Severe Storms

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0250 PM CDT Mon Sep 23 2024 Valid 232000Z - 241200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS NORTHERN ARKANSAS INTO THE LOWER OHIO AND TENNESSEE RIVER VALLEYS... ...SUMMARY... Isolated strong to severe thunderstorms are possible this afternoon into evening from the Ozarks into parts of the Tennessee and lower Ohio Valleys. ...20z Update... The previous forecast remains on track with only minor adjustments needed based on recent observations and trends in guidance. Latest surface observations and upper-air analyses show the gradual organization of a surface low over northern AR/southern MO. The frontal boundary draped from southeast MO into the upper OH River Valley has begun to stall and is expected to gradually advance north through the evening hours. VWP observations along the frontal zone currently show relatively straight low-level hodographs, but helicity should slowly improve through the 20-03 UTC period as isentropic ascent along the front increases. As a result, the convective environment should become more favorable for organized convection - particularly during the 22-03 UTC period across far southeast MO into far southern IL and western KY. Latest high-res guidance suggests that storms developing along an approaching cold front across north-central AR will intensify as they migrate east towards this zone and should pose the primary severe threat this evening. However, loosely-organized thunderstorms recently developing within the mid-MS River Valley cast some uncertainty onto this scenario due to the potential for overturning portions of the downstream warm sector. This early convection may see improving organization in the coming hours as mid-level flow slowly improves late this afternoon, but limit storm longevity over the past hour cast some uncertainty onto the propensity for severe storms. Regardless, this stalled/warm frontal boundary will still present the best corridor for a more focused severe event through the evening hours, including the potential for a tornado or two. As such, the 2% risk probabilities have been expanded east into western KY. Consideration was given for 15% wind probabilities through this corridor, but confidence in storm mode and coverage remains too limited given the aforementioned concerns. Farther east across southern KY and TN, the forecast remains on track. See MCD #2097 for details regarding recent convective trends. ..Moore.. 09/23/2024 .PREV DISCUSSION... /ISSUED 1143 AM CDT Mon Sep 23 2024/ ...Ozarks to TN/OH Valleys and southern Appalachians... A positive-tilt upper trough will influence the region, with a general increase in relatively strong deep-layer southwesterly winds. Severe storms are possible this afternoon, particularly and initially across the Ozarks including far south-central to southeast Missouri, as well as far northern Arkansas and far southern Illinois. This will be in vicinity of a weak surface wave and a northward-shifting warm front as lingering morning convection along/north of the Ohio River abates and shifts eastward. Increasingly strong deep-layer winds could support some supercells. Some hail is possible given the buoyancy/deep-layer wind profiles, although mid-level lapse rates are not steep. Locally damaging winds may also occur, with some potential for a tornado or two mainly near the warm front. Although uncertainties linger regarding destabilization and the magnitude of the severe risk later this afternoon, portions of southeast Missouri and far southern Illinois will continue to be reevaluated into mid-afternoon (20Z update) for a potential risk upgrade. Farther east, isolated to scattered thunderstorms will probably develop near the ridge tops of the southern Appalachians and adjacent parts of the Carolinas Piedmont this afternoon. Moist low levels coupled with heating will result in around 1000 J/kg MLCAPE. Some modest multicell organization may occur due to adequately strong upper-level westerly flow, with a few locally damaging wind gusts a possibility. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0250 PM CDT Mon Sep 23 2024 Valid 232000Z - 241200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS NORTHERN ARKANSAS INTO THE LOWER OHIO AND TENNESSEE RIVER VALLEYS... ...SUMMARY... Isolated strong to severe thunderstorms are possible this afternoon into evening from the Ozarks into parts of the Tennessee and lower Ohio Valleys. ...20z Update... The previous forecast remains on track with only minor adjustments needed based on recent observations and trends in guidance. Latest surface observations and upper-air analyses show the gradual organization of a surface low over northern AR/southern MO. The frontal boundary draped from southeast MO into the upper OH River Valley has begun to stall and is expected to gradually advance north through the evening hours. VWP observations along the frontal zone currently show relatively straight low-level hodographs, but helicity should slowly improve through the 20-03 UTC period as isentropic ascent along the front increases. As a result, the convective environment should become more favorable for organized convection - particularly during the 22-03 UTC period across far southeast MO into far southern IL and western KY. Latest high-res guidance suggests that storms developing along an approaching cold front across north-central AR will intensify as they migrate east towards this zone and should pose the primary severe threat this evening. However, loosely-organized thunderstorms recently developing within the mid-MS River Valley cast some uncertainty onto this scenario due to the potential for overturning portions of the downstream warm sector. This early convection may see improving organization in the coming hours as mid-level flow slowly improves late this afternoon, but limit storm longevity over the past hour cast some uncertainty onto the propensity for severe storms. Regardless, this stalled/warm frontal boundary will still present the best corridor for a more focused severe event through the evening hours, including the potential for a tornado or two. As such, the 2% risk probabilities have been expanded east into western KY. Consideration was given for 15% wind probabilities through this corridor, but confidence in storm mode and coverage remains too limited given the aforementioned concerns. Farther east across southern KY and TN, the forecast remains on track. See MCD #2097 for details regarding recent convective trends. ..Moore.. 09/23/2024 .PREV DISCUSSION... /ISSUED 1143 AM CDT Mon Sep 23 2024/ ...Ozarks to TN/OH Valleys and southern Appalachians... A positive-tilt upper trough will influence the region, with a general increase in relatively strong deep-layer southwesterly winds. Severe storms are possible this afternoon, particularly and initially across the Ozarks including far south-central to southeast Missouri, as well as far northern Arkansas and far southern Illinois. This will be in vicinity of a weak surface wave and a northward-shifting warm front as lingering morning convection along/north of the Ohio River abates and shifts eastward. Increasingly strong deep-layer winds could support some supercells. Some hail is possible given the buoyancy/deep-layer wind profiles, although mid-level lapse rates are not steep. Locally damaging winds may also occur, with some potential for a tornado or two mainly near the warm front. Although uncertainties linger regarding destabilization and the magnitude of the severe risk later this afternoon, portions of southeast Missouri and far southern Illinois will continue to be reevaluated into mid-afternoon (20Z update) for a potential risk upgrade. Farther east, isolated to scattered thunderstorms will probably develop near the ridge tops of the southern Appalachians and adjacent parts of the Carolinas Piedmont this afternoon. Moist low levels coupled with heating will result in around 1000 J/kg MLCAPE. Some modest multicell organization may occur due to adequately strong upper-level westerly flow, with a few locally damaging wind gusts a possibility. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0250 PM CDT Mon Sep 23 2024 Valid 232000Z - 241200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS NORTHERN ARKANSAS INTO THE LOWER OHIO AND TENNESSEE RIVER VALLEYS... ...SUMMARY... Isolated strong to severe thunderstorms are possible this afternoon into evening from the Ozarks into parts of the Tennessee and lower Ohio Valleys. ...20z Update... The previous forecast remains on track with only minor adjustments needed based on recent observations and trends in guidance. Latest surface observations and upper-air analyses show the gradual organization of a surface low over northern AR/southern MO. The frontal boundary draped from southeast MO into the upper OH River Valley has begun to stall and is expected to gradually advance north through the evening hours. VWP observations along the frontal zone currently show relatively straight low-level hodographs, but helicity should slowly improve through the 20-03 UTC period as isentropic ascent along the front increases. As a result, the convective environment should become more favorable for organized convection - particularly during the 22-03 UTC period across far southeast MO into far southern IL and western KY. Latest high-res guidance suggests that storms developing along an approaching cold front across north-central AR will intensify as they migrate east towards this zone and should pose the primary severe threat this evening. However, loosely-organized thunderstorms recently developing within the mid-MS River Valley cast some uncertainty onto this scenario due to the potential for overturning portions of the downstream warm sector. This early convection may see improving organization in the coming hours as mid-level flow slowly improves late this afternoon, but limit storm longevity over the past hour cast some uncertainty onto the propensity for severe storms. Regardless, this stalled/warm frontal boundary will still present the best corridor for a more focused severe event through the evening hours, including the potential for a tornado or two. As such, the 2% risk probabilities have been expanded east into western KY. Consideration was given for 15% wind probabilities through this corridor, but confidence in storm mode and coverage remains too limited given the aforementioned concerns. Farther east across southern KY and TN, the forecast remains on track. See MCD #2097 for details regarding recent convective trends. ..Moore.. 09/23/2024 .PREV DISCUSSION... /ISSUED 1143 AM CDT Mon Sep 23 2024/ ...Ozarks to TN/OH Valleys and southern Appalachians... A positive-tilt upper trough will influence the region, with a general increase in relatively strong deep-layer southwesterly winds. Severe storms are possible this afternoon, particularly and initially across the Ozarks including far south-central to southeast Missouri, as well as far northern Arkansas and far southern Illinois. This will be in vicinity of a weak surface wave and a northward-shifting warm front as lingering morning convection along/north of the Ohio River abates and shifts eastward. Increasingly strong deep-layer winds could support some supercells. Some hail is possible given the buoyancy/deep-layer wind profiles, although mid-level lapse rates are not steep. Locally damaging winds may also occur, with some potential for a tornado or two mainly near the warm front. Although uncertainties linger regarding destabilization and the magnitude of the severe risk later this afternoon, portions of southeast Missouri and far southern Illinois will continue to be reevaluated into mid-afternoon (20Z update) for a potential risk upgrade. Farther east, isolated to scattered thunderstorms will probably develop near the ridge tops of the southern Appalachians and adjacent parts of the Carolinas Piedmont this afternoon. Moist low levels coupled with heating will result in around 1000 J/kg MLCAPE. Some modest multicell organization may occur due to adequately strong upper-level westerly flow, with a few locally damaging wind gusts a possibility. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0250 PM CDT Mon Sep 23 2024 Valid 232000Z - 241200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS NORTHERN ARKANSAS INTO THE LOWER OHIO AND TENNESSEE RIVER VALLEYS... ...SUMMARY... Isolated strong to severe thunderstorms are possible this afternoon into evening from the Ozarks into parts of the Tennessee and lower Ohio Valleys. ...20z Update... The previous forecast remains on track with only minor adjustments needed based on recent observations and trends in guidance. Latest surface observations and upper-air analyses show the gradual organization of a surface low over northern AR/southern MO. The frontal boundary draped from southeast MO into the upper OH River Valley has begun to stall and is expected to gradually advance north through the evening hours. VWP observations along the frontal zone currently show relatively straight low-level hodographs, but helicity should slowly improve through the 20-03 UTC period as isentropic ascent along the front increases. As a result, the convective environment should become more favorable for organized convection - particularly during the 22-03 UTC period across far southeast MO into far southern IL and western KY. Latest high-res guidance suggests that storms developing along an approaching cold front across north-central AR will intensify as they migrate east towards this zone and should pose the primary severe threat this evening. However, loosely-organized thunderstorms recently developing within the mid-MS River Valley cast some uncertainty onto this scenario due to the potential for overturning portions of the downstream warm sector. This early convection may see improving organization in the coming hours as mid-level flow slowly improves late this afternoon, but limit storm longevity over the past hour cast some uncertainty onto the propensity for severe storms. Regardless, this stalled/warm frontal boundary will still present the best corridor for a more focused severe event through the evening hours, including the potential for a tornado or two. As such, the 2% risk probabilities have been expanded east into western KY. Consideration was given for 15% wind probabilities through this corridor, but confidence in storm mode and coverage remains too limited given the aforementioned concerns. Farther east across southern KY and TN, the forecast remains on track. See MCD #2097 for details regarding recent convective trends. ..Moore.. 09/23/2024 .PREV DISCUSSION... /ISSUED 1143 AM CDT Mon Sep 23 2024/ ...Ozarks to TN/OH Valleys and southern Appalachians... A positive-tilt upper trough will influence the region, with a general increase in relatively strong deep-layer southwesterly winds. Severe storms are possible this afternoon, particularly and initially across the Ozarks including far south-central to southeast Missouri, as well as far northern Arkansas and far southern Illinois. This will be in vicinity of a weak surface wave and a northward-shifting warm front as lingering morning convection along/north of the Ohio River abates and shifts eastward. Increasingly strong deep-layer winds could support some supercells. Some hail is possible given the buoyancy/deep-layer wind profiles, although mid-level lapse rates are not steep. Locally damaging winds may also occur, with some potential for a tornado or two mainly near the warm front. Although uncertainties linger regarding destabilization and the magnitude of the severe risk later this afternoon, portions of southeast Missouri and far southern Illinois will continue to be reevaluated into mid-afternoon (20Z update) for a potential risk upgrade. Farther east, isolated to scattered thunderstorms will probably develop near the ridge tops of the southern Appalachians and adjacent parts of the Carolinas Piedmont this afternoon. Moist low levels coupled with heating will result in around 1000 J/kg MLCAPE. Some modest multicell organization may occur due to adequately strong upper-level westerly flow, with a few locally damaging wind gusts a possibility. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0250 PM CDT Mon Sep 23 2024 Valid 232000Z - 241200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS NORTHERN ARKANSAS INTO THE LOWER OHIO AND TENNESSEE RIVER VALLEYS... ...SUMMARY... Isolated strong to severe thunderstorms are possible this afternoon into evening from the Ozarks into parts of the Tennessee and lower Ohio Valleys. ...20z Update... The previous forecast remains on track with only minor adjustments needed based on recent observations and trends in guidance. Latest surface observations and upper-air analyses show the gradual organization of a surface low over northern AR/southern MO. The frontal boundary draped from southeast MO into the upper OH River Valley has begun to stall and is expected to gradually advance north through the evening hours. VWP observations along the frontal zone currently show relatively straight low-level hodographs, but helicity should slowly improve through the 20-03 UTC period as isentropic ascent along the front increases. As a result, the convective environment should become more favorable for organized convection - particularly during the 22-03 UTC period across far southeast MO into far southern IL and western KY. Latest high-res guidance suggests that storms developing along an approaching cold front across north-central AR will intensify as they migrate east towards this zone and should pose the primary severe threat this evening. However, loosely-organized thunderstorms recently developing within the mid-MS River Valley cast some uncertainty onto this scenario due to the potential for overturning portions of the downstream warm sector. This early convection may see improving organization in the coming hours as mid-level flow slowly improves late this afternoon, but limit storm longevity over the past hour cast some uncertainty onto the propensity for severe storms. Regardless, this stalled/warm frontal boundary will still present the best corridor for a more focused severe event through the evening hours, including the potential for a tornado or two. As such, the 2% risk probabilities have been expanded east into western KY. Consideration was given for 15% wind probabilities through this corridor, but confidence in storm mode and coverage remains too limited given the aforementioned concerns. Farther east across southern KY and TN, the forecast remains on track. See MCD #2097 for details regarding recent convective trends. ..Moore.. 09/23/2024 .PREV DISCUSSION... /ISSUED 1143 AM CDT Mon Sep 23 2024/ ...Ozarks to TN/OH Valleys and southern Appalachians... A positive-tilt upper trough will influence the region, with a general increase in relatively strong deep-layer southwesterly winds. Severe storms are possible this afternoon, particularly and initially across the Ozarks including far south-central to southeast Missouri, as well as far northern Arkansas and far southern Illinois. This will be in vicinity of a weak surface wave and a northward-shifting warm front as lingering morning convection along/north of the Ohio River abates and shifts eastward. Increasingly strong deep-layer winds could support some supercells. Some hail is possible given the buoyancy/deep-layer wind profiles, although mid-level lapse rates are not steep. Locally damaging winds may also occur, with some potential for a tornado or two mainly near the warm front. Although uncertainties linger regarding destabilization and the magnitude of the severe risk later this afternoon, portions of southeast Missouri and far southern Illinois will continue to be reevaluated into mid-afternoon (20Z update) for a potential risk upgrade. Farther east, isolated to scattered thunderstorms will probably develop near the ridge tops of the southern Appalachians and adjacent parts of the Carolinas Piedmont this afternoon. Moist low levels coupled with heating will result in around 1000 J/kg MLCAPE. Some modest multicell organization may occur due to adequately strong upper-level westerly flow, with a few locally damaging wind gusts a possibility. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0250 PM CDT Mon Sep 23 2024 Valid 232000Z - 241200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS NORTHERN ARKANSAS INTO THE LOWER OHIO AND TENNESSEE RIVER VALLEYS... ...SUMMARY... Isolated strong to severe thunderstorms are possible this afternoon into evening from the Ozarks into parts of the Tennessee and lower Ohio Valleys. ...20z Update... The previous forecast remains on track with only minor adjustments needed based on recent observations and trends in guidance. Latest surface observations and upper-air analyses show the gradual organization of a surface low over northern AR/southern MO. The frontal boundary draped from southeast MO into the upper OH River Valley has begun to stall and is expected to gradually advance north through the evening hours. VWP observations along the frontal zone currently show relatively straight low-level hodographs, but helicity should slowly improve through the 20-03 UTC period as isentropic ascent along the front increases. As a result, the convective environment should become more favorable for organized convection - particularly during the 22-03 UTC period across far southeast MO into far southern IL and western KY. Latest high-res guidance suggests that storms developing along an approaching cold front across north-central AR will intensify as they migrate east towards this zone and should pose the primary severe threat this evening. However, loosely-organized thunderstorms recently developing within the mid-MS River Valley cast some uncertainty onto this scenario due to the potential for overturning portions of the downstream warm sector. This early convection may see improving organization in the coming hours as mid-level flow slowly improves late this afternoon, but limit storm longevity over the past hour cast some uncertainty onto the propensity for severe storms. Regardless, this stalled/warm frontal boundary will still present the best corridor for a more focused severe event through the evening hours, including the potential for a tornado or two. As such, the 2% risk probabilities have been expanded east into western KY. Consideration was given for 15% wind probabilities through this corridor, but confidence in storm mode and coverage remains too limited given the aforementioned concerns. Farther east across southern KY and TN, the forecast remains on track. See MCD #2097 for details regarding recent convective trends. ..Moore.. 09/23/2024 .PREV DISCUSSION... /ISSUED 1143 AM CDT Mon Sep 23 2024/ ...Ozarks to TN/OH Valleys and southern Appalachians... A positive-tilt upper trough will influence the region, with a general increase in relatively strong deep-layer southwesterly winds. Severe storms are possible this afternoon, particularly and initially across the Ozarks including far south-central to southeast Missouri, as well as far northern Arkansas and far southern Illinois. This will be in vicinity of a weak surface wave and a northward-shifting warm front as lingering morning convection along/north of the Ohio River abates and shifts eastward. Increasingly strong deep-layer winds could support some supercells. Some hail is possible given the buoyancy/deep-layer wind profiles, although mid-level lapse rates are not steep. Locally damaging winds may also occur, with some potential for a tornado or two mainly near the warm front. Although uncertainties linger regarding destabilization and the magnitude of the severe risk later this afternoon, portions of southeast Missouri and far southern Illinois will continue to be reevaluated into mid-afternoon (20Z update) for a potential risk upgrade. Farther east, isolated to scattered thunderstorms will probably develop near the ridge tops of the southern Appalachians and adjacent parts of the Carolinas Piedmont this afternoon. Moist low levels coupled with heating will result in around 1000 J/kg MLCAPE. Some modest multicell organization may occur due to adequately strong upper-level westerly flow, with a few locally damaging wind gusts a possibility. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0250 PM CDT Mon Sep 23 2024 Valid 232000Z - 241200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS NORTHERN ARKANSAS INTO THE LOWER OHIO AND TENNESSEE RIVER VALLEYS... ...SUMMARY... Isolated strong to severe thunderstorms are possible this afternoon into evening from the Ozarks into parts of the Tennessee and lower Ohio Valleys. ...20z Update... The previous forecast remains on track with only minor adjustments needed based on recent observations and trends in guidance. Latest surface observations and upper-air analyses show the gradual organization of a surface low over northern AR/southern MO. The frontal boundary draped from southeast MO into the upper OH River Valley has begun to stall and is expected to gradually advance north through the evening hours. VWP observations along the frontal zone currently show relatively straight low-level hodographs, but helicity should slowly improve through the 20-03 UTC period as isentropic ascent along the front increases. As a result, the convective environment should become more favorable for organized convection - particularly during the 22-03 UTC period across far southeast MO into far southern IL and western KY. Latest high-res guidance suggests that storms developing along an approaching cold front across north-central AR will intensify as they migrate east towards this zone and should pose the primary severe threat this evening. However, loosely-organized thunderstorms recently developing within the mid-MS River Valley cast some uncertainty onto this scenario due to the potential for overturning portions of the downstream warm sector. This early convection may see improving organization in the coming hours as mid-level flow slowly improves late this afternoon, but limit storm longevity over the past hour cast some uncertainty onto the propensity for severe storms. Regardless, this stalled/warm frontal boundary will still present the best corridor for a more focused severe event through the evening hours, including the potential for a tornado or two. As such, the 2% risk probabilities have been expanded east into western KY. Consideration was given for 15% wind probabilities through this corridor, but confidence in storm mode and coverage remains too limited given the aforementioned concerns. Farther east across southern KY and TN, the forecast remains on track. See MCD #2097 for details regarding recent convective trends. ..Moore.. 09/23/2024 .PREV DISCUSSION... /ISSUED 1143 AM CDT Mon Sep 23 2024/ ...Ozarks to TN/OH Valleys and southern Appalachians... A positive-tilt upper trough will influence the region, with a general increase in relatively strong deep-layer southwesterly winds. Severe storms are possible this afternoon, particularly and initially across the Ozarks including far south-central to southeast Missouri, as well as far northern Arkansas and far southern Illinois. This will be in vicinity of a weak surface wave and a northward-shifting warm front as lingering morning convection along/north of the Ohio River abates and shifts eastward. Increasingly strong deep-layer winds could support some supercells. Some hail is possible given the buoyancy/deep-layer wind profiles, although mid-level lapse rates are not steep. Locally damaging winds may also occur, with some potential for a tornado or two mainly near the warm front. Although uncertainties linger regarding destabilization and the magnitude of the severe risk later this afternoon, portions of southeast Missouri and far southern Illinois will continue to be reevaluated into mid-afternoon (20Z update) for a potential risk upgrade. Farther east, isolated to scattered thunderstorms will probably develop near the ridge tops of the southern Appalachians and adjacent parts of the Carolinas Piedmont this afternoon. Moist low levels coupled with heating will result in around 1000 J/kg MLCAPE. Some modest multicell organization may occur due to adequately strong upper-level westerly flow, with a few locally damaging wind gusts a possibility. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0250 PM CDT Mon Sep 23 2024 Valid 232000Z - 241200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS NORTHERN ARKANSAS INTO THE LOWER OHIO AND TENNESSEE RIVER VALLEYS... ...SUMMARY... Isolated strong to severe thunderstorms are possible this afternoon into evening from the Ozarks into parts of the Tennessee and lower Ohio Valleys. ...20z Update... The previous forecast remains on track with only minor adjustments needed based on recent observations and trends in guidance. Latest surface observations and upper-air analyses show the gradual organization of a surface low over northern AR/southern MO. The frontal boundary draped from southeast MO into the upper OH River Valley has begun to stall and is expected to gradually advance north through the evening hours. VWP observations along the frontal zone currently show relatively straight low-level hodographs, but helicity should slowly improve through the 20-03 UTC period as isentropic ascent along the front increases. As a result, the convective environment should become more favorable for organized convection - particularly during the 22-03 UTC period across far southeast MO into far southern IL and western KY. Latest high-res guidance suggests that storms developing along an approaching cold front across north-central AR will intensify as they migrate east towards this zone and should pose the primary severe threat this evening. However, loosely-organized thunderstorms recently developing within the mid-MS River Valley cast some uncertainty onto this scenario due to the potential for overturning portions of the downstream warm sector. This early convection may see improving organization in the coming hours as mid-level flow slowly improves late this afternoon, but limit storm longevity over the past hour cast some uncertainty onto the propensity for severe storms. Regardless, this stalled/warm frontal boundary will still present the best corridor for a more focused severe event through the evening hours, including the potential for a tornado or two. As such, the 2% risk probabilities have been expanded east into western KY. Consideration was given for 15% wind probabilities through this corridor, but confidence in storm mode and coverage remains too limited given the aforementioned concerns. Farther east across southern KY and TN, the forecast remains on track. See MCD #2097 for details regarding recent convective trends. ..Moore.. 09/23/2024 .PREV DISCUSSION... /ISSUED 1143 AM CDT Mon Sep 23 2024/ ...Ozarks to TN/OH Valleys and southern Appalachians... A positive-tilt upper trough will influence the region, with a general increase in relatively strong deep-layer southwesterly winds. Severe storms are possible this afternoon, particularly and initially across the Ozarks including far south-central to southeast Missouri, as well as far northern Arkansas and far southern Illinois. This will be in vicinity of a weak surface wave and a northward-shifting warm front as lingering morning convection along/north of the Ohio River abates and shifts eastward. Increasingly strong deep-layer winds could support some supercells. Some hail is possible given the buoyancy/deep-layer wind profiles, although mid-level lapse rates are not steep. Locally damaging winds may also occur, with some potential for a tornado or two mainly near the warm front. Although uncertainties linger regarding destabilization and the magnitude of the severe risk later this afternoon, portions of southeast Missouri and far southern Illinois will continue to be reevaluated into mid-afternoon (20Z update) for a potential risk upgrade. Farther east, isolated to scattered thunderstorms will probably develop near the ridge tops of the southern Appalachians and adjacent parts of the Carolinas Piedmont this afternoon. Moist low levels coupled with heating will result in around 1000 J/kg MLCAPE. Some modest multicell organization may occur due to adequately strong upper-level westerly flow, with a few locally damaging wind gusts a possibility. Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0223 PM CDT Mon Sep 23 2024 Valid 251200Z - 261200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorm potential is uncertain, but limited, on Wednesday. ...Synopsis... The upper-level trough across the Midwest into the Mid-South is expected to evolve into a strong trough in the lower Great Lakes/Northeast and a cut-off low in the Ozarks. A surface cold front is expected to be positioned from near the upper Ohio Valley southward into Mid-South and westward into the southern Plains. In the Gulf of Mexico, current NHC forecasts show a hurricane moving north-northeastward in parts of the eastern Gulf. ...Western/central New York... A narrow warm sector may exist ahead of the cold front. Subtle forcing from the trough to the north may promote storm development during the afternoon. Given the potential for cloud cover/precipitation early in the day, along with the strongest mid-level ascent arriving during the evening, uncertainty is too high for severe probabilities. ...Mid-South/Southeast... Strong mid-level flow around the eventual cut-off low could allow for some storm organization near the cold front. There is a fairly strong signal for precipitation to be ongoing during morning and into the afternoon. Surface-based destabilization is at best uncertain and perhaps not very likely. No severe probabilities will be added. ...Portions of the Florida Peninsula... Given the forecast track of the tropical cyclone by NHC and available model guidance, there is some potential for low-level wind fields to increase in parts of the southern/central Florida Peninsula towards Thursday morning. Given the trough to the north of the expected hurricane and the uncertainty of the exact position of the system and any related outer convective bands, will continue to withhold low tornado probabilities. ..Wendt.. 09/23/2024 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0223 PM CDT Mon Sep 23 2024 Valid 251200Z - 261200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorm potential is uncertain, but limited, on Wednesday. ...Synopsis... The upper-level trough across the Midwest into the Mid-South is expected to evolve into a strong trough in the lower Great Lakes/Northeast and a cut-off low in the Ozarks. A surface cold front is expected to be positioned from near the upper Ohio Valley southward into Mid-South and westward into the southern Plains. In the Gulf of Mexico, current NHC forecasts show a hurricane moving north-northeastward in parts of the eastern Gulf. ...Western/central New York... A narrow warm sector may exist ahead of the cold front. Subtle forcing from the trough to the north may promote storm development during the afternoon. Given the potential for cloud cover/precipitation early in the day, along with the strongest mid-level ascent arriving during the evening, uncertainty is too high for severe probabilities. ...Mid-South/Southeast... Strong mid-level flow around the eventual cut-off low could allow for some storm organization near the cold front. There is a fairly strong signal for precipitation to be ongoing during morning and into the afternoon. Surface-based destabilization is at best uncertain and perhaps not very likely. No severe probabilities will be added. ...Portions of the Florida Peninsula... Given the forecast track of the tropical cyclone by NHC and available model guidance, there is some potential for low-level wind fields to increase in parts of the southern/central Florida Peninsula towards Thursday morning. Given the trough to the north of the expected hurricane and the uncertainty of the exact position of the system and any related outer convective bands, will continue to withhold low tornado probabilities. ..Wendt.. 09/23/2024 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0223 PM CDT Mon Sep 23 2024 Valid 251200Z - 261200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorm potential is uncertain, but limited, on Wednesday. ...Synopsis... The upper-level trough across the Midwest into the Mid-South is expected to evolve into a strong trough in the lower Great Lakes/Northeast and a cut-off low in the Ozarks. A surface cold front is expected to be positioned from near the upper Ohio Valley southward into Mid-South and westward into the southern Plains. In the Gulf of Mexico, current NHC forecasts show a hurricane moving north-northeastward in parts of the eastern Gulf. ...Western/central New York... A narrow warm sector may exist ahead of the cold front. Subtle forcing from the trough to the north may promote storm development during the afternoon. Given the potential for cloud cover/precipitation early in the day, along with the strongest mid-level ascent arriving during the evening, uncertainty is too high for severe probabilities. ...Mid-South/Southeast... Strong mid-level flow around the eventual cut-off low could allow for some storm organization near the cold front. There is a fairly strong signal for precipitation to be ongoing during morning and into the afternoon. Surface-based destabilization is at best uncertain and perhaps not very likely. No severe probabilities will be added. ...Portions of the Florida Peninsula... Given the forecast track of the tropical cyclone by NHC and available model guidance, there is some potential for low-level wind fields to increase in parts of the southern/central Florida Peninsula towards Thursday morning. Given the trough to the north of the expected hurricane and the uncertainty of the exact position of the system and any related outer convective bands, will continue to withhold low tornado probabilities. ..Wendt.. 09/23/2024 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0223 PM CDT Mon Sep 23 2024 Valid 251200Z - 261200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorm potential is uncertain, but limited, on Wednesday. ...Synopsis... The upper-level trough across the Midwest into the Mid-South is expected to evolve into a strong trough in the lower Great Lakes/Northeast and a cut-off low in the Ozarks. A surface cold front is expected to be positioned from near the upper Ohio Valley southward into Mid-South and westward into the southern Plains. In the Gulf of Mexico, current NHC forecasts show a hurricane moving north-northeastward in parts of the eastern Gulf. ...Western/central New York... A narrow warm sector may exist ahead of the cold front. Subtle forcing from the trough to the north may promote storm development during the afternoon. Given the potential for cloud cover/precipitation early in the day, along with the strongest mid-level ascent arriving during the evening, uncertainty is too high for severe probabilities. ...Mid-South/Southeast... Strong mid-level flow around the eventual cut-off low could allow for some storm organization near the cold front. There is a fairly strong signal for precipitation to be ongoing during morning and into the afternoon. Surface-based destabilization is at best uncertain and perhaps not very likely. No severe probabilities will be added. ...Portions of the Florida Peninsula... Given the forecast track of the tropical cyclone by NHC and available model guidance, there is some potential for low-level wind fields to increase in parts of the southern/central Florida Peninsula towards Thursday morning. Given the trough to the north of the expected hurricane and the uncertainty of the exact position of the system and any related outer convective bands, will continue to withhold low tornado probabilities. ..Wendt.. 09/23/2024 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0223 PM CDT Mon Sep 23 2024 Valid 251200Z - 261200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorm potential is uncertain, but limited, on Wednesday. ...Synopsis... The upper-level trough across the Midwest into the Mid-South is expected to evolve into a strong trough in the lower Great Lakes/Northeast and a cut-off low in the Ozarks. A surface cold front is expected to be positioned from near the upper Ohio Valley southward into Mid-South and westward into the southern Plains. In the Gulf of Mexico, current NHC forecasts show a hurricane moving north-northeastward in parts of the eastern Gulf. ...Western/central New York... A narrow warm sector may exist ahead of the cold front. Subtle forcing from the trough to the north may promote storm development during the afternoon. Given the potential for cloud cover/precipitation early in the day, along with the strongest mid-level ascent arriving during the evening, uncertainty is too high for severe probabilities. ...Mid-South/Southeast... Strong mid-level flow around the eventual cut-off low could allow for some storm organization near the cold front. There is a fairly strong signal for precipitation to be ongoing during morning and into the afternoon. Surface-based destabilization is at best uncertain and perhaps not very likely. No severe probabilities will be added. ...Portions of the Florida Peninsula... Given the forecast track of the tropical cyclone by NHC and available model guidance, there is some potential for low-level wind fields to increase in parts of the southern/central Florida Peninsula towards Thursday morning. Given the trough to the north of the expected hurricane and the uncertainty of the exact position of the system and any related outer convective bands, will continue to withhold low tornado probabilities. ..Wendt.. 09/23/2024 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0223 PM CDT Mon Sep 23 2024 Valid 251200Z - 261200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorm potential is uncertain, but limited, on Wednesday. ...Synopsis... The upper-level trough across the Midwest into the Mid-South is expected to evolve into a strong trough in the lower Great Lakes/Northeast and a cut-off low in the Ozarks. A surface cold front is expected to be positioned from near the upper Ohio Valley southward into Mid-South and westward into the southern Plains. In the Gulf of Mexico, current NHC forecasts show a hurricane moving north-northeastward in parts of the eastern Gulf. ...Western/central New York... A narrow warm sector may exist ahead of the cold front. Subtle forcing from the trough to the north may promote storm development during the afternoon. Given the potential for cloud cover/precipitation early in the day, along with the strongest mid-level ascent arriving during the evening, uncertainty is too high for severe probabilities. ...Mid-South/Southeast... Strong mid-level flow around the eventual cut-off low could allow for some storm organization near the cold front. There is a fairly strong signal for precipitation to be ongoing during morning and into the afternoon. Surface-based destabilization is at best uncertain and perhaps not very likely. No severe probabilities will be added. ...Portions of the Florida Peninsula... Given the forecast track of the tropical cyclone by NHC and available model guidance, there is some potential for low-level wind fields to increase in parts of the southern/central Florida Peninsula towards Thursday morning. Given the trough to the north of the expected hurricane and the uncertainty of the exact position of the system and any related outer convective bands, will continue to withhold low tornado probabilities. ..Wendt.. 09/23/2024 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0223 PM CDT Mon Sep 23 2024 Valid 251200Z - 261200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorm potential is uncertain, but limited, on Wednesday. ...Synopsis... The upper-level trough across the Midwest into the Mid-South is expected to evolve into a strong trough in the lower Great Lakes/Northeast and a cut-off low in the Ozarks. A surface cold front is expected to be positioned from near the upper Ohio Valley southward into Mid-South and westward into the southern Plains. In the Gulf of Mexico, current NHC forecasts show a hurricane moving north-northeastward in parts of the eastern Gulf. ...Western/central New York... A narrow warm sector may exist ahead of the cold front. Subtle forcing from the trough to the north may promote storm development during the afternoon. Given the potential for cloud cover/precipitation early in the day, along with the strongest mid-level ascent arriving during the evening, uncertainty is too high for severe probabilities. ...Mid-South/Southeast... Strong mid-level flow around the eventual cut-off low could allow for some storm organization near the cold front. There is a fairly strong signal for precipitation to be ongoing during morning and into the afternoon. Surface-based destabilization is at best uncertain and perhaps not very likely. No severe probabilities will be added. ...Portions of the Florida Peninsula... Given the forecast track of the tropical cyclone by NHC and available model guidance, there is some potential for low-level wind fields to increase in parts of the southern/central Florida Peninsula towards Thursday morning. Given the trough to the north of the expected hurricane and the uncertainty of the exact position of the system and any related outer convective bands, will continue to withhold low tornado probabilities. ..Wendt.. 09/23/2024 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0223 PM CDT Mon Sep 23 2024 Valid 251200Z - 261200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorm potential is uncertain, but limited, on Wednesday. ...Synopsis... The upper-level trough across the Midwest into the Mid-South is expected to evolve into a strong trough in the lower Great Lakes/Northeast and a cut-off low in the Ozarks. A surface cold front is expected to be positioned from near the upper Ohio Valley southward into Mid-South and westward into the southern Plains. In the Gulf of Mexico, current NHC forecasts show a hurricane moving north-northeastward in parts of the eastern Gulf. ...Western/central New York... A narrow warm sector may exist ahead of the cold front. Subtle forcing from the trough to the north may promote storm development during the afternoon. Given the potential for cloud cover/precipitation early in the day, along with the strongest mid-level ascent arriving during the evening, uncertainty is too high for severe probabilities. ...Mid-South/Southeast... Strong mid-level flow around the eventual cut-off low could allow for some storm organization near the cold front. There is a fairly strong signal for precipitation to be ongoing during morning and into the afternoon. Surface-based destabilization is at best uncertain and perhaps not very likely. No severe probabilities will be added. ...Portions of the Florida Peninsula... Given the forecast track of the tropical cyclone by NHC and available model guidance, there is some potential for low-level wind fields to increase in parts of the southern/central Florida Peninsula towards Thursday morning. Given the trough to the north of the expected hurricane and the uncertainty of the exact position of the system and any related outer convective bands, will continue to withhold low tornado probabilities. ..Wendt.. 09/23/2024 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0223 PM CDT Mon Sep 23 2024 Valid 251200Z - 261200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorm potential is uncertain, but limited, on Wednesday. ...Synopsis... The upper-level trough across the Midwest into the Mid-South is expected to evolve into a strong trough in the lower Great Lakes/Northeast and a cut-off low in the Ozarks. A surface cold front is expected to be positioned from near the upper Ohio Valley southward into Mid-South and westward into the southern Plains. In the Gulf of Mexico, current NHC forecasts show a hurricane moving north-northeastward in parts of the eastern Gulf. ...Western/central New York... A narrow warm sector may exist ahead of the cold front. Subtle forcing from the trough to the north may promote storm development during the afternoon. Given the potential for cloud cover/precipitation early in the day, along with the strongest mid-level ascent arriving during the evening, uncertainty is too high for severe probabilities. ...Mid-South/Southeast... Strong mid-level flow around the eventual cut-off low could allow for some storm organization near the cold front. There is a fairly strong signal for precipitation to be ongoing during morning and into the afternoon. Surface-based destabilization is at best uncertain and perhaps not very likely. No severe probabilities will be added. ...Portions of the Florida Peninsula... Given the forecast track of the tropical cyclone by NHC and available model guidance, there is some potential for low-level wind fields to increase in parts of the southern/central Florida Peninsula towards Thursday morning. Given the trough to the north of the expected hurricane and the uncertainty of the exact position of the system and any related outer convective bands, will continue to withhold low tornado probabilities. ..Wendt.. 09/23/2024 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0223 PM CDT Mon Sep 23 2024 Valid 251200Z - 261200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorm potential is uncertain, but limited, on Wednesday. ...Synopsis... The upper-level trough across the Midwest into the Mid-South is expected to evolve into a strong trough in the lower Great Lakes/Northeast and a cut-off low in the Ozarks. A surface cold front is expected to be positioned from near the upper Ohio Valley southward into Mid-South and westward into the southern Plains. In the Gulf of Mexico, current NHC forecasts show a hurricane moving north-northeastward in parts of the eastern Gulf. ...Western/central New York... A narrow warm sector may exist ahead of the cold front. Subtle forcing from the trough to the north may promote storm development during the afternoon. Given the potential for cloud cover/precipitation early in the day, along with the strongest mid-level ascent arriving during the evening, uncertainty is too high for severe probabilities. ...Mid-South/Southeast... Strong mid-level flow around the eventual cut-off low could allow for some storm organization near the cold front. There is a fairly strong signal for precipitation to be ongoing during morning and into the afternoon. Surface-based destabilization is at best uncertain and perhaps not very likely. No severe probabilities will be added. ...Portions of the Florida Peninsula... Given the forecast track of the tropical cyclone by NHC and available model guidance, there is some potential for low-level wind fields to increase in parts of the southern/central Florida Peninsula towards Thursday morning. Given the trough to the north of the expected hurricane and the uncertainty of the exact position of the system and any related outer convective bands, will continue to withhold low tornado probabilities. ..Wendt.. 09/23/2024 Read more

MD 2097 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR PORTIONS OF SOUTHERN KENTUCKY...MIDDLE/EASTERN TENNESSEE AND FAR WESTERN NORTH CAROLINA
Mesoscale Discussion 2097 NWS Storm Prediction Center Norman OK 0113 PM CDT Mon Sep 23 2024 Areas affected...Portions of southern Kentucky...middle/eastern Tennessee and far western North Carolina Concerning...Severe potential...Watch unlikely Valid 231813Z - 231945Z Probability of Watch Issuance...20 percent SUMMARY...Convection should gradually expand in coverage this afternoon with a few stronger multi-cell clusters possible. Isolated damaging winds are the most likely threat with the more persistent/stronger storms. Environmental conditions are not overly conducive for longevity or severity, a watch appears unlikely. DISCUSSION...As of 1810 UTC, afternoon visible and radar imagery showed scattered thunderstorms developing south of a stationary frontal zone over parts of the TN Valley and southern KY. Driven primarily by strong diurnal heating of a seasonably moist (upper 60s to low 70s F dewpoints) air mass, SPC mesoanalysis shows 1000-1500 J/kg of MLCAPE, despite poor mid-level lapse rates. In the absence of significant height falls aloft, convective coverage should gradually increase through the afternoon with continued heating. As storms deepen, flow aloft will also gradually increase from the west. While area VADs are not overly strong, especially with eastward extent, 25-30 kt of flow aloft will support some potential for organization into multi-cell clusters. Damaging winds associated with water-loaded downdrafts appear to be the most likely threat given poor low and mid-level lapse rates and limited storm organization. Hi-res model guidance and observational trends suggest storms will gradually move eastward into parts of eastern TN/southeast KY and the western Carolinas later this afternoon/evening. An isolated risk for damaging winds will accompany the stronger/more persistent clusters. However, the lack of more significant upper-level support, poor lapse rates and marginal deep-layer shear suggests the threat is unlikely to be widespread enough to warrant a WW. ..Lyons/Guyer.. 09/23/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...RNK...RLX...GSP...MRX...JKL...FFC...LMK...OHX... HUN... LAT...LON 37698535 36928641 36288662 35678647 35258610 35168512 34918339 34948284 35218233 35468170 35818142 36348144 37378254 37738517 37698535 Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0118 PM CDT Mon Sep 23 2024 Valid 241200Z - 251200Z ...NO CRITICAL AREAS... No changes. See previous discussion below. ..Bentley.. 09/23/2024 .PREV DISCUSSION... /ISSUED 0148 AM CDT Mon Sep 23 2024/ ...Synopsis... Fire weather concerns will remain low on Tuesday across the CONUS. A ridge will build in across the western US, with dry and warming conditions amid generally light winds. Longwave troughing will deepen across the Plains, with some post-frontal northwesterly breezes across the High Plains. Overall, cool conditions will keep relative humidity values high and there is potential for wetting rainfall Monday into Tuesday. ...Please see www.spc.noaa.gov/fire for graphic product... Read more