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SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1141 AM CDT Thu Sep 12 2024 Valid 121700Z - 131200Z ...CRITICAL FIRE WEATHER AREA FOR MUCH OF THE CENTRAL AND NORTHERN HIGH PLAINS... No changes to the ongoing forecast. Locally elevated conditions are possible as northerly/northeasterly winds continue in the Sacramento Valley into the afternoon. Additionally, locally elevated conditions are also possible in parts of the Upper Midwest. These conditions will be both marginal and brief and no highlights will be added. ..Wendt.. 09/12/2024 .PREV DISCUSSION... /ISSUED 0135 AM CDT Thu Sep 12 2024/ ...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. ...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 1141 AM CDT Thu Sep 12 2024 Valid 121700Z - 131200Z ...CRITICAL FIRE WEATHER AREA FOR MUCH OF THE CENTRAL AND NORTHERN HIGH PLAINS... No changes to the ongoing forecast. Locally elevated conditions are possible as northerly/northeasterly winds continue in the Sacramento Valley into the afternoon. Additionally, locally elevated conditions are also possible in parts of the Upper Midwest. These conditions will be both marginal and brief and no highlights will be added. ..Wendt.. 09/12/2024 .PREV DISCUSSION... /ISSUED 0135 AM CDT Thu Sep 12 2024/ ...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. ...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 1141 AM CDT Thu Sep 12 2024 Valid 121700Z - 131200Z ...CRITICAL FIRE WEATHER AREA FOR MUCH OF THE CENTRAL AND NORTHERN HIGH PLAINS... No changes to the ongoing forecast. Locally elevated conditions are possible as northerly/northeasterly winds continue in the Sacramento Valley into the afternoon. Additionally, locally elevated conditions are also possible in parts of the Upper Midwest. These conditions will be both marginal and brief and no highlights will be added. ..Wendt.. 09/12/2024 .PREV DISCUSSION... /ISSUED 0135 AM CDT Thu Sep 12 2024/ ...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. ...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 1141 AM CDT Thu Sep 12 2024 Valid 121700Z - 131200Z ...CRITICAL FIRE WEATHER AREA FOR MUCH OF THE CENTRAL AND NORTHERN HIGH PLAINS... No changes to the ongoing forecast. Locally elevated conditions are possible as northerly/northeasterly winds continue in the Sacramento Valley into the afternoon. Additionally, locally elevated conditions are also possible in parts of the Upper Midwest. These conditions will be both marginal and brief and no highlights will be added. ..Wendt.. 09/12/2024 .PREV DISCUSSION... /ISSUED 0135 AM CDT Thu Sep 12 2024/ ...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. ...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 1141 AM CDT Thu Sep 12 2024 Valid 121700Z - 131200Z ...CRITICAL FIRE WEATHER AREA FOR MUCH OF THE CENTRAL AND NORTHERN HIGH PLAINS... No changes to the ongoing forecast. Locally elevated conditions are possible as northerly/northeasterly winds continue in the Sacramento Valley into the afternoon. Additionally, locally elevated conditions are also possible in parts of the Upper Midwest. These conditions will be both marginal and brief and no highlights will be added. ..Wendt.. 09/12/2024 .PREV DISCUSSION... /ISSUED 0135 AM CDT Thu Sep 12 2024/ ...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. ...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 1141 AM CDT Thu Sep 12 2024 Valid 121700Z - 131200Z ...CRITICAL FIRE WEATHER AREA FOR MUCH OF THE CENTRAL AND NORTHERN HIGH PLAINS... No changes to the ongoing forecast. Locally elevated conditions are possible as northerly/northeasterly winds continue in the Sacramento Valley into the afternoon. Additionally, locally elevated conditions are also possible in parts of the Upper Midwest. These conditions will be both marginal and brief and no highlights will be added. ..Wendt.. 09/12/2024 .PREV DISCUSSION... /ISSUED 0135 AM CDT Thu Sep 12 2024/ ...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. ...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 1141 AM CDT Thu Sep 12 2024 Valid 121700Z - 131200Z ...CRITICAL FIRE WEATHER AREA FOR MUCH OF THE CENTRAL AND NORTHERN HIGH PLAINS... No changes to the ongoing forecast. Locally elevated conditions are possible as northerly/northeasterly winds continue in the Sacramento Valley into the afternoon. Additionally, locally elevated conditions are also possible in parts of the Upper Midwest. These conditions will be both marginal and brief and no highlights will be added. ..Wendt.. 09/12/2024 .PREV DISCUSSION... /ISSUED 0135 AM CDT Thu Sep 12 2024/ ...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. ...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 1141 AM CDT Thu Sep 12 2024 Valid 121700Z - 131200Z ...CRITICAL FIRE WEATHER AREA FOR MUCH OF THE CENTRAL AND NORTHERN HIGH PLAINS... No changes to the ongoing forecast. Locally elevated conditions are possible as northerly/northeasterly winds continue in the Sacramento Valley into the afternoon. Additionally, locally elevated conditions are also possible in parts of the Upper Midwest. These conditions will be both marginal and brief and no highlights will be added. ..Wendt.. 09/12/2024 .PREV DISCUSSION... /ISSUED 0135 AM CDT Thu Sep 12 2024/ ...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. ...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 1141 AM CDT Thu Sep 12 2024 Valid 121700Z - 131200Z ...CRITICAL FIRE WEATHER AREA FOR MUCH OF THE CENTRAL AND NORTHERN HIGH PLAINS... No changes to the ongoing forecast. Locally elevated conditions are possible as northerly/northeasterly winds continue in the Sacramento Valley into the afternoon. Additionally, locally elevated conditions are also possible in parts of the Upper Midwest. These conditions will be both marginal and brief and no highlights will be added. ..Wendt.. 09/12/2024 .PREV DISCUSSION... /ISSUED 0135 AM CDT Thu Sep 12 2024/ ...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. ...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 1141 AM CDT Thu Sep 12 2024 Valid 121700Z - 131200Z ...CRITICAL FIRE WEATHER AREA FOR MUCH OF THE CENTRAL AND NORTHERN HIGH PLAINS... No changes to the ongoing forecast. Locally elevated conditions are possible as northerly/northeasterly winds continue in the Sacramento Valley into the afternoon. Additionally, locally elevated conditions are also possible in parts of the Upper Midwest. These conditions will be both marginal and brief and no highlights will be added. ..Wendt.. 09/12/2024 .PREV DISCUSSION... /ISSUED 0135 AM CDT Thu Sep 12 2024/ ...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. ...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 1141 AM CDT Thu Sep 12 2024 Valid 121700Z - 131200Z ...CRITICAL FIRE WEATHER AREA FOR MUCH OF THE CENTRAL AND NORTHERN HIGH PLAINS... No changes to the ongoing forecast. Locally elevated conditions are possible as northerly/northeasterly winds continue in the Sacramento Valley into the afternoon. Additionally, locally elevated conditions are also possible in parts of the Upper Midwest. These conditions will be both marginal and brief and no highlights will be added. ..Wendt.. 09/12/2024 .PREV DISCUSSION... /ISSUED 0135 AM CDT Thu Sep 12 2024/ ...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. ...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 1141 AM CDT Thu Sep 12 2024 Valid 121700Z - 131200Z ...CRITICAL FIRE WEATHER AREA FOR MUCH OF THE CENTRAL AND NORTHERN HIGH PLAINS... No changes to the ongoing forecast. Locally elevated conditions are possible as northerly/northeasterly winds continue in the Sacramento Valley into the afternoon. Additionally, locally elevated conditions are also possible in parts of the Upper Midwest. These conditions will be both marginal and brief and no highlights will be added. ..Wendt.. 09/12/2024 .PREV DISCUSSION... /ISSUED 0135 AM CDT Thu Sep 12 2024/ ...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. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1138 AM CDT Thu Sep 12 2024 Valid 121630Z - 131200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS EASTERN MONTANA AND WESTERN NORTH DAKOTA... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE SOUTHEAST... ...SUMMARY... A few tornadoes are possible today from northern Florida to north-central Alabama. Scattered large hail and severe wind gusts (some significant) are expected across eastern Montana into western North Dakota this afternoon through early/mid-evening. ...Northern Great Plains including eastern MT/western ND... Have upgraded portions of eastern Montana and western North Dakota for a heightened/focused potential for severe storms capable of large hail and potentially significant-caliber severe wind gusts later this afternoon through around mid-evening. Strong-severe thunderstorms are expected, along and behind the front, as early as early/mid-afternoon, with the most probable severe potential arising from activity moving north-northeastward from northern Wyoming and far southern Montana. High-based supercells and multicells are possible, offering large hail and severe wind gusts. These storms may aggregate and grow upscale into one or two bowing clusters, racing north-northeastward accompanied by a swath of better-organized, potentially significant (65+ kt) gust potential. This scenario will be supported by trough-related cooling mid-level temperatures and steep low/mid-level rates atop a modestly moist boundary layer, as the exit region of a strong upper-level jet overspreads the region. MLCAPE of 500-1200 J/kg and 45-55 kt effective-shear magnitudes will support the severe potential including fast-moving and relatively long-lived storms into western North Dakota. The near-surface airmass over the central Dakotas should stabilize with time and eastward extent tonight, limiting duration and eastward shift of the threat. ...Southeast... Current Tropical Depression Francine is forecast to continue moving generally northward over Mississippi, and to lose definition as it interacts more closely with the mid/upper-level low. Associated deep-layer winds will continue to weaken, but low-level shear will remain favorable through most of the day, well to the east-southeast of its center. A destabilizing airmass along and south of the warm/marine front will support a continued, slow inland shift of supercell potential amid enlarged hodographs. The favorable environment will be bounded on the west by a dry slot and veering low-level flow, on the northeast by more stable air in heavy precip north of the front, and on the south by a gradual weakening of low-level winds and shear as the cyclone center pulls away and fills. In the favorable corridor, where inflow parcels are surface-based, expect effective SRH in the 200-500 m2/s2 range, very rich moisture, low LCL, and weak MLCINH. In the shorter term, a tornado threat may persist this afternoon across northern Florida, while potentially increasing later this afternoon through early evening near the warm front across southern into central Alabama. ..Guyer/Jirak.. 09/12/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1138 AM CDT Thu Sep 12 2024 Valid 121630Z - 131200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS EASTERN MONTANA AND WESTERN NORTH DAKOTA... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE SOUTHEAST... ...SUMMARY... A few tornadoes are possible today from northern Florida to north-central Alabama. Scattered large hail and severe wind gusts (some significant) are expected across eastern Montana into western North Dakota this afternoon through early/mid-evening. ...Northern Great Plains including eastern MT/western ND... Have upgraded portions of eastern Montana and western North Dakota for a heightened/focused potential for severe storms capable of large hail and potentially significant-caliber severe wind gusts later this afternoon through around mid-evening. Strong-severe thunderstorms are expected, along and behind the front, as early as early/mid-afternoon, with the most probable severe potential arising from activity moving north-northeastward from northern Wyoming and far southern Montana. High-based supercells and multicells are possible, offering large hail and severe wind gusts. These storms may aggregate and grow upscale into one or two bowing clusters, racing north-northeastward accompanied by a swath of better-organized, potentially significant (65+ kt) gust potential. This scenario will be supported by trough-related cooling mid-level temperatures and steep low/mid-level rates atop a modestly moist boundary layer, as the exit region of a strong upper-level jet overspreads the region. MLCAPE of 500-1200 J/kg and 45-55 kt effective-shear magnitudes will support the severe potential including fast-moving and relatively long-lived storms into western North Dakota. The near-surface airmass over the central Dakotas should stabilize with time and eastward extent tonight, limiting duration and eastward shift of the threat. ...Southeast... Current Tropical Depression Francine is forecast to continue moving generally northward over Mississippi, and to lose definition as it interacts more closely with the mid/upper-level low. Associated deep-layer winds will continue to weaken, but low-level shear will remain favorable through most of the day, well to the east-southeast of its center. A destabilizing airmass along and south of the warm/marine front will support a continued, slow inland shift of supercell potential amid enlarged hodographs. The favorable environment will be bounded on the west by a dry slot and veering low-level flow, on the northeast by more stable air in heavy precip north of the front, and on the south by a gradual weakening of low-level winds and shear as the cyclone center pulls away and fills. In the favorable corridor, where inflow parcels are surface-based, expect effective SRH in the 200-500 m2/s2 range, very rich moisture, low LCL, and weak MLCINH. In the shorter term, a tornado threat may persist this afternoon across northern Florida, while potentially increasing later this afternoon through early evening near the warm front across southern into central Alabama. ..Guyer/Jirak.. 09/12/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1138 AM CDT Thu Sep 12 2024 Valid 121630Z - 131200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS EASTERN MONTANA AND WESTERN NORTH DAKOTA... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE SOUTHEAST... ...SUMMARY... A few tornadoes are possible today from northern Florida to north-central Alabama. Scattered large hail and severe wind gusts (some significant) are expected across eastern Montana into western North Dakota this afternoon through early/mid-evening. ...Northern Great Plains including eastern MT/western ND... Have upgraded portions of eastern Montana and western North Dakota for a heightened/focused potential for severe storms capable of large hail and potentially significant-caliber severe wind gusts later this afternoon through around mid-evening. Strong-severe thunderstorms are expected, along and behind the front, as early as early/mid-afternoon, with the most probable severe potential arising from activity moving north-northeastward from northern Wyoming and far southern Montana. High-based supercells and multicells are possible, offering large hail and severe wind gusts. These storms may aggregate and grow upscale into one or two bowing clusters, racing north-northeastward accompanied by a swath of better-organized, potentially significant (65+ kt) gust potential. This scenario will be supported by trough-related cooling mid-level temperatures and steep low/mid-level rates atop a modestly moist boundary layer, as the exit region of a strong upper-level jet overspreads the region. MLCAPE of 500-1200 J/kg and 45-55 kt effective-shear magnitudes will support the severe potential including fast-moving and relatively long-lived storms into western North Dakota. The near-surface airmass over the central Dakotas should stabilize with time and eastward extent tonight, limiting duration and eastward shift of the threat. ...Southeast... Current Tropical Depression Francine is forecast to continue moving generally northward over Mississippi, and to lose definition as it interacts more closely with the mid/upper-level low. Associated deep-layer winds will continue to weaken, but low-level shear will remain favorable through most of the day, well to the east-southeast of its center. A destabilizing airmass along and south of the warm/marine front will support a continued, slow inland shift of supercell potential amid enlarged hodographs. The favorable environment will be bounded on the west by a dry slot and veering low-level flow, on the northeast by more stable air in heavy precip north of the front, and on the south by a gradual weakening of low-level winds and shear as the cyclone center pulls away and fills. In the favorable corridor, where inflow parcels are surface-based, expect effective SRH in the 200-500 m2/s2 range, very rich moisture, low LCL, and weak MLCINH. In the shorter term, a tornado threat may persist this afternoon across northern Florida, while potentially increasing later this afternoon through early evening near the warm front across southern into central Alabama. ..Guyer/Jirak.. 09/12/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1138 AM CDT Thu Sep 12 2024 Valid 121630Z - 131200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS EASTERN MONTANA AND WESTERN NORTH DAKOTA... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE SOUTHEAST... ...SUMMARY... A few tornadoes are possible today from northern Florida to north-central Alabama. Scattered large hail and severe wind gusts (some significant) are expected across eastern Montana into western North Dakota this afternoon through early/mid-evening. ...Northern Great Plains including eastern MT/western ND... Have upgraded portions of eastern Montana and western North Dakota for a heightened/focused potential for severe storms capable of large hail and potentially significant-caliber severe wind gusts later this afternoon through around mid-evening. Strong-severe thunderstorms are expected, along and behind the front, as early as early/mid-afternoon, with the most probable severe potential arising from activity moving north-northeastward from northern Wyoming and far southern Montana. High-based supercells and multicells are possible, offering large hail and severe wind gusts. These storms may aggregate and grow upscale into one or two bowing clusters, racing north-northeastward accompanied by a swath of better-organized, potentially significant (65+ kt) gust potential. This scenario will be supported by trough-related cooling mid-level temperatures and steep low/mid-level rates atop a modestly moist boundary layer, as the exit region of a strong upper-level jet overspreads the region. MLCAPE of 500-1200 J/kg and 45-55 kt effective-shear magnitudes will support the severe potential including fast-moving and relatively long-lived storms into western North Dakota. The near-surface airmass over the central Dakotas should stabilize with time and eastward extent tonight, limiting duration and eastward shift of the threat. ...Southeast... Current Tropical Depression Francine is forecast to continue moving generally northward over Mississippi, and to lose definition as it interacts more closely with the mid/upper-level low. Associated deep-layer winds will continue to weaken, but low-level shear will remain favorable through most of the day, well to the east-southeast of its center. A destabilizing airmass along and south of the warm/marine front will support a continued, slow inland shift of supercell potential amid enlarged hodographs. The favorable environment will be bounded on the west by a dry slot and veering low-level flow, on the northeast by more stable air in heavy precip north of the front, and on the south by a gradual weakening of low-level winds and shear as the cyclone center pulls away and fills. In the favorable corridor, where inflow parcels are surface-based, expect effective SRH in the 200-500 m2/s2 range, very rich moisture, low LCL, and weak MLCINH. In the shorter term, a tornado threat may persist this afternoon across northern Florida, while potentially increasing later this afternoon through early evening near the warm front across southern into central Alabama. ..Guyer/Jirak.. 09/12/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1138 AM CDT Thu Sep 12 2024 Valid 121630Z - 131200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS EASTERN MONTANA AND WESTERN NORTH DAKOTA... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE SOUTHEAST... ...SUMMARY... A few tornadoes are possible today from northern Florida to north-central Alabama. Scattered large hail and severe wind gusts (some significant) are expected across eastern Montana into western North Dakota this afternoon through early/mid-evening. ...Northern Great Plains including eastern MT/western ND... Have upgraded portions of eastern Montana and western North Dakota for a heightened/focused potential for severe storms capable of large hail and potentially significant-caliber severe wind gusts later this afternoon through around mid-evening. Strong-severe thunderstorms are expected, along and behind the front, as early as early/mid-afternoon, with the most probable severe potential arising from activity moving north-northeastward from northern Wyoming and far southern Montana. High-based supercells and multicells are possible, offering large hail and severe wind gusts. These storms may aggregate and grow upscale into one or two bowing clusters, racing north-northeastward accompanied by a swath of better-organized, potentially significant (65+ kt) gust potential. This scenario will be supported by trough-related cooling mid-level temperatures and steep low/mid-level rates atop a modestly moist boundary layer, as the exit region of a strong upper-level jet overspreads the region. MLCAPE of 500-1200 J/kg and 45-55 kt effective-shear magnitudes will support the severe potential including fast-moving and relatively long-lived storms into western North Dakota. The near-surface airmass over the central Dakotas should stabilize with time and eastward extent tonight, limiting duration and eastward shift of the threat. ...Southeast... Current Tropical Depression Francine is forecast to continue moving generally northward over Mississippi, and to lose definition as it interacts more closely with the mid/upper-level low. Associated deep-layer winds will continue to weaken, but low-level shear will remain favorable through most of the day, well to the east-southeast of its center. A destabilizing airmass along and south of the warm/marine front will support a continued, slow inland shift of supercell potential amid enlarged hodographs. The favorable environment will be bounded on the west by a dry slot and veering low-level flow, on the northeast by more stable air in heavy precip north of the front, and on the south by a gradual weakening of low-level winds and shear as the cyclone center pulls away and fills. In the favorable corridor, where inflow parcels are surface-based, expect effective SRH in the 200-500 m2/s2 range, very rich moisture, low LCL, and weak MLCINH. In the shorter term, a tornado threat may persist this afternoon across northern Florida, while potentially increasing later this afternoon through early evening near the warm front across southern into central Alabama. ..Guyer/Jirak.. 09/12/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1138 AM CDT Thu Sep 12 2024 Valid 121630Z - 131200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS EASTERN MONTANA AND WESTERN NORTH DAKOTA... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE SOUTHEAST... ...SUMMARY... A few tornadoes are possible today from northern Florida to north-central Alabama. Scattered large hail and severe wind gusts (some significant) are expected across eastern Montana into western North Dakota this afternoon through early/mid-evening. ...Northern Great Plains including eastern MT/western ND... Have upgraded portions of eastern Montana and western North Dakota for a heightened/focused potential for severe storms capable of large hail and potentially significant-caliber severe wind gusts later this afternoon through around mid-evening. Strong-severe thunderstorms are expected, along and behind the front, as early as early/mid-afternoon, with the most probable severe potential arising from activity moving north-northeastward from northern Wyoming and far southern Montana. High-based supercells and multicells are possible, offering large hail and severe wind gusts. These storms may aggregate and grow upscale into one or two bowing clusters, racing north-northeastward accompanied by a swath of better-organized, potentially significant (65+ kt) gust potential. This scenario will be supported by trough-related cooling mid-level temperatures and steep low/mid-level rates atop a modestly moist boundary layer, as the exit region of a strong upper-level jet overspreads the region. MLCAPE of 500-1200 J/kg and 45-55 kt effective-shear magnitudes will support the severe potential including fast-moving and relatively long-lived storms into western North Dakota. The near-surface airmass over the central Dakotas should stabilize with time and eastward extent tonight, limiting duration and eastward shift of the threat. ...Southeast... Current Tropical Depression Francine is forecast to continue moving generally northward over Mississippi, and to lose definition as it interacts more closely with the mid/upper-level low. Associated deep-layer winds will continue to weaken, but low-level shear will remain favorable through most of the day, well to the east-southeast of its center. A destabilizing airmass along and south of the warm/marine front will support a continued, slow inland shift of supercell potential amid enlarged hodographs. The favorable environment will be bounded on the west by a dry slot and veering low-level flow, on the northeast by more stable air in heavy precip north of the front, and on the south by a gradual weakening of low-level winds and shear as the cyclone center pulls away and fills. In the favorable corridor, where inflow parcels are surface-based, expect effective SRH in the 200-500 m2/s2 range, very rich moisture, low LCL, and weak MLCINH. In the shorter term, a tornado threat may persist this afternoon across northern Florida, while potentially increasing later this afternoon through early evening near the warm front across southern into central Alabama. ..Guyer/Jirak.. 09/12/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1138 AM CDT Thu Sep 12 2024 Valid 121630Z - 131200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS EASTERN MONTANA AND WESTERN NORTH DAKOTA... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE SOUTHEAST... ...SUMMARY... A few tornadoes are possible today from northern Florida to north-central Alabama. Scattered large hail and severe wind gusts (some significant) are expected across eastern Montana into western North Dakota this afternoon through early/mid-evening. ...Northern Great Plains including eastern MT/western ND... Have upgraded portions of eastern Montana and western North Dakota for a heightened/focused potential for severe storms capable of large hail and potentially significant-caliber severe wind gusts later this afternoon through around mid-evening. Strong-severe thunderstorms are expected, along and behind the front, as early as early/mid-afternoon, with the most probable severe potential arising from activity moving north-northeastward from northern Wyoming and far southern Montana. High-based supercells and multicells are possible, offering large hail and severe wind gusts. These storms may aggregate and grow upscale into one or two bowing clusters, racing north-northeastward accompanied by a swath of better-organized, potentially significant (65+ kt) gust potential. This scenario will be supported by trough-related cooling mid-level temperatures and steep low/mid-level rates atop a modestly moist boundary layer, as the exit region of a strong upper-level jet overspreads the region. MLCAPE of 500-1200 J/kg and 45-55 kt effective-shear magnitudes will support the severe potential including fast-moving and relatively long-lived storms into western North Dakota. The near-surface airmass over the central Dakotas should stabilize with time and eastward extent tonight, limiting duration and eastward shift of the threat. ...Southeast... Current Tropical Depression Francine is forecast to continue moving generally northward over Mississippi, and to lose definition as it interacts more closely with the mid/upper-level low. Associated deep-layer winds will continue to weaken, but low-level shear will remain favorable through most of the day, well to the east-southeast of its center. A destabilizing airmass along and south of the warm/marine front will support a continued, slow inland shift of supercell potential amid enlarged hodographs. The favorable environment will be bounded on the west by a dry slot and veering low-level flow, on the northeast by more stable air in heavy precip north of the front, and on the south by a gradual weakening of low-level winds and shear as the cyclone center pulls away and fills. In the favorable corridor, where inflow parcels are surface-based, expect effective SRH in the 200-500 m2/s2 range, very rich moisture, low LCL, and weak MLCINH. In the shorter term, a tornado threat may persist this afternoon across northern Florida, while potentially increasing later this afternoon through early evening near the warm front across southern into central Alabama. ..Guyer/Jirak.. 09/12/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1138 AM CDT Thu Sep 12 2024 Valid 121630Z - 131200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS EASTERN MONTANA AND WESTERN NORTH DAKOTA... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE SOUTHEAST... ...SUMMARY... A few tornadoes are possible today from northern Florida to north-central Alabama. Scattered large hail and severe wind gusts (some significant) are expected across eastern Montana into western North Dakota this afternoon through early/mid-evening. ...Northern Great Plains including eastern MT/western ND... Have upgraded portions of eastern Montana and western North Dakota for a heightened/focused potential for severe storms capable of large hail and potentially significant-caliber severe wind gusts later this afternoon through around mid-evening. Strong-severe thunderstorms are expected, along and behind the front, as early as early/mid-afternoon, with the most probable severe potential arising from activity moving north-northeastward from northern Wyoming and far southern Montana. High-based supercells and multicells are possible, offering large hail and severe wind gusts. These storms may aggregate and grow upscale into one or two bowing clusters, racing north-northeastward accompanied by a swath of better-organized, potentially significant (65+ kt) gust potential. This scenario will be supported by trough-related cooling mid-level temperatures and steep low/mid-level rates atop a modestly moist boundary layer, as the exit region of a strong upper-level jet overspreads the region. MLCAPE of 500-1200 J/kg and 45-55 kt effective-shear magnitudes will support the severe potential including fast-moving and relatively long-lived storms into western North Dakota. The near-surface airmass over the central Dakotas should stabilize with time and eastward extent tonight, limiting duration and eastward shift of the threat. ...Southeast... Current Tropical Depression Francine is forecast to continue moving generally northward over Mississippi, and to lose definition as it interacts more closely with the mid/upper-level low. Associated deep-layer winds will continue to weaken, but low-level shear will remain favorable through most of the day, well to the east-southeast of its center. A destabilizing airmass along and south of the warm/marine front will support a continued, slow inland shift of supercell potential amid enlarged hodographs. The favorable environment will be bounded on the west by a dry slot and veering low-level flow, on the northeast by more stable air in heavy precip north of the front, and on the south by a gradual weakening of low-level winds and shear as the cyclone center pulls away and fills. In the favorable corridor, where inflow parcels are surface-based, expect effective SRH in the 200-500 m2/s2 range, very rich moisture, low LCL, and weak MLCINH. In the shorter term, a tornado threat may persist this afternoon across northern Florida, while potentially increasing later this afternoon through early evening near the warm front across southern into central Alabama. ..Guyer/Jirak.. 09/12/2024 Read more