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SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0146 AM CST Tue Nov 21 2023 Valid 221200Z - 231200Z ...NO CRITICAL AREAS... ...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. ..Lyons.. 11/21/2023 ...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 0146 AM CST Tue Nov 21 2023 Valid 221200Z - 231200Z ...NO CRITICAL AREAS... ...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. ..Lyons.. 11/21/2023 ...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 0146 AM CST Tue Nov 21 2023 Valid 221200Z - 231200Z ...NO CRITICAL AREAS... ...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. ..Lyons.. 11/21/2023 ...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 0146 AM CST Tue Nov 21 2023 Valid 221200Z - 231200Z ...NO CRITICAL AREAS... ...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. ..Lyons.. 11/21/2023 ...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 0143 AM CST Tue Nov 21 2023 Valid 211200Z - 221200Z ...NO CRITICAL AREAS... ...Synopsis... Across the CONUS, the mid-level flow pattern should continue to amplify as broad troughing over the central CONUS slides eastward. At the same time, ridging will intensify over the West Coast as strong surface high pressure develops over the Pacific Northwest and northern Great Basin. Offshore flow will continue over parts of southern CA for the first half of the period, before weakening as the high pressure moves toward the Plains. Dry northerly winds are also expected over much of the central and southern High Plains. However, with limited fuels owing to cooler temperatures and recent precipitation, fire-weather concerns are expected to remain localized. Weak low pressure and a cold front will bring much cooler temperatures and widespread precipitation to the eastern US, limiting the fire-weather threat. ..Lyons.. 11/21/2023 ...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 0143 AM CST Tue Nov 21 2023 Valid 211200Z - 221200Z ...NO CRITICAL AREAS... ...Synopsis... Across the CONUS, the mid-level flow pattern should continue to amplify as broad troughing over the central CONUS slides eastward. At the same time, ridging will intensify over the West Coast as strong surface high pressure develops over the Pacific Northwest and northern Great Basin. Offshore flow will continue over parts of southern CA for the first half of the period, before weakening as the high pressure moves toward the Plains. Dry northerly winds are also expected over much of the central and southern High Plains. However, with limited fuels owing to cooler temperatures and recent precipitation, fire-weather concerns are expected to remain localized. Weak low pressure and a cold front will bring much cooler temperatures and widespread precipitation to the eastern US, limiting the fire-weather threat. ..Lyons.. 11/21/2023 ...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 0143 AM CST Tue Nov 21 2023 Valid 211200Z - 221200Z ...NO CRITICAL AREAS... ...Synopsis... Across the CONUS, the mid-level flow pattern should continue to amplify as broad troughing over the central CONUS slides eastward. At the same time, ridging will intensify over the West Coast as strong surface high pressure develops over the Pacific Northwest and northern Great Basin. Offshore flow will continue over parts of southern CA for the first half of the period, before weakening as the high pressure moves toward the Plains. Dry northerly winds are also expected over much of the central and southern High Plains. However, with limited fuels owing to cooler temperatures and recent precipitation, fire-weather concerns are expected to remain localized. Weak low pressure and a cold front will bring much cooler temperatures and widespread precipitation to the eastern US, limiting the fire-weather threat. ..Lyons.. 11/21/2023 ...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 0143 AM CST Tue Nov 21 2023 Valid 211200Z - 221200Z ...NO CRITICAL AREAS... ...Synopsis... Across the CONUS, the mid-level flow pattern should continue to amplify as broad troughing over the central CONUS slides eastward. At the same time, ridging will intensify over the West Coast as strong surface high pressure develops over the Pacific Northwest and northern Great Basin. Offshore flow will continue over parts of southern CA for the first half of the period, before weakening as the high pressure moves toward the Plains. Dry northerly winds are also expected over much of the central and southern High Plains. However, with limited fuels owing to cooler temperatures and recent precipitation, fire-weather concerns are expected to remain localized. Weak low pressure and a cold front will bring much cooler temperatures and widespread precipitation to the eastern US, limiting the fire-weather threat. ..Lyons.. 11/21/2023 ...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 0143 AM CST Tue Nov 21 2023 Valid 211200Z - 221200Z ...NO CRITICAL AREAS... ...Synopsis... Across the CONUS, the mid-level flow pattern should continue to amplify as broad troughing over the central CONUS slides eastward. At the same time, ridging will intensify over the West Coast as strong surface high pressure develops over the Pacific Northwest and northern Great Basin. Offshore flow will continue over parts of southern CA for the first half of the period, before weakening as the high pressure moves toward the Plains. Dry northerly winds are also expected over much of the central and southern High Plains. However, with limited fuels owing to cooler temperatures and recent precipitation, fire-weather concerns are expected to remain localized. Weak low pressure and a cold front will bring much cooler temperatures and widespread precipitation to the eastern US, limiting the fire-weather threat. ..Lyons.. 11/21/2023 ...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 0143 AM CST Tue Nov 21 2023 Valid 211200Z - 221200Z ...NO CRITICAL AREAS... ...Synopsis... Across the CONUS, the mid-level flow pattern should continue to amplify as broad troughing over the central CONUS slides eastward. At the same time, ridging will intensify over the West Coast as strong surface high pressure develops over the Pacific Northwest and northern Great Basin. Offshore flow will continue over parts of southern CA for the first half of the period, before weakening as the high pressure moves toward the Plains. Dry northerly winds are also expected over much of the central and southern High Plains. However, with limited fuels owing to cooler temperatures and recent precipitation, fire-weather concerns are expected to remain localized. Weak low pressure and a cold front will bring much cooler temperatures and widespread precipitation to the eastern US, limiting the fire-weather threat. ..Lyons.. 11/21/2023 ...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 1258 AM CST Tue Nov 21 2023 Valid 221200Z - 231200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR EASTERN NC... ...SUMMARY... Isolated severe thunderstorms are possible Wednesday morning across eastern North Carolina and the Outer Banks. Locally damaging gusts and a brief tornado are possible. ...Synopsis... A positively tilted upper-level trough will move across the eastern CONUS on Wednesday. Latest guidance depicts a notable embedded shortwave that will move eastward from the TN Valley toward the Carolinas through the day. The primary surface cyclone is expected to move from near the Mid Atlantic coast northeastward toward Nova Scotia by early Thursday morning. A trailing cold front will move through eastern NC, where some isolated severe threat may persist early in the forecast period. Generally weak frontal convection will be possible across parts of the FL Peninsula. ...Eastern NC... A Marginal Risk has been included for eastern NC, as a continuation of the conditional severe threat that may begin late in the D1/Tuesday period. Most recent guidance suggests that the cold front will not clear the Outer Banks until around 15Z Wednesday morning, with a slightly later frontal passage possible if a surface wave develops along the front in response to the approaching shortwave trough. The prefrontal environment will be characterized by rich low-level moisture and strong low-level and deep-layer shear, but poor lapse rates and widespread precipitation will limit destabilization prior to frontal passage. The potential for organized storm structures within this environment remains uncertain due to the limited instability, but a transient supercell or stronger line segment cannot be ruled out, with an attendant threat of a brief tornado and locally damaging wind. ..Dean.. 11/21/2023 Read more

SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1258 AM CST Tue Nov 21 2023 Valid 221200Z - 231200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR EASTERN NC... ...SUMMARY... Isolated severe thunderstorms are possible Wednesday morning across eastern North Carolina and the Outer Banks. Locally damaging gusts and a brief tornado are possible. ...Synopsis... A positively tilted upper-level trough will move across the eastern CONUS on Wednesday. Latest guidance depicts a notable embedded shortwave that will move eastward from the TN Valley toward the Carolinas through the day. The primary surface cyclone is expected to move from near the Mid Atlantic coast northeastward toward Nova Scotia by early Thursday morning. A trailing cold front will move through eastern NC, where some isolated severe threat may persist early in the forecast period. Generally weak frontal convection will be possible across parts of the FL Peninsula. ...Eastern NC... A Marginal Risk has been included for eastern NC, as a continuation of the conditional severe threat that may begin late in the D1/Tuesday period. Most recent guidance suggests that the cold front will not clear the Outer Banks until around 15Z Wednesday morning, with a slightly later frontal passage possible if a surface wave develops along the front in response to the approaching shortwave trough. The prefrontal environment will be characterized by rich low-level moisture and strong low-level and deep-layer shear, but poor lapse rates and widespread precipitation will limit destabilization prior to frontal passage. The potential for organized storm structures within this environment remains uncertain due to the limited instability, but a transient supercell or stronger line segment cannot be ruled out, with an attendant threat of a brief tornado and locally damaging wind. ..Dean.. 11/21/2023 Read more

SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1258 AM CST Tue Nov 21 2023 Valid 221200Z - 231200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR EASTERN NC... ...SUMMARY... Isolated severe thunderstorms are possible Wednesday morning across eastern North Carolina and the Outer Banks. Locally damaging gusts and a brief tornado are possible. ...Synopsis... A positively tilted upper-level trough will move across the eastern CONUS on Wednesday. Latest guidance depicts a notable embedded shortwave that will move eastward from the TN Valley toward the Carolinas through the day. The primary surface cyclone is expected to move from near the Mid Atlantic coast northeastward toward Nova Scotia by early Thursday morning. A trailing cold front will move through eastern NC, where some isolated severe threat may persist early in the forecast period. Generally weak frontal convection will be possible across parts of the FL Peninsula. ...Eastern NC... A Marginal Risk has been included for eastern NC, as a continuation of the conditional severe threat that may begin late in the D1/Tuesday period. Most recent guidance suggests that the cold front will not clear the Outer Banks until around 15Z Wednesday morning, with a slightly later frontal passage possible if a surface wave develops along the front in response to the approaching shortwave trough. The prefrontal environment will be characterized by rich low-level moisture and strong low-level and deep-layer shear, but poor lapse rates and widespread precipitation will limit destabilization prior to frontal passage. The potential for organized storm structures within this environment remains uncertain due to the limited instability, but a transient supercell or stronger line segment cannot be ruled out, with an attendant threat of a brief tornado and locally damaging wind. ..Dean.. 11/21/2023 Read more

SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1258 AM CST Tue Nov 21 2023 Valid 221200Z - 231200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR EASTERN NC... ...SUMMARY... Isolated severe thunderstorms are possible Wednesday morning across eastern North Carolina and the Outer Banks. Locally damaging gusts and a brief tornado are possible. ...Synopsis... A positively tilted upper-level trough will move across the eastern CONUS on Wednesday. Latest guidance depicts a notable embedded shortwave that will move eastward from the TN Valley toward the Carolinas through the day. The primary surface cyclone is expected to move from near the Mid Atlantic coast northeastward toward Nova Scotia by early Thursday morning. A trailing cold front will move through eastern NC, where some isolated severe threat may persist early in the forecast period. Generally weak frontal convection will be possible across parts of the FL Peninsula. ...Eastern NC... A Marginal Risk has been included for eastern NC, as a continuation of the conditional severe threat that may begin late in the D1/Tuesday period. Most recent guidance suggests that the cold front will not clear the Outer Banks until around 15Z Wednesday morning, with a slightly later frontal passage possible if a surface wave develops along the front in response to the approaching shortwave trough. The prefrontal environment will be characterized by rich low-level moisture and strong low-level and deep-layer shear, but poor lapse rates and widespread precipitation will limit destabilization prior to frontal passage. The potential for organized storm structures within this environment remains uncertain due to the limited instability, but a transient supercell or stronger line segment cannot be ruled out, with an attendant threat of a brief tornado and locally damaging wind. ..Dean.. 11/21/2023 Read more

SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1258 AM CST Tue Nov 21 2023 Valid 221200Z - 231200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR EASTERN NC... ...SUMMARY... Isolated severe thunderstorms are possible Wednesday morning across eastern North Carolina and the Outer Banks. Locally damaging gusts and a brief tornado are possible. ...Synopsis... A positively tilted upper-level trough will move across the eastern CONUS on Wednesday. Latest guidance depicts a notable embedded shortwave that will move eastward from the TN Valley toward the Carolinas through the day. The primary surface cyclone is expected to move from near the Mid Atlantic coast northeastward toward Nova Scotia by early Thursday morning. A trailing cold front will move through eastern NC, where some isolated severe threat may persist early in the forecast period. Generally weak frontal convection will be possible across parts of the FL Peninsula. ...Eastern NC... A Marginal Risk has been included for eastern NC, as a continuation of the conditional severe threat that may begin late in the D1/Tuesday period. Most recent guidance suggests that the cold front will not clear the Outer Banks until around 15Z Wednesday morning, with a slightly later frontal passage possible if a surface wave develops along the front in response to the approaching shortwave trough. The prefrontal environment will be characterized by rich low-level moisture and strong low-level and deep-layer shear, but poor lapse rates and widespread precipitation will limit destabilization prior to frontal passage. The potential for organized storm structures within this environment remains uncertain due to the limited instability, but a transient supercell or stronger line segment cannot be ruled out, with an attendant threat of a brief tornado and locally damaging wind. ..Dean.. 11/21/2023 Read more

SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1258 AM CST Tue Nov 21 2023 Valid 221200Z - 231200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR EASTERN NC... ...SUMMARY... Isolated severe thunderstorms are possible Wednesday morning across eastern North Carolina and the Outer Banks. Locally damaging gusts and a brief tornado are possible. ...Synopsis... A positively tilted upper-level trough will move across the eastern CONUS on Wednesday. Latest guidance depicts a notable embedded shortwave that will move eastward from the TN Valley toward the Carolinas through the day. The primary surface cyclone is expected to move from near the Mid Atlantic coast northeastward toward Nova Scotia by early Thursday morning. A trailing cold front will move through eastern NC, where some isolated severe threat may persist early in the forecast period. Generally weak frontal convection will be possible across parts of the FL Peninsula. ...Eastern NC... A Marginal Risk has been included for eastern NC, as a continuation of the conditional severe threat that may begin late in the D1/Tuesday period. Most recent guidance suggests that the cold front will not clear the Outer Banks until around 15Z Wednesday morning, with a slightly later frontal passage possible if a surface wave develops along the front in response to the approaching shortwave trough. The prefrontal environment will be characterized by rich low-level moisture and strong low-level and deep-layer shear, but poor lapse rates and widespread precipitation will limit destabilization prior to frontal passage. The potential for organized storm structures within this environment remains uncertain due to the limited instability, but a transient supercell or stronger line segment cannot be ruled out, with an attendant threat of a brief tornado and locally damaging wind. ..Dean.. 11/21/2023 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1150 PM CST Mon Nov 20 2023 Valid 211200Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF SOUTHERN ALABAMA AND THE WESTERN FLORIDA PANHANDLE AND SOUTHWEST GEORGIA... ...SUMMARY... A few tornadoes are possible across south Alabama and the Florida Panhandle, mainly during the morning into the afternoon. The potential for locally damaging winds and a couple brief tornadoes will shift farther north and east this afternoon into early morning Wednesday across most of Georgia, the Carolinas, and far southern Virginia. ...Southeastern US... Latest satellite imagery suggests center of upper low is located near JLN. This feature is forecast to eventually dig southeast toward the mid-South as a secondary 500mb speed max translates southeast across eastern OK into southern AR by the end of the period. Immediately downstream, a corridor of strong midlevel flow will extend across the lower MS Valley into the middle Atlantic. 00z model guidance suggests modest height falls will develop ahead of this trough with values approaching 90m in 12hr, especially across the northern middle Atlantic region. In response to this trough, a weak surface low will advance across the OH Valley into southeast lower MI by late afternoon; however, a secondary surface low should evolve along the southern fringe of the Appalachians then track northeast into the Delmarva by 22/12z. This secondary surface low will prove instrumental in allowing modified air mass to advance across the Carolinas during the latter half of the period, with even weak buoyancy likely developing farther north during the overnight hours. Late this evening, an extensive corridor of deep convection has evolved within a strongly diffluent high-level flow regime from western AL-southern MS-southeast LA-western Gulf Basin. This corridor should progress steadily east through sunrise and likely extend across much of AL into the MS delta region by the start of the period. Strong deep-layer flow/shear will support organized convection, and embedded supercells are likely along this band. Forecast soundings at the start of the period exhibit MLCAPE in excess of 500 J/kg within a very moist and poor-lapse rate-environment. NAM soundings for PNS and GZH at 12z display 0-3km SRH between 400-700 m2/s2. Large-scale forcing should encourage an organized band of convection to migrate east, but this activity should weaken a bit downstream as it encounters less buoyancy and weaker forcing over northern FL/southeast GA. During the latter half of the period, primarily after 06z, boundary-layer recovery is expected across coastal Carolinas such that buoyancy will become more supportive of deep updrafts. Strong shear will favor organized convection, along with some supercell potential. Forecast soundings are quite moist with poor lapse rates through 9km. This will limit instability but isolated damaging winds and/or a tornado seem possible with this activity. ..Darrow/Lyons.. 11/21/2023 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1150 PM CST Mon Nov 20 2023 Valid 211200Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF SOUTHERN ALABAMA AND THE WESTERN FLORIDA PANHANDLE AND SOUTHWEST GEORGIA... ...SUMMARY... A few tornadoes are possible across south Alabama and the Florida Panhandle, mainly during the morning into the afternoon. The potential for locally damaging winds and a couple brief tornadoes will shift farther north and east this afternoon into early morning Wednesday across most of Georgia, the Carolinas, and far southern Virginia. ...Southeastern US... Latest satellite imagery suggests center of upper low is located near JLN. This feature is forecast to eventually dig southeast toward the mid-South as a secondary 500mb speed max translates southeast across eastern OK into southern AR by the end of the period. Immediately downstream, a corridor of strong midlevel flow will extend across the lower MS Valley into the middle Atlantic. 00z model guidance suggests modest height falls will develop ahead of this trough with values approaching 90m in 12hr, especially across the northern middle Atlantic region. In response to this trough, a weak surface low will advance across the OH Valley into southeast lower MI by late afternoon; however, a secondary surface low should evolve along the southern fringe of the Appalachians then track northeast into the Delmarva by 22/12z. This secondary surface low will prove instrumental in allowing modified air mass to advance across the Carolinas during the latter half of the period, with even weak buoyancy likely developing farther north during the overnight hours. Late this evening, an extensive corridor of deep convection has evolved within a strongly diffluent high-level flow regime from western AL-southern MS-southeast LA-western Gulf Basin. This corridor should progress steadily east through sunrise and likely extend across much of AL into the MS delta region by the start of the period. Strong deep-layer flow/shear will support organized convection, and embedded supercells are likely along this band. Forecast soundings at the start of the period exhibit MLCAPE in excess of 500 J/kg within a very moist and poor-lapse rate-environment. NAM soundings for PNS and GZH at 12z display 0-3km SRH between 400-700 m2/s2. Large-scale forcing should encourage an organized band of convection to migrate east, but this activity should weaken a bit downstream as it encounters less buoyancy and weaker forcing over northern FL/southeast GA. During the latter half of the period, primarily after 06z, boundary-layer recovery is expected across coastal Carolinas such that buoyancy will become more supportive of deep updrafts. Strong shear will favor organized convection, along with some supercell potential. Forecast soundings are quite moist with poor lapse rates through 9km. This will limit instability but isolated damaging winds and/or a tornado seem possible with this activity. ..Darrow/Lyons.. 11/21/2023 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1150 PM CST Mon Nov 20 2023 Valid 211200Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF SOUTHERN ALABAMA AND THE WESTERN FLORIDA PANHANDLE AND SOUTHWEST GEORGIA... ...SUMMARY... A few tornadoes are possible across south Alabama and the Florida Panhandle, mainly during the morning into the afternoon. The potential for locally damaging winds and a couple brief tornadoes will shift farther north and east this afternoon into early morning Wednesday across most of Georgia, the Carolinas, and far southern Virginia. ...Southeastern US... Latest satellite imagery suggests center of upper low is located near JLN. This feature is forecast to eventually dig southeast toward the mid-South as a secondary 500mb speed max translates southeast across eastern OK into southern AR by the end of the period. Immediately downstream, a corridor of strong midlevel flow will extend across the lower MS Valley into the middle Atlantic. 00z model guidance suggests modest height falls will develop ahead of this trough with values approaching 90m in 12hr, especially across the northern middle Atlantic region. In response to this trough, a weak surface low will advance across the OH Valley into southeast lower MI by late afternoon; however, a secondary surface low should evolve along the southern fringe of the Appalachians then track northeast into the Delmarva by 22/12z. This secondary surface low will prove instrumental in allowing modified air mass to advance across the Carolinas during the latter half of the period, with even weak buoyancy likely developing farther north during the overnight hours. Late this evening, an extensive corridor of deep convection has evolved within a strongly diffluent high-level flow regime from western AL-southern MS-southeast LA-western Gulf Basin. This corridor should progress steadily east through sunrise and likely extend across much of AL into the MS delta region by the start of the period. Strong deep-layer flow/shear will support organized convection, and embedded supercells are likely along this band. Forecast soundings at the start of the period exhibit MLCAPE in excess of 500 J/kg within a very moist and poor-lapse rate-environment. NAM soundings for PNS and GZH at 12z display 0-3km SRH between 400-700 m2/s2. Large-scale forcing should encourage an organized band of convection to migrate east, but this activity should weaken a bit downstream as it encounters less buoyancy and weaker forcing over northern FL/southeast GA. During the latter half of the period, primarily after 06z, boundary-layer recovery is expected across coastal Carolinas such that buoyancy will become more supportive of deep updrafts. Strong shear will favor organized convection, along with some supercell potential. Forecast soundings are quite moist with poor lapse rates through 9km. This will limit instability but isolated damaging winds and/or a tornado seem possible with this activity. ..Darrow/Lyons.. 11/21/2023 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1150 PM CST Mon Nov 20 2023 Valid 211200Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF SOUTHERN ALABAMA AND THE WESTERN FLORIDA PANHANDLE AND SOUTHWEST GEORGIA... ...SUMMARY... A few tornadoes are possible across south Alabama and the Florida Panhandle, mainly during the morning into the afternoon. The potential for locally damaging winds and a couple brief tornadoes will shift farther north and east this afternoon into early morning Wednesday across most of Georgia, the Carolinas, and far southern Virginia. ...Southeastern US... Latest satellite imagery suggests center of upper low is located near JLN. This feature is forecast to eventually dig southeast toward the mid-South as a secondary 500mb speed max translates southeast across eastern OK into southern AR by the end of the period. Immediately downstream, a corridor of strong midlevel flow will extend across the lower MS Valley into the middle Atlantic. 00z model guidance suggests modest height falls will develop ahead of this trough with values approaching 90m in 12hr, especially across the northern middle Atlantic region. In response to this trough, a weak surface low will advance across the OH Valley into southeast lower MI by late afternoon; however, a secondary surface low should evolve along the southern fringe of the Appalachians then track northeast into the Delmarva by 22/12z. This secondary surface low will prove instrumental in allowing modified air mass to advance across the Carolinas during the latter half of the period, with even weak buoyancy likely developing farther north during the overnight hours. Late this evening, an extensive corridor of deep convection has evolved within a strongly diffluent high-level flow regime from western AL-southern MS-southeast LA-western Gulf Basin. This corridor should progress steadily east through sunrise and likely extend across much of AL into the MS delta region by the start of the period. Strong deep-layer flow/shear will support organized convection, and embedded supercells are likely along this band. Forecast soundings at the start of the period exhibit MLCAPE in excess of 500 J/kg within a very moist and poor-lapse rate-environment. NAM soundings for PNS and GZH at 12z display 0-3km SRH between 400-700 m2/s2. Large-scale forcing should encourage an organized band of convection to migrate east, but this activity should weaken a bit downstream as it encounters less buoyancy and weaker forcing over northern FL/southeast GA. During the latter half of the period, primarily after 06z, boundary-layer recovery is expected across coastal Carolinas such that buoyancy will become more supportive of deep updrafts. Strong shear will favor organized convection, along with some supercell potential. Forecast soundings are quite moist with poor lapse rates through 9km. This will limit instability but isolated damaging winds and/or a tornado seem possible with this activity. ..Darrow/Lyons.. 11/21/2023 Read more