Severe Storms

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0135 AM CDT Thu Sep 12 2024 Valid 121200Z - 131200Z ...CRITICAL FIRE WEATHER AREA FOR MUCH OF THE HIGH PLAINS AND FRONT RANGE... ...Synopsis... A deep mid-level trough over the northern Rockies is forecast to intensify as it moves eastward and ejects over the northern/central Plains today and tonight. As the trough moves east, a lee low/trough will quickly deepen, supporting strong surface winds over the Plains. A cold front approaching from the west will move through the Great Basin also supporting strong surface winds over the Rockies. Dry and windy conditions will favor critical fire-weather concerns across the Intermountain West and western Plains through this evening. ...Central and northern Plains... As the upper-level trough approaches from the west this morning, southerly surface winds are expected to rapidly increase over much of the High Plains. Winds should continue to intensify through the day as low pressure and the trailing lee trough deepen. South/southwesterly gusts of 20-30 mph are possible along with RH values below 25%. RH will be considerably higher farther east, as low-level moisture advects northward. Still, strong gusts of 25-30 mph are likely with pockets of afternoon RH as low as 25-30%. Strong winds will accelerate drying of fine fuels after recent scattered precipitation, with critically dry fuels expected over much of the central and northern Plains by this afternoon. With the potent combination of strong winds and low RH likely over several hours, widespread elevated to critical fire-weather conditions are expected. ...Intermountain West... Across parts of western CO/WY, strong southwesterly winds are expected ahead of the cold front moving out of the eastern Great Basin. Aided by the strong flow aloft, wind gusts of 25-30 mph are likely. Dry southwesterly flow and warm temperatures will support afternoon RH values below 20%. Meteorological conditions are quite conducive to fire spread. Despite some recent drying, area fuels are not particularly dry after rainfall in the last 48 hours. However, given the magnitude of the wind and relatively dry conditions, several hours of elevated to near-critical fire-weather conditions still appear likely, especially over parts of western CO and eastern UT. ..Lyons.. 09/12/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0135 AM CDT Thu Sep 12 2024 Valid 121200Z - 131200Z ...CRITICAL FIRE WEATHER AREA FOR MUCH OF THE HIGH PLAINS AND FRONT RANGE... ...Synopsis... A deep mid-level trough over the northern Rockies is forecast to intensify as it moves eastward and ejects over the northern/central Plains today and tonight. As the trough moves east, a lee low/trough will quickly deepen, supporting strong surface winds over the Plains. A cold front approaching from the west will move through the Great Basin also supporting strong surface winds over the Rockies. Dry and windy conditions will favor critical fire-weather concerns across the Intermountain West and western Plains through this evening. ...Central and northern Plains... As the upper-level trough approaches from the west this morning, southerly surface winds are expected to rapidly increase over much of the High Plains. Winds should continue to intensify through the day as low pressure and the trailing lee trough deepen. South/southwesterly gusts of 20-30 mph are possible along with RH values below 25%. RH will be considerably higher farther east, as low-level moisture advects northward. Still, strong gusts of 25-30 mph are likely with pockets of afternoon RH as low as 25-30%. Strong winds will accelerate drying of fine fuels after recent scattered precipitation, with critically dry fuels expected over much of the central and northern Plains by this afternoon. With the potent combination of strong winds and low RH likely over several hours, widespread elevated to critical fire-weather conditions are expected. ...Intermountain West... Across parts of western CO/WY, strong southwesterly winds are expected ahead of the cold front moving out of the eastern Great Basin. Aided by the strong flow aloft, wind gusts of 25-30 mph are likely. Dry southwesterly flow and warm temperatures will support afternoon RH values below 20%. Meteorological conditions are quite conducive to fire spread. Despite some recent drying, area fuels are not particularly dry after rainfall in the last 48 hours. However, given the magnitude of the wind and relatively dry conditions, several hours of elevated to near-critical fire-weather conditions still appear likely, especially over parts of western CO and eastern UT. ..Lyons.. 09/12/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0135 AM CDT Thu Sep 12 2024 Valid 121200Z - 131200Z ...CRITICAL FIRE WEATHER AREA FOR MUCH OF THE HIGH PLAINS AND FRONT RANGE... ...Synopsis... A deep mid-level trough over the northern Rockies is forecast to intensify as it moves eastward and ejects over the northern/central Plains today and tonight. As the trough moves east, a lee low/trough will quickly deepen, supporting strong surface winds over the Plains. A cold front approaching from the west will move through the Great Basin also supporting strong surface winds over the Rockies. Dry and windy conditions will favor critical fire-weather concerns across the Intermountain West and western Plains through this evening. ...Central and northern Plains... As the upper-level trough approaches from the west this morning, southerly surface winds are expected to rapidly increase over much of the High Plains. Winds should continue to intensify through the day as low pressure and the trailing lee trough deepen. South/southwesterly gusts of 20-30 mph are possible along with RH values below 25%. RH will be considerably higher farther east, as low-level moisture advects northward. Still, strong gusts of 25-30 mph are likely with pockets of afternoon RH as low as 25-30%. Strong winds will accelerate drying of fine fuels after recent scattered precipitation, with critically dry fuels expected over much of the central and northern Plains by this afternoon. With the potent combination of strong winds and low RH likely over several hours, widespread elevated to critical fire-weather conditions are expected. ...Intermountain West... Across parts of western CO/WY, strong southwesterly winds are expected ahead of the cold front moving out of the eastern Great Basin. Aided by the strong flow aloft, wind gusts of 25-30 mph are likely. Dry southwesterly flow and warm temperatures will support afternoon RH values below 20%. Meteorological conditions are quite conducive to fire spread. Despite some recent drying, area fuels are not particularly dry after rainfall in the last 48 hours. However, given the magnitude of the wind and relatively dry conditions, several hours of elevated to near-critical fire-weather conditions still appear likely, especially over parts of western CO and eastern UT. ..Lyons.. 09/12/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0135 AM CDT Thu Sep 12 2024 Valid 121200Z - 131200Z ...CRITICAL FIRE WEATHER AREA FOR MUCH OF THE HIGH PLAINS AND FRONT RANGE... ...Synopsis... A deep mid-level trough over the northern Rockies is forecast to intensify as it moves eastward and ejects over the northern/central Plains today and tonight. As the trough moves east, a lee low/trough will quickly deepen, supporting strong surface winds over the Plains. A cold front approaching from the west will move through the Great Basin also supporting strong surface winds over the Rockies. Dry and windy conditions will favor critical fire-weather concerns across the Intermountain West and western Plains through this evening. ...Central and northern Plains... As the upper-level trough approaches from the west this morning, southerly surface winds are expected to rapidly increase over much of the High Plains. Winds should continue to intensify through the day as low pressure and the trailing lee trough deepen. South/southwesterly gusts of 20-30 mph are possible along with RH values below 25%. RH will be considerably higher farther east, as low-level moisture advects northward. Still, strong gusts of 25-30 mph are likely with pockets of afternoon RH as low as 25-30%. Strong winds will accelerate drying of fine fuels after recent scattered precipitation, with critically dry fuels expected over much of the central and northern Plains by this afternoon. With the potent combination of strong winds and low RH likely over several hours, widespread elevated to critical fire-weather conditions are expected. ...Intermountain West... Across parts of western CO/WY, strong southwesterly winds are expected ahead of the cold front moving out of the eastern Great Basin. Aided by the strong flow aloft, wind gusts of 25-30 mph are likely. Dry southwesterly flow and warm temperatures will support afternoon RH values below 20%. Meteorological conditions are quite conducive to fire spread. Despite some recent drying, area fuels are not particularly dry after rainfall in the last 48 hours. However, given the magnitude of the wind and relatively dry conditions, several hours of elevated to near-critical fire-weather conditions still appear likely, especially over parts of western CO and eastern UT. ..Lyons.. 09/12/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0135 AM CDT Thu Sep 12 2024 Valid 121200Z - 131200Z ...CRITICAL FIRE WEATHER AREA FOR MUCH OF THE HIGH PLAINS AND FRONT RANGE... ...Synopsis... A deep mid-level trough over the northern Rockies is forecast to intensify as it moves eastward and ejects over the northern/central Plains today and tonight. As the trough moves east, a lee low/trough will quickly deepen, supporting strong surface winds over the Plains. A cold front approaching from the west will move through the Great Basin also supporting strong surface winds over the Rockies. Dry and windy conditions will favor critical fire-weather concerns across the Intermountain West and western Plains through this evening. ...Central and northern Plains... As the upper-level trough approaches from the west this morning, southerly surface winds are expected to rapidly increase over much of the High Plains. Winds should continue to intensify through the day as low pressure and the trailing lee trough deepen. South/southwesterly gusts of 20-30 mph are possible along with RH values below 25%. RH will be considerably higher farther east, as low-level moisture advects northward. Still, strong gusts of 25-30 mph are likely with pockets of afternoon RH as low as 25-30%. Strong winds will accelerate drying of fine fuels after recent scattered precipitation, with critically dry fuels expected over much of the central and northern Plains by this afternoon. With the potent combination of strong winds and low RH likely over several hours, widespread elevated to critical fire-weather conditions are expected. ...Intermountain West... Across parts of western CO/WY, strong southwesterly winds are expected ahead of the cold front moving out of the eastern Great Basin. Aided by the strong flow aloft, wind gusts of 25-30 mph are likely. Dry southwesterly flow and warm temperatures will support afternoon RH values below 20%. Meteorological conditions are quite conducive to fire spread. Despite some recent drying, area fuels are not particularly dry after rainfall in the last 48 hours. However, given the magnitude of the wind and relatively dry conditions, several hours of elevated to near-critical fire-weather conditions still appear likely, especially over parts of western CO and eastern UT. ..Lyons.. 09/12/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0135 AM CDT Thu Sep 12 2024 Valid 121200Z - 131200Z ...CRITICAL FIRE WEATHER AREA FOR MUCH OF THE HIGH PLAINS AND FRONT RANGE... ...Synopsis... A deep mid-level trough over the northern Rockies is forecast to intensify as it moves eastward and ejects over the northern/central Plains today and tonight. As the trough moves east, a lee low/trough will quickly deepen, supporting strong surface winds over the Plains. A cold front approaching from the west will move through the Great Basin also supporting strong surface winds over the Rockies. Dry and windy conditions will favor critical fire-weather concerns across the Intermountain West and western Plains through this evening. ...Central and northern Plains... As the upper-level trough approaches from the west this morning, southerly surface winds are expected to rapidly increase over much of the High Plains. Winds should continue to intensify through the day as low pressure and the trailing lee trough deepen. South/southwesterly gusts of 20-30 mph are possible along with RH values below 25%. RH will be considerably higher farther east, as low-level moisture advects northward. Still, strong gusts of 25-30 mph are likely with pockets of afternoon RH as low as 25-30%. Strong winds will accelerate drying of fine fuels after recent scattered precipitation, with critically dry fuels expected over much of the central and northern Plains by this afternoon. With the potent combination of strong winds and low RH likely over several hours, widespread elevated to critical fire-weather conditions are expected. ...Intermountain West... Across parts of western CO/WY, strong southwesterly winds are expected ahead of the cold front moving out of the eastern Great Basin. Aided by the strong flow aloft, wind gusts of 25-30 mph are likely. Dry southwesterly flow and warm temperatures will support afternoon RH values below 20%. Meteorological conditions are quite conducive to fire spread. Despite some recent drying, area fuels are not particularly dry after rainfall in the last 48 hours. However, given the magnitude of the wind and relatively dry conditions, several hours of elevated to near-critical fire-weather conditions still appear likely, especially over parts of western CO and eastern UT. ..Lyons.. 09/12/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1235 AM CDT Thu Sep 12 2024 Valid 131200Z - 141200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS IN A PART OF THE TN VALLEY TO THE FL PANHANDLE... ...SUMMARY... A couple brief tornadoes and locally damaging winds are possible across a part of the Southeast on Friday morning into the afternoon. ...Southeast... The remnants of TC Francine are expected to decay in place near the AR/TN/MO border vicinity on Friday, with greater weakening of low-level winds relative to today. Still, the strongest lingering belt of low-level southeasterlies should persist through Friday morning into the afternoon to the east, centered on the TN Valley. This should yield moderate SRH coincident with the northern extent of weak surface-based instability from central AL/far western GA northward into Middle TN. This corridor will likely be narrow at any one time and steadily shift east through the day. A drier air mass with veered low-level winds is expected to its west, and cooler surface temps beneath pervasive cloudiness should occur to its northeast. A couple brief tornadoes will be possible, mainly from mid-morning into the afternoon. Low-level winds will diminish with southern extent to the FL Panhandle, but moderate mid-level southwesterlies should yield adequate deep-layer shear for transient mid-level rotation. Modest boundary-layer heating of a residual tropical air mass should occur within a corridor ahead of an occluded surface front. Locally strong gusts capable of sporadic tree damage remain possible. ..Grams.. 09/12/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1235 AM CDT Thu Sep 12 2024 Valid 131200Z - 141200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS IN A PART OF THE TN VALLEY TO THE FL PANHANDLE... ...SUMMARY... A couple brief tornadoes and locally damaging winds are possible across a part of the Southeast on Friday morning into the afternoon. ...Southeast... The remnants of TC Francine are expected to decay in place near the AR/TN/MO border vicinity on Friday, with greater weakening of low-level winds relative to today. Still, the strongest lingering belt of low-level southeasterlies should persist through Friday morning into the afternoon to the east, centered on the TN Valley. This should yield moderate SRH coincident with the northern extent of weak surface-based instability from central AL/far western GA northward into Middle TN. This corridor will likely be narrow at any one time and steadily shift east through the day. A drier air mass with veered low-level winds is expected to its west, and cooler surface temps beneath pervasive cloudiness should occur to its northeast. A couple brief tornadoes will be possible, mainly from mid-morning into the afternoon. Low-level winds will diminish with southern extent to the FL Panhandle, but moderate mid-level southwesterlies should yield adequate deep-layer shear for transient mid-level rotation. Modest boundary-layer heating of a residual tropical air mass should occur within a corridor ahead of an occluded surface front. Locally strong gusts capable of sporadic tree damage remain possible. ..Grams.. 09/12/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1235 AM CDT Thu Sep 12 2024 Valid 131200Z - 141200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS IN A PART OF THE TN VALLEY TO THE FL PANHANDLE... ...SUMMARY... A couple brief tornadoes and locally damaging winds are possible across a part of the Southeast on Friday morning into the afternoon. ...Southeast... The remnants of TC Francine are expected to decay in place near the AR/TN/MO border vicinity on Friday, with greater weakening of low-level winds relative to today. Still, the strongest lingering belt of low-level southeasterlies should persist through Friday morning into the afternoon to the east, centered on the TN Valley. This should yield moderate SRH coincident with the northern extent of weak surface-based instability from central AL/far western GA northward into Middle TN. This corridor will likely be narrow at any one time and steadily shift east through the day. A drier air mass with veered low-level winds is expected to its west, and cooler surface temps beneath pervasive cloudiness should occur to its northeast. A couple brief tornadoes will be possible, mainly from mid-morning into the afternoon. Low-level winds will diminish with southern extent to the FL Panhandle, but moderate mid-level southwesterlies should yield adequate deep-layer shear for transient mid-level rotation. Modest boundary-layer heating of a residual tropical air mass should occur within a corridor ahead of an occluded surface front. Locally strong gusts capable of sporadic tree damage remain possible. ..Grams.. 09/12/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1235 AM CDT Thu Sep 12 2024 Valid 131200Z - 141200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS IN A PART OF THE TN VALLEY TO THE FL PANHANDLE... ...SUMMARY... A couple brief tornadoes and locally damaging winds are possible across a part of the Southeast on Friday morning into the afternoon. ...Southeast... The remnants of TC Francine are expected to decay in place near the AR/TN/MO border vicinity on Friday, with greater weakening of low-level winds relative to today. Still, the strongest lingering belt of low-level southeasterlies should persist through Friday morning into the afternoon to the east, centered on the TN Valley. This should yield moderate SRH coincident with the northern extent of weak surface-based instability from central AL/far western GA northward into Middle TN. This corridor will likely be narrow at any one time and steadily shift east through the day. A drier air mass with veered low-level winds is expected to its west, and cooler surface temps beneath pervasive cloudiness should occur to its northeast. A couple brief tornadoes will be possible, mainly from mid-morning into the afternoon. Low-level winds will diminish with southern extent to the FL Panhandle, but moderate mid-level southwesterlies should yield adequate deep-layer shear for transient mid-level rotation. Modest boundary-layer heating of a residual tropical air mass should occur within a corridor ahead of an occluded surface front. Locally strong gusts capable of sporadic tree damage remain possible. ..Grams.. 09/12/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1235 AM CDT Thu Sep 12 2024 Valid 131200Z - 141200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS IN A PART OF THE TN VALLEY TO THE FL PANHANDLE... ...SUMMARY... A couple brief tornadoes and locally damaging winds are possible across a part of the Southeast on Friday morning into the afternoon. ...Southeast... The remnants of TC Francine are expected to decay in place near the AR/TN/MO border vicinity on Friday, with greater weakening of low-level winds relative to today. Still, the strongest lingering belt of low-level southeasterlies should persist through Friday morning into the afternoon to the east, centered on the TN Valley. This should yield moderate SRH coincident with the northern extent of weak surface-based instability from central AL/far western GA northward into Middle TN. This corridor will likely be narrow at any one time and steadily shift east through the day. A drier air mass with veered low-level winds is expected to its west, and cooler surface temps beneath pervasive cloudiness should occur to its northeast. A couple brief tornadoes will be possible, mainly from mid-morning into the afternoon. Low-level winds will diminish with southern extent to the FL Panhandle, but moderate mid-level southwesterlies should yield adequate deep-layer shear for transient mid-level rotation. Modest boundary-layer heating of a residual tropical air mass should occur within a corridor ahead of an occluded surface front. Locally strong gusts capable of sporadic tree damage remain possible. ..Grams.. 09/12/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1235 AM CDT Thu Sep 12 2024 Valid 131200Z - 141200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS IN A PART OF THE TN VALLEY TO THE FL PANHANDLE... ...SUMMARY... A couple brief tornadoes and locally damaging winds are possible across a part of the Southeast on Friday morning into the afternoon. ...Southeast... The remnants of TC Francine are expected to decay in place near the AR/TN/MO border vicinity on Friday, with greater weakening of low-level winds relative to today. Still, the strongest lingering belt of low-level southeasterlies should persist through Friday morning into the afternoon to the east, centered on the TN Valley. This should yield moderate SRH coincident with the northern extent of weak surface-based instability from central AL/far western GA northward into Middle TN. This corridor will likely be narrow at any one time and steadily shift east through the day. A drier air mass with veered low-level winds is expected to its west, and cooler surface temps beneath pervasive cloudiness should occur to its northeast. A couple brief tornadoes will be possible, mainly from mid-morning into the afternoon. Low-level winds will diminish with southern extent to the FL Panhandle, but moderate mid-level southwesterlies should yield adequate deep-layer shear for transient mid-level rotation. Modest boundary-layer heating of a residual tropical air mass should occur within a corridor ahead of an occluded surface front. Locally strong gusts capable of sporadic tree damage remain possible. ..Grams.. 09/12/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1235 AM CDT Thu Sep 12 2024 Valid 131200Z - 141200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS IN A PART OF THE TN VALLEY TO THE FL PANHANDLE... ...SUMMARY... A couple brief tornadoes and locally damaging winds are possible across a part of the Southeast on Friday morning into the afternoon. ...Southeast... The remnants of TC Francine are expected to decay in place near the AR/TN/MO border vicinity on Friday, with greater weakening of low-level winds relative to today. Still, the strongest lingering belt of low-level southeasterlies should persist through Friday morning into the afternoon to the east, centered on the TN Valley. This should yield moderate SRH coincident with the northern extent of weak surface-based instability from central AL/far western GA northward into Middle TN. This corridor will likely be narrow at any one time and steadily shift east through the day. A drier air mass with veered low-level winds is expected to its west, and cooler surface temps beneath pervasive cloudiness should occur to its northeast. A couple brief tornadoes will be possible, mainly from mid-morning into the afternoon. Low-level winds will diminish with southern extent to the FL Panhandle, but moderate mid-level southwesterlies should yield adequate deep-layer shear for transient mid-level rotation. Modest boundary-layer heating of a residual tropical air mass should occur within a corridor ahead of an occluded surface front. Locally strong gusts capable of sporadic tree damage remain possible. ..Grams.. 09/12/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1235 AM CDT Thu Sep 12 2024 Valid 131200Z - 141200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS IN A PART OF THE TN VALLEY TO THE FL PANHANDLE... ...SUMMARY... A couple brief tornadoes and locally damaging winds are possible across a part of the Southeast on Friday morning into the afternoon. ...Southeast... The remnants of TC Francine are expected to decay in place near the AR/TN/MO border vicinity on Friday, with greater weakening of low-level winds relative to today. Still, the strongest lingering belt of low-level southeasterlies should persist through Friday morning into the afternoon to the east, centered on the TN Valley. This should yield moderate SRH coincident with the northern extent of weak surface-based instability from central AL/far western GA northward into Middle TN. This corridor will likely be narrow at any one time and steadily shift east through the day. A drier air mass with veered low-level winds is expected to its west, and cooler surface temps beneath pervasive cloudiness should occur to its northeast. A couple brief tornadoes will be possible, mainly from mid-morning into the afternoon. Low-level winds will diminish with southern extent to the FL Panhandle, but moderate mid-level southwesterlies should yield adequate deep-layer shear for transient mid-level rotation. Modest boundary-layer heating of a residual tropical air mass should occur within a corridor ahead of an occluded surface front. Locally strong gusts capable of sporadic tree damage remain possible. ..Grams.. 09/12/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1235 AM CDT Thu Sep 12 2024 Valid 131200Z - 141200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS IN A PART OF THE TN VALLEY TO THE FL PANHANDLE... ...SUMMARY... A couple brief tornadoes and locally damaging winds are possible across a part of the Southeast on Friday morning into the afternoon. ...Southeast... The remnants of TC Francine are expected to decay in place near the AR/TN/MO border vicinity on Friday, with greater weakening of low-level winds relative to today. Still, the strongest lingering belt of low-level southeasterlies should persist through Friday morning into the afternoon to the east, centered on the TN Valley. This should yield moderate SRH coincident with the northern extent of weak surface-based instability from central AL/far western GA northward into Middle TN. This corridor will likely be narrow at any one time and steadily shift east through the day. A drier air mass with veered low-level winds is expected to its west, and cooler surface temps beneath pervasive cloudiness should occur to its northeast. A couple brief tornadoes will be possible, mainly from mid-morning into the afternoon. Low-level winds will diminish with southern extent to the FL Panhandle, but moderate mid-level southwesterlies should yield adequate deep-layer shear for transient mid-level rotation. Modest boundary-layer heating of a residual tropical air mass should occur within a corridor ahead of an occluded surface front. Locally strong gusts capable of sporadic tree damage remain possible. ..Grams.. 09/12/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1243 AM CDT Thu Sep 12 2024 Valid 121200Z - 131200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS IN ASSOCIATION WITH TS FRANCINE AND OVER THE EASTERN MONTANA REGION... ...SUMMARY... A few tornadoes are possible today, mainly in the morning and afternoon from the Florida Panhandle to north-central Alabama. Scattered large hail and severe gusts are expected across the eastern Montana vicinity during the afternoon to early evening. ...Tropical Storm Francine... TS Francine continues its slow drift inland, and is expected to progress across southern/central MS to near Memphis by the end of the period. Strong low-level shear will spread/develop north, to the immediate north-east of the center of circulation. As is typical, poor lapse rates will limit buoyancy today, and latest model guidance suggests only a narrow corridor of weak-modest 0-3km lapse rates, primarily across southwestern into west-central AL. Robust, long-lived supercells have struggled to develop with this system, and forecast thermodynamic profiles are not particularly impressive. Even so, scattered lightning is noted with deeper updrafts offshore, along with a few supercells. This activity will spread inland later this morning and there remains some concern for a few tornadoes where boundary-layer destabilization is maximized. ...Eastern Montana Region... Strong upper trough has progressed into the northern Intermountain region, from western ID into NV. This trough will advance into the northern Rockies later today as a 500mb speed max translates across UT into eastern WY/MT. This evolution will warrant a cold front surging into eastern MT/northwest WY by 18z. Greatest boundary-layer heating will initially be across eastern WY, but significant surface heating across eastern MT should lead to steep 0-3km lapse rates and convective temperatures will likely be breached across northern WY/southern MT by 20z. Deep convection should readily develop over the Big Horn Mountains/surrounding higher terrain as the left-exit region of the 500mb speed max approaches. Latest HREF guidance strongly favors robust convection evolving by mid afternoon, with several long-lived supercells depicted in most members. Forecast soundings favor sustained rotating updrafts and high-based convection should generate strong winds, and perhaps large hail. While PWs are seasonally low, ample buoyancy will likely exist for allowing this activity to spread into western ND later in the evening, especially given the strengthening LLJ across this portion of the Dakotas after sunset. ..Darrow/Lyons.. 09/12/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1243 AM CDT Thu Sep 12 2024 Valid 121200Z - 131200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS IN ASSOCIATION WITH TS FRANCINE AND OVER THE EASTERN MONTANA REGION... ...SUMMARY... A few tornadoes are possible today, mainly in the morning and afternoon from the Florida Panhandle to north-central Alabama. Scattered large hail and severe gusts are expected across the eastern Montana vicinity during the afternoon to early evening. ...Tropical Storm Francine... TS Francine continues its slow drift inland, and is expected to progress across southern/central MS to near Memphis by the end of the period. Strong low-level shear will spread/develop north, to the immediate north-east of the center of circulation. As is typical, poor lapse rates will limit buoyancy today, and latest model guidance suggests only a narrow corridor of weak-modest 0-3km lapse rates, primarily across southwestern into west-central AL. Robust, long-lived supercells have struggled to develop with this system, and forecast thermodynamic profiles are not particularly impressive. Even so, scattered lightning is noted with deeper updrafts offshore, along with a few supercells. This activity will spread inland later this morning and there remains some concern for a few tornadoes where boundary-layer destabilization is maximized. ...Eastern Montana Region... Strong upper trough has progressed into the northern Intermountain region, from western ID into NV. This trough will advance into the northern Rockies later today as a 500mb speed max translates across UT into eastern WY/MT. This evolution will warrant a cold front surging into eastern MT/northwest WY by 18z. Greatest boundary-layer heating will initially be across eastern WY, but significant surface heating across eastern MT should lead to steep 0-3km lapse rates and convective temperatures will likely be breached across northern WY/southern MT by 20z. Deep convection should readily develop over the Big Horn Mountains/surrounding higher terrain as the left-exit region of the 500mb speed max approaches. Latest HREF guidance strongly favors robust convection evolving by mid afternoon, with several long-lived supercells depicted in most members. Forecast soundings favor sustained rotating updrafts and high-based convection should generate strong winds, and perhaps large hail. While PWs are seasonally low, ample buoyancy will likely exist for allowing this activity to spread into western ND later in the evening, especially given the strengthening LLJ across this portion of the Dakotas after sunset. ..Darrow/Lyons.. 09/12/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1243 AM CDT Thu Sep 12 2024 Valid 121200Z - 131200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS IN ASSOCIATION WITH TS FRANCINE AND OVER THE EASTERN MONTANA REGION... ...SUMMARY... A few tornadoes are possible today, mainly in the morning and afternoon from the Florida Panhandle to north-central Alabama. Scattered large hail and severe gusts are expected across the eastern Montana vicinity during the afternoon to early evening. ...Tropical Storm Francine... TS Francine continues its slow drift inland, and is expected to progress across southern/central MS to near Memphis by the end of the period. Strong low-level shear will spread/develop north, to the immediate north-east of the center of circulation. As is typical, poor lapse rates will limit buoyancy today, and latest model guidance suggests only a narrow corridor of weak-modest 0-3km lapse rates, primarily across southwestern into west-central AL. Robust, long-lived supercells have struggled to develop with this system, and forecast thermodynamic profiles are not particularly impressive. Even so, scattered lightning is noted with deeper updrafts offshore, along with a few supercells. This activity will spread inland later this morning and there remains some concern for a few tornadoes where boundary-layer destabilization is maximized. ...Eastern Montana Region... Strong upper trough has progressed into the northern Intermountain region, from western ID into NV. This trough will advance into the northern Rockies later today as a 500mb speed max translates across UT into eastern WY/MT. This evolution will warrant a cold front surging into eastern MT/northwest WY by 18z. Greatest boundary-layer heating will initially be across eastern WY, but significant surface heating across eastern MT should lead to steep 0-3km lapse rates and convective temperatures will likely be breached across northern WY/southern MT by 20z. Deep convection should readily develop over the Big Horn Mountains/surrounding higher terrain as the left-exit region of the 500mb speed max approaches. Latest HREF guidance strongly favors robust convection evolving by mid afternoon, with several long-lived supercells depicted in most members. Forecast soundings favor sustained rotating updrafts and high-based convection should generate strong winds, and perhaps large hail. While PWs are seasonally low, ample buoyancy will likely exist for allowing this activity to spread into western ND later in the evening, especially given the strengthening LLJ across this portion of the Dakotas after sunset. ..Darrow/Lyons.. 09/12/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1243 AM CDT Thu Sep 12 2024 Valid 121200Z - 131200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS IN ASSOCIATION WITH TS FRANCINE AND OVER THE EASTERN MONTANA REGION... ...SUMMARY... A few tornadoes are possible today, mainly in the morning and afternoon from the Florida Panhandle to north-central Alabama. Scattered large hail and severe gusts are expected across the eastern Montana vicinity during the afternoon to early evening. ...Tropical Storm Francine... TS Francine continues its slow drift inland, and is expected to progress across southern/central MS to near Memphis by the end of the period. Strong low-level shear will spread/develop north, to the immediate north-east of the center of circulation. As is typical, poor lapse rates will limit buoyancy today, and latest model guidance suggests only a narrow corridor of weak-modest 0-3km lapse rates, primarily across southwestern into west-central AL. Robust, long-lived supercells have struggled to develop with this system, and forecast thermodynamic profiles are not particularly impressive. Even so, scattered lightning is noted with deeper updrafts offshore, along with a few supercells. This activity will spread inland later this morning and there remains some concern for a few tornadoes where boundary-layer destabilization is maximized. ...Eastern Montana Region... Strong upper trough has progressed into the northern Intermountain region, from western ID into NV. This trough will advance into the northern Rockies later today as a 500mb speed max translates across UT into eastern WY/MT. This evolution will warrant a cold front surging into eastern MT/northwest WY by 18z. Greatest boundary-layer heating will initially be across eastern WY, but significant surface heating across eastern MT should lead to steep 0-3km lapse rates and convective temperatures will likely be breached across northern WY/southern MT by 20z. Deep convection should readily develop over the Big Horn Mountains/surrounding higher terrain as the left-exit region of the 500mb speed max approaches. Latest HREF guidance strongly favors robust convection evolving by mid afternoon, with several long-lived supercells depicted in most members. Forecast soundings favor sustained rotating updrafts and high-based convection should generate strong winds, and perhaps large hail. While PWs are seasonally low, ample buoyancy will likely exist for allowing this activity to spread into western ND later in the evening, especially given the strengthening LLJ across this portion of the Dakotas after sunset. ..Darrow/Lyons.. 09/12/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1243 AM CDT Thu Sep 12 2024 Valid 121200Z - 131200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS IN ASSOCIATION WITH TS FRANCINE AND OVER THE EASTERN MONTANA REGION... ...SUMMARY... A few tornadoes are possible today, mainly in the morning and afternoon from the Florida Panhandle to north-central Alabama. Scattered large hail and severe gusts are expected across the eastern Montana vicinity during the afternoon to early evening. ...Tropical Storm Francine... TS Francine continues its slow drift inland, and is expected to progress across southern/central MS to near Memphis by the end of the period. Strong low-level shear will spread/develop north, to the immediate north-east of the center of circulation. As is typical, poor lapse rates will limit buoyancy today, and latest model guidance suggests only a narrow corridor of weak-modest 0-3km lapse rates, primarily across southwestern into west-central AL. Robust, long-lived supercells have struggled to develop with this system, and forecast thermodynamic profiles are not particularly impressive. Even so, scattered lightning is noted with deeper updrafts offshore, along with a few supercells. This activity will spread inland later this morning and there remains some concern for a few tornadoes where boundary-layer destabilization is maximized. ...Eastern Montana Region... Strong upper trough has progressed into the northern Intermountain region, from western ID into NV. This trough will advance into the northern Rockies later today as a 500mb speed max translates across UT into eastern WY/MT. This evolution will warrant a cold front surging into eastern MT/northwest WY by 18z. Greatest boundary-layer heating will initially be across eastern WY, but significant surface heating across eastern MT should lead to steep 0-3km lapse rates and convective temperatures will likely be breached across northern WY/southern MT by 20z. Deep convection should readily develop over the Big Horn Mountains/surrounding higher terrain as the left-exit region of the 500mb speed max approaches. Latest HREF guidance strongly favors robust convection evolving by mid afternoon, with several long-lived supercells depicted in most members. Forecast soundings favor sustained rotating updrafts and high-based convection should generate strong winds, and perhaps large hail. While PWs are seasonally low, ample buoyancy will likely exist for allowing this activity to spread into western ND later in the evening, especially given the strengthening LLJ across this portion of the Dakotas after sunset. ..Darrow/Lyons.. 09/12/2024 Read more