of the Southeast States through tonight. ...Southeast... A generally low probability but broad severe threat area will likely continue through tonight where strong low-level shear can persist amid weak instability. Through early evening, the primary corridor for a brief tornado or two appears to be focused near the GA/AL/FL border areas. Low-topped convection along/just ahead of the cold front might deepen sufficiently to acquire low-level updraft rotation, a scenario still supported by 18-19Z WoFS runs. Large low-level hodographs will generally be confined to the minimal/scant instability on the northern periphery of the surface-based buoyancy plume. Farther south, low-level hodographs will gradually shrink as flow becomes more veered where somewhat greater instability and richer low-level moisture are present into the FL Panhandle. See MCD 2282 for additional near-term forecast information. Elsewhere, the forecast appears reasonably on-track with no changes necessary. ..Grams.. 11/21/2023 .PREV DISCUSSION... /ISSUED 1028 AM CST Tue Nov 21 2023/ ...Synopsis... A large mid/upper-level cyclone over the Great Lakes this morning will continue to move eastward today. A trailing, positively tilted upper trough extends across the Midwest into the mid/lower MS Valley and southern Plains. The primary surface low over the Midwest is also forecast to develop slowly east-northeastward toward the Lower Great Lakes through tonight. A trailing cold front will progress eastward today and tonight across the Southeast and Mid-Atlantic states as a secondary surface low eventually forms over VA/MD and develops quickly northeastward across the coastal Mid-Atlantic. ...Central to Northeast Gulf Coast States... Swaths of warm-advection-related precipitation and widespread cloud cover have hindered daytime heating so far this morning across southern AL, the FL Panhandle, and GA. Still, some clearing has recently been noted between the cold front ongoing precipitation. Most guidance suggests that surface temperatures reaching into the low 70s will be needed for sufficient boundary-layer destabilization to support surface-based thunderstorms. Even with this modest heating, poor lapse rates aloft will likely hinder the degree of MLCAPE across the warm sector this afternoon. This should temper updraft intensities to some extent. But, latest VWPs from area radars show rather strong low-level and deep-layer shear are still present across this region. Any robust convection that can develop along/near the cold front this afternoon could become supercellular, with an associated threat for a few tornadoes and isolated damaging winds. But, confidence remains low that enough instability will develop to support intense thunderstorms. Have therefore maintained the low-confidence Slight Risk across this region with minimal changes. ...Georgia into the Carolinas and Southeastern Virginia... Widespread cloud cover and areas of precipitation remain prevalent from GA into the NC/SC and VA, with a warm front/retreating wedge front delineating the northern extent of low-level moisture return. Instability should remain fairly weak through the period with northeastward extent from central/northern GA into the Carolinas. This limits confidence in thunderstorm intensities this afternoon. Still, a conditional threat for damaging wind gusts and perhaps a tornado or two exists with mainly linear convection that can develop/strengthen along the eastward-moving cold front this afternoon and evening. Late tonight, a low-topped line of convection may develop along the front from NC into southeastern VA and vicinity. While instability is forecast to remain minimal, strong flow at low/mid levels may still reach the surface through convective downdrafts. Have expanded the Marginal Risk for isolated damaging winds northward a bit based on this potential. Confidence in supercells developing across coastal/eastern NC in the last few hours of the period remains low. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0203 PM CST Tue Nov 21 2023 Valid 212000Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS PARTS OF SOUTHEAST AL...WEST-CENTRAL/SOUTHWEST GA AND THE FL PANHANDLE... ...SUMMARY... A few brief tornadoes and isolated damaging gusts may occur across parts of the Southeast States through tonight. ...Southeast... A generally low probability but broad severe threat area will likely continue through tonight where strong low-level shear can persist amid weak instability. Through early evening, the primary corridor for a brief tornado or two appears to be focused near the GA/AL/FL border areas. Low-topped convection along/just ahead of the cold front might deepen sufficiently to acquire low-level updraft rotation, a scenario still supported by 18-19Z WoFS runs. Large low-level hodographs will generally be confined to the minimal/scant instability on the northern periphery of the surface-based buoyancy plume. Farther south, low-level hodographs will gradually shrink as flow becomes more veered where somewhat greater instability and richer low-level moisture are present into the FL Panhandle. See MCD 2282 for additional near-term forecast information. Elsewhere, the forecast appears reasonably on-track with no changes necessary. ..Grams.. 11/21/2023 .PREV DISCUSSION... /ISSUED 1028 AM CST Tue Nov 21 2023/ ...Synopsis... A large mid/upper-level cyclone over the Great Lakes this morning will continue to move eastward today. A trailing, positively tilted upper trough extends across the Midwest into the mid/lower MS Valley and southern Plains. The primary surface low over the Midwest is also forecast to develop slowly east-northeastward toward the Lower Great Lakes through tonight. A trailing cold front will progress eastward today and tonight across the Southeast and Mid-Atlantic states as a secondary surface low eventually forms over VA/MD and develops quickly northeastward across the coastal Mid-Atlantic. ...Central to Northeast Gulf Coast States... Swaths of warm-advection-related precipitation and widespread cloud cover have hindered daytime heating so far this morning across southern AL, the FL Panhandle, and GA. Still, some clearing has recently been noted between the cold front ongoing precipitation. Most guidance suggests that surface temperatures reaching into the low 70s will be needed for sufficient boundary-layer destabilization to support surface-based thunderstorms. Even with this modest heating, poor lapse rates aloft will likely hinder the degree of MLCAPE across the warm sector this afternoon. This should temper updraft intensities to some extent. But, latest VWPs from area radars show rather strong low-level and deep-layer shear are still present across this region. Any robust convection that can develop along/near the cold front this afternoon could become supercellular, with an associated threat for a few tornadoes and isolated damaging winds. But, confidence remains low that enough instability will develop to support intense thunderstorms. Have therefore maintained the low-confidence Slight Risk across this region with minimal changes. ...Georgia into the Carolinas and Southeastern Virginia... Widespread cloud cover and areas of precipitation remain prevalent from GA into the NC/SC and VA, with a warm front/retreating wedge front delineating the northern extent of low-level moisture return. Instability should remain fairly weak through the period with northeastward extent from central/northern GA into the Carolinas. This limits confidence in thunderstorm intensities this afternoon. Still, a conditional threat for damaging wind gusts and perhaps a tornado or two exists with mainly linear convection that can develop/strengthen along the eastward-moving cold front this afternoon and evening. Late tonight, a low-topped line of convection may develop along the front from NC into southeastern VA and vicinity. While instability is forecast to remain minimal, strong flow at low/mid levels may still reach the surface through convective downdrafts. Have expanded the Marginal Risk for isolated damaging winds northward a bit based on this potential. Confidence in supercells developing across coastal/eastern NC in the last few hours of the period remains low. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0203 PM CST Tue Nov 21 2023 Valid 212000Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS PARTS OF SOUTHEAST AL...WEST-CENTRAL/SOUTHWEST GA AND THE FL PANHANDLE... ...SUMMARY... A few brief tornadoes and isolated damaging gusts may occur across parts of the Southeast States through tonight. ...Southeast... A generally low probability but broad severe threat area will likely continue through tonight where strong low-level shear can persist amid weak instability. Through early evening, the primary corridor for a brief tornado or two appears to be focused near the GA/AL/FL border areas. Low-topped convection along/just ahead of the cold front might deepen sufficiently to acquire low-level updraft rotation, a scenario still supported by 18-19Z WoFS runs. Large low-level hodographs will generally be confined to the minimal/scant instability on the northern periphery of the surface-based buoyancy plume. Farther south, low-level hodographs will gradually shrink as flow becomes more veered where somewhat greater instability and richer low-level moisture are present into the FL Panhandle. See MCD 2282 for additional near-term forecast information. Elsewhere, the forecast appears reasonably on-track with no changes necessary. ..Grams.. 11/21/2023 .PREV DISCUSSION... /ISSUED 1028 AM CST Tue Nov 21 2023/ ...Synopsis... A large mid/upper-level cyclone over the Great Lakes this morning will continue to move eastward today. A trailing, positively tilted upper trough extends across the Midwest into the mid/lower MS Valley and southern Plains. The primary surface low over the Midwest is also forecast to develop slowly east-northeastward toward the Lower Great Lakes through tonight. A trailing cold front will progress eastward today and tonight across the Southeast and Mid-Atlantic states as a secondary surface low eventually forms over VA/MD and develops quickly northeastward across the coastal Mid-Atlantic. ...Central to Northeast Gulf Coast States... Swaths of warm-advection-related precipitation and widespread cloud cover have hindered daytime heating so far this morning across southern AL, the FL Panhandle, and GA. Still, some clearing has recently been noted between the cold front ongoing precipitation. Most guidance suggests that surface temperatures reaching into the low 70s will be needed for sufficient boundary-layer destabilization to support surface-based thunderstorms. Even with this modest heating, poor lapse rates aloft will likely hinder the degree of MLCAPE across the warm sector this afternoon. This should temper updraft intensities to some extent. But, latest VWPs from area radars show rather strong low-level and deep-layer shear are still present across this region. Any robust convection that can develop along/near the cold front this afternoon could become supercellular, with an associated threat for a few tornadoes and isolated damaging winds. But, confidence remains low that enough instability will develop to support intense thunderstorms. Have therefore maintained the low-confidence Slight Risk across this region with minimal changes. ...Georgia into the Carolinas and Southeastern Virginia... Widespread cloud cover and areas of precipitation remain prevalent from GA into the NC/SC and VA, with a warm front/retreating wedge front delineating the northern extent of low-level moisture return. Instability should remain fairly weak through the period with northeastward extent from central/northern GA into the Carolinas. This limits confidence in thunderstorm intensities this afternoon. Still, a conditional threat for damaging wind gusts and perhaps a tornado or two exists with mainly linear convection that can develop/strengthen along the eastward-moving cold front this afternoon and evening. Late tonight, a low-topped line of convection may develop along the front from NC into southeastern VA and vicinity. While instability is forecast to remain minimal, strong flow at low/mid levels may still reach the surface through convective downdrafts. Have expanded the Marginal Risk for isolated damaging winds northward a bit based on this potential. Confidence in supercells developing across coastal/eastern NC in the last few hours of the period remains low. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0203 PM CST Tue Nov 21 2023 Valid 212000Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS PARTS OF SOUTHEAST AL...WEST-CENTRAL/SOUTHWEST GA AND THE FL PANHANDLE... ...SUMMARY... A few brief tornadoes and isolated damaging gusts may occur across parts of the Southeast States through tonight. ...Southeast... A generally low probability but broad severe threat area will likely continue through tonight where strong low-level shear can persist amid weak instability. Through early evening, the primary corridor for a brief tornado or two appears to be focused near the GA/AL/FL border areas. Low-topped convection along/just ahead of the cold front might deepen sufficiently to acquire low-level updraft rotation, a scenario still supported by 18-19Z WoFS runs. Large low-level hodographs will generally be confined to the minimal/scant instability on the northern periphery of the surface-based buoyancy plume. Farther south, low-level hodographs will gradually shrink as flow becomes more veered where somewhat greater instability and richer low-level moisture are present into the FL Panhandle. See MCD 2282 for additional near-term forecast information. Elsewhere, the forecast appears reasonably on-track with no changes necessary. ..Grams.. 11/21/2023 .PREV DISCUSSION... /ISSUED 1028 AM CST Tue Nov 21 2023/ ...Synopsis... A large mid/upper-level cyclone over the Great Lakes this morning will continue to move eastward today. A trailing, positively tilted upper trough extends across the Midwest into the mid/lower MS Valley and southern Plains. The primary surface low over the Midwest is also forecast to develop slowly east-northeastward toward the Lower Great Lakes through tonight. A trailing cold front will progress eastward today and tonight across the Southeast and Mid-Atlantic states as a secondary surface low eventually forms over VA/MD and develops quickly northeastward across the coastal Mid-Atlantic. ...Central to Northeast Gulf Coast States... Swaths of warm-advection-related precipitation and widespread cloud cover have hindered daytime heating so far this morning across southern AL, the FL Panhandle, and GA. Still, some clearing has recently been noted between the cold front ongoing precipitation. Most guidance suggests that surface temperatures reaching into the low 70s will be needed for sufficient boundary-layer destabilization to support surface-based thunderstorms. Even with this modest heating, poor lapse rates aloft will likely hinder the degree of MLCAPE across the warm sector this afternoon. This should temper updraft intensities to some extent. But, latest VWPs from area radars show rather strong low-level and deep-layer shear are still present across this region. Any robust convection that can develop along/near the cold front this afternoon could become supercellular, with an associated threat for a few tornadoes and isolated damaging winds. But, confidence remains low that enough instability will develop to support intense thunderstorms. Have therefore maintained the low-confidence Slight Risk across this region with minimal changes. ...Georgia into the Carolinas and Southeastern Virginia... Widespread cloud cover and areas of precipitation remain prevalent from GA into the NC/SC and VA, with a warm front/retreating wedge front delineating the northern extent of low-level moisture return. Instability should remain fairly weak through the period with northeastward extent from central/northern GA into the Carolinas. This limits confidence in thunderstorm intensities this afternoon. Still, a conditional threat for damaging wind gusts and perhaps a tornado or two exists with mainly linear convection that can develop/strengthen along the eastward-moving cold front this afternoon and evening. Late tonight, a low-topped line of convection may develop along the front from NC into southeastern VA and vicinity. While instability is forecast to remain minimal, strong flow at low/mid levels may still reach the surface through convective downdrafts. Have expanded the Marginal Risk for isolated damaging winds northward a bit based on this potential. Confidence in supercells developing across coastal/eastern NC in the last few hours of the period remains low. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0203 PM CST Tue Nov 21 2023 Valid 212000Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS PARTS OF SOUTHEAST AL...WEST-CENTRAL/SOUTHWEST GA AND THE FL PANHANDLE... ...SUMMARY... A few brief tornadoes and isolated damaging gusts may occur across parts of the Southeast States through tonight. ...Southeast... A generally low probability but broad severe threat area will likely continue through tonight where strong low-level shear can persist amid weak instability. Through early evening, the primary corridor for a brief tornado or two appears to be focused near the GA/AL/FL border areas. Low-topped convection along/just ahead of the cold front might deepen sufficiently to acquire low-level updraft rotation, a scenario still supported by 18-19Z WoFS runs. Large low-level hodographs will generally be confined to the minimal/scant instability on the northern periphery of the surface-based buoyancy plume. Farther south, low-level hodographs will gradually shrink as flow becomes more veered where somewhat greater instability and richer low-level moisture are present into the FL Panhandle. See MCD 2282 for additional near-term forecast information. Elsewhere, the forecast appears reasonably on-track with no changes necessary. ..Grams.. 11/21/2023 .PREV DISCUSSION... /ISSUED 1028 AM CST Tue Nov 21 2023/ ...Synopsis... A large mid/upper-level cyclone over the Great Lakes this morning will continue to move eastward today. A trailing, positively tilted upper trough extends across the Midwest into the mid/lower MS Valley and southern Plains. The primary surface low over the Midwest is also forecast to develop slowly east-northeastward toward the Lower Great Lakes through tonight. A trailing cold front will progress eastward today and tonight across the Southeast and Mid-Atlantic states as a secondary surface low eventually forms over VA/MD and develops quickly northeastward across the coastal Mid-Atlantic. ...Central to Northeast Gulf Coast States... Swaths of warm-advection-related precipitation and widespread cloud cover have hindered daytime heating so far this morning across southern AL, the FL Panhandle, and GA. Still, some clearing has recently been noted between the cold front ongoing precipitation. Most guidance suggests that surface temperatures reaching into the low 70s will be needed for sufficient boundary-layer destabilization to support surface-based thunderstorms. Even with this modest heating, poor lapse rates aloft will likely hinder the degree of MLCAPE across the warm sector this afternoon. This should temper updraft intensities to some extent. But, latest VWPs from area radars show rather strong low-level and deep-layer shear are still present across this region. Any robust convection that can develop along/near the cold front this afternoon could become supercellular, with an associated threat for a few tornadoes and isolated damaging winds. But, confidence remains low that enough instability will develop to support intense thunderstorms. Have therefore maintained the low-confidence Slight Risk across this region with minimal changes. ...Georgia into the Carolinas and Southeastern Virginia... Widespread cloud cover and areas of precipitation remain prevalent from GA into the NC/SC and VA, with a warm front/retreating wedge front delineating the northern extent of low-level moisture return. Instability should remain fairly weak through the period with northeastward extent from central/northern GA into the Carolinas. This limits confidence in thunderstorm intensities this afternoon. Still, a conditional threat for damaging wind gusts and perhaps a tornado or two exists with mainly linear convection that can develop/strengthen along the eastward-moving cold front this afternoon and evening. Late tonight, a low-topped line of convection may develop along the front from NC into southeastern VA and vicinity. While instability is forecast to remain minimal, strong flow at low/mid levels may still reach the surface through convective downdrafts. Have expanded the Marginal Risk for isolated damaging winds northward a bit based on this potential. Confidence in supercells developing across coastal/eastern NC in the last few hours of the period remains low. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0203 PM CST Tue Nov 21 2023 Valid 212000Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS PARTS OF SOUTHEAST AL...WEST-CENTRAL/SOUTHWEST GA AND THE FL PANHANDLE... ...SUMMARY... A few brief tornadoes and isolated damaging gusts may occur across parts of the Southeast States through tonight. ...Southeast... A generally low probability but broad severe threat area will likely continue through tonight where strong low-level shear can persist amid weak instability. Through early evening, the primary corridor for a brief tornado or two appears to be focused near the GA/AL/FL border areas. Low-topped convection along/just ahead of the cold front might deepen sufficiently to acquire low-level updraft rotation, a scenario still supported by 18-19Z WoFS runs. Large low-level hodographs will generally be confined to the minimal/scant instability on the northern periphery of the surface-based buoyancy plume. Farther south, low-level hodographs will gradually shrink as flow becomes more veered where somewhat greater instability and richer low-level moisture are present into the FL Panhandle. See MCD 2282 for additional near-term forecast information. Elsewhere, the forecast appears reasonably on-track with no changes necessary. ..Grams.. 11/21/2023 .PREV DISCUSSION... /ISSUED 1028 AM CST Tue Nov 21 2023/ ...Synopsis... A large mid/upper-level cyclone over the Great Lakes this morning will continue to move eastward today. A trailing, positively tilted upper trough extends across the Midwest into the mid/lower MS Valley and southern Plains. The primary surface low over the Midwest is also forecast to develop slowly east-northeastward toward the Lower Great Lakes through tonight. A trailing cold front will progress eastward today and tonight across the Southeast and Mid-Atlantic states as a secondary surface low eventually forms over VA/MD and develops quickly northeastward across the coastal Mid-Atlantic. ...Central to Northeast Gulf Coast States... Swaths of warm-advection-related precipitation and widespread cloud cover have hindered daytime heating so far this morning across southern AL, the FL Panhandle, and GA. Still, some clearing has recently been noted between the cold front ongoing precipitation. Most guidance suggests that surface temperatures reaching into the low 70s will be needed for sufficient boundary-layer destabilization to support surface-based thunderstorms. Even with this modest heating, poor lapse rates aloft will likely hinder the degree of MLCAPE across the warm sector this afternoon. This should temper updraft intensities to some extent. But, latest VWPs from area radars show rather strong low-level and deep-layer shear are still present across this region. Any robust convection that can develop along/near the cold front this afternoon could become supercellular, with an associated threat for a few tornadoes and isolated damaging winds. But, confidence remains low that enough instability will develop to support intense thunderstorms. Have therefore maintained the low-confidence Slight Risk across this region with minimal changes. ...Georgia into the Carolinas and Southeastern Virginia... Widespread cloud cover and areas of precipitation remain prevalent from GA into the NC/SC and VA, with a warm front/retreating wedge front delineating the northern extent of low-level moisture return. Instability should remain fairly weak through the period with northeastward extent from central/northern GA into the Carolinas. This limits confidence in thunderstorm intensities this afternoon. Still, a conditional threat for damaging wind gusts and perhaps a tornado or two exists with mainly linear convection that can develop/strengthen along the eastward-moving cold front this afternoon and evening. Late tonight, a low-topped line of convection may develop along the front from NC into southeastern VA and vicinity. While instability is forecast to remain minimal, strong flow at low/mid levels may still reach the surface through convective downdrafts. Have expanded the Marginal Risk for isolated damaging winds northward a bit based on this potential. Confidence in supercells developing across coastal/eastern NC in the last few hours of the period remains low. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0203 PM CST Tue Nov 21 2023 Valid 212000Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS PARTS OF SOUTHEAST AL...WEST-CENTRAL/SOUTHWEST GA AND THE FL PANHANDLE... ...SUMMARY... A few brief tornadoes and isolated damaging gusts may occur across parts of the Southeast States through tonight. ...Southeast... A generally low probability but broad severe threat area will likely continue through tonight where strong low-level shear can persist amid weak instability. Through early evening, the primary corridor for a brief tornado or two appears to be focused near the GA/AL/FL border areas. Low-topped convection along/just ahead of the cold front might deepen sufficiently to acquire low-level updraft rotation, a scenario still supported by 18-19Z WoFS runs. Large low-level hodographs will generally be confined to the minimal/scant instability on the northern periphery of the surface-based buoyancy plume. Farther south, low-level hodographs will gradually shrink as flow becomes more veered where somewhat greater instability and richer low-level moisture are present into the FL Panhandle. See MCD 2282 for additional near-term forecast information. Elsewhere, the forecast appears reasonably on-track with no changes necessary. ..Grams.. 11/21/2023 .PREV DISCUSSION... /ISSUED 1028 AM CST Tue Nov 21 2023/ ...Synopsis... A large mid/upper-level cyclone over the Great Lakes this morning will continue to move eastward today. A trailing, positively tilted upper trough extends across the Midwest into the mid/lower MS Valley and southern Plains. The primary surface low over the Midwest is also forecast to develop slowly east-northeastward toward the Lower Great Lakes through tonight. A trailing cold front will progress eastward today and tonight across the Southeast and Mid-Atlantic states as a secondary surface low eventually forms over VA/MD and develops quickly northeastward across the coastal Mid-Atlantic. ...Central to Northeast Gulf Coast States... Swaths of warm-advection-related precipitation and widespread cloud cover have hindered daytime heating so far this morning across southern AL, the FL Panhandle, and GA. Still, some clearing has recently been noted between the cold front ongoing precipitation. Most guidance suggests that surface temperatures reaching into the low 70s will be needed for sufficient boundary-layer destabilization to support surface-based thunderstorms. Even with this modest heating, poor lapse rates aloft will likely hinder the degree of MLCAPE across the warm sector this afternoon. This should temper updraft intensities to some extent. But, latest VWPs from area radars show rather strong low-level and deep-layer shear are still present across this region. Any robust convection that can develop along/near the cold front this afternoon could become supercellular, with an associated threat for a few tornadoes and isolated damaging winds. But, confidence remains low that enough instability will develop to support intense thunderstorms. Have therefore maintained the low-confidence Slight Risk across this region with minimal changes. ...Georgia into the Carolinas and Southeastern Virginia... Widespread cloud cover and areas of precipitation remain prevalent from GA into the NC/SC and VA, with a warm front/retreating wedge front delineating the northern extent of low-level moisture return. Instability should remain fairly weak through the period with northeastward extent from central/northern GA into the Carolinas. This limits confidence in thunderstorm intensities this afternoon. Still, a conditional threat for damaging wind gusts and perhaps a tornado or two exists with mainly linear convection that can develop/strengthen along the eastward-moving cold front this afternoon and evening. Late tonight, a low-topped line of convection may develop along the front from NC into southeastern VA and vicinity. While instability is forecast to remain minimal, strong flow at low/mid levels may still reach the surface through convective downdrafts. Have expanded the Marginal Risk for isolated damaging winds northward a bit based on this potential. Confidence in supercells developing across coastal/eastern NC in the last few hours of the period remains low. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0203 PM CST Tue Nov 21 2023 Valid 212000Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS PARTS OF SOUTHEAST AL...WEST-CENTRAL/SOUTHWEST GA AND THE FL PANHANDLE... ...SUMMARY... A few brief tornadoes and isolated damaging gusts may occur across parts of the Southeast States through tonight. ...Southeast... A generally low probability but broad severe threat area will likely continue through tonight where strong low-level shear can persist amid weak instability. Through early evening, the primary corridor for a brief tornado or two appears to be focused near the GA/AL/FL border areas. Low-topped convection along/just ahead of the cold front might deepen sufficiently to acquire low-level updraft rotation, a scenario still supported by 18-19Z WoFS runs. Large low-level hodographs will generally be confined to the minimal/scant instability on the northern periphery of the surface-based buoyancy plume. Farther south, low-level hodographs will gradually shrink as flow becomes more veered where somewhat greater instability and richer low-level moisture are present into the FL Panhandle. See MCD 2282 for additional near-term forecast information. Elsewhere, the forecast appears reasonably on-track with no changes necessary. ..Grams.. 11/21/2023 .PREV DISCUSSION... /ISSUED 1028 AM CST Tue Nov 21 2023/ ...Synopsis... A large mid/upper-level cyclone over the Great Lakes this morning will continue to move eastward today. A trailing, positively tilted upper trough extends across the Midwest into the mid/lower MS Valley and southern Plains. The primary surface low over the Midwest is also forecast to develop slowly east-northeastward toward the Lower Great Lakes through tonight. A trailing cold front will progress eastward today and tonight across the Southeast and Mid-Atlantic states as a secondary surface low eventually forms over VA/MD and develops quickly northeastward across the coastal Mid-Atlantic. ...Central to Northeast Gulf Coast States... Swaths of warm-advection-related precipitation and widespread cloud cover have hindered daytime heating so far this morning across southern AL, the FL Panhandle, and GA. Still, some clearing has recently been noted between the cold front ongoing precipitation. Most guidance suggests that surface temperatures reaching into the low 70s will be needed for sufficient boundary-layer destabilization to support surface-based thunderstorms. Even with this modest heating, poor lapse rates aloft will likely hinder the degree of MLCAPE across the warm sector this afternoon. This should temper updraft intensities to some extent. But, latest VWPs from area radars show rather strong low-level and deep-layer shear are still present across this region. Any robust convection that can develop along/near the cold front this afternoon could become supercellular, with an associated threat for a few tornadoes and isolated damaging winds. But, confidence remains low that enough instability will develop to support intense thunderstorms. Have therefore maintained the low-confidence Slight Risk across this region with minimal changes. ...Georgia into the Carolinas and Southeastern Virginia... Widespread cloud cover and areas of precipitation remain prevalent from GA into the NC/SC and VA, with a warm front/retreating wedge front delineating the northern extent of low-level moisture return. Instability should remain fairly weak through the period with northeastward extent from central/northern GA into the Carolinas. This limits confidence in thunderstorm intensities this afternoon. Still, a conditional threat for damaging wind gusts and perhaps a tornado or two exists with mainly linear convection that can develop/strengthen along the eastward-moving cold front this afternoon and evening. Late tonight, a low-topped line of convection may develop along the front from NC into southeastern VA and vicinity. While instability is forecast to remain minimal, strong flow at low/mid levels may still reach the surface through convective downdrafts. Have expanded the Marginal Risk for isolated damaging winds northward a bit based on this potential. Confidence in supercells developing across coastal/eastern NC in the last few hours of the period remains low. Read more

MD 2282 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR PORTIONS OF EASTERN ALABAMA INTO WESTERN GEORGIA AND THE WESTERN FLORIDA PANHANDLE
Mesoscale Discussion 2282 NWS Storm Prediction Center Norman OK 0152 PM CST Tue Nov 21 2023 Areas affected...portions of eastern Alabama into western Georgia and the western Florida Panhandle Concerning...Severe potential...Watch unlikely Valid 211952Z - 212215Z Probability of Watch Issuance...20 percent SUMMARY...A couple of damaging gusts or brief tornadoes cannot be ruled out with any of the stronger storms that can materialize this afternoon into early evening. The severe threat will likely be isolated. DISCUSSION...Convection is slowly deepening along a line immediately ahead of a surface cold front that progressing eastward across central AL. Limited diurnal heating amid low-level warm-air advection has allowed for scant buoyancy to develop ahead of the aforementioned convective line. Surface temperatures warming into the low to mid 70s F amid mid 60s F dewpoints beneath poor tropospheric lapse rates supports narrow SBCAPE profiles (mainly below 500 J/kg), with evidence of embedded thin inversion layers (per latest RAP forecast soundings). While a strong low-level jet is in place (contributing to enlarged, curved hodographs), the surface low over the OH Valley should continue to drift northeastward with time, supporting an eastward shift of the low-level jet and resultant veering of flow in the surface-850 mb layer. When also considering the scant buoyancy, the severe threat appears limited. Nonetheless, there may be a window of opportunity for some of the stronger convective cells embedded in the line to overlap with locally higher CAPE before low-level flow veers and hodographs lose their curvature. For a few hours during the afternoon, some of these storms may acquire brief/transient low-level rotation. As such, a couple of damaging gusts or brief tornadoes cannot be completely ruled out. Nonetheless, the anticipated isolated nature of the severe threat suggests that a WW issuance will probably not be needed later today. ..Squitieri/Gleason.. 11/21/2023 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...CAE...GSP...FFC...TAE...BMX...MOB... LAT...LON 30348686 32228565 33688445 33938428 34228372 34168303 34018266 33358246 32798247 32388265 31848308 30738362 30158390 29758442 29598498 29678548 30038594 30108602 30348686 Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1259 PM CST Tue Nov 21 2023 Valid 221200Z - 231200Z ...NO CRITICAL AREAS... No changes to the ongoing forecast. ..Wendt.. 11/21/2023 .PREV DISCUSSION... /ISSUED 0146 AM CST Tue Nov 21 2023/ ...Synopsis... Shortwave ridging across the central CONUS will persist into D2/Wednesday as the eastern trough weakens and moves offshore. Stronger westerly flow aloft north of the western ridge will support weak lee cyclogenesis over the central High Plains. Otherwise, broad high pressure is expected over much of the US and surface winds should remain light, with the exception of some stronger offshore gusts over southern CA early in the day. Cooler temperatures, weak winds, moderate RH, and widespread recent rainfall will limit overall fire-weather concerns throughout much of the country. ...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 1259 PM CST Tue Nov 21 2023 Valid 221200Z - 231200Z ...NO CRITICAL AREAS... No changes to the ongoing forecast. ..Wendt.. 11/21/2023 .PREV DISCUSSION... /ISSUED 0146 AM CST Tue Nov 21 2023/ ...Synopsis... Shortwave ridging across the central CONUS will persist into D2/Wednesday as the eastern trough weakens and moves offshore. Stronger westerly flow aloft north of the western ridge will support weak lee cyclogenesis over the central High Plains. Otherwise, broad high pressure is expected over much of the US and surface winds should remain light, with the exception of some stronger offshore gusts over southern CA early in the day. Cooler temperatures, weak winds, moderate RH, and widespread recent rainfall will limit overall fire-weather concerns throughout much of the country. ...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 1259 PM CST Tue Nov 21 2023 Valid 221200Z - 231200Z ...NO CRITICAL AREAS... No changes to the ongoing forecast. ..Wendt.. 11/21/2023 .PREV DISCUSSION... /ISSUED 0146 AM CST Tue Nov 21 2023/ ...Synopsis... Shortwave ridging across the central CONUS will persist into D2/Wednesday as the eastern trough weakens and moves offshore. Stronger westerly flow aloft north of the western ridge will support weak lee cyclogenesis over the central High Plains. Otherwise, broad high pressure is expected over much of the US and surface winds should remain light, with the exception of some stronger offshore gusts over southern CA early in the day. Cooler temperatures, weak winds, moderate RH, and widespread recent rainfall will limit overall fire-weather concerns throughout much of the country. ...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 1259 PM CST Tue Nov 21 2023 Valid 221200Z - 231200Z ...NO CRITICAL AREAS... No changes to the ongoing forecast. ..Wendt.. 11/21/2023 .PREV DISCUSSION... /ISSUED 0146 AM CST Tue Nov 21 2023/ ...Synopsis... Shortwave ridging across the central CONUS will persist into D2/Wednesday as the eastern trough weakens and moves offshore. Stronger westerly flow aloft north of the western ridge will support weak lee cyclogenesis over the central High Plains. Otherwise, broad high pressure is expected over much of the US and surface winds should remain light, with the exception of some stronger offshore gusts over southern CA early in the day. Cooler temperatures, weak winds, moderate RH, and widespread recent rainfall will limit overall fire-weather concerns throughout much of the country. ...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 1259 PM CST Tue Nov 21 2023 Valid 221200Z - 231200Z ...NO CRITICAL AREAS... No changes to the ongoing forecast. ..Wendt.. 11/21/2023 .PREV DISCUSSION... /ISSUED 0146 AM CST Tue Nov 21 2023/ ...Synopsis... Shortwave ridging across the central CONUS will persist into D2/Wednesday as the eastern trough weakens and moves offshore. Stronger westerly flow aloft north of the western ridge will support weak lee cyclogenesis over the central High Plains. Otherwise, broad high pressure is expected over much of the US and surface winds should remain light, with the exception of some stronger offshore gusts over southern CA early in the day. Cooler temperatures, weak winds, moderate RH, and widespread recent rainfall will limit overall fire-weather concerns throughout much of the country. ...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 1259 PM CST Tue Nov 21 2023 Valid 221200Z - 231200Z ...NO CRITICAL AREAS... No changes to the ongoing forecast. ..Wendt.. 11/21/2023 .PREV DISCUSSION... /ISSUED 0146 AM CST Tue Nov 21 2023/ ...Synopsis... Shortwave ridging across the central CONUS will persist into D2/Wednesday as the eastern trough weakens and moves offshore. Stronger westerly flow aloft north of the western ridge will support weak lee cyclogenesis over the central High Plains. Otherwise, broad high pressure is expected over much of the US and surface winds should remain light, with the exception of some stronger offshore gusts over southern CA early in the day. Cooler temperatures, weak winds, moderate RH, and widespread recent rainfall will limit overall fire-weather concerns throughout much of the country. ...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 1259 PM CST Tue Nov 21 2023 Valid 221200Z - 231200Z ...NO CRITICAL AREAS... No changes to the ongoing forecast. ..Wendt.. 11/21/2023 .PREV DISCUSSION... /ISSUED 0146 AM CST Tue Nov 21 2023/ ...Synopsis... Shortwave ridging across the central CONUS will persist into D2/Wednesday as the eastern trough weakens and moves offshore. Stronger westerly flow aloft north of the western ridge will support weak lee cyclogenesis over the central High Plains. Otherwise, broad high pressure is expected over much of the US and surface winds should remain light, with the exception of some stronger offshore gusts over southern CA early in the day. Cooler temperatures, weak winds, moderate RH, and widespread recent rainfall will limit overall fire-weather concerns throughout much of the country. ...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 1259 PM CST Tue Nov 21 2023 Valid 221200Z - 231200Z ...NO CRITICAL AREAS... No changes to the ongoing forecast. ..Wendt.. 11/21/2023 .PREV DISCUSSION... /ISSUED 0146 AM CST Tue Nov 21 2023/ ...Synopsis... Shortwave ridging across the central CONUS will persist into D2/Wednesday as the eastern trough weakens and moves offshore. Stronger westerly flow aloft north of the western ridge will support weak lee cyclogenesis over the central High Plains. Otherwise, broad high pressure is expected over much of the US and surface winds should remain light, with the exception of some stronger offshore gusts over southern CA early in the day. Cooler temperatures, weak winds, moderate RH, and widespread recent rainfall will limit overall fire-weather concerns throughout much of the country. ...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 1259 PM CST Tue Nov 21 2023 Valid 221200Z - 231200Z ...NO CRITICAL AREAS... No changes to the ongoing forecast. ..Wendt.. 11/21/2023 .PREV DISCUSSION... /ISSUED 0146 AM CST Tue Nov 21 2023/ ...Synopsis... Shortwave ridging across the central CONUS will persist into D2/Wednesday as the eastern trough weakens and moves offshore. Stronger westerly flow aloft north of the western ridge will support weak lee cyclogenesis over the central High Plains. Otherwise, broad high pressure is expected over much of the US and surface winds should remain light, with the exception of some stronger offshore gusts over southern CA early in the day. Cooler temperatures, weak winds, moderate RH, and widespread recent rainfall will limit overall fire-weather concerns throughout much of the country. ...Please see www.spc.noaa.gov/fire for graphic product... Read more