Aggregator

WW 0724 Status Updates
STATUS REPORT ON WW 724 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 15 NNE VDI TO 25 W CAE TO 20 ENE AVL. FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 2318. ..GRAMS..12/29/24 ATTN...WFO...CHS...CAE...GSP... STATUS REPORT FOR WT 724 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS GAC029-031-043-051-103-109-165-179-183-191-251-267-291440- GA . GEORGIA COUNTIES INCLUDED ARE BRYAN BULLOCH CANDLER CHATHAM EFFINGHAM EVANS JENKINS LIBERTY LONG MCINTOSH SCREVEN TATTNALL NCC003-023-025-035-045-059-071-097-109-119-159-161-179-291440- NC . NORTH CAROLINA COUNTIES INCLUDED ARE ALEXANDER BURKE CABARRUS CATAWBA CLEVELAND DAVIE GASTON IREDELL LINCOLN MECKLENBURG ROWAN RUTHERFORD UNION Read more

WW 0725 Status Updates
STATUS FOR WATCH 0725 HAS NOT BEEN ISSUED YET Read more

WW 0725 Status Updates
STATUS FOR WATCH 0725 HAS NOT BEEN ISSUED YET Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0700 AM CST Sun Dec 29 2024 Valid 291300Z - 301200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE EASTERN GULF COAST NORTHWARD INTO THE CAROLINAS AND SOUTHERN VIRGINIA... ...SUMMARY... A few tornadoes and sporadic damaging to severe gusts are possible today from the eastern Gulf Coast northward into the Carolinas and southern Virginia. More-isolated severe storms may occur across parts of the central Appalachians and Ohio Valley, and over southernmost Florida. ...Synopsis... In mid/upper levels, a progressive pattern will persist across the CONUS. A strong shortwave trough will move ashore in the Pacific Northwest and northern CA today. This will be preceded by some thunder potential, as lapse rates steepen from large-scale ascent, over areas where at least marginal low/middle-level moisture exists to support convection. Downstream, a strong shortwave trough was evident in moisture-channel imagery between the Mid-South and Tennessee Valley. This perturbation will pivot northeastward over TN, KY and IN today, forming a closed 500-mb low by 00Z over the Michiana region, and phasing with an initially upstream perturbation now over the central Plains. By 12Z, the resultant trough should assume considerable negative tilt, extending from a low over eastern Lake Huron to the Hampton Roads of VA/northeastern NC region. The associated surface cyclone was centered at 11Z over southwestern IN, with cold front across middle TN, central AL, past the Mississippi River mouth, then across the northwestern Gulf. The low is forecast to deepen and occlude today as it moves to near TOL. The cold front should sweep across much of the eastern CONUS through the period. By 00Z, the front should reach central parts of PA/VA/ NC/SC, southeastern GA, and the eastern Gulf, preceded by a strong-severe line of thunderstorms. By 12Z, the front should reach eastern NY, then offshore until central FL. ...Southern Atlantic Coast States... An ongoing, prefrontal squall line, with sporadic/embedded LEWP/ bowing features and an occasional embedded mesovortex, extends from northwestern SC across central/southern GA and the FL Panhandle, to the adjoining Gulf. This convection should become more northeast/ southwest oriented as its northern portion races through the central Appalachians/Piedmont region today, amid meager but still locally sufficient buoyancy (MLCAPE mostly less than 400 J/kg), long and curved low-level hodographs with 200-400 J/kg effective SRH, and favorable deep shear. Damaging gusts and a few embedded QLCS tornadoes will be the main concerns. See SPC Tornado Watches 723-724 and associated mesoscale discussions for the latest near-term coverage. ...Central Appalachians/Ohio Valley... Widely scattered low-topped thunderstorms are possible from midday through afternoon in a pocket of marginally unstable air ahead of the surface low and ejecting mid/upper trough. A marginal threat exists for damaging gusts or a brief tornado from this activity. As the trough approaches, midlevel flow will strengthen considerably, associated large-scale ascent will steepen low/middle-level lapse rates, while the mass response increases low-level and deep-layer shear. Temperatures from the upper 50s F to mid 60s (southeastern parts) would support MLCAPE in the 100-400 J/kg range amidst 40-50 kt effective-shear magnitudes and SRH of 100-200 J/kg in the lowest 1/2 km. Damaging gusts may be brought to the surface via momentum transfer in downdrafts from the LLJ, and conditional potential exists for mini-supercells to develop. Given the weak overall lapse rates and lack of greater buoyancy, the already marginal threat should diminish quickly by around 00Z. ...South FL/Keys... A small but persistent MCS, with an embedded MCV on its northwest side, has been moving slowly eastward across the easternmost Gulf toward Florida Bay for most of the prior overnight hours. This complex should affect at least parts of the mid/upper Keys, and southern Everglades, through midday. The ambient/synoptic gradients suggest only modest deep-layer shear this far from the ejecting shortwave trough. However, mesoscale midlevel flow enhancement and low-level mass response will promote some hodograph enlargement in a small corridor southeast through east of the MCV. Accordingly, sporadic and mostly short-lived mesocirculations have been observed in the complex for several hours, amid rich inflow-layer moisture and low LCL. An associated low-end tornado threat may extend into the outlook area before the complex weakens substantially. See SPC Mesoscale Discussion 2317 for near-term details. ..Edwards/Grams.. 12/29/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0700 AM CST Sun Dec 29 2024 Valid 291300Z - 301200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE EASTERN GULF COAST NORTHWARD INTO THE CAROLINAS AND SOUTHERN VIRGINIA... ...SUMMARY... A few tornadoes and sporadic damaging to severe gusts are possible today from the eastern Gulf Coast northward into the Carolinas and southern Virginia. More-isolated severe storms may occur across parts of the central Appalachians and Ohio Valley, and over southernmost Florida. ...Synopsis... In mid/upper levels, a progressive pattern will persist across the CONUS. A strong shortwave trough will move ashore in the Pacific Northwest and northern CA today. This will be preceded by some thunder potential, as lapse rates steepen from large-scale ascent, over areas where at least marginal low/middle-level moisture exists to support convection. Downstream, a strong shortwave trough was evident in moisture-channel imagery between the Mid-South and Tennessee Valley. This perturbation will pivot northeastward over TN, KY and IN today, forming a closed 500-mb low by 00Z over the Michiana region, and phasing with an initially upstream perturbation now over the central Plains. By 12Z, the resultant trough should assume considerable negative tilt, extending from a low over eastern Lake Huron to the Hampton Roads of VA/northeastern NC region. The associated surface cyclone was centered at 11Z over southwestern IN, with cold front across middle TN, central AL, past the Mississippi River mouth, then across the northwestern Gulf. The low is forecast to deepen and occlude today as it moves to near TOL. The cold front should sweep across much of the eastern CONUS through the period. By 00Z, the front should reach central parts of PA/VA/ NC/SC, southeastern GA, and the eastern Gulf, preceded by a strong-severe line of thunderstorms. By 12Z, the front should reach eastern NY, then offshore until central FL. ...Southern Atlantic Coast States... An ongoing, prefrontal squall line, with sporadic/embedded LEWP/ bowing features and an occasional embedded mesovortex, extends from northwestern SC across central/southern GA and the FL Panhandle, to the adjoining Gulf. This convection should become more northeast/ southwest oriented as its northern portion races through the central Appalachians/Piedmont region today, amid meager but still locally sufficient buoyancy (MLCAPE mostly less than 400 J/kg), long and curved low-level hodographs with 200-400 J/kg effective SRH, and favorable deep shear. Damaging gusts and a few embedded QLCS tornadoes will be the main concerns. See SPC Tornado Watches 723-724 and associated mesoscale discussions for the latest near-term coverage. ...Central Appalachians/Ohio Valley... Widely scattered low-topped thunderstorms are possible from midday through afternoon in a pocket of marginally unstable air ahead of the surface low and ejecting mid/upper trough. A marginal threat exists for damaging gusts or a brief tornado from this activity. As the trough approaches, midlevel flow will strengthen considerably, associated large-scale ascent will steepen low/middle-level lapse rates, while the mass response increases low-level and deep-layer shear. Temperatures from the upper 50s F to mid 60s (southeastern parts) would support MLCAPE in the 100-400 J/kg range amidst 40-50 kt effective-shear magnitudes and SRH of 100-200 J/kg in the lowest 1/2 km. Damaging gusts may be brought to the surface via momentum transfer in downdrafts from the LLJ, and conditional potential exists for mini-supercells to develop. Given the weak overall lapse rates and lack of greater buoyancy, the already marginal threat should diminish quickly by around 00Z. ...South FL/Keys... A small but persistent MCS, with an embedded MCV on its northwest side, has been moving slowly eastward across the easternmost Gulf toward Florida Bay for most of the prior overnight hours. This complex should affect at least parts of the mid/upper Keys, and southern Everglades, through midday. The ambient/synoptic gradients suggest only modest deep-layer shear this far from the ejecting shortwave trough. However, mesoscale midlevel flow enhancement and low-level mass response will promote some hodograph enlargement in a small corridor southeast through east of the MCV. Accordingly, sporadic and mostly short-lived mesocirculations have been observed in the complex for several hours, amid rich inflow-layer moisture and low LCL. An associated low-end tornado threat may extend into the outlook area before the complex weakens substantially. See SPC Mesoscale Discussion 2317 for near-term details. ..Edwards/Grams.. 12/29/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0700 AM CST Sun Dec 29 2024 Valid 291300Z - 301200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE EASTERN GULF COAST NORTHWARD INTO THE CAROLINAS AND SOUTHERN VIRGINIA... ...SUMMARY... A few tornadoes and sporadic damaging to severe gusts are possible today from the eastern Gulf Coast northward into the Carolinas and southern Virginia. More-isolated severe storms may occur across parts of the central Appalachians and Ohio Valley, and over southernmost Florida. ...Synopsis... In mid/upper levels, a progressive pattern will persist across the CONUS. A strong shortwave trough will move ashore in the Pacific Northwest and northern CA today. This will be preceded by some thunder potential, as lapse rates steepen from large-scale ascent, over areas where at least marginal low/middle-level moisture exists to support convection. Downstream, a strong shortwave trough was evident in moisture-channel imagery between the Mid-South and Tennessee Valley. This perturbation will pivot northeastward over TN, KY and IN today, forming a closed 500-mb low by 00Z over the Michiana region, and phasing with an initially upstream perturbation now over the central Plains. By 12Z, the resultant trough should assume considerable negative tilt, extending from a low over eastern Lake Huron to the Hampton Roads of VA/northeastern NC region. The associated surface cyclone was centered at 11Z over southwestern IN, with cold front across middle TN, central AL, past the Mississippi River mouth, then across the northwestern Gulf. The low is forecast to deepen and occlude today as it moves to near TOL. The cold front should sweep across much of the eastern CONUS through the period. By 00Z, the front should reach central parts of PA/VA/ NC/SC, southeastern GA, and the eastern Gulf, preceded by a strong-severe line of thunderstorms. By 12Z, the front should reach eastern NY, then offshore until central FL. ...Southern Atlantic Coast States... An ongoing, prefrontal squall line, with sporadic/embedded LEWP/ bowing features and an occasional embedded mesovortex, extends from northwestern SC across central/southern GA and the FL Panhandle, to the adjoining Gulf. This convection should become more northeast/ southwest oriented as its northern portion races through the central Appalachians/Piedmont region today, amid meager but still locally sufficient buoyancy (MLCAPE mostly less than 400 J/kg), long and curved low-level hodographs with 200-400 J/kg effective SRH, and favorable deep shear. Damaging gusts and a few embedded QLCS tornadoes will be the main concerns. See SPC Tornado Watches 723-724 and associated mesoscale discussions for the latest near-term coverage. ...Central Appalachians/Ohio Valley... Widely scattered low-topped thunderstorms are possible from midday through afternoon in a pocket of marginally unstable air ahead of the surface low and ejecting mid/upper trough. A marginal threat exists for damaging gusts or a brief tornado from this activity. As the trough approaches, midlevel flow will strengthen considerably, associated large-scale ascent will steepen low/middle-level lapse rates, while the mass response increases low-level and deep-layer shear. Temperatures from the upper 50s F to mid 60s (southeastern parts) would support MLCAPE in the 100-400 J/kg range amidst 40-50 kt effective-shear magnitudes and SRH of 100-200 J/kg in the lowest 1/2 km. Damaging gusts may be brought to the surface via momentum transfer in downdrafts from the LLJ, and conditional potential exists for mini-supercells to develop. Given the weak overall lapse rates and lack of greater buoyancy, the already marginal threat should diminish quickly by around 00Z. ...South FL/Keys... A small but persistent MCS, with an embedded MCV on its northwest side, has been moving slowly eastward across the easternmost Gulf toward Florida Bay for most of the prior overnight hours. This complex should affect at least parts of the mid/upper Keys, and southern Everglades, through midday. The ambient/synoptic gradients suggest only modest deep-layer shear this far from the ejecting shortwave trough. However, mesoscale midlevel flow enhancement and low-level mass response will promote some hodograph enlargement in a small corridor southeast through east of the MCV. Accordingly, sporadic and mostly short-lived mesocirculations have been observed in the complex for several hours, amid rich inflow-layer moisture and low LCL. An associated low-end tornado threat may extend into the outlook area before the complex weakens substantially. See SPC Mesoscale Discussion 2317 for near-term details. ..Edwards/Grams.. 12/29/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0700 AM CST Sun Dec 29 2024 Valid 291300Z - 301200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE EASTERN GULF COAST NORTHWARD INTO THE CAROLINAS AND SOUTHERN VIRGINIA... ...SUMMARY... A few tornadoes and sporadic damaging to severe gusts are possible today from the eastern Gulf Coast northward into the Carolinas and southern Virginia. More-isolated severe storms may occur across parts of the central Appalachians and Ohio Valley, and over southernmost Florida. ...Synopsis... In mid/upper levels, a progressive pattern will persist across the CONUS. A strong shortwave trough will move ashore in the Pacific Northwest and northern CA today. This will be preceded by some thunder potential, as lapse rates steepen from large-scale ascent, over areas where at least marginal low/middle-level moisture exists to support convection. Downstream, a strong shortwave trough was evident in moisture-channel imagery between the Mid-South and Tennessee Valley. This perturbation will pivot northeastward over TN, KY and IN today, forming a closed 500-mb low by 00Z over the Michiana region, and phasing with an initially upstream perturbation now over the central Plains. By 12Z, the resultant trough should assume considerable negative tilt, extending from a low over eastern Lake Huron to the Hampton Roads of VA/northeastern NC region. The associated surface cyclone was centered at 11Z over southwestern IN, with cold front across middle TN, central AL, past the Mississippi River mouth, then across the northwestern Gulf. The low is forecast to deepen and occlude today as it moves to near TOL. The cold front should sweep across much of the eastern CONUS through the period. By 00Z, the front should reach central parts of PA/VA/ NC/SC, southeastern GA, and the eastern Gulf, preceded by a strong-severe line of thunderstorms. By 12Z, the front should reach eastern NY, then offshore until central FL. ...Southern Atlantic Coast States... An ongoing, prefrontal squall line, with sporadic/embedded LEWP/ bowing features and an occasional embedded mesovortex, extends from northwestern SC across central/southern GA and the FL Panhandle, to the adjoining Gulf. This convection should become more northeast/ southwest oriented as its northern portion races through the central Appalachians/Piedmont region today, amid meager but still locally sufficient buoyancy (MLCAPE mostly less than 400 J/kg), long and curved low-level hodographs with 200-400 J/kg effective SRH, and favorable deep shear. Damaging gusts and a few embedded QLCS tornadoes will be the main concerns. See SPC Tornado Watches 723-724 and associated mesoscale discussions for the latest near-term coverage. ...Central Appalachians/Ohio Valley... Widely scattered low-topped thunderstorms are possible from midday through afternoon in a pocket of marginally unstable air ahead of the surface low and ejecting mid/upper trough. A marginal threat exists for damaging gusts or a brief tornado from this activity. As the trough approaches, midlevel flow will strengthen considerably, associated large-scale ascent will steepen low/middle-level lapse rates, while the mass response increases low-level and deep-layer shear. Temperatures from the upper 50s F to mid 60s (southeastern parts) would support MLCAPE in the 100-400 J/kg range amidst 40-50 kt effective-shear magnitudes and SRH of 100-200 J/kg in the lowest 1/2 km. Damaging gusts may be brought to the surface via momentum transfer in downdrafts from the LLJ, and conditional potential exists for mini-supercells to develop. Given the weak overall lapse rates and lack of greater buoyancy, the already marginal threat should diminish quickly by around 00Z. ...South FL/Keys... A small but persistent MCS, with an embedded MCV on its northwest side, has been moving slowly eastward across the easternmost Gulf toward Florida Bay for most of the prior overnight hours. This complex should affect at least parts of the mid/upper Keys, and southern Everglades, through midday. The ambient/synoptic gradients suggest only modest deep-layer shear this far from the ejecting shortwave trough. However, mesoscale midlevel flow enhancement and low-level mass response will promote some hodograph enlargement in a small corridor southeast through east of the MCV. Accordingly, sporadic and mostly short-lived mesocirculations have been observed in the complex for several hours, amid rich inflow-layer moisture and low LCL. An associated low-end tornado threat may extend into the outlook area before the complex weakens substantially. See SPC Mesoscale Discussion 2317 for near-term details. ..Edwards/Grams.. 12/29/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0700 AM CST Sun Dec 29 2024 Valid 291300Z - 301200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE EASTERN GULF COAST NORTHWARD INTO THE CAROLINAS AND SOUTHERN VIRGINIA... ...SUMMARY... A few tornadoes and sporadic damaging to severe gusts are possible today from the eastern Gulf Coast northward into the Carolinas and southern Virginia. More-isolated severe storms may occur across parts of the central Appalachians and Ohio Valley, and over southernmost Florida. ...Synopsis... In mid/upper levels, a progressive pattern will persist across the CONUS. A strong shortwave trough will move ashore in the Pacific Northwest and northern CA today. This will be preceded by some thunder potential, as lapse rates steepen from large-scale ascent, over areas where at least marginal low/middle-level moisture exists to support convection. Downstream, a strong shortwave trough was evident in moisture-channel imagery between the Mid-South and Tennessee Valley. This perturbation will pivot northeastward over TN, KY and IN today, forming a closed 500-mb low by 00Z over the Michiana region, and phasing with an initially upstream perturbation now over the central Plains. By 12Z, the resultant trough should assume considerable negative tilt, extending from a low over eastern Lake Huron to the Hampton Roads of VA/northeastern NC region. The associated surface cyclone was centered at 11Z over southwestern IN, with cold front across middle TN, central AL, past the Mississippi River mouth, then across the northwestern Gulf. The low is forecast to deepen and occlude today as it moves to near TOL. The cold front should sweep across much of the eastern CONUS through the period. By 00Z, the front should reach central parts of PA/VA/ NC/SC, southeastern GA, and the eastern Gulf, preceded by a strong-severe line of thunderstorms. By 12Z, the front should reach eastern NY, then offshore until central FL. ...Southern Atlantic Coast States... An ongoing, prefrontal squall line, with sporadic/embedded LEWP/ bowing features and an occasional embedded mesovortex, extends from northwestern SC across central/southern GA and the FL Panhandle, to the adjoining Gulf. This convection should become more northeast/ southwest oriented as its northern portion races through the central Appalachians/Piedmont region today, amid meager but still locally sufficient buoyancy (MLCAPE mostly less than 400 J/kg), long and curved low-level hodographs with 200-400 J/kg effective SRH, and favorable deep shear. Damaging gusts and a few embedded QLCS tornadoes will be the main concerns. See SPC Tornado Watches 723-724 and associated mesoscale discussions for the latest near-term coverage. ...Central Appalachians/Ohio Valley... Widely scattered low-topped thunderstorms are possible from midday through afternoon in a pocket of marginally unstable air ahead of the surface low and ejecting mid/upper trough. A marginal threat exists for damaging gusts or a brief tornado from this activity. As the trough approaches, midlevel flow will strengthen considerably, associated large-scale ascent will steepen low/middle-level lapse rates, while the mass response increases low-level and deep-layer shear. Temperatures from the upper 50s F to mid 60s (southeastern parts) would support MLCAPE in the 100-400 J/kg range amidst 40-50 kt effective-shear magnitudes and SRH of 100-200 J/kg in the lowest 1/2 km. Damaging gusts may be brought to the surface via momentum transfer in downdrafts from the LLJ, and conditional potential exists for mini-supercells to develop. Given the weak overall lapse rates and lack of greater buoyancy, the already marginal threat should diminish quickly by around 00Z. ...South FL/Keys... A small but persistent MCS, with an embedded MCV on its northwest side, has been moving slowly eastward across the easternmost Gulf toward Florida Bay for most of the prior overnight hours. This complex should affect at least parts of the mid/upper Keys, and southern Everglades, through midday. The ambient/synoptic gradients suggest only modest deep-layer shear this far from the ejecting shortwave trough. However, mesoscale midlevel flow enhancement and low-level mass response will promote some hodograph enlargement in a small corridor southeast through east of the MCV. Accordingly, sporadic and mostly short-lived mesocirculations have been observed in the complex for several hours, amid rich inflow-layer moisture and low LCL. An associated low-end tornado threat may extend into the outlook area before the complex weakens substantially. See SPC Mesoscale Discussion 2317 for near-term details. ..Edwards/Grams.. 12/29/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0700 AM CST Sun Dec 29 2024 Valid 291300Z - 301200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE EASTERN GULF COAST NORTHWARD INTO THE CAROLINAS AND SOUTHERN VIRGINIA... ...SUMMARY... A few tornadoes and sporadic damaging to severe gusts are possible today from the eastern Gulf Coast northward into the Carolinas and southern Virginia. More-isolated severe storms may occur across parts of the central Appalachians and Ohio Valley, and over southernmost Florida. ...Synopsis... In mid/upper levels, a progressive pattern will persist across the CONUS. A strong shortwave trough will move ashore in the Pacific Northwest and northern CA today. This will be preceded by some thunder potential, as lapse rates steepen from large-scale ascent, over areas where at least marginal low/middle-level moisture exists to support convection. Downstream, a strong shortwave trough was evident in moisture-channel imagery between the Mid-South and Tennessee Valley. This perturbation will pivot northeastward over TN, KY and IN today, forming a closed 500-mb low by 00Z over the Michiana region, and phasing with an initially upstream perturbation now over the central Plains. By 12Z, the resultant trough should assume considerable negative tilt, extending from a low over eastern Lake Huron to the Hampton Roads of VA/northeastern NC region. The associated surface cyclone was centered at 11Z over southwestern IN, with cold front across middle TN, central AL, past the Mississippi River mouth, then across the northwestern Gulf. The low is forecast to deepen and occlude today as it moves to near TOL. The cold front should sweep across much of the eastern CONUS through the period. By 00Z, the front should reach central parts of PA/VA/ NC/SC, southeastern GA, and the eastern Gulf, preceded by a strong-severe line of thunderstorms. By 12Z, the front should reach eastern NY, then offshore until central FL. ...Southern Atlantic Coast States... An ongoing, prefrontal squall line, with sporadic/embedded LEWP/ bowing features and an occasional embedded mesovortex, extends from northwestern SC across central/southern GA and the FL Panhandle, to the adjoining Gulf. This convection should become more northeast/ southwest oriented as its northern portion races through the central Appalachians/Piedmont region today, amid meager but still locally sufficient buoyancy (MLCAPE mostly less than 400 J/kg), long and curved low-level hodographs with 200-400 J/kg effective SRH, and favorable deep shear. Damaging gusts and a few embedded QLCS tornadoes will be the main concerns. See SPC Tornado Watches 723-724 and associated mesoscale discussions for the latest near-term coverage. ...Central Appalachians/Ohio Valley... Widely scattered low-topped thunderstorms are possible from midday through afternoon in a pocket of marginally unstable air ahead of the surface low and ejecting mid/upper trough. A marginal threat exists for damaging gusts or a brief tornado from this activity. As the trough approaches, midlevel flow will strengthen considerably, associated large-scale ascent will steepen low/middle-level lapse rates, while the mass response increases low-level and deep-layer shear. Temperatures from the upper 50s F to mid 60s (southeastern parts) would support MLCAPE in the 100-400 J/kg range amidst 40-50 kt effective-shear magnitudes and SRH of 100-200 J/kg in the lowest 1/2 km. Damaging gusts may be brought to the surface via momentum transfer in downdrafts from the LLJ, and conditional potential exists for mini-supercells to develop. Given the weak overall lapse rates and lack of greater buoyancy, the already marginal threat should diminish quickly by around 00Z. ...South FL/Keys... A small but persistent MCS, with an embedded MCV on its northwest side, has been moving slowly eastward across the easternmost Gulf toward Florida Bay for most of the prior overnight hours. This complex should affect at least parts of the mid/upper Keys, and southern Everglades, through midday. The ambient/synoptic gradients suggest only modest deep-layer shear this far from the ejecting shortwave trough. However, mesoscale midlevel flow enhancement and low-level mass response will promote some hodograph enlargement in a small corridor southeast through east of the MCV. Accordingly, sporadic and mostly short-lived mesocirculations have been observed in the complex for several hours, amid rich inflow-layer moisture and low LCL. An associated low-end tornado threat may extend into the outlook area before the complex weakens substantially. See SPC Mesoscale Discussion 2317 for near-term details. ..Edwards/Grams.. 12/29/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0700 AM CST Sun Dec 29 2024 Valid 291300Z - 301200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE EASTERN GULF COAST NORTHWARD INTO THE CAROLINAS AND SOUTHERN VIRGINIA... ...SUMMARY... A few tornadoes and sporadic damaging to severe gusts are possible today from the eastern Gulf Coast northward into the Carolinas and southern Virginia. More-isolated severe storms may occur across parts of the central Appalachians and Ohio Valley, and over southernmost Florida. ...Synopsis... In mid/upper levels, a progressive pattern will persist across the CONUS. A strong shortwave trough will move ashore in the Pacific Northwest and northern CA today. This will be preceded by some thunder potential, as lapse rates steepen from large-scale ascent, over areas where at least marginal low/middle-level moisture exists to support convection. Downstream, a strong shortwave trough was evident in moisture-channel imagery between the Mid-South and Tennessee Valley. This perturbation will pivot northeastward over TN, KY and IN today, forming a closed 500-mb low by 00Z over the Michiana region, and phasing with an initially upstream perturbation now over the central Plains. By 12Z, the resultant trough should assume considerable negative tilt, extending from a low over eastern Lake Huron to the Hampton Roads of VA/northeastern NC region. The associated surface cyclone was centered at 11Z over southwestern IN, with cold front across middle TN, central AL, past the Mississippi River mouth, then across the northwestern Gulf. The low is forecast to deepen and occlude today as it moves to near TOL. The cold front should sweep across much of the eastern CONUS through the period. By 00Z, the front should reach central parts of PA/VA/ NC/SC, southeastern GA, and the eastern Gulf, preceded by a strong-severe line of thunderstorms. By 12Z, the front should reach eastern NY, then offshore until central FL. ...Southern Atlantic Coast States... An ongoing, prefrontal squall line, with sporadic/embedded LEWP/ bowing features and an occasional embedded mesovortex, extends from northwestern SC across central/southern GA and the FL Panhandle, to the adjoining Gulf. This convection should become more northeast/ southwest oriented as its northern portion races through the central Appalachians/Piedmont region today, amid meager but still locally sufficient buoyancy (MLCAPE mostly less than 400 J/kg), long and curved low-level hodographs with 200-400 J/kg effective SRH, and favorable deep shear. Damaging gusts and a few embedded QLCS tornadoes will be the main concerns. See SPC Tornado Watches 723-724 and associated mesoscale discussions for the latest near-term coverage. ...Central Appalachians/Ohio Valley... Widely scattered low-topped thunderstorms are possible from midday through afternoon in a pocket of marginally unstable air ahead of the surface low and ejecting mid/upper trough. A marginal threat exists for damaging gusts or a brief tornado from this activity. As the trough approaches, midlevel flow will strengthen considerably, associated large-scale ascent will steepen low/middle-level lapse rates, while the mass response increases low-level and deep-layer shear. Temperatures from the upper 50s F to mid 60s (southeastern parts) would support MLCAPE in the 100-400 J/kg range amidst 40-50 kt effective-shear magnitudes and SRH of 100-200 J/kg in the lowest 1/2 km. Damaging gusts may be brought to the surface via momentum transfer in downdrafts from the LLJ, and conditional potential exists for mini-supercells to develop. Given the weak overall lapse rates and lack of greater buoyancy, the already marginal threat should diminish quickly by around 00Z. ...South FL/Keys... A small but persistent MCS, with an embedded MCV on its northwest side, has been moving slowly eastward across the easternmost Gulf toward Florida Bay for most of the prior overnight hours. This complex should affect at least parts of the mid/upper Keys, and southern Everglades, through midday. The ambient/synoptic gradients suggest only modest deep-layer shear this far from the ejecting shortwave trough. However, mesoscale midlevel flow enhancement and low-level mass response will promote some hodograph enlargement in a small corridor southeast through east of the MCV. Accordingly, sporadic and mostly short-lived mesocirculations have been observed in the complex for several hours, amid rich inflow-layer moisture and low LCL. An associated low-end tornado threat may extend into the outlook area before the complex weakens substantially. See SPC Mesoscale Discussion 2317 for near-term details. ..Edwards/Grams.. 12/29/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0700 AM CST Sun Dec 29 2024 Valid 291300Z - 301200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE EASTERN GULF COAST NORTHWARD INTO THE CAROLINAS AND SOUTHERN VIRGINIA... ...SUMMARY... A few tornadoes and sporadic damaging to severe gusts are possible today from the eastern Gulf Coast northward into the Carolinas and southern Virginia. More-isolated severe storms may occur across parts of the central Appalachians and Ohio Valley, and over southernmost Florida. ...Synopsis... In mid/upper levels, a progressive pattern will persist across the CONUS. A strong shortwave trough will move ashore in the Pacific Northwest and northern CA today. This will be preceded by some thunder potential, as lapse rates steepen from large-scale ascent, over areas where at least marginal low/middle-level moisture exists to support convection. Downstream, a strong shortwave trough was evident in moisture-channel imagery between the Mid-South and Tennessee Valley. This perturbation will pivot northeastward over TN, KY and IN today, forming a closed 500-mb low by 00Z over the Michiana region, and phasing with an initially upstream perturbation now over the central Plains. By 12Z, the resultant trough should assume considerable negative tilt, extending from a low over eastern Lake Huron to the Hampton Roads of VA/northeastern NC region. The associated surface cyclone was centered at 11Z over southwestern IN, with cold front across middle TN, central AL, past the Mississippi River mouth, then across the northwestern Gulf. The low is forecast to deepen and occlude today as it moves to near TOL. The cold front should sweep across much of the eastern CONUS through the period. By 00Z, the front should reach central parts of PA/VA/ NC/SC, southeastern GA, and the eastern Gulf, preceded by a strong-severe line of thunderstorms. By 12Z, the front should reach eastern NY, then offshore until central FL. ...Southern Atlantic Coast States... An ongoing, prefrontal squall line, with sporadic/embedded LEWP/ bowing features and an occasional embedded mesovortex, extends from northwestern SC across central/southern GA and the FL Panhandle, to the adjoining Gulf. This convection should become more northeast/ southwest oriented as its northern portion races through the central Appalachians/Piedmont region today, amid meager but still locally sufficient buoyancy (MLCAPE mostly less than 400 J/kg), long and curved low-level hodographs with 200-400 J/kg effective SRH, and favorable deep shear. Damaging gusts and a few embedded QLCS tornadoes will be the main concerns. See SPC Tornado Watches 723-724 and associated mesoscale discussions for the latest near-term coverage. ...Central Appalachians/Ohio Valley... Widely scattered low-topped thunderstorms are possible from midday through afternoon in a pocket of marginally unstable air ahead of the surface low and ejecting mid/upper trough. A marginal threat exists for damaging gusts or a brief tornado from this activity. As the trough approaches, midlevel flow will strengthen considerably, associated large-scale ascent will steepen low/middle-level lapse rates, while the mass response increases low-level and deep-layer shear. Temperatures from the upper 50s F to mid 60s (southeastern parts) would support MLCAPE in the 100-400 J/kg range amidst 40-50 kt effective-shear magnitudes and SRH of 100-200 J/kg in the lowest 1/2 km. Damaging gusts may be brought to the surface via momentum transfer in downdrafts from the LLJ, and conditional potential exists for mini-supercells to develop. Given the weak overall lapse rates and lack of greater buoyancy, the already marginal threat should diminish quickly by around 00Z. ...South FL/Keys... A small but persistent MCS, with an embedded MCV on its northwest side, has been moving slowly eastward across the easternmost Gulf toward Florida Bay for most of the prior overnight hours. This complex should affect at least parts of the mid/upper Keys, and southern Everglades, through midday. The ambient/synoptic gradients suggest only modest deep-layer shear this far from the ejecting shortwave trough. However, mesoscale midlevel flow enhancement and low-level mass response will promote some hodograph enlargement in a small corridor southeast through east of the MCV. Accordingly, sporadic and mostly short-lived mesocirculations have been observed in the complex for several hours, amid rich inflow-layer moisture and low LCL. An associated low-end tornado threat may extend into the outlook area before the complex weakens substantially. See SPC Mesoscale Discussion 2317 for near-term details. ..Edwards/Grams.. 12/29/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0700 AM CST Sun Dec 29 2024 Valid 291300Z - 301200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE EASTERN GULF COAST NORTHWARD INTO THE CAROLINAS AND SOUTHERN VIRGINIA... ...SUMMARY... A few tornadoes and sporadic damaging to severe gusts are possible today from the eastern Gulf Coast northward into the Carolinas and southern Virginia. More-isolated severe storms may occur across parts of the central Appalachians and Ohio Valley, and over southernmost Florida. ...Synopsis... In mid/upper levels, a progressive pattern will persist across the CONUS. A strong shortwave trough will move ashore in the Pacific Northwest and northern CA today. This will be preceded by some thunder potential, as lapse rates steepen from large-scale ascent, over areas where at least marginal low/middle-level moisture exists to support convection. Downstream, a strong shortwave trough was evident in moisture-channel imagery between the Mid-South and Tennessee Valley. This perturbation will pivot northeastward over TN, KY and IN today, forming a closed 500-mb low by 00Z over the Michiana region, and phasing with an initially upstream perturbation now over the central Plains. By 12Z, the resultant trough should assume considerable negative tilt, extending from a low over eastern Lake Huron to the Hampton Roads of VA/northeastern NC region. The associated surface cyclone was centered at 11Z over southwestern IN, with cold front across middle TN, central AL, past the Mississippi River mouth, then across the northwestern Gulf. The low is forecast to deepen and occlude today as it moves to near TOL. The cold front should sweep across much of the eastern CONUS through the period. By 00Z, the front should reach central parts of PA/VA/ NC/SC, southeastern GA, and the eastern Gulf, preceded by a strong-severe line of thunderstorms. By 12Z, the front should reach eastern NY, then offshore until central FL. ...Southern Atlantic Coast States... An ongoing, prefrontal squall line, with sporadic/embedded LEWP/ bowing features and an occasional embedded mesovortex, extends from northwestern SC across central/southern GA and the FL Panhandle, to the adjoining Gulf. This convection should become more northeast/ southwest oriented as its northern portion races through the central Appalachians/Piedmont region today, amid meager but still locally sufficient buoyancy (MLCAPE mostly less than 400 J/kg), long and curved low-level hodographs with 200-400 J/kg effective SRH, and favorable deep shear. Damaging gusts and a few embedded QLCS tornadoes will be the main concerns. See SPC Tornado Watches 723-724 and associated mesoscale discussions for the latest near-term coverage. ...Central Appalachians/Ohio Valley... Widely scattered low-topped thunderstorms are possible from midday through afternoon in a pocket of marginally unstable air ahead of the surface low and ejecting mid/upper trough. A marginal threat exists for damaging gusts or a brief tornado from this activity. As the trough approaches, midlevel flow will strengthen considerably, associated large-scale ascent will steepen low/middle-level lapse rates, while the mass response increases low-level and deep-layer shear. Temperatures from the upper 50s F to mid 60s (southeastern parts) would support MLCAPE in the 100-400 J/kg range amidst 40-50 kt effective-shear magnitudes and SRH of 100-200 J/kg in the lowest 1/2 km. Damaging gusts may be brought to the surface via momentum transfer in downdrafts from the LLJ, and conditional potential exists for mini-supercells to develop. Given the weak overall lapse rates and lack of greater buoyancy, the already marginal threat should diminish quickly by around 00Z. ...South FL/Keys... A small but persistent MCS, with an embedded MCV on its northwest side, has been moving slowly eastward across the easternmost Gulf toward Florida Bay for most of the prior overnight hours. This complex should affect at least parts of the mid/upper Keys, and southern Everglades, through midday. The ambient/synoptic gradients suggest only modest deep-layer shear this far from the ejecting shortwave trough. However, mesoscale midlevel flow enhancement and low-level mass response will promote some hodograph enlargement in a small corridor southeast through east of the MCV. Accordingly, sporadic and mostly short-lived mesocirculations have been observed in the complex for several hours, amid rich inflow-layer moisture and low LCL. An associated low-end tornado threat may extend into the outlook area before the complex weakens substantially. See SPC Mesoscale Discussion 2317 for near-term details. ..Edwards/Grams.. 12/29/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0700 AM CST Sun Dec 29 2024 Valid 291300Z - 301200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE EASTERN GULF COAST NORTHWARD INTO THE CAROLINAS AND SOUTHERN VIRGINIA... ...SUMMARY... A few tornadoes and sporadic damaging to severe gusts are possible today from the eastern Gulf Coast northward into the Carolinas and southern Virginia. More-isolated severe storms may occur across parts of the central Appalachians and Ohio Valley, and over southernmost Florida. ...Synopsis... In mid/upper levels, a progressive pattern will persist across the CONUS. A strong shortwave trough will move ashore in the Pacific Northwest and northern CA today. This will be preceded by some thunder potential, as lapse rates steepen from large-scale ascent, over areas where at least marginal low/middle-level moisture exists to support convection. Downstream, a strong shortwave trough was evident in moisture-channel imagery between the Mid-South and Tennessee Valley. This perturbation will pivot northeastward over TN, KY and IN today, forming a closed 500-mb low by 00Z over the Michiana region, and phasing with an initially upstream perturbation now over the central Plains. By 12Z, the resultant trough should assume considerable negative tilt, extending from a low over eastern Lake Huron to the Hampton Roads of VA/northeastern NC region. The associated surface cyclone was centered at 11Z over southwestern IN, with cold front across middle TN, central AL, past the Mississippi River mouth, then across the northwestern Gulf. The low is forecast to deepen and occlude today as it moves to near TOL. The cold front should sweep across much of the eastern CONUS through the period. By 00Z, the front should reach central parts of PA/VA/ NC/SC, southeastern GA, and the eastern Gulf, preceded by a strong-severe line of thunderstorms. By 12Z, the front should reach eastern NY, then offshore until central FL. ...Southern Atlantic Coast States... An ongoing, prefrontal squall line, with sporadic/embedded LEWP/ bowing features and an occasional embedded mesovortex, extends from northwestern SC across central/southern GA and the FL Panhandle, to the adjoining Gulf. This convection should become more northeast/ southwest oriented as its northern portion races through the central Appalachians/Piedmont region today, amid meager but still locally sufficient buoyancy (MLCAPE mostly less than 400 J/kg), long and curved low-level hodographs with 200-400 J/kg effective SRH, and favorable deep shear. Damaging gusts and a few embedded QLCS tornadoes will be the main concerns. See SPC Tornado Watches 723-724 and associated mesoscale discussions for the latest near-term coverage. ...Central Appalachians/Ohio Valley... Widely scattered low-topped thunderstorms are possible from midday through afternoon in a pocket of marginally unstable air ahead of the surface low and ejecting mid/upper trough. A marginal threat exists for damaging gusts or a brief tornado from this activity. As the trough approaches, midlevel flow will strengthen considerably, associated large-scale ascent will steepen low/middle-level lapse rates, while the mass response increases low-level and deep-layer shear. Temperatures from the upper 50s F to mid 60s (southeastern parts) would support MLCAPE in the 100-400 J/kg range amidst 40-50 kt effective-shear magnitudes and SRH of 100-200 J/kg in the lowest 1/2 km. Damaging gusts may be brought to the surface via momentum transfer in downdrafts from the LLJ, and conditional potential exists for mini-supercells to develop. Given the weak overall lapse rates and lack of greater buoyancy, the already marginal threat should diminish quickly by around 00Z. ...South FL/Keys... A small but persistent MCS, with an embedded MCV on its northwest side, has been moving slowly eastward across the easternmost Gulf toward Florida Bay for most of the prior overnight hours. This complex should affect at least parts of the mid/upper Keys, and southern Everglades, through midday. The ambient/synoptic gradients suggest only modest deep-layer shear this far from the ejecting shortwave trough. However, mesoscale midlevel flow enhancement and low-level mass response will promote some hodograph enlargement in a small corridor southeast through east of the MCV. Accordingly, sporadic and mostly short-lived mesocirculations have been observed in the complex for several hours, amid rich inflow-layer moisture and low LCL. An associated low-end tornado threat may extend into the outlook area before the complex weakens substantially. See SPC Mesoscale Discussion 2317 for near-term details. ..Edwards/Grams.. 12/29/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0700 AM CST Sun Dec 29 2024 Valid 291300Z - 301200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE EASTERN GULF COAST NORTHWARD INTO THE CAROLINAS AND SOUTHERN VIRGINIA... ...SUMMARY... A few tornadoes and sporadic damaging to severe gusts are possible today from the eastern Gulf Coast northward into the Carolinas and southern Virginia. More-isolated severe storms may occur across parts of the central Appalachians and Ohio Valley, and over southernmost Florida. ...Synopsis... In mid/upper levels, a progressive pattern will persist across the CONUS. A strong shortwave trough will move ashore in the Pacific Northwest and northern CA today. This will be preceded by some thunder potential, as lapse rates steepen from large-scale ascent, over areas where at least marginal low/middle-level moisture exists to support convection. Downstream, a strong shortwave trough was evident in moisture-channel imagery between the Mid-South and Tennessee Valley. This perturbation will pivot northeastward over TN, KY and IN today, forming a closed 500-mb low by 00Z over the Michiana region, and phasing with an initially upstream perturbation now over the central Plains. By 12Z, the resultant trough should assume considerable negative tilt, extending from a low over eastern Lake Huron to the Hampton Roads of VA/northeastern NC region. The associated surface cyclone was centered at 11Z over southwestern IN, with cold front across middle TN, central AL, past the Mississippi River mouth, then across the northwestern Gulf. The low is forecast to deepen and occlude today as it moves to near TOL. The cold front should sweep across much of the eastern CONUS through the period. By 00Z, the front should reach central parts of PA/VA/ NC/SC, southeastern GA, and the eastern Gulf, preceded by a strong-severe line of thunderstorms. By 12Z, the front should reach eastern NY, then offshore until central FL. ...Southern Atlantic Coast States... An ongoing, prefrontal squall line, with sporadic/embedded LEWP/ bowing features and an occasional embedded mesovortex, extends from northwestern SC across central/southern GA and the FL Panhandle, to the adjoining Gulf. This convection should become more northeast/ southwest oriented as its northern portion races through the central Appalachians/Piedmont region today, amid meager but still locally sufficient buoyancy (MLCAPE mostly less than 400 J/kg), long and curved low-level hodographs with 200-400 J/kg effective SRH, and favorable deep shear. Damaging gusts and a few embedded QLCS tornadoes will be the main concerns. See SPC Tornado Watches 723-724 and associated mesoscale discussions for the latest near-term coverage. ...Central Appalachians/Ohio Valley... Widely scattered low-topped thunderstorms are possible from midday through afternoon in a pocket of marginally unstable air ahead of the surface low and ejecting mid/upper trough. A marginal threat exists for damaging gusts or a brief tornado from this activity. As the trough approaches, midlevel flow will strengthen considerably, associated large-scale ascent will steepen low/middle-level lapse rates, while the mass response increases low-level and deep-layer shear. Temperatures from the upper 50s F to mid 60s (southeastern parts) would support MLCAPE in the 100-400 J/kg range amidst 40-50 kt effective-shear magnitudes and SRH of 100-200 J/kg in the lowest 1/2 km. Damaging gusts may be brought to the surface via momentum transfer in downdrafts from the LLJ, and conditional potential exists for mini-supercells to develop. Given the weak overall lapse rates and lack of greater buoyancy, the already marginal threat should diminish quickly by around 00Z. ...South FL/Keys... A small but persistent MCS, with an embedded MCV on its northwest side, has been moving slowly eastward across the easternmost Gulf toward Florida Bay for most of the prior overnight hours. This complex should affect at least parts of the mid/upper Keys, and southern Everglades, through midday. The ambient/synoptic gradients suggest only modest deep-layer shear this far from the ejecting shortwave trough. However, mesoscale midlevel flow enhancement and low-level mass response will promote some hodograph enlargement in a small corridor southeast through east of the MCV. Accordingly, sporadic and mostly short-lived mesocirculations have been observed in the complex for several hours, amid rich inflow-layer moisture and low LCL. An associated low-end tornado threat may extend into the outlook area before the complex weakens substantially. See SPC Mesoscale Discussion 2317 for near-term details. ..Edwards/Grams.. 12/29/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0700 AM CST Sun Dec 29 2024 Valid 291300Z - 301200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE EASTERN GULF COAST NORTHWARD INTO THE CAROLINAS AND SOUTHERN VIRGINIA... ...SUMMARY... A few tornadoes and sporadic damaging to severe gusts are possible today from the eastern Gulf Coast northward into the Carolinas and southern Virginia. More-isolated severe storms may occur across parts of the central Appalachians and Ohio Valley, and over southernmost Florida. ...Synopsis... In mid/upper levels, a progressive pattern will persist across the CONUS. A strong shortwave trough will move ashore in the Pacific Northwest and northern CA today. This will be preceded by some thunder potential, as lapse rates steepen from large-scale ascent, over areas where at least marginal low/middle-level moisture exists to support convection. Downstream, a strong shortwave trough was evident in moisture-channel imagery between the Mid-South and Tennessee Valley. This perturbation will pivot northeastward over TN, KY and IN today, forming a closed 500-mb low by 00Z over the Michiana region, and phasing with an initially upstream perturbation now over the central Plains. By 12Z, the resultant trough should assume considerable negative tilt, extending from a low over eastern Lake Huron to the Hampton Roads of VA/northeastern NC region. The associated surface cyclone was centered at 11Z over southwestern IN, with cold front across middle TN, central AL, past the Mississippi River mouth, then across the northwestern Gulf. The low is forecast to deepen and occlude today as it moves to near TOL. The cold front should sweep across much of the eastern CONUS through the period. By 00Z, the front should reach central parts of PA/VA/ NC/SC, southeastern GA, and the eastern Gulf, preceded by a strong-severe line of thunderstorms. By 12Z, the front should reach eastern NY, then offshore until central FL. ...Southern Atlantic Coast States... An ongoing, prefrontal squall line, with sporadic/embedded LEWP/ bowing features and an occasional embedded mesovortex, extends from northwestern SC across central/southern GA and the FL Panhandle, to the adjoining Gulf. This convection should become more northeast/ southwest oriented as its northern portion races through the central Appalachians/Piedmont region today, amid meager but still locally sufficient buoyancy (MLCAPE mostly less than 400 J/kg), long and curved low-level hodographs with 200-400 J/kg effective SRH, and favorable deep shear. Damaging gusts and a few embedded QLCS tornadoes will be the main concerns. See SPC Tornado Watches 723-724 and associated mesoscale discussions for the latest near-term coverage. ...Central Appalachians/Ohio Valley... Widely scattered low-topped thunderstorms are possible from midday through afternoon in a pocket of marginally unstable air ahead of the surface low and ejecting mid/upper trough. A marginal threat exists for damaging gusts or a brief tornado from this activity. As the trough approaches, midlevel flow will strengthen considerably, associated large-scale ascent will steepen low/middle-level lapse rates, while the mass response increases low-level and deep-layer shear. Temperatures from the upper 50s F to mid 60s (southeastern parts) would support MLCAPE in the 100-400 J/kg range amidst 40-50 kt effective-shear magnitudes and SRH of 100-200 J/kg in the lowest 1/2 km. Damaging gusts may be brought to the surface via momentum transfer in downdrafts from the LLJ, and conditional potential exists for mini-supercells to develop. Given the weak overall lapse rates and lack of greater buoyancy, the already marginal threat should diminish quickly by around 00Z. ...South FL/Keys... A small but persistent MCS, with an embedded MCV on its northwest side, has been moving slowly eastward across the easternmost Gulf toward Florida Bay for most of the prior overnight hours. This complex should affect at least parts of the mid/upper Keys, and southern Everglades, through midday. The ambient/synoptic gradients suggest only modest deep-layer shear this far from the ejecting shortwave trough. However, mesoscale midlevel flow enhancement and low-level mass response will promote some hodograph enlargement in a small corridor southeast through east of the MCV. Accordingly, sporadic and mostly short-lived mesocirculations have been observed in the complex for several hours, amid rich inflow-layer moisture and low LCL. An associated low-end tornado threat may extend into the outlook area before the complex weakens substantially. See SPC Mesoscale Discussion 2317 for near-term details. ..Edwards/Grams.. 12/29/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0700 AM CST Sun Dec 29 2024 Valid 291300Z - 301200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE EASTERN GULF COAST NORTHWARD INTO THE CAROLINAS AND SOUTHERN VIRGINIA... ...SUMMARY... A few tornadoes and sporadic damaging to severe gusts are possible today from the eastern Gulf Coast northward into the Carolinas and southern Virginia. More-isolated severe storms may occur across parts of the central Appalachians and Ohio Valley, and over southernmost Florida. ...Synopsis... In mid/upper levels, a progressive pattern will persist across the CONUS. A strong shortwave trough will move ashore in the Pacific Northwest and northern CA today. This will be preceded by some thunder potential, as lapse rates steepen from large-scale ascent, over areas where at least marginal low/middle-level moisture exists to support convection. Downstream, a strong shortwave trough was evident in moisture-channel imagery between the Mid-South and Tennessee Valley. This perturbation will pivot northeastward over TN, KY and IN today, forming a closed 500-mb low by 00Z over the Michiana region, and phasing with an initially upstream perturbation now over the central Plains. By 12Z, the resultant trough should assume considerable negative tilt, extending from a low over eastern Lake Huron to the Hampton Roads of VA/northeastern NC region. The associated surface cyclone was centered at 11Z over southwestern IN, with cold front across middle TN, central AL, past the Mississippi River mouth, then across the northwestern Gulf. The low is forecast to deepen and occlude today as it moves to near TOL. The cold front should sweep across much of the eastern CONUS through the period. By 00Z, the front should reach central parts of PA/VA/ NC/SC, southeastern GA, and the eastern Gulf, preceded by a strong-severe line of thunderstorms. By 12Z, the front should reach eastern NY, then offshore until central FL. ...Southern Atlantic Coast States... An ongoing, prefrontal squall line, with sporadic/embedded LEWP/ bowing features and an occasional embedded mesovortex, extends from northwestern SC across central/southern GA and the FL Panhandle, to the adjoining Gulf. This convection should become more northeast/ southwest oriented as its northern portion races through the central Appalachians/Piedmont region today, amid meager but still locally sufficient buoyancy (MLCAPE mostly less than 400 J/kg), long and curved low-level hodographs with 200-400 J/kg effective SRH, and favorable deep shear. Damaging gusts and a few embedded QLCS tornadoes will be the main concerns. See SPC Tornado Watches 723-724 and associated mesoscale discussions for the latest near-term coverage. ...Central Appalachians/Ohio Valley... Widely scattered low-topped thunderstorms are possible from midday through afternoon in a pocket of marginally unstable air ahead of the surface low and ejecting mid/upper trough. A marginal threat exists for damaging gusts or a brief tornado from this activity. As the trough approaches, midlevel flow will strengthen considerably, associated large-scale ascent will steepen low/middle-level lapse rates, while the mass response increases low-level and deep-layer shear. Temperatures from the upper 50s F to mid 60s (southeastern parts) would support MLCAPE in the 100-400 J/kg range amidst 40-50 kt effective-shear magnitudes and SRH of 100-200 J/kg in the lowest 1/2 km. Damaging gusts may be brought to the surface via momentum transfer in downdrafts from the LLJ, and conditional potential exists for mini-supercells to develop. Given the weak overall lapse rates and lack of greater buoyancy, the already marginal threat should diminish quickly by around 00Z. ...South FL/Keys... A small but persistent MCS, with an embedded MCV on its northwest side, has been moving slowly eastward across the easternmost Gulf toward Florida Bay for most of the prior overnight hours. This complex should affect at least parts of the mid/upper Keys, and southern Everglades, through midday. The ambient/synoptic gradients suggest only modest deep-layer shear this far from the ejecting shortwave trough. However, mesoscale midlevel flow enhancement and low-level mass response will promote some hodograph enlargement in a small corridor southeast through east of the MCV. Accordingly, sporadic and mostly short-lived mesocirculations have been observed in the complex for several hours, amid rich inflow-layer moisture and low LCL. An associated low-end tornado threat may extend into the outlook area before the complex weakens substantially. See SPC Mesoscale Discussion 2317 for near-term details. ..Edwards/Grams.. 12/29/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0700 AM CST Sun Dec 29 2024 Valid 291300Z - 301200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE EASTERN GULF COAST NORTHWARD INTO THE CAROLINAS AND SOUTHERN VIRGINIA... ...SUMMARY... A few tornadoes and sporadic damaging to severe gusts are possible today from the eastern Gulf Coast northward into the Carolinas and southern Virginia. More-isolated severe storms may occur across parts of the central Appalachians and Ohio Valley, and over southernmost Florida. ...Synopsis... In mid/upper levels, a progressive pattern will persist across the CONUS. A strong shortwave trough will move ashore in the Pacific Northwest and northern CA today. This will be preceded by some thunder potential, as lapse rates steepen from large-scale ascent, over areas where at least marginal low/middle-level moisture exists to support convection. Downstream, a strong shortwave trough was evident in moisture-channel imagery between the Mid-South and Tennessee Valley. This perturbation will pivot northeastward over TN, KY and IN today, forming a closed 500-mb low by 00Z over the Michiana region, and phasing with an initially upstream perturbation now over the central Plains. By 12Z, the resultant trough should assume considerable negative tilt, extending from a low over eastern Lake Huron to the Hampton Roads of VA/northeastern NC region. The associated surface cyclone was centered at 11Z over southwestern IN, with cold front across middle TN, central AL, past the Mississippi River mouth, then across the northwestern Gulf. The low is forecast to deepen and occlude today as it moves to near TOL. The cold front should sweep across much of the eastern CONUS through the period. By 00Z, the front should reach central parts of PA/VA/ NC/SC, southeastern GA, and the eastern Gulf, preceded by a strong-severe line of thunderstorms. By 12Z, the front should reach eastern NY, then offshore until central FL. ...Southern Atlantic Coast States... An ongoing, prefrontal squall line, with sporadic/embedded LEWP/ bowing features and an occasional embedded mesovortex, extends from northwestern SC across central/southern GA and the FL Panhandle, to the adjoining Gulf. This convection should become more northeast/ southwest oriented as its northern portion races through the central Appalachians/Piedmont region today, amid meager but still locally sufficient buoyancy (MLCAPE mostly less than 400 J/kg), long and curved low-level hodographs with 200-400 J/kg effective SRH, and favorable deep shear. Damaging gusts and a few embedded QLCS tornadoes will be the main concerns. See SPC Tornado Watches 723-724 and associated mesoscale discussions for the latest near-term coverage. ...Central Appalachians/Ohio Valley... Widely scattered low-topped thunderstorms are possible from midday through afternoon in a pocket of marginally unstable air ahead of the surface low and ejecting mid/upper trough. A marginal threat exists for damaging gusts or a brief tornado from this activity. As the trough approaches, midlevel flow will strengthen considerably, associated large-scale ascent will steepen low/middle-level lapse rates, while the mass response increases low-level and deep-layer shear. Temperatures from the upper 50s F to mid 60s (southeastern parts) would support MLCAPE in the 100-400 J/kg range amidst 40-50 kt effective-shear magnitudes and SRH of 100-200 J/kg in the lowest 1/2 km. Damaging gusts may be brought to the surface via momentum transfer in downdrafts from the LLJ, and conditional potential exists for mini-supercells to develop. Given the weak overall lapse rates and lack of greater buoyancy, the already marginal threat should diminish quickly by around 00Z. ...South FL/Keys... A small but persistent MCS, with an embedded MCV on its northwest side, has been moving slowly eastward across the easternmost Gulf toward Florida Bay for most of the prior overnight hours. This complex should affect at least parts of the mid/upper Keys, and southern Everglades, through midday. The ambient/synoptic gradients suggest only modest deep-layer shear this far from the ejecting shortwave trough. However, mesoscale midlevel flow enhancement and low-level mass response will promote some hodograph enlargement in a small corridor southeast through east of the MCV. Accordingly, sporadic and mostly short-lived mesocirculations have been observed in the complex for several hours, amid rich inflow-layer moisture and low LCL. An associated low-end tornado threat may extend into the outlook area before the complex weakens substantially. See SPC Mesoscale Discussion 2317 for near-term details. ..Edwards/Grams.. 12/29/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0700 AM CST Sun Dec 29 2024 Valid 291300Z - 301200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE EASTERN GULF COAST NORTHWARD INTO THE CAROLINAS AND SOUTHERN VIRGINIA... ...SUMMARY... A few tornadoes and sporadic damaging to severe gusts are possible today from the eastern Gulf Coast northward into the Carolinas and southern Virginia. More-isolated severe storms may occur across parts of the central Appalachians and Ohio Valley, and over southernmost Florida. ...Synopsis... In mid/upper levels, a progressive pattern will persist across the CONUS. A strong shortwave trough will move ashore in the Pacific Northwest and northern CA today. This will be preceded by some thunder potential, as lapse rates steepen from large-scale ascent, over areas where at least marginal low/middle-level moisture exists to support convection. Downstream, a strong shortwave trough was evident in moisture-channel imagery between the Mid-South and Tennessee Valley. This perturbation will pivot northeastward over TN, KY and IN today, forming a closed 500-mb low by 00Z over the Michiana region, and phasing with an initially upstream perturbation now over the central Plains. By 12Z, the resultant trough should assume considerable negative tilt, extending from a low over eastern Lake Huron to the Hampton Roads of VA/northeastern NC region. The associated surface cyclone was centered at 11Z over southwestern IN, with cold front across middle TN, central AL, past the Mississippi River mouth, then across the northwestern Gulf. The low is forecast to deepen and occlude today as it moves to near TOL. The cold front should sweep across much of the eastern CONUS through the period. By 00Z, the front should reach central parts of PA/VA/ NC/SC, southeastern GA, and the eastern Gulf, preceded by a strong-severe line of thunderstorms. By 12Z, the front should reach eastern NY, then offshore until central FL. ...Southern Atlantic Coast States... An ongoing, prefrontal squall line, with sporadic/embedded LEWP/ bowing features and an occasional embedded mesovortex, extends from northwestern SC across central/southern GA and the FL Panhandle, to the adjoining Gulf. This convection should become more northeast/ southwest oriented as its northern portion races through the central Appalachians/Piedmont region today, amid meager but still locally sufficient buoyancy (MLCAPE mostly less than 400 J/kg), long and curved low-level hodographs with 200-400 J/kg effective SRH, and favorable deep shear. Damaging gusts and a few embedded QLCS tornadoes will be the main concerns. See SPC Tornado Watches 723-724 and associated mesoscale discussions for the latest near-term coverage. ...Central Appalachians/Ohio Valley... Widely scattered low-topped thunderstorms are possible from midday through afternoon in a pocket of marginally unstable air ahead of the surface low and ejecting mid/upper trough. A marginal threat exists for damaging gusts or a brief tornado from this activity. As the trough approaches, midlevel flow will strengthen considerably, associated large-scale ascent will steepen low/middle-level lapse rates, while the mass response increases low-level and deep-layer shear. Temperatures from the upper 50s F to mid 60s (southeastern parts) would support MLCAPE in the 100-400 J/kg range amidst 40-50 kt effective-shear magnitudes and SRH of 100-200 J/kg in the lowest 1/2 km. Damaging gusts may be brought to the surface via momentum transfer in downdrafts from the LLJ, and conditional potential exists for mini-supercells to develop. Given the weak overall lapse rates and lack of greater buoyancy, the already marginal threat should diminish quickly by around 00Z. ...South FL/Keys... A small but persistent MCS, with an embedded MCV on its northwest side, has been moving slowly eastward across the easternmost Gulf toward Florida Bay for most of the prior overnight hours. This complex should affect at least parts of the mid/upper Keys, and southern Everglades, through midday. The ambient/synoptic gradients suggest only modest deep-layer shear this far from the ejecting shortwave trough. However, mesoscale midlevel flow enhancement and low-level mass response will promote some hodograph enlargement in a small corridor southeast through east of the MCV. Accordingly, sporadic and mostly short-lived mesocirculations have been observed in the complex for several hours, amid rich inflow-layer moisture and low LCL. An associated low-end tornado threat may extend into the outlook area before the complex weakens substantially. See SPC Mesoscale Discussion 2317 for near-term details. ..Edwards/Grams.. 12/29/2024 Read more

MD 2316 CONCERNING TORNADO WATCH 723... FOR EASTERN FL PANHANDLE TO SOUTH GA
Mesoscale Discussion 2316 NWS Storm Prediction Center Norman OK 0601 AM CST Sun Dec 29 2024 Areas affected...eastern FL Panhandle to south GA Concerning...Tornado Watch 723... Valid 291201Z - 291300Z The severe weather threat for Tornado Watch 723 continues. SUMMARY...Potential for strong to isolated severe gusts and a couple brief tornadoes will primarily be focused with the trailing portion of an extensive QLCS across the Florida Panhandle. It appears unlikely to exit WW 723 before 14Z expiration. A replacement WW that includes downstream areas in north Florida to southeast Georgia is being considered. DISCUSSION...The trailing portion of the extensive QLCS across the Southeast has been the lone area to produce a measured severe wind gust (50 kts at ECP) this morning. This portion of the line has sped up its forward progression, but still appears unlikely to exit WW 723 prior to the scheduled expiration of 14Z. This acceleration tendency appears to be coupled with a slowing of the west-southwest to east-northeast oriented, non-severe part of the QLCS in southwest GA. The inflection where the north/south oriented line progresses across the leading outflow may augment 0-1 km SRH above the background shear of about 25 kts per the TLH VWP. This should sustain a continued damaging-wind and brief-tornado threat through late morning. ..Grams/Edwards.. 12/29/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...JAX...TAE... LAT...LON 30798491 30898445 30958411 31088374 31188337 31288300 31288272 31188246 30968233 30598241 30298264 30018303 29738340 29628469 29588499 29698553 30308534 30798491 Read more

Public Severe Weather Outlook
PUBLIC SEVERE WEATHER OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0715 PM CST SAT DEC 28 2024 ...Severe thunderstorms expected over parts of the Gulf Coast States this evening and overnight... * LOCATIONS... Central and Southern Mississippi Western and Central Alabama Southeast Louisiana * HAZARDS... Widespread damaging winds, some hurricane force Several tornadoes, a few intense Isolated large hail * SUMMARY... Tornadoes (some strong with at least EF-2 damage possible) and numerous severe/damaging wind gusts are expected this evening through tonight. The threat area will shift eastward across parts of the lower Mississippi Valley this evening, and continue overnight through early Sunday morning over portions of the Tennessee Valley, central Gulf Coast states, and western Georgia. Preparedness actions... Tornadoes at night can be particularly dangerous because they are usually fast-moving and difficult to see. Stay tuned to NOAA Weather Radio, weather.gov, or other media for watches and warnings. A tornado watch means that conditions are favorable for tornadoes to form during the next several hours. If a tornado warning is issued for your area, move to a place of safety, ideally in a basement or interior room on the lowest floor of a sturdy building. Read more