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SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0258 PM CDT Thu Jun 19 2025 Valid 201200Z - 211200Z ...CRITICAL FIRE WEATHER AREA FOR MUCH OF THE GREAT BASIN INTO THE SOUTHWEST... ...Great Basin into the Southwest... A prominent low pressure system and associated 60-70 mph mid-level jet entering the northwestern U.S. will promote an expansive area of critical fire weather conditions across much of the Great Basin, northern Arizona and Four Corners area on Friday. The pronounced juxtaposition of a mid-level jet maxima, a deep and well-mixed boundary layer and surface relative humidity of 10 percent or below is expected across eastern Utah and western Colorado. The combination of sustained winds of 25-30 mph and very dry surface layer could yield locally extremely critical fire weather conditions across western portions of the Colorado Plateau Friday. ...Southern California into the San Joaquin Valley... Enhanced west-northwest flow and within a dry boundary layer will support an elevated fire weather threat mainly leeward of interior mountain ranges across Southern California Friday. Previous forecast (see below) remains on track. ..Williams.. 06/19/2025 .PREV DISCUSSION... /ISSUED 0209 AM CDT Thu Jun 19 2025/ ...Synopsis... A robust midlevel low will advance eastward across the Northwest during the day, while a swath of strong deep-layer westerly flow overspreads much of the western CONUS. In response, surface low pressure will deepen over the northern Great Basin, promoting a tightening pressure gradient across the Great Basin into the Southwest. This large-scale pattern will support widespread critical fire-weather conditions across the Great Basin into the Southwest. ...Great Basin into the Southwest... Strong diurnal heating amid a dry antecedent air mass will support another day of widespread single-digit RH across the region. At the same time, deep boundary-layer mixing into the strong flow aloft, combined with the tightening pressure gradient, will yield an expansive area of 20-30 mph sustained southwesterly surface winds. Given increasingly dry fuels across much of the Great Basin into the Southwest, widespread critical fire-weather conditions are expected, with localized extremely critical conditions possible over terrain-favored areas. ...Southern CA into the San Joaquin Valley... Deep-layer west-northwesterly flow on the upstream-side of the midlevel low will overspread central and southern CA, where the tight regional pressure gradient will be in place. This will promote breezy/gusty surface winds primarily over the interior mountains and valley -- where 15-20 percent RH is expected. These dry/breezy conditions will favor elevated fire-weather conditions where fuels are receptive to wildfire spread. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0258 PM CDT Thu Jun 19 2025 Valid 201200Z - 211200Z ...CRITICAL FIRE WEATHER AREA FOR MUCH OF THE GREAT BASIN INTO THE SOUTHWEST... ...Great Basin into the Southwest... A prominent low pressure system and associated 60-70 mph mid-level jet entering the northwestern U.S. will promote an expansive area of critical fire weather conditions across much of the Great Basin, northern Arizona and Four Corners area on Friday. The pronounced juxtaposition of a mid-level jet maxima, a deep and well-mixed boundary layer and surface relative humidity of 10 percent or below is expected across eastern Utah and western Colorado. The combination of sustained winds of 25-30 mph and very dry surface layer could yield locally extremely critical fire weather conditions across western portions of the Colorado Plateau Friday. ...Southern California into the San Joaquin Valley... Enhanced west-northwest flow and within a dry boundary layer will support an elevated fire weather threat mainly leeward of interior mountain ranges across Southern California Friday. Previous forecast (see below) remains on track. ..Williams.. 06/19/2025 .PREV DISCUSSION... /ISSUED 0209 AM CDT Thu Jun 19 2025/ ...Synopsis... A robust midlevel low will advance eastward across the Northwest during the day, while a swath of strong deep-layer westerly flow overspreads much of the western CONUS. In response, surface low pressure will deepen over the northern Great Basin, promoting a tightening pressure gradient across the Great Basin into the Southwest. This large-scale pattern will support widespread critical fire-weather conditions across the Great Basin into the Southwest. ...Great Basin into the Southwest... Strong diurnal heating amid a dry antecedent air mass will support another day of widespread single-digit RH across the region. At the same time, deep boundary-layer mixing into the strong flow aloft, combined with the tightening pressure gradient, will yield an expansive area of 20-30 mph sustained southwesterly surface winds. Given increasingly dry fuels across much of the Great Basin into the Southwest, widespread critical fire-weather conditions are expected, with localized extremely critical conditions possible over terrain-favored areas. ...Southern CA into the San Joaquin Valley... Deep-layer west-northwesterly flow on the upstream-side of the midlevel low will overspread central and southern CA, where the tight regional pressure gradient will be in place. This will promote breezy/gusty surface winds primarily over the interior mountains and valley -- where 15-20 percent RH is expected. These dry/breezy conditions will favor elevated fire-weather conditions where fuels are receptive to wildfire spread. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0258 PM CDT Thu Jun 19 2025 Valid 201200Z - 211200Z ...CRITICAL FIRE WEATHER AREA FOR MUCH OF THE GREAT BASIN INTO THE SOUTHWEST... ...Great Basin into the Southwest... A prominent low pressure system and associated 60-70 mph mid-level jet entering the northwestern U.S. will promote an expansive area of critical fire weather conditions across much of the Great Basin, northern Arizona and Four Corners area on Friday. The pronounced juxtaposition of a mid-level jet maxima, a deep and well-mixed boundary layer and surface relative humidity of 10 percent or below is expected across eastern Utah and western Colorado. The combination of sustained winds of 25-30 mph and very dry surface layer could yield locally extremely critical fire weather conditions across western portions of the Colorado Plateau Friday. ...Southern California into the San Joaquin Valley... Enhanced west-northwest flow and within a dry boundary layer will support an elevated fire weather threat mainly leeward of interior mountain ranges across Southern California Friday. Previous forecast (see below) remains on track. ..Williams.. 06/19/2025 .PREV DISCUSSION... /ISSUED 0209 AM CDT Thu Jun 19 2025/ ...Synopsis... A robust midlevel low will advance eastward across the Northwest during the day, while a swath of strong deep-layer westerly flow overspreads much of the western CONUS. In response, surface low pressure will deepen over the northern Great Basin, promoting a tightening pressure gradient across the Great Basin into the Southwest. This large-scale pattern will support widespread critical fire-weather conditions across the Great Basin into the Southwest. ...Great Basin into the Southwest... Strong diurnal heating amid a dry antecedent air mass will support another day of widespread single-digit RH across the region. At the same time, deep boundary-layer mixing into the strong flow aloft, combined with the tightening pressure gradient, will yield an expansive area of 20-30 mph sustained southwesterly surface winds. Given increasingly dry fuels across much of the Great Basin into the Southwest, widespread critical fire-weather conditions are expected, with localized extremely critical conditions possible over terrain-favored areas. ...Southern CA into the San Joaquin Valley... Deep-layer west-northwesterly flow on the upstream-side of the midlevel low will overspread central and southern CA, where the tight regional pressure gradient will be in place. This will promote breezy/gusty surface winds primarily over the interior mountains and valley -- where 15-20 percent RH is expected. These dry/breezy conditions will favor elevated fire-weather conditions where fuels are receptive to wildfire spread. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0258 PM CDT Thu Jun 19 2025 Valid 201200Z - 211200Z ...CRITICAL FIRE WEATHER AREA FOR MUCH OF THE GREAT BASIN INTO THE SOUTHWEST... ...Great Basin into the Southwest... A prominent low pressure system and associated 60-70 mph mid-level jet entering the northwestern U.S. will promote an expansive area of critical fire weather conditions across much of the Great Basin, northern Arizona and Four Corners area on Friday. The pronounced juxtaposition of a mid-level jet maxima, a deep and well-mixed boundary layer and surface relative humidity of 10 percent or below is expected across eastern Utah and western Colorado. The combination of sustained winds of 25-30 mph and very dry surface layer could yield locally extremely critical fire weather conditions across western portions of the Colorado Plateau Friday. ...Southern California into the San Joaquin Valley... Enhanced west-northwest flow and within a dry boundary layer will support an elevated fire weather threat mainly leeward of interior mountain ranges across Southern California Friday. Previous forecast (see below) remains on track. ..Williams.. 06/19/2025 .PREV DISCUSSION... /ISSUED 0209 AM CDT Thu Jun 19 2025/ ...Synopsis... A robust midlevel low will advance eastward across the Northwest during the day, while a swath of strong deep-layer westerly flow overspreads much of the western CONUS. In response, surface low pressure will deepen over the northern Great Basin, promoting a tightening pressure gradient across the Great Basin into the Southwest. This large-scale pattern will support widespread critical fire-weather conditions across the Great Basin into the Southwest. ...Great Basin into the Southwest... Strong diurnal heating amid a dry antecedent air mass will support another day of widespread single-digit RH across the region. At the same time, deep boundary-layer mixing into the strong flow aloft, combined with the tightening pressure gradient, will yield an expansive area of 20-30 mph sustained southwesterly surface winds. Given increasingly dry fuels across much of the Great Basin into the Southwest, widespread critical fire-weather conditions are expected, with localized extremely critical conditions possible over terrain-favored areas. ...Southern CA into the San Joaquin Valley... Deep-layer west-northwesterly flow on the upstream-side of the midlevel low will overspread central and southern CA, where the tight regional pressure gradient will be in place. This will promote breezy/gusty surface winds primarily over the interior mountains and valley -- where 15-20 percent RH is expected. These dry/breezy conditions will favor elevated fire-weather conditions where fuels are receptive to wildfire spread. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0258 PM CDT Thu Jun 19 2025 Valid 201200Z - 211200Z ...CRITICAL FIRE WEATHER AREA FOR MUCH OF THE GREAT BASIN INTO THE SOUTHWEST... ...Great Basin into the Southwest... A prominent low pressure system and associated 60-70 mph mid-level jet entering the northwestern U.S. will promote an expansive area of critical fire weather conditions across much of the Great Basin, northern Arizona and Four Corners area on Friday. The pronounced juxtaposition of a mid-level jet maxima, a deep and well-mixed boundary layer and surface relative humidity of 10 percent or below is expected across eastern Utah and western Colorado. The combination of sustained winds of 25-30 mph and very dry surface layer could yield locally extremely critical fire weather conditions across western portions of the Colorado Plateau Friday. ...Southern California into the San Joaquin Valley... Enhanced west-northwest flow and within a dry boundary layer will support an elevated fire weather threat mainly leeward of interior mountain ranges across Southern California Friday. Previous forecast (see below) remains on track. ..Williams.. 06/19/2025 .PREV DISCUSSION... /ISSUED 0209 AM CDT Thu Jun 19 2025/ ...Synopsis... A robust midlevel low will advance eastward across the Northwest during the day, while a swath of strong deep-layer westerly flow overspreads much of the western CONUS. In response, surface low pressure will deepen over the northern Great Basin, promoting a tightening pressure gradient across the Great Basin into the Southwest. This large-scale pattern will support widespread critical fire-weather conditions across the Great Basin into the Southwest. ...Great Basin into the Southwest... Strong diurnal heating amid a dry antecedent air mass will support another day of widespread single-digit RH across the region. At the same time, deep boundary-layer mixing into the strong flow aloft, combined with the tightening pressure gradient, will yield an expansive area of 20-30 mph sustained southwesterly surface winds. Given increasingly dry fuels across much of the Great Basin into the Southwest, widespread critical fire-weather conditions are expected, with localized extremely critical conditions possible over terrain-favored areas. ...Southern CA into the San Joaquin Valley... Deep-layer west-northwesterly flow on the upstream-side of the midlevel low will overspread central and southern CA, where the tight regional pressure gradient will be in place. This will promote breezy/gusty surface winds primarily over the interior mountains and valley -- where 15-20 percent RH is expected. These dry/breezy conditions will favor elevated fire-weather conditions where fuels are receptive to wildfire spread. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0258 PM CDT Thu Jun 19 2025 Valid 201200Z - 211200Z ...CRITICAL FIRE WEATHER AREA FOR MUCH OF THE GREAT BASIN INTO THE SOUTHWEST... ...Great Basin into the Southwest... A prominent low pressure system and associated 60-70 mph mid-level jet entering the northwestern U.S. will promote an expansive area of critical fire weather conditions across much of the Great Basin, northern Arizona and Four Corners area on Friday. The pronounced juxtaposition of a mid-level jet maxima, a deep and well-mixed boundary layer and surface relative humidity of 10 percent or below is expected across eastern Utah and western Colorado. The combination of sustained winds of 25-30 mph and very dry surface layer could yield locally extremely critical fire weather conditions across western portions of the Colorado Plateau Friday. ...Southern California into the San Joaquin Valley... Enhanced west-northwest flow and within a dry boundary layer will support an elevated fire weather threat mainly leeward of interior mountain ranges across Southern California Friday. Previous forecast (see below) remains on track. ..Williams.. 06/19/2025 .PREV DISCUSSION... /ISSUED 0209 AM CDT Thu Jun 19 2025/ ...Synopsis... A robust midlevel low will advance eastward across the Northwest during the day, while a swath of strong deep-layer westerly flow overspreads much of the western CONUS. In response, surface low pressure will deepen over the northern Great Basin, promoting a tightening pressure gradient across the Great Basin into the Southwest. This large-scale pattern will support widespread critical fire-weather conditions across the Great Basin into the Southwest. ...Great Basin into the Southwest... Strong diurnal heating amid a dry antecedent air mass will support another day of widespread single-digit RH across the region. At the same time, deep boundary-layer mixing into the strong flow aloft, combined with the tightening pressure gradient, will yield an expansive area of 20-30 mph sustained southwesterly surface winds. Given increasingly dry fuels across much of the Great Basin into the Southwest, widespread critical fire-weather conditions are expected, with localized extremely critical conditions possible over terrain-favored areas. ...Southern CA into the San Joaquin Valley... Deep-layer west-northwesterly flow on the upstream-side of the midlevel low will overspread central and southern CA, where the tight regional pressure gradient will be in place. This will promote breezy/gusty surface winds primarily over the interior mountains and valley -- where 15-20 percent RH is expected. These dry/breezy conditions will favor elevated fire-weather conditions where fuels are receptive to wildfire spread. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0258 PM CDT Thu Jun 19 2025 Valid 201200Z - 211200Z ...CRITICAL FIRE WEATHER AREA FOR MUCH OF THE GREAT BASIN INTO THE SOUTHWEST... ...Great Basin into the Southwest... A prominent low pressure system and associated 60-70 mph mid-level jet entering the northwestern U.S. will promote an expansive area of critical fire weather conditions across much of the Great Basin, northern Arizona and Four Corners area on Friday. The pronounced juxtaposition of a mid-level jet maxima, a deep and well-mixed boundary layer and surface relative humidity of 10 percent or below is expected across eastern Utah and western Colorado. The combination of sustained winds of 25-30 mph and very dry surface layer could yield locally extremely critical fire weather conditions across western portions of the Colorado Plateau Friday. ...Southern California into the San Joaquin Valley... Enhanced west-northwest flow and within a dry boundary layer will support an elevated fire weather threat mainly leeward of interior mountain ranges across Southern California Friday. Previous forecast (see below) remains on track. ..Williams.. 06/19/2025 .PREV DISCUSSION... /ISSUED 0209 AM CDT Thu Jun 19 2025/ ...Synopsis... A robust midlevel low will advance eastward across the Northwest during the day, while a swath of strong deep-layer westerly flow overspreads much of the western CONUS. In response, surface low pressure will deepen over the northern Great Basin, promoting a tightening pressure gradient across the Great Basin into the Southwest. This large-scale pattern will support widespread critical fire-weather conditions across the Great Basin into the Southwest. ...Great Basin into the Southwest... Strong diurnal heating amid a dry antecedent air mass will support another day of widespread single-digit RH across the region. At the same time, deep boundary-layer mixing into the strong flow aloft, combined with the tightening pressure gradient, will yield an expansive area of 20-30 mph sustained southwesterly surface winds. Given increasingly dry fuels across much of the Great Basin into the Southwest, widespread critical fire-weather conditions are expected, with localized extremely critical conditions possible over terrain-favored areas. ...Southern CA into the San Joaquin Valley... Deep-layer west-northwesterly flow on the upstream-side of the midlevel low will overspread central and southern CA, where the tight regional pressure gradient will be in place. This will promote breezy/gusty surface winds primarily over the interior mountains and valley -- where 15-20 percent RH is expected. These dry/breezy conditions will favor elevated fire-weather conditions where fuels are receptive to wildfire spread. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0258 PM CDT Thu Jun 19 2025 Valid 201200Z - 211200Z ...CRITICAL FIRE WEATHER AREA FOR MUCH OF THE GREAT BASIN INTO THE SOUTHWEST... ...Great Basin into the Southwest... A prominent low pressure system and associated 60-70 mph mid-level jet entering the northwestern U.S. will promote an expansive area of critical fire weather conditions across much of the Great Basin, northern Arizona and Four Corners area on Friday. The pronounced juxtaposition of a mid-level jet maxima, a deep and well-mixed boundary layer and surface relative humidity of 10 percent or below is expected across eastern Utah and western Colorado. The combination of sustained winds of 25-30 mph and very dry surface layer could yield locally extremely critical fire weather conditions across western portions of the Colorado Plateau Friday. ...Southern California into the San Joaquin Valley... Enhanced west-northwest flow and within a dry boundary layer will support an elevated fire weather threat mainly leeward of interior mountain ranges across Southern California Friday. Previous forecast (see below) remains on track. ..Williams.. 06/19/2025 .PREV DISCUSSION... /ISSUED 0209 AM CDT Thu Jun 19 2025/ ...Synopsis... A robust midlevel low will advance eastward across the Northwest during the day, while a swath of strong deep-layer westerly flow overspreads much of the western CONUS. In response, surface low pressure will deepen over the northern Great Basin, promoting a tightening pressure gradient across the Great Basin into the Southwest. This large-scale pattern will support widespread critical fire-weather conditions across the Great Basin into the Southwest. ...Great Basin into the Southwest... Strong diurnal heating amid a dry antecedent air mass will support another day of widespread single-digit RH across the region. At the same time, deep boundary-layer mixing into the strong flow aloft, combined with the tightening pressure gradient, will yield an expansive area of 20-30 mph sustained southwesterly surface winds. Given increasingly dry fuels across much of the Great Basin into the Southwest, widespread critical fire-weather conditions are expected, with localized extremely critical conditions possible over terrain-favored areas. ...Southern CA into the San Joaquin Valley... Deep-layer west-northwesterly flow on the upstream-side of the midlevel low will overspread central and southern CA, where the tight regional pressure gradient will be in place. This will promote breezy/gusty surface winds primarily over the interior mountains and valley -- where 15-20 percent RH is expected. These dry/breezy conditions will favor elevated fire-weather conditions where fuels are receptive to wildfire spread. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0258 PM CDT Thu Jun 19 2025 Valid 201200Z - 211200Z ...CRITICAL FIRE WEATHER AREA FOR MUCH OF THE GREAT BASIN INTO THE SOUTHWEST... ...Great Basin into the Southwest... A prominent low pressure system and associated 60-70 mph mid-level jet entering the northwestern U.S. will promote an expansive area of critical fire weather conditions across much of the Great Basin, northern Arizona and Four Corners area on Friday. The pronounced juxtaposition of a mid-level jet maxima, a deep and well-mixed boundary layer and surface relative humidity of 10 percent or below is expected across eastern Utah and western Colorado. The combination of sustained winds of 25-30 mph and very dry surface layer could yield locally extremely critical fire weather conditions across western portions of the Colorado Plateau Friday. ...Southern California into the San Joaquin Valley... Enhanced west-northwest flow and within a dry boundary layer will support an elevated fire weather threat mainly leeward of interior mountain ranges across Southern California Friday. Previous forecast (see below) remains on track. ..Williams.. 06/19/2025 .PREV DISCUSSION... /ISSUED 0209 AM CDT Thu Jun 19 2025/ ...Synopsis... A robust midlevel low will advance eastward across the Northwest during the day, while a swath of strong deep-layer westerly flow overspreads much of the western CONUS. In response, surface low pressure will deepen over the northern Great Basin, promoting a tightening pressure gradient across the Great Basin into the Southwest. This large-scale pattern will support widespread critical fire-weather conditions across the Great Basin into the Southwest. ...Great Basin into the Southwest... Strong diurnal heating amid a dry antecedent air mass will support another day of widespread single-digit RH across the region. At the same time, deep boundary-layer mixing into the strong flow aloft, combined with the tightening pressure gradient, will yield an expansive area of 20-30 mph sustained southwesterly surface winds. Given increasingly dry fuels across much of the Great Basin into the Southwest, widespread critical fire-weather conditions are expected, with localized extremely critical conditions possible over terrain-favored areas. ...Southern CA into the San Joaquin Valley... Deep-layer west-northwesterly flow on the upstream-side of the midlevel low will overspread central and southern CA, where the tight regional pressure gradient will be in place. This will promote breezy/gusty surface winds primarily over the interior mountains and valley -- where 15-20 percent RH is expected. These dry/breezy conditions will favor elevated fire-weather conditions where fuels are receptive to wildfire spread. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0258 PM CDT Thu Jun 19 2025 Valid 201200Z - 211200Z ...CRITICAL FIRE WEATHER AREA FOR MUCH OF THE GREAT BASIN INTO THE SOUTHWEST... ...Great Basin into the Southwest... A prominent low pressure system and associated 60-70 mph mid-level jet entering the northwestern U.S. will promote an expansive area of critical fire weather conditions across much of the Great Basin, northern Arizona and Four Corners area on Friday. The pronounced juxtaposition of a mid-level jet maxima, a deep and well-mixed boundary layer and surface relative humidity of 10 percent or below is expected across eastern Utah and western Colorado. The combination of sustained winds of 25-30 mph and very dry surface layer could yield locally extremely critical fire weather conditions across western portions of the Colorado Plateau Friday. ...Southern California into the San Joaquin Valley... Enhanced west-northwest flow and within a dry boundary layer will support an elevated fire weather threat mainly leeward of interior mountain ranges across Southern California Friday. Previous forecast (see below) remains on track. ..Williams.. 06/19/2025 .PREV DISCUSSION... /ISSUED 0209 AM CDT Thu Jun 19 2025/ ...Synopsis... A robust midlevel low will advance eastward across the Northwest during the day, while a swath of strong deep-layer westerly flow overspreads much of the western CONUS. In response, surface low pressure will deepen over the northern Great Basin, promoting a tightening pressure gradient across the Great Basin into the Southwest. This large-scale pattern will support widespread critical fire-weather conditions across the Great Basin into the Southwest. ...Great Basin into the Southwest... Strong diurnal heating amid a dry antecedent air mass will support another day of widespread single-digit RH across the region. At the same time, deep boundary-layer mixing into the strong flow aloft, combined with the tightening pressure gradient, will yield an expansive area of 20-30 mph sustained southwesterly surface winds. Given increasingly dry fuels across much of the Great Basin into the Southwest, widespread critical fire-weather conditions are expected, with localized extremely critical conditions possible over terrain-favored areas. ...Southern CA into the San Joaquin Valley... Deep-layer west-northwesterly flow on the upstream-side of the midlevel low will overspread central and southern CA, where the tight regional pressure gradient will be in place. This will promote breezy/gusty surface winds primarily over the interior mountains and valley -- where 15-20 percent RH is expected. These dry/breezy conditions will favor elevated fire-weather conditions where fuels are receptive to wildfire spread. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0258 PM CDT Thu Jun 19 2025 Valid 201200Z - 211200Z ...CRITICAL FIRE WEATHER AREA FOR MUCH OF THE GREAT BASIN INTO THE SOUTHWEST... ...Great Basin into the Southwest... A prominent low pressure system and associated 60-70 mph mid-level jet entering the northwestern U.S. will promote an expansive area of critical fire weather conditions across much of the Great Basin, northern Arizona and Four Corners area on Friday. The pronounced juxtaposition of a mid-level jet maxima, a deep and well-mixed boundary layer and surface relative humidity of 10 percent or below is expected across eastern Utah and western Colorado. The combination of sustained winds of 25-30 mph and very dry surface layer could yield locally extremely critical fire weather conditions across western portions of the Colorado Plateau Friday. ...Southern California into the San Joaquin Valley... Enhanced west-northwest flow and within a dry boundary layer will support an elevated fire weather threat mainly leeward of interior mountain ranges across Southern California Friday. Previous forecast (see below) remains on track. ..Williams.. 06/19/2025 .PREV DISCUSSION... /ISSUED 0209 AM CDT Thu Jun 19 2025/ ...Synopsis... A robust midlevel low will advance eastward across the Northwest during the day, while a swath of strong deep-layer westerly flow overspreads much of the western CONUS. In response, surface low pressure will deepen over the northern Great Basin, promoting a tightening pressure gradient across the Great Basin into the Southwest. This large-scale pattern will support widespread critical fire-weather conditions across the Great Basin into the Southwest. ...Great Basin into the Southwest... Strong diurnal heating amid a dry antecedent air mass will support another day of widespread single-digit RH across the region. At the same time, deep boundary-layer mixing into the strong flow aloft, combined with the tightening pressure gradient, will yield an expansive area of 20-30 mph sustained southwesterly surface winds. Given increasingly dry fuels across much of the Great Basin into the Southwest, widespread critical fire-weather conditions are expected, with localized extremely critical conditions possible over terrain-favored areas. ...Southern CA into the San Joaquin Valley... Deep-layer west-northwesterly flow on the upstream-side of the midlevel low will overspread central and southern CA, where the tight regional pressure gradient will be in place. This will promote breezy/gusty surface winds primarily over the interior mountains and valley -- where 15-20 percent RH is expected. These dry/breezy conditions will favor elevated fire-weather conditions where fuels are receptive to wildfire spread. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0258 PM CDT Thu Jun 19 2025 Valid 201200Z - 211200Z ...CRITICAL FIRE WEATHER AREA FOR MUCH OF THE GREAT BASIN INTO THE SOUTHWEST... ...Great Basin into the Southwest... A prominent low pressure system and associated 60-70 mph mid-level jet entering the northwestern U.S. will promote an expansive area of critical fire weather conditions across much of the Great Basin, northern Arizona and Four Corners area on Friday. The pronounced juxtaposition of a mid-level jet maxima, a deep and well-mixed boundary layer and surface relative humidity of 10 percent or below is expected across eastern Utah and western Colorado. The combination of sustained winds of 25-30 mph and very dry surface layer could yield locally extremely critical fire weather conditions across western portions of the Colorado Plateau Friday. ...Southern California into the San Joaquin Valley... Enhanced west-northwest flow and within a dry boundary layer will support an elevated fire weather threat mainly leeward of interior mountain ranges across Southern California Friday. Previous forecast (see below) remains on track. ..Williams.. 06/19/2025 .PREV DISCUSSION... /ISSUED 0209 AM CDT Thu Jun 19 2025/ ...Synopsis... A robust midlevel low will advance eastward across the Northwest during the day, while a swath of strong deep-layer westerly flow overspreads much of the western CONUS. In response, surface low pressure will deepen over the northern Great Basin, promoting a tightening pressure gradient across the Great Basin into the Southwest. This large-scale pattern will support widespread critical fire-weather conditions across the Great Basin into the Southwest. ...Great Basin into the Southwest... Strong diurnal heating amid a dry antecedent air mass will support another day of widespread single-digit RH across the region. At the same time, deep boundary-layer mixing into the strong flow aloft, combined with the tightening pressure gradient, will yield an expansive area of 20-30 mph sustained southwesterly surface winds. Given increasingly dry fuels across much of the Great Basin into the Southwest, widespread critical fire-weather conditions are expected, with localized extremely critical conditions possible over terrain-favored areas. ...Southern CA into the San Joaquin Valley... Deep-layer west-northwesterly flow on the upstream-side of the midlevel low will overspread central and southern CA, where the tight regional pressure gradient will be in place. This will promote breezy/gusty surface winds primarily over the interior mountains and valley -- where 15-20 percent RH is expected. These dry/breezy conditions will favor elevated fire-weather conditions where fuels are receptive to wildfire spread. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0258 PM CDT Thu Jun 19 2025 Valid 201200Z - 211200Z ...CRITICAL FIRE WEATHER AREA FOR MUCH OF THE GREAT BASIN INTO THE SOUTHWEST... ...Great Basin into the Southwest... A prominent low pressure system and associated 60-70 mph mid-level jet entering the northwestern U.S. will promote an expansive area of critical fire weather conditions across much of the Great Basin, northern Arizona and Four Corners area on Friday. The pronounced juxtaposition of a mid-level jet maxima, a deep and well-mixed boundary layer and surface relative humidity of 10 percent or below is expected across eastern Utah and western Colorado. The combination of sustained winds of 25-30 mph and very dry surface layer could yield locally extremely critical fire weather conditions across western portions of the Colorado Plateau Friday. ...Southern California into the San Joaquin Valley... Enhanced west-northwest flow and within a dry boundary layer will support an elevated fire weather threat mainly leeward of interior mountain ranges across Southern California Friday. Previous forecast (see below) remains on track. ..Williams.. 06/19/2025 .PREV DISCUSSION... /ISSUED 0209 AM CDT Thu Jun 19 2025/ ...Synopsis... A robust midlevel low will advance eastward across the Northwest during the day, while a swath of strong deep-layer westerly flow overspreads much of the western CONUS. In response, surface low pressure will deepen over the northern Great Basin, promoting a tightening pressure gradient across the Great Basin into the Southwest. This large-scale pattern will support widespread critical fire-weather conditions across the Great Basin into the Southwest. ...Great Basin into the Southwest... Strong diurnal heating amid a dry antecedent air mass will support another day of widespread single-digit RH across the region. At the same time, deep boundary-layer mixing into the strong flow aloft, combined with the tightening pressure gradient, will yield an expansive area of 20-30 mph sustained southwesterly surface winds. Given increasingly dry fuels across much of the Great Basin into the Southwest, widespread critical fire-weather conditions are expected, with localized extremely critical conditions possible over terrain-favored areas. ...Southern CA into the San Joaquin Valley... Deep-layer west-northwesterly flow on the upstream-side of the midlevel low will overspread central and southern CA, where the tight regional pressure gradient will be in place. This will promote breezy/gusty surface winds primarily over the interior mountains and valley -- where 15-20 percent RH is expected. These dry/breezy conditions will favor elevated fire-weather conditions where fuels are receptive to wildfire spread. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0258 PM CDT Thu Jun 19 2025 Valid 201200Z - 211200Z ...CRITICAL FIRE WEATHER AREA FOR MUCH OF THE GREAT BASIN INTO THE SOUTHWEST... ...Great Basin into the Southwest... A prominent low pressure system and associated 60-70 mph mid-level jet entering the northwestern U.S. will promote an expansive area of critical fire weather conditions across much of the Great Basin, northern Arizona and Four Corners area on Friday. The pronounced juxtaposition of a mid-level jet maxima, a deep and well-mixed boundary layer and surface relative humidity of 10 percent or below is expected across eastern Utah and western Colorado. The combination of sustained winds of 25-30 mph and very dry surface layer could yield locally extremely critical fire weather conditions across western portions of the Colorado Plateau Friday. ...Southern California into the San Joaquin Valley... Enhanced west-northwest flow and within a dry boundary layer will support an elevated fire weather threat mainly leeward of interior mountain ranges across Southern California Friday. Previous forecast (see below) remains on track. ..Williams.. 06/19/2025 .PREV DISCUSSION... /ISSUED 0209 AM CDT Thu Jun 19 2025/ ...Synopsis... A robust midlevel low will advance eastward across the Northwest during the day, while a swath of strong deep-layer westerly flow overspreads much of the western CONUS. In response, surface low pressure will deepen over the northern Great Basin, promoting a tightening pressure gradient across the Great Basin into the Southwest. This large-scale pattern will support widespread critical fire-weather conditions across the Great Basin into the Southwest. ...Great Basin into the Southwest... Strong diurnal heating amid a dry antecedent air mass will support another day of widespread single-digit RH across the region. At the same time, deep boundary-layer mixing into the strong flow aloft, combined with the tightening pressure gradient, will yield an expansive area of 20-30 mph sustained southwesterly surface winds. Given increasingly dry fuels across much of the Great Basin into the Southwest, widespread critical fire-weather conditions are expected, with localized extremely critical conditions possible over terrain-favored areas. ...Southern CA into the San Joaquin Valley... Deep-layer west-northwesterly flow on the upstream-side of the midlevel low will overspread central and southern CA, where the tight regional pressure gradient will be in place. This will promote breezy/gusty surface winds primarily over the interior mountains and valley -- where 15-20 percent RH is expected. These dry/breezy conditions will favor elevated fire-weather conditions where fuels are receptive to wildfire spread. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0258 PM CDT Thu Jun 19 2025 Valid 201200Z - 211200Z ...CRITICAL FIRE WEATHER AREA FOR MUCH OF THE GREAT BASIN INTO THE SOUTHWEST... ...Great Basin into the Southwest... A prominent low pressure system and associated 60-70 mph mid-level jet entering the northwestern U.S. will promote an expansive area of critical fire weather conditions across much of the Great Basin, northern Arizona and Four Corners area on Friday. The pronounced juxtaposition of a mid-level jet maxima, a deep and well-mixed boundary layer and surface relative humidity of 10 percent or below is expected across eastern Utah and western Colorado. The combination of sustained winds of 25-30 mph and very dry surface layer could yield locally extremely critical fire weather conditions across western portions of the Colorado Plateau Friday. ...Southern California into the San Joaquin Valley... Enhanced west-northwest flow and within a dry boundary layer will support an elevated fire weather threat mainly leeward of interior mountain ranges across Southern California Friday. Previous forecast (see below) remains on track. ..Williams.. 06/19/2025 .PREV DISCUSSION... /ISSUED 0209 AM CDT Thu Jun 19 2025/ ...Synopsis... A robust midlevel low will advance eastward across the Northwest during the day, while a swath of strong deep-layer westerly flow overspreads much of the western CONUS. In response, surface low pressure will deepen over the northern Great Basin, promoting a tightening pressure gradient across the Great Basin into the Southwest. This large-scale pattern will support widespread critical fire-weather conditions across the Great Basin into the Southwest. ...Great Basin into the Southwest... Strong diurnal heating amid a dry antecedent air mass will support another day of widespread single-digit RH across the region. At the same time, deep boundary-layer mixing into the strong flow aloft, combined with the tightening pressure gradient, will yield an expansive area of 20-30 mph sustained southwesterly surface winds. Given increasingly dry fuels across much of the Great Basin into the Southwest, widespread critical fire-weather conditions are expected, with localized extremely critical conditions possible over terrain-favored areas. ...Southern CA into the San Joaquin Valley... Deep-layer west-northwesterly flow on the upstream-side of the midlevel low will overspread central and southern CA, where the tight regional pressure gradient will be in place. This will promote breezy/gusty surface winds primarily over the interior mountains and valley -- where 15-20 percent RH is expected. These dry/breezy conditions will favor elevated fire-weather conditions where fuels are receptive to wildfire spread. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0251 PM CDT Thu Jun 19 2025 Valid 192000Z - 201200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS OVER THE NORTHEAST AND MID ATLANTIC STATES... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE DAKOTAS AND THE UPPER MIDWEST... ...SUMMARY... Severe thunderstorms are expected across much of the Mid-Atlantic region through this evening, and to a lesser extent into the Carolinas and over portions of New England. Severe/damaging wind gusts are the primary concern. An isolated large hail and damaging wind threat should also develop across parts of the northern Plains/Upper Midwest, primarily during the evening/overnight hours. ...20z Update... The prior outlook remains valid with only minimal changes. Across parts of the Northeast and Mid Atlantic, several bands/clusters of strong to severe storms are ongoing ahead of an upper trough over the upper OH Valley. Moderate buoyancy and deep-layer shear will continue to support storm organization into line segments and clusters with an attendant risk for damaging gusts focused across the Enhanced area. A few weak supercell structures were also noted over eastern PA into southern New England, where some isolated hail and a brief tornado will be possible. Convection should continue into this evening before slowly weakening after sunset. ...Southeast... In the wake of early morning remnant storms, an advancing outflow has shifted south across MS/AL and eastern AR. The cluster of storms on the surging outflow may occasionally produce damaging guts given the moderate instability. Weak vertical shear should keep the threat isolated. Have trimmed the MRGL and thunder behind this activity where additional storms are not expected. Otherwise, additional storms are possible across the Northern Plains tonight. See the prior discussion for more info. ..Lyons.. 06/19/2025 .PREV DISCUSSION... /ISSUED 1115 AM CDT Thu Jun 19 2025/ ...Eastern US... A broad and low-amplitude shortwave trough is moving across the Great Lakes region and Ohio Valley today. Ahead of the trough, visible satellite imagery shows mostly clear skies from eastern NY and much of New England southward across the Mid-Atlantic region and Carolinas. Warm/moist conditions will develop by mid-afternoon, yielding MLCAPE values of 2000-3000 J/kg across this broad area. Scattered thunderstorms are expected to develop, with the highest concentrations moving off the higher terrain of PA/VA/NC and tracking eastward across the ENH risk area. Forecast soundings along this corridor show 35-50 knot westerly flow aloft, which will aid in thunderstorm organization and longevity. Low-level winds are relatively weak/veered, and mid-level lapse rates are marginal for intense updrafts. This suggests that damaging wind gusts are the primary concern today. ...ND/MN/WI This Evening/Tonight... A large upper ridge has become established across the Rockies and High Plains, with the primary westerlies now extending from MT into the Dakotas and Great Lakes. Several weak perturbations will top the ridge today and tonight, and a strengthening low-level jet will encourage the development of clusters of thunderstorms. One cluster is expected this evening over parts of MN/WI, with a risk of large hail. There is increasing concern for a cluster of storms developing across southern ND, which may persist through the night into southern MN. While this scenario is only shown in a handful of 12z models, have shifted the SLGT farther south for this conditional risk. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0251 PM CDT Thu Jun 19 2025 Valid 192000Z - 201200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS OVER THE NORTHEAST AND MID ATLANTIC STATES... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE DAKOTAS AND THE UPPER MIDWEST... ...SUMMARY... Severe thunderstorms are expected across much of the Mid-Atlantic region through this evening, and to a lesser extent into the Carolinas and over portions of New England. Severe/damaging wind gusts are the primary concern. An isolated large hail and damaging wind threat should also develop across parts of the northern Plains/Upper Midwest, primarily during the evening/overnight hours. ...20z Update... The prior outlook remains valid with only minimal changes. Across parts of the Northeast and Mid Atlantic, several bands/clusters of strong to severe storms are ongoing ahead of an upper trough over the upper OH Valley. Moderate buoyancy and deep-layer shear will continue to support storm organization into line segments and clusters with an attendant risk for damaging gusts focused across the Enhanced area. A few weak supercell structures were also noted over eastern PA into southern New England, where some isolated hail and a brief tornado will be possible. Convection should continue into this evening before slowly weakening after sunset. ...Southeast... In the wake of early morning remnant storms, an advancing outflow has shifted south across MS/AL and eastern AR. The cluster of storms on the surging outflow may occasionally produce damaging guts given the moderate instability. Weak vertical shear should keep the threat isolated. Have trimmed the MRGL and thunder behind this activity where additional storms are not expected. Otherwise, additional storms are possible across the Northern Plains tonight. See the prior discussion for more info. ..Lyons.. 06/19/2025 .PREV DISCUSSION... /ISSUED 1115 AM CDT Thu Jun 19 2025/ ...Eastern US... A broad and low-amplitude shortwave trough is moving across the Great Lakes region and Ohio Valley today. Ahead of the trough, visible satellite imagery shows mostly clear skies from eastern NY and much of New England southward across the Mid-Atlantic region and Carolinas. Warm/moist conditions will develop by mid-afternoon, yielding MLCAPE values of 2000-3000 J/kg across this broad area. Scattered thunderstorms are expected to develop, with the highest concentrations moving off the higher terrain of PA/VA/NC and tracking eastward across the ENH risk area. Forecast soundings along this corridor show 35-50 knot westerly flow aloft, which will aid in thunderstorm organization and longevity. Low-level winds are relatively weak/veered, and mid-level lapse rates are marginal for intense updrafts. This suggests that damaging wind gusts are the primary concern today. ...ND/MN/WI This Evening/Tonight... A large upper ridge has become established across the Rockies and High Plains, with the primary westerlies now extending from MT into the Dakotas and Great Lakes. Several weak perturbations will top the ridge today and tonight, and a strengthening low-level jet will encourage the development of clusters of thunderstorms. One cluster is expected this evening over parts of MN/WI, with a risk of large hail. There is increasing concern for a cluster of storms developing across southern ND, which may persist through the night into southern MN. While this scenario is only shown in a handful of 12z models, have shifted the SLGT farther south for this conditional risk. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0251 PM CDT Thu Jun 19 2025 Valid 192000Z - 201200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS OVER THE NORTHEAST AND MID ATLANTIC STATES... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE DAKOTAS AND THE UPPER MIDWEST... ...SUMMARY... Severe thunderstorms are expected across much of the Mid-Atlantic region through this evening, and to a lesser extent into the Carolinas and over portions of New England. Severe/damaging wind gusts are the primary concern. An isolated large hail and damaging wind threat should also develop across parts of the northern Plains/Upper Midwest, primarily during the evening/overnight hours. ...20z Update... The prior outlook remains valid with only minimal changes. Across parts of the Northeast and Mid Atlantic, several bands/clusters of strong to severe storms are ongoing ahead of an upper trough over the upper OH Valley. Moderate buoyancy and deep-layer shear will continue to support storm organization into line segments and clusters with an attendant risk for damaging gusts focused across the Enhanced area. A few weak supercell structures were also noted over eastern PA into southern New England, where some isolated hail and a brief tornado will be possible. Convection should continue into this evening before slowly weakening after sunset. ...Southeast... In the wake of early morning remnant storms, an advancing outflow has shifted south across MS/AL and eastern AR. The cluster of storms on the surging outflow may occasionally produce damaging guts given the moderate instability. Weak vertical shear should keep the threat isolated. Have trimmed the MRGL and thunder behind this activity where additional storms are not expected. Otherwise, additional storms are possible across the Northern Plains tonight. See the prior discussion for more info. ..Lyons.. 06/19/2025 .PREV DISCUSSION... /ISSUED 1115 AM CDT Thu Jun 19 2025/ ...Eastern US... A broad and low-amplitude shortwave trough is moving across the Great Lakes region and Ohio Valley today. Ahead of the trough, visible satellite imagery shows mostly clear skies from eastern NY and much of New England southward across the Mid-Atlantic region and Carolinas. Warm/moist conditions will develop by mid-afternoon, yielding MLCAPE values of 2000-3000 J/kg across this broad area. Scattered thunderstorms are expected to develop, with the highest concentrations moving off the higher terrain of PA/VA/NC and tracking eastward across the ENH risk area. Forecast soundings along this corridor show 35-50 knot westerly flow aloft, which will aid in thunderstorm organization and longevity. Low-level winds are relatively weak/veered, and mid-level lapse rates are marginal for intense updrafts. This suggests that damaging wind gusts are the primary concern today. ...ND/MN/WI This Evening/Tonight... A large upper ridge has become established across the Rockies and High Plains, with the primary westerlies now extending from MT into the Dakotas and Great Lakes. Several weak perturbations will top the ridge today and tonight, and a strengthening low-level jet will encourage the development of clusters of thunderstorms. One cluster is expected this evening over parts of MN/WI, with a risk of large hail. There is increasing concern for a cluster of storms developing across southern ND, which may persist through the night into southern MN. While this scenario is only shown in a handful of 12z models, have shifted the SLGT farther south for this conditional risk. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0251 PM CDT Thu Jun 19 2025 Valid 192000Z - 201200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS OVER THE NORTHEAST AND MID ATLANTIC STATES... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE DAKOTAS AND THE UPPER MIDWEST... ...SUMMARY... Severe thunderstorms are expected across much of the Mid-Atlantic region through this evening, and to a lesser extent into the Carolinas and over portions of New England. Severe/damaging wind gusts are the primary concern. An isolated large hail and damaging wind threat should also develop across parts of the northern Plains/Upper Midwest, primarily during the evening/overnight hours. ...20z Update... The prior outlook remains valid with only minimal changes. Across parts of the Northeast and Mid Atlantic, several bands/clusters of strong to severe storms are ongoing ahead of an upper trough over the upper OH Valley. Moderate buoyancy and deep-layer shear will continue to support storm organization into line segments and clusters with an attendant risk for damaging gusts focused across the Enhanced area. A few weak supercell structures were also noted over eastern PA into southern New England, where some isolated hail and a brief tornado will be possible. Convection should continue into this evening before slowly weakening after sunset. ...Southeast... In the wake of early morning remnant storms, an advancing outflow has shifted south across MS/AL and eastern AR. The cluster of storms on the surging outflow may occasionally produce damaging guts given the moderate instability. Weak vertical shear should keep the threat isolated. Have trimmed the MRGL and thunder behind this activity where additional storms are not expected. Otherwise, additional storms are possible across the Northern Plains tonight. See the prior discussion for more info. ..Lyons.. 06/19/2025 .PREV DISCUSSION... /ISSUED 1115 AM CDT Thu Jun 19 2025/ ...Eastern US... A broad and low-amplitude shortwave trough is moving across the Great Lakes region and Ohio Valley today. Ahead of the trough, visible satellite imagery shows mostly clear skies from eastern NY and much of New England southward across the Mid-Atlantic region and Carolinas. Warm/moist conditions will develop by mid-afternoon, yielding MLCAPE values of 2000-3000 J/kg across this broad area. Scattered thunderstorms are expected to develop, with the highest concentrations moving off the higher terrain of PA/VA/NC and tracking eastward across the ENH risk area. Forecast soundings along this corridor show 35-50 knot westerly flow aloft, which will aid in thunderstorm organization and longevity. Low-level winds are relatively weak/veered, and mid-level lapse rates are marginal for intense updrafts. This suggests that damaging wind gusts are the primary concern today. ...ND/MN/WI This Evening/Tonight... A large upper ridge has become established across the Rockies and High Plains, with the primary westerlies now extending from MT into the Dakotas and Great Lakes. Several weak perturbations will top the ridge today and tonight, and a strengthening low-level jet will encourage the development of clusters of thunderstorms. One cluster is expected this evening over parts of MN/WI, with a risk of large hail. There is increasing concern for a cluster of storms developing across southern ND, which may persist through the night into southern MN. While this scenario is only shown in a handful of 12z models, have shifted the SLGT farther south for this conditional risk. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0251 PM CDT Thu Jun 19 2025 Valid 192000Z - 201200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS OVER THE NORTHEAST AND MID ATLANTIC STATES... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE DAKOTAS AND THE UPPER MIDWEST... ...SUMMARY... Severe thunderstorms are expected across much of the Mid-Atlantic region through this evening, and to a lesser extent into the Carolinas and over portions of New England. Severe/damaging wind gusts are the primary concern. An isolated large hail and damaging wind threat should also develop across parts of the northern Plains/Upper Midwest, primarily during the evening/overnight hours. ...20z Update... The prior outlook remains valid with only minimal changes. Across parts of the Northeast and Mid Atlantic, several bands/clusters of strong to severe storms are ongoing ahead of an upper trough over the upper OH Valley. Moderate buoyancy and deep-layer shear will continue to support storm organization into line segments and clusters with an attendant risk for damaging gusts focused across the Enhanced area. A few weak supercell structures were also noted over eastern PA into southern New England, where some isolated hail and a brief tornado will be possible. Convection should continue into this evening before slowly weakening after sunset. ...Southeast... In the wake of early morning remnant storms, an advancing outflow has shifted south across MS/AL and eastern AR. The cluster of storms on the surging outflow may occasionally produce damaging guts given the moderate instability. Weak vertical shear should keep the threat isolated. Have trimmed the MRGL and thunder behind this activity where additional storms are not expected. Otherwise, additional storms are possible across the Northern Plains tonight. See the prior discussion for more info. ..Lyons.. 06/19/2025 .PREV DISCUSSION... /ISSUED 1115 AM CDT Thu Jun 19 2025/ ...Eastern US... A broad and low-amplitude shortwave trough is moving across the Great Lakes region and Ohio Valley today. Ahead of the trough, visible satellite imagery shows mostly clear skies from eastern NY and much of New England southward across the Mid-Atlantic region and Carolinas. Warm/moist conditions will develop by mid-afternoon, yielding MLCAPE values of 2000-3000 J/kg across this broad area. Scattered thunderstorms are expected to develop, with the highest concentrations moving off the higher terrain of PA/VA/NC and tracking eastward across the ENH risk area. Forecast soundings along this corridor show 35-50 knot westerly flow aloft, which will aid in thunderstorm organization and longevity. Low-level winds are relatively weak/veered, and mid-level lapse rates are marginal for intense updrafts. This suggests that damaging wind gusts are the primary concern today. ...ND/MN/WI This Evening/Tonight... A large upper ridge has become established across the Rockies and High Plains, with the primary westerlies now extending from MT into the Dakotas and Great Lakes. Several weak perturbations will top the ridge today and tonight, and a strengthening low-level jet will encourage the development of clusters of thunderstorms. One cluster is expected this evening over parts of MN/WI, with a risk of large hail. There is increasing concern for a cluster of storms developing across southern ND, which may persist through the night into southern MN. While this scenario is only shown in a handful of 12z models, have shifted the SLGT farther south for this conditional risk. Read more