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SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1104 AM CST Wed Nov 22 2023 Valid 231200Z - 241200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thanksgiving thunderstorm potential appears low. ...Synopsis... An upper low now over northern portions of Mexico is expected to eject northeastward and become more of an open wave as it approaches the western/central Gulf Coast Thursday afternoon/evening. With surface high pressure and offshore flow centered over the Southeast, conditions will likely remain too stable for inland thunderstorm development. Farther west, an upper-level trough will dig southeastward into the Great Basin by early Friday morning. Despite cooling aloft, thermodynamic profiles suggest very limited buoyancy and, likewise, very low potential for lightning production. ..Wendt.. 11/22/2023 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1104 AM CST Wed Nov 22 2023 Valid 231200Z - 241200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thanksgiving thunderstorm potential appears low. ...Synopsis... An upper low now over northern portions of Mexico is expected to eject northeastward and become more of an open wave as it approaches the western/central Gulf Coast Thursday afternoon/evening. With surface high pressure and offshore flow centered over the Southeast, conditions will likely remain too stable for inland thunderstorm development. Farther west, an upper-level trough will dig southeastward into the Great Basin by early Friday morning. Despite cooling aloft, thermodynamic profiles suggest very limited buoyancy and, likewise, very low potential for lightning production. ..Wendt.. 11/22/2023 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1104 AM CST Wed Nov 22 2023 Valid 231200Z - 241200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thanksgiving thunderstorm potential appears low. ...Synopsis... An upper low now over northern portions of Mexico is expected to eject northeastward and become more of an open wave as it approaches the western/central Gulf Coast Thursday afternoon/evening. With surface high pressure and offshore flow centered over the Southeast, conditions will likely remain too stable for inland thunderstorm development. Farther west, an upper-level trough will dig southeastward into the Great Basin by early Friday morning. Despite cooling aloft, thermodynamic profiles suggest very limited buoyancy and, likewise, very low potential for lightning production. ..Wendt.. 11/22/2023 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1037 AM CST Wed Nov 22 2023 Valid 221700Z - 231200Z ...NO CRITICAL AREAS... The current D1 Fire Weather Outlook remains on track with no updates needed. See previous discussion below. ..Thornton.. 11/22/2023 .PREV DISCUSSION... /ISSUED 0159 AM CST Wed Nov 22 2023/ ...Synopsis... Across the US, fire-weather concerns are low in the wake of broad precipitation from the departing eastern US trough. Shortwave ridging over the West Coast will slowly weaken as an upper low moves south across the Pacific Northwest into the Great Basin. Weak high pressure will persist over the central US, keeping winds light, with the exception of some stronger offshore gusts over southern CA early in the day. At the same time, a cold front and an accompanying Arctic air mass will being moving south across the northern Rockies and Plains. Much colder temperatures and snow are forecast to develop there late into D2/Thursday. The cooler temperatures, weak winds, moderate RH should keep fire-weather concerns limited across the CONUS. ...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 1037 AM CST Wed Nov 22 2023 Valid 221700Z - 231200Z ...NO CRITICAL AREAS... The current D1 Fire Weather Outlook remains on track with no updates needed. See previous discussion below. ..Thornton.. 11/22/2023 .PREV DISCUSSION... /ISSUED 0159 AM CST Wed Nov 22 2023/ ...Synopsis... Across the US, fire-weather concerns are low in the wake of broad precipitation from the departing eastern US trough. Shortwave ridging over the West Coast will slowly weaken as an upper low moves south across the Pacific Northwest into the Great Basin. Weak high pressure will persist over the central US, keeping winds light, with the exception of some stronger offshore gusts over southern CA early in the day. At the same time, a cold front and an accompanying Arctic air mass will being moving south across the northern Rockies and Plains. Much colder temperatures and snow are forecast to develop there late into D2/Thursday. The cooler temperatures, weak winds, moderate RH should keep fire-weather concerns limited across the CONUS. ...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 1037 AM CST Wed Nov 22 2023 Valid 221700Z - 231200Z ...NO CRITICAL AREAS... The current D1 Fire Weather Outlook remains on track with no updates needed. See previous discussion below. ..Thornton.. 11/22/2023 .PREV DISCUSSION... /ISSUED 0159 AM CST Wed Nov 22 2023/ ...Synopsis... Across the US, fire-weather concerns are low in the wake of broad precipitation from the departing eastern US trough. Shortwave ridging over the West Coast will slowly weaken as an upper low moves south across the Pacific Northwest into the Great Basin. Weak high pressure will persist over the central US, keeping winds light, with the exception of some stronger offshore gusts over southern CA early in the day. At the same time, a cold front and an accompanying Arctic air mass will being moving south across the northern Rockies and Plains. Much colder temperatures and snow are forecast to develop there late into D2/Thursday. The cooler temperatures, weak winds, moderate RH should keep fire-weather concerns limited across the CONUS. ...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 1037 AM CST Wed Nov 22 2023 Valid 221700Z - 231200Z ...NO CRITICAL AREAS... The current D1 Fire Weather Outlook remains on track with no updates needed. See previous discussion below. ..Thornton.. 11/22/2023 .PREV DISCUSSION... /ISSUED 0159 AM CST Wed Nov 22 2023/ ...Synopsis... Across the US, fire-weather concerns are low in the wake of broad precipitation from the departing eastern US trough. Shortwave ridging over the West Coast will slowly weaken as an upper low moves south across the Pacific Northwest into the Great Basin. Weak high pressure will persist over the central US, keeping winds light, with the exception of some stronger offshore gusts over southern CA early in the day. At the same time, a cold front and an accompanying Arctic air mass will being moving south across the northern Rockies and Plains. Much colder temperatures and snow are forecast to develop there late into D2/Thursday. The cooler temperatures, weak winds, moderate RH should keep fire-weather concerns limited across the CONUS. ...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 1037 AM CST Wed Nov 22 2023 Valid 221700Z - 231200Z ...NO CRITICAL AREAS... The current D1 Fire Weather Outlook remains on track with no updates needed. See previous discussion below. ..Thornton.. 11/22/2023 .PREV DISCUSSION... /ISSUED 0159 AM CST Wed Nov 22 2023/ ...Synopsis... Across the US, fire-weather concerns are low in the wake of broad precipitation from the departing eastern US trough. Shortwave ridging over the West Coast will slowly weaken as an upper low moves south across the Pacific Northwest into the Great Basin. Weak high pressure will persist over the central US, keeping winds light, with the exception of some stronger offshore gusts over southern CA early in the day. At the same time, a cold front and an accompanying Arctic air mass will being moving south across the northern Rockies and Plains. Much colder temperatures and snow are forecast to develop there late into D2/Thursday. The cooler temperatures, weak winds, moderate RH should keep fire-weather concerns limited across the CONUS. ...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 1037 AM CST Wed Nov 22 2023 Valid 221700Z - 231200Z ...NO CRITICAL AREAS... The current D1 Fire Weather Outlook remains on track with no updates needed. See previous discussion below. ..Thornton.. 11/22/2023 .PREV DISCUSSION... /ISSUED 0159 AM CST Wed Nov 22 2023/ ...Synopsis... Across the US, fire-weather concerns are low in the wake of broad precipitation from the departing eastern US trough. Shortwave ridging over the West Coast will slowly weaken as an upper low moves south across the Pacific Northwest into the Great Basin. Weak high pressure will persist over the central US, keeping winds light, with the exception of some stronger offshore gusts over southern CA early in the day. At the same time, a cold front and an accompanying Arctic air mass will being moving south across the northern Rockies and Plains. Much colder temperatures and snow are forecast to develop there late into D2/Thursday. The cooler temperatures, weak winds, moderate RH should keep fire-weather concerns limited across the CONUS. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1026 AM CST Wed Nov 22 2023 Valid 221630Z - 231200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Organized severe thunderstorms are not expected through tonight. ...Coastal North and South Carolina... Extensive precipitation continues in the vicinity of a cold front currently approaching the NC coast as of 16z. Transient areas of higher reflectivity denoting somewhat stronger updrafts have been observed earlier this morning in the vicinity of New Bern, Jacksonville and Morehead City, however overall storm structures remain disorganized. Large scale ascent will increase in the vicinity of the cold front and a pre-frontal confluence zone as an upper-level trough moves steadily towards the mid-Atlantic coast this afternoon. Weak inland buoyancy (MLCAPE locally 750 J/kg) and 40 kts of westerly shear may prove sufficient for a couple of stronger storms through early afternoon, especially in the immediate coastal waters, however the overall severe threat over land appears to have diminished. As a result, the Marginal Risk has been removed with this outlook. Elsewhere, the potential for scattered thunderstorms will exist in advance of the front over the FL Peninsula, otherwise generally stable conditions should preclude thunderstorms over most of the CONUS. ..Bunting/Flournoy.. 11/22/2023 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1026 AM CST Wed Nov 22 2023 Valid 221630Z - 231200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Organized severe thunderstorms are not expected through tonight. ...Coastal North and South Carolina... Extensive precipitation continues in the vicinity of a cold front currently approaching the NC coast as of 16z. Transient areas of higher reflectivity denoting somewhat stronger updrafts have been observed earlier this morning in the vicinity of New Bern, Jacksonville and Morehead City, however overall storm structures remain disorganized. Large scale ascent will increase in the vicinity of the cold front and a pre-frontal confluence zone as an upper-level trough moves steadily towards the mid-Atlantic coast this afternoon. Weak inland buoyancy (MLCAPE locally 750 J/kg) and 40 kts of westerly shear may prove sufficient for a couple of stronger storms through early afternoon, especially in the immediate coastal waters, however the overall severe threat over land appears to have diminished. As a result, the Marginal Risk has been removed with this outlook. Elsewhere, the potential for scattered thunderstorms will exist in advance of the front over the FL Peninsula, otherwise generally stable conditions should preclude thunderstorms over most of the CONUS. ..Bunting/Flournoy.. 11/22/2023 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1026 AM CST Wed Nov 22 2023 Valid 221630Z - 231200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Organized severe thunderstorms are not expected through tonight. ...Coastal North and South Carolina... Extensive precipitation continues in the vicinity of a cold front currently approaching the NC coast as of 16z. Transient areas of higher reflectivity denoting somewhat stronger updrafts have been observed earlier this morning in the vicinity of New Bern, Jacksonville and Morehead City, however overall storm structures remain disorganized. Large scale ascent will increase in the vicinity of the cold front and a pre-frontal confluence zone as an upper-level trough moves steadily towards the mid-Atlantic coast this afternoon. Weak inland buoyancy (MLCAPE locally 750 J/kg) and 40 kts of westerly shear may prove sufficient for a couple of stronger storms through early afternoon, especially in the immediate coastal waters, however the overall severe threat over land appears to have diminished. As a result, the Marginal Risk has been removed with this outlook. Elsewhere, the potential for scattered thunderstorms will exist in advance of the front over the FL Peninsula, otherwise generally stable conditions should preclude thunderstorms over most of the CONUS. ..Bunting/Flournoy.. 11/22/2023 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1026 AM CST Wed Nov 22 2023 Valid 221630Z - 231200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Organized severe thunderstorms are not expected through tonight. ...Coastal North and South Carolina... Extensive precipitation continues in the vicinity of a cold front currently approaching the NC coast as of 16z. Transient areas of higher reflectivity denoting somewhat stronger updrafts have been observed earlier this morning in the vicinity of New Bern, Jacksonville and Morehead City, however overall storm structures remain disorganized. Large scale ascent will increase in the vicinity of the cold front and a pre-frontal confluence zone as an upper-level trough moves steadily towards the mid-Atlantic coast this afternoon. Weak inland buoyancy (MLCAPE locally 750 J/kg) and 40 kts of westerly shear may prove sufficient for a couple of stronger storms through early afternoon, especially in the immediate coastal waters, however the overall severe threat over land appears to have diminished. As a result, the Marginal Risk has been removed with this outlook. Elsewhere, the potential for scattered thunderstorms will exist in advance of the front over the FL Peninsula, otherwise generally stable conditions should preclude thunderstorms over most of the CONUS. ..Bunting/Flournoy.. 11/22/2023 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1026 AM CST Wed Nov 22 2023 Valid 221630Z - 231200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Organized severe thunderstorms are not expected through tonight. ...Coastal North and South Carolina... Extensive precipitation continues in the vicinity of a cold front currently approaching the NC coast as of 16z. Transient areas of higher reflectivity denoting somewhat stronger updrafts have been observed earlier this morning in the vicinity of New Bern, Jacksonville and Morehead City, however overall storm structures remain disorganized. Large scale ascent will increase in the vicinity of the cold front and a pre-frontal confluence zone as an upper-level trough moves steadily towards the mid-Atlantic coast this afternoon. Weak inland buoyancy (MLCAPE locally 750 J/kg) and 40 kts of westerly shear may prove sufficient for a couple of stronger storms through early afternoon, especially in the immediate coastal waters, however the overall severe threat over land appears to have diminished. As a result, the Marginal Risk has been removed with this outlook. Elsewhere, the potential for scattered thunderstorms will exist in advance of the front over the FL Peninsula, otherwise generally stable conditions should preclude thunderstorms over most of the CONUS. ..Bunting/Flournoy.. 11/22/2023 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1026 AM CST Wed Nov 22 2023 Valid 221630Z - 231200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Organized severe thunderstorms are not expected through tonight. ...Coastal North and South Carolina... Extensive precipitation continues in the vicinity of a cold front currently approaching the NC coast as of 16z. Transient areas of higher reflectivity denoting somewhat stronger updrafts have been observed earlier this morning in the vicinity of New Bern, Jacksonville and Morehead City, however overall storm structures remain disorganized. Large scale ascent will increase in the vicinity of the cold front and a pre-frontal confluence zone as an upper-level trough moves steadily towards the mid-Atlantic coast this afternoon. Weak inland buoyancy (MLCAPE locally 750 J/kg) and 40 kts of westerly shear may prove sufficient for a couple of stronger storms through early afternoon, especially in the immediate coastal waters, however the overall severe threat over land appears to have diminished. As a result, the Marginal Risk has been removed with this outlook. Elsewhere, the potential for scattered thunderstorms will exist in advance of the front over the FL Peninsula, otherwise generally stable conditions should preclude thunderstorms over most of the CONUS. ..Bunting/Flournoy.. 11/22/2023 Read more

MD 2286 CONCERNING HEAVY SNOW FOR NORTHERN MAINE AND NORTHEASTERN NEW HAMPSHIRE
Mesoscale Discussion 2286 NWS Storm Prediction Center Norman OK 0850 AM CST Wed Nov 22 2023 Areas affected...northern Maine and northeastern New Hampshire Concerning...Heavy snow Valid 221450Z - 221845Z SUMMARY...Periods of heavy snowfall, with rates up to 1-1.5 inches per hour, are possible for the next few hours across northern Maine and northeastern New Hampshire. DISCUSSION...Heavy snowfall rates have been observed this morning across portions of northern Maine. This activity is associated with a surface cyclone currently analyzed along the southern New England coast. The cyclone should continue to gradually deepen throughout the morning due to differential cyclonic vorticity advection (ahead of a mid-level shortwave trough) and low-level coastal baroclinity as it moves east-northeastward. 12z GYX/CAR soundings exhibited strong veering in the lowest ~3 km AGL, indicative of widespread low-level warm-air advection. Temperatures aloft in the lowest 3 km AGL are nearly isothermal and below freezing, except nearer to the coast where surface temperatures rising into the 40s F are observed. Farther inland, the continued northward moisture flux atop colder surface conditions could contribute to periods of heavy snowfall (1-1.5 inches per hour) for the next few hours. ..Flournoy.. 11/22/2023 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...CAR...GYX... LAT...LON 44307029 44606929 45106840 45656787 46916786 47196816 47096881 46596959 45767021 45257067 44887117 44427133 44177094 44307029 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0647 AM CST Wed Nov 22 2023 Valid 221300Z - 231200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS PORTIONS OF EASTERN NORTH CAROLINA AND THE OUTER BANKS... ...SUMMARY... A brief tornado and localized damaging-gust threat are possible this morning across portions of eastern North Carolina and the Outer Banks. ...Synopsis... A progressive mid/upper-level pattern will remain in place through the period, except for a split-flow regime around a cut-off low over northwestern MX. Farther northeast, a nearly closed 500-mb low was apparent in moisture-channel imagery over the Mid-South, anchoring an intense shortwave trough that extended south-southwestward over parts of LA. The low and trough are pivoting eastward and should cross the Tennessee Valley and southern Appalachians today, reaching the NC/SC Piedmont by 00Z. The perturbation then should race offshore. At the surface, a cold front was analyzed at 11Z from NJ to a frontal wave over north-central NC, then across central SC, eastern GA, the FL coastal-bend area, and northeastern Gulf. The front is expected to move offshore from NC around 17-18Z, while crossing parts of north FL. The front should reach central/southwestern FL around 00Z, and move off south FL and the Keys by 12Z. ...Eastern NC... A marginal tornado and severe-wind threat remains over this area for a few more hours, especially ahead of the front, and perhaps until convection along the front passes. See SPC mesoscale discussion 2285 for near-term details. The approaching shortwave trough and related mass response may increase both low-level lift and large-scale ascent over the area through midday, while maintaining somewhat veered but enlarged low-level hodographs (as seen in the 12Z MHX RAOB), along with moisture transport/theta-e advection near the coast. Meanwhile, strengthening mid/upper winds will help to offset some veering of surface flow in maintaining favorable deep shear for supercells, and/or organized line(s) of convection with embedded areas of at least transient rotation. Messy convective mode and lack of greater buoyancy (due to weak deep-layer lapse rates) over land will be limiting factors for severe potential. ..Edwards/Broyles.. 11/22/2023 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0647 AM CST Wed Nov 22 2023 Valid 221300Z - 231200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS PORTIONS OF EASTERN NORTH CAROLINA AND THE OUTER BANKS... ...SUMMARY... A brief tornado and localized damaging-gust threat are possible this morning across portions of eastern North Carolina and the Outer Banks. ...Synopsis... A progressive mid/upper-level pattern will remain in place through the period, except for a split-flow regime around a cut-off low over northwestern MX. Farther northeast, a nearly closed 500-mb low was apparent in moisture-channel imagery over the Mid-South, anchoring an intense shortwave trough that extended south-southwestward over parts of LA. The low and trough are pivoting eastward and should cross the Tennessee Valley and southern Appalachians today, reaching the NC/SC Piedmont by 00Z. The perturbation then should race offshore. At the surface, a cold front was analyzed at 11Z from NJ to a frontal wave over north-central NC, then across central SC, eastern GA, the FL coastal-bend area, and northeastern Gulf. The front is expected to move offshore from NC around 17-18Z, while crossing parts of north FL. The front should reach central/southwestern FL around 00Z, and move off south FL and the Keys by 12Z. ...Eastern NC... A marginal tornado and severe-wind threat remains over this area for a few more hours, especially ahead of the front, and perhaps until convection along the front passes. See SPC mesoscale discussion 2285 for near-term details. The approaching shortwave trough and related mass response may increase both low-level lift and large-scale ascent over the area through midday, while maintaining somewhat veered but enlarged low-level hodographs (as seen in the 12Z MHX RAOB), along with moisture transport/theta-e advection near the coast. Meanwhile, strengthening mid/upper winds will help to offset some veering of surface flow in maintaining favorable deep shear for supercells, and/or organized line(s) of convection with embedded areas of at least transient rotation. Messy convective mode and lack of greater buoyancy (due to weak deep-layer lapse rates) over land will be limiting factors for severe potential. ..Edwards/Broyles.. 11/22/2023 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0647 AM CST Wed Nov 22 2023 Valid 221300Z - 231200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS PORTIONS OF EASTERN NORTH CAROLINA AND THE OUTER BANKS... ...SUMMARY... A brief tornado and localized damaging-gust threat are possible this morning across portions of eastern North Carolina and the Outer Banks. ...Synopsis... A progressive mid/upper-level pattern will remain in place through the period, except for a split-flow regime around a cut-off low over northwestern MX. Farther northeast, a nearly closed 500-mb low was apparent in moisture-channel imagery over the Mid-South, anchoring an intense shortwave trough that extended south-southwestward over parts of LA. The low and trough are pivoting eastward and should cross the Tennessee Valley and southern Appalachians today, reaching the NC/SC Piedmont by 00Z. The perturbation then should race offshore. At the surface, a cold front was analyzed at 11Z from NJ to a frontal wave over north-central NC, then across central SC, eastern GA, the FL coastal-bend area, and northeastern Gulf. The front is expected to move offshore from NC around 17-18Z, while crossing parts of north FL. The front should reach central/southwestern FL around 00Z, and move off south FL and the Keys by 12Z. ...Eastern NC... A marginal tornado and severe-wind threat remains over this area for a few more hours, especially ahead of the front, and perhaps until convection along the front passes. See SPC mesoscale discussion 2285 for near-term details. The approaching shortwave trough and related mass response may increase both low-level lift and large-scale ascent over the area through midday, while maintaining somewhat veered but enlarged low-level hodographs (as seen in the 12Z MHX RAOB), along with moisture transport/theta-e advection near the coast. Meanwhile, strengthening mid/upper winds will help to offset some veering of surface flow in maintaining favorable deep shear for supercells, and/or organized line(s) of convection with embedded areas of at least transient rotation. Messy convective mode and lack of greater buoyancy (due to weak deep-layer lapse rates) over land will be limiting factors for severe potential. ..Edwards/Broyles.. 11/22/2023 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0647 AM CST Wed Nov 22 2023 Valid 221300Z - 231200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS PORTIONS OF EASTERN NORTH CAROLINA AND THE OUTER BANKS... ...SUMMARY... A brief tornado and localized damaging-gust threat are possible this morning across portions of eastern North Carolina and the Outer Banks. ...Synopsis... A progressive mid/upper-level pattern will remain in place through the period, except for a split-flow regime around a cut-off low over northwestern MX. Farther northeast, a nearly closed 500-mb low was apparent in moisture-channel imagery over the Mid-South, anchoring an intense shortwave trough that extended south-southwestward over parts of LA. The low and trough are pivoting eastward and should cross the Tennessee Valley and southern Appalachians today, reaching the NC/SC Piedmont by 00Z. The perturbation then should race offshore. At the surface, a cold front was analyzed at 11Z from NJ to a frontal wave over north-central NC, then across central SC, eastern GA, the FL coastal-bend area, and northeastern Gulf. The front is expected to move offshore from NC around 17-18Z, while crossing parts of north FL. The front should reach central/southwestern FL around 00Z, and move off south FL and the Keys by 12Z. ...Eastern NC... A marginal tornado and severe-wind threat remains over this area for a few more hours, especially ahead of the front, and perhaps until convection along the front passes. See SPC mesoscale discussion 2285 for near-term details. The approaching shortwave trough and related mass response may increase both low-level lift and large-scale ascent over the area through midday, while maintaining somewhat veered but enlarged low-level hodographs (as seen in the 12Z MHX RAOB), along with moisture transport/theta-e advection near the coast. Meanwhile, strengthening mid/upper winds will help to offset some veering of surface flow in maintaining favorable deep shear for supercells, and/or organized line(s) of convection with embedded areas of at least transient rotation. Messy convective mode and lack of greater buoyancy (due to weak deep-layer lapse rates) over land will be limiting factors for severe potential. ..Edwards/Broyles.. 11/22/2023 Read more