Severe Storms

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1157 AM CDT Wed Jul 09 2025 Valid 091700Z - 101200Z ...CRITICAL FIRE WEATHER AREA FOR EASTERN NEVADA AND FAR WESTERN UTAH... ...Montana... A mid-level trough translating east across the Canada/U.S. border and subsequent breakdown of upper-level ridge over the Northern Rockies along with sufficient mid-level moisture/instability will aid in high-based thunderstorm development across the higher terrain of western MT, moving into eastern MT by evening. Fast east-northeastward thunderstorm trajectories on the order of 25-30 knots will limit rainfall (in addition to gusty/erratic outflow winds) over dry fuels, supporting an increased wildfire spread potential for portions of central and eastern MT where isolated dry thunderstorm highlights were added. Otherwise, previous forecast (see below) for additional fire weather threats across the Western U.S. remains on track with minimal changes. ..Williams.. 07/09/2025 .PREV DISCUSSION... /ISSUED 0156 AM CDT Wed Jul 09 2025/ ...Synopsis... A compact midlevel trough will advance eastward across the northern Great Basin during the day. At the same time, a separate large-scale trough will move eastward across western Canada. ...Great Basin... Preceding the compact midlevel trough, moderate deep-layer southwesterly flow will overspread the Great Basin during peak heating. Deep boundary-layer mixing into this strengthening flow aloft will result in an expansive area of lower-teens RH and 20-25 mph sustained west-southwesterly surface winds. Given increasingly dry fuels across the region, critical fire-weather conditions are expected from central NV into western UT (with elevated conditions surrounding this area across the Great Basin). ...Northwest... Large-scale ascent accompanying the compact midlevel trough will aid in isolated to widely scattered thunderstorm development over southeastern OR, southwestern ID, and far northeastern CA during the afternoon/evening hours. Deep inverted-V soundings and 0.5-0.7 inch PW will favor dry thunderstorms -- with a risk of lightning-induced ignitions and strong/erratic outflow winds. Additionally, strong westerly flow in the base of the large-scale trough moving across western Canada will persist across the Cascades. Despite slightly higher RH than previous days, strong downslope/westerly surface winds will favor elevated to locally critical fire-weather conditions in the Columbia Basin. ...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 1157 AM CDT Wed Jul 09 2025 Valid 091700Z - 101200Z ...CRITICAL FIRE WEATHER AREA FOR EASTERN NEVADA AND FAR WESTERN UTAH... ...Montana... A mid-level trough translating east across the Canada/U.S. border and subsequent breakdown of upper-level ridge over the Northern Rockies along with sufficient mid-level moisture/instability will aid in high-based thunderstorm development across the higher terrain of western MT, moving into eastern MT by evening. Fast east-northeastward thunderstorm trajectories on the order of 25-30 knots will limit rainfall (in addition to gusty/erratic outflow winds) over dry fuels, supporting an increased wildfire spread potential for portions of central and eastern MT where isolated dry thunderstorm highlights were added. Otherwise, previous forecast (see below) for additional fire weather threats across the Western U.S. remains on track with minimal changes. ..Williams.. 07/09/2025 .PREV DISCUSSION... /ISSUED 0156 AM CDT Wed Jul 09 2025/ ...Synopsis... A compact midlevel trough will advance eastward across the northern Great Basin during the day. At the same time, a separate large-scale trough will move eastward across western Canada. ...Great Basin... Preceding the compact midlevel trough, moderate deep-layer southwesterly flow will overspread the Great Basin during peak heating. Deep boundary-layer mixing into this strengthening flow aloft will result in an expansive area of lower-teens RH and 20-25 mph sustained west-southwesterly surface winds. Given increasingly dry fuels across the region, critical fire-weather conditions are expected from central NV into western UT (with elevated conditions surrounding this area across the Great Basin). ...Northwest... Large-scale ascent accompanying the compact midlevel trough will aid in isolated to widely scattered thunderstorm development over southeastern OR, southwestern ID, and far northeastern CA during the afternoon/evening hours. Deep inverted-V soundings and 0.5-0.7 inch PW will favor dry thunderstorms -- with a risk of lightning-induced ignitions and strong/erratic outflow winds. Additionally, strong westerly flow in the base of the large-scale trough moving across western Canada will persist across the Cascades. Despite slightly higher RH than previous days, strong downslope/westerly surface winds will favor elevated to locally critical fire-weather conditions in the Columbia Basin. ...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 1157 AM CDT Wed Jul 09 2025 Valid 091700Z - 101200Z ...CRITICAL FIRE WEATHER AREA FOR EASTERN NEVADA AND FAR WESTERN UTAH... ...Montana... A mid-level trough translating east across the Canada/U.S. border and subsequent breakdown of upper-level ridge over the Northern Rockies along with sufficient mid-level moisture/instability will aid in high-based thunderstorm development across the higher terrain of western MT, moving into eastern MT by evening. Fast east-northeastward thunderstorm trajectories on the order of 25-30 knots will limit rainfall (in addition to gusty/erratic outflow winds) over dry fuels, supporting an increased wildfire spread potential for portions of central and eastern MT where isolated dry thunderstorm highlights were added. Otherwise, previous forecast (see below) for additional fire weather threats across the Western U.S. remains on track with minimal changes. ..Williams.. 07/09/2025 .PREV DISCUSSION... /ISSUED 0156 AM CDT Wed Jul 09 2025/ ...Synopsis... A compact midlevel trough will advance eastward across the northern Great Basin during the day. At the same time, a separate large-scale trough will move eastward across western Canada. ...Great Basin... Preceding the compact midlevel trough, moderate deep-layer southwesterly flow will overspread the Great Basin during peak heating. Deep boundary-layer mixing into this strengthening flow aloft will result in an expansive area of lower-teens RH and 20-25 mph sustained west-southwesterly surface winds. Given increasingly dry fuels across the region, critical fire-weather conditions are expected from central NV into western UT (with elevated conditions surrounding this area across the Great Basin). ...Northwest... Large-scale ascent accompanying the compact midlevel trough will aid in isolated to widely scattered thunderstorm development over southeastern OR, southwestern ID, and far northeastern CA during the afternoon/evening hours. Deep inverted-V soundings and 0.5-0.7 inch PW will favor dry thunderstorms -- with a risk of lightning-induced ignitions and strong/erratic outflow winds. Additionally, strong westerly flow in the base of the large-scale trough moving across western Canada will persist across the Cascades. Despite slightly higher RH than previous days, strong downslope/westerly surface winds will favor elevated to locally critical fire-weather conditions in the Columbia Basin. ...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 1157 AM CDT Wed Jul 09 2025 Valid 091700Z - 101200Z ...CRITICAL FIRE WEATHER AREA FOR EASTERN NEVADA AND FAR WESTERN UTAH... ...Montana... A mid-level trough translating east across the Canada/U.S. border and subsequent breakdown of upper-level ridge over the Northern Rockies along with sufficient mid-level moisture/instability will aid in high-based thunderstorm development across the higher terrain of western MT, moving into eastern MT by evening. Fast east-northeastward thunderstorm trajectories on the order of 25-30 knots will limit rainfall (in addition to gusty/erratic outflow winds) over dry fuels, supporting an increased wildfire spread potential for portions of central and eastern MT where isolated dry thunderstorm highlights were added. Otherwise, previous forecast (see below) for additional fire weather threats across the Western U.S. remains on track with minimal changes. ..Williams.. 07/09/2025 .PREV DISCUSSION... /ISSUED 0156 AM CDT Wed Jul 09 2025/ ...Synopsis... A compact midlevel trough will advance eastward across the northern Great Basin during the day. At the same time, a separate large-scale trough will move eastward across western Canada. ...Great Basin... Preceding the compact midlevel trough, moderate deep-layer southwesterly flow will overspread the Great Basin during peak heating. Deep boundary-layer mixing into this strengthening flow aloft will result in an expansive area of lower-teens RH and 20-25 mph sustained west-southwesterly surface winds. Given increasingly dry fuels across the region, critical fire-weather conditions are expected from central NV into western UT (with elevated conditions surrounding this area across the Great Basin). ...Northwest... Large-scale ascent accompanying the compact midlevel trough will aid in isolated to widely scattered thunderstorm development over southeastern OR, southwestern ID, and far northeastern CA during the afternoon/evening hours. Deep inverted-V soundings and 0.5-0.7 inch PW will favor dry thunderstorms -- with a risk of lightning-induced ignitions and strong/erratic outflow winds. Additionally, strong westerly flow in the base of the large-scale trough moving across western Canada will persist across the Cascades. Despite slightly higher RH than previous days, strong downslope/westerly surface winds will favor elevated to locally critical fire-weather conditions in the Columbia Basin. ...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 1157 AM CDT Wed Jul 09 2025 Valid 091700Z - 101200Z ...CRITICAL FIRE WEATHER AREA FOR EASTERN NEVADA AND FAR WESTERN UTAH... ...Montana... A mid-level trough translating east across the Canada/U.S. border and subsequent breakdown of upper-level ridge over the Northern Rockies along with sufficient mid-level moisture/instability will aid in high-based thunderstorm development across the higher terrain of western MT, moving into eastern MT by evening. Fast east-northeastward thunderstorm trajectories on the order of 25-30 knots will limit rainfall (in addition to gusty/erratic outflow winds) over dry fuels, supporting an increased wildfire spread potential for portions of central and eastern MT where isolated dry thunderstorm highlights were added. Otherwise, previous forecast (see below) for additional fire weather threats across the Western U.S. remains on track with minimal changes. ..Williams.. 07/09/2025 .PREV DISCUSSION... /ISSUED 0156 AM CDT Wed Jul 09 2025/ ...Synopsis... A compact midlevel trough will advance eastward across the northern Great Basin during the day. At the same time, a separate large-scale trough will move eastward across western Canada. ...Great Basin... Preceding the compact midlevel trough, moderate deep-layer southwesterly flow will overspread the Great Basin during peak heating. Deep boundary-layer mixing into this strengthening flow aloft will result in an expansive area of lower-teens RH and 20-25 mph sustained west-southwesterly surface winds. Given increasingly dry fuels across the region, critical fire-weather conditions are expected from central NV into western UT (with elevated conditions surrounding this area across the Great Basin). ...Northwest... Large-scale ascent accompanying the compact midlevel trough will aid in isolated to widely scattered thunderstorm development over southeastern OR, southwestern ID, and far northeastern CA during the afternoon/evening hours. Deep inverted-V soundings and 0.5-0.7 inch PW will favor dry thunderstorms -- with a risk of lightning-induced ignitions and strong/erratic outflow winds. Additionally, strong westerly flow in the base of the large-scale trough moving across western Canada will persist across the Cascades. Despite slightly higher RH than previous days, strong downslope/westerly surface winds will favor elevated to locally critical fire-weather conditions in the Columbia Basin. ...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 1157 AM CDT Wed Jul 09 2025 Valid 091700Z - 101200Z ...CRITICAL FIRE WEATHER AREA FOR EASTERN NEVADA AND FAR WESTERN UTAH... ...Montana... A mid-level trough translating east across the Canada/U.S. border and subsequent breakdown of upper-level ridge over the Northern Rockies along with sufficient mid-level moisture/instability will aid in high-based thunderstorm development across the higher terrain of western MT, moving into eastern MT by evening. Fast east-northeastward thunderstorm trajectories on the order of 25-30 knots will limit rainfall (in addition to gusty/erratic outflow winds) over dry fuels, supporting an increased wildfire spread potential for portions of central and eastern MT where isolated dry thunderstorm highlights were added. Otherwise, previous forecast (see below) for additional fire weather threats across the Western U.S. remains on track with minimal changes. ..Williams.. 07/09/2025 .PREV DISCUSSION... /ISSUED 0156 AM CDT Wed Jul 09 2025/ ...Synopsis... A compact midlevel trough will advance eastward across the northern Great Basin during the day. At the same time, a separate large-scale trough will move eastward across western Canada. ...Great Basin... Preceding the compact midlevel trough, moderate deep-layer southwesterly flow will overspread the Great Basin during peak heating. Deep boundary-layer mixing into this strengthening flow aloft will result in an expansive area of lower-teens RH and 20-25 mph sustained west-southwesterly surface winds. Given increasingly dry fuels across the region, critical fire-weather conditions are expected from central NV into western UT (with elevated conditions surrounding this area across the Great Basin). ...Northwest... Large-scale ascent accompanying the compact midlevel trough will aid in isolated to widely scattered thunderstorm development over southeastern OR, southwestern ID, and far northeastern CA during the afternoon/evening hours. Deep inverted-V soundings and 0.5-0.7 inch PW will favor dry thunderstorms -- with a risk of lightning-induced ignitions and strong/erratic outflow winds. Additionally, strong westerly flow in the base of the large-scale trough moving across western Canada will persist across the Cascades. Despite slightly higher RH than previous days, strong downslope/westerly surface winds will favor elevated to locally critical fire-weather conditions in the Columbia Basin. ...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 1157 AM CDT Wed Jul 09 2025 Valid 091700Z - 101200Z ...CRITICAL FIRE WEATHER AREA FOR EASTERN NEVADA AND FAR WESTERN UTAH... ...Montana... A mid-level trough translating east across the Canada/U.S. border and subsequent breakdown of upper-level ridge over the Northern Rockies along with sufficient mid-level moisture/instability will aid in high-based thunderstorm development across the higher terrain of western MT, moving into eastern MT by evening. Fast east-northeastward thunderstorm trajectories on the order of 25-30 knots will limit rainfall (in addition to gusty/erratic outflow winds) over dry fuels, supporting an increased wildfire spread potential for portions of central and eastern MT where isolated dry thunderstorm highlights were added. Otherwise, previous forecast (see below) for additional fire weather threats across the Western U.S. remains on track with minimal changes. ..Williams.. 07/09/2025 .PREV DISCUSSION... /ISSUED 0156 AM CDT Wed Jul 09 2025/ ...Synopsis... A compact midlevel trough will advance eastward across the northern Great Basin during the day. At the same time, a separate large-scale trough will move eastward across western Canada. ...Great Basin... Preceding the compact midlevel trough, moderate deep-layer southwesterly flow will overspread the Great Basin during peak heating. Deep boundary-layer mixing into this strengthening flow aloft will result in an expansive area of lower-teens RH and 20-25 mph sustained west-southwesterly surface winds. Given increasingly dry fuels across the region, critical fire-weather conditions are expected from central NV into western UT (with elevated conditions surrounding this area across the Great Basin). ...Northwest... Large-scale ascent accompanying the compact midlevel trough will aid in isolated to widely scattered thunderstorm development over southeastern OR, southwestern ID, and far northeastern CA during the afternoon/evening hours. Deep inverted-V soundings and 0.5-0.7 inch PW will favor dry thunderstorms -- with a risk of lightning-induced ignitions and strong/erratic outflow winds. Additionally, strong westerly flow in the base of the large-scale trough moving across western Canada will persist across the Cascades. Despite slightly higher RH than previous days, strong downslope/westerly surface winds will favor elevated to locally critical fire-weather conditions in the Columbia Basin. ...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 1157 AM CDT Wed Jul 09 2025 Valid 091700Z - 101200Z ...CRITICAL FIRE WEATHER AREA FOR EASTERN NEVADA AND FAR WESTERN UTAH... ...Montana... A mid-level trough translating east across the Canada/U.S. border and subsequent breakdown of upper-level ridge over the Northern Rockies along with sufficient mid-level moisture/instability will aid in high-based thunderstorm development across the higher terrain of western MT, moving into eastern MT by evening. Fast east-northeastward thunderstorm trajectories on the order of 25-30 knots will limit rainfall (in addition to gusty/erratic outflow winds) over dry fuels, supporting an increased wildfire spread potential for portions of central and eastern MT where isolated dry thunderstorm highlights were added. Otherwise, previous forecast (see below) for additional fire weather threats across the Western U.S. remains on track with minimal changes. ..Williams.. 07/09/2025 .PREV DISCUSSION... /ISSUED 0156 AM CDT Wed Jul 09 2025/ ...Synopsis... A compact midlevel trough will advance eastward across the northern Great Basin during the day. At the same time, a separate large-scale trough will move eastward across western Canada. ...Great Basin... Preceding the compact midlevel trough, moderate deep-layer southwesterly flow will overspread the Great Basin during peak heating. Deep boundary-layer mixing into this strengthening flow aloft will result in an expansive area of lower-teens RH and 20-25 mph sustained west-southwesterly surface winds. Given increasingly dry fuels across the region, critical fire-weather conditions are expected from central NV into western UT (with elevated conditions surrounding this area across the Great Basin). ...Northwest... Large-scale ascent accompanying the compact midlevel trough will aid in isolated to widely scattered thunderstorm development over southeastern OR, southwestern ID, and far northeastern CA during the afternoon/evening hours. Deep inverted-V soundings and 0.5-0.7 inch PW will favor dry thunderstorms -- with a risk of lightning-induced ignitions and strong/erratic outflow winds. Additionally, strong westerly flow in the base of the large-scale trough moving across western Canada will persist across the Cascades. Despite slightly higher RH than previous days, strong downslope/westerly surface winds will favor elevated to locally critical fire-weather conditions in the Columbia Basin. ...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 1157 AM CDT Wed Jul 09 2025 Valid 091700Z - 101200Z ...CRITICAL FIRE WEATHER AREA FOR EASTERN NEVADA AND FAR WESTERN UTAH... ...Montana... A mid-level trough translating east across the Canada/U.S. border and subsequent breakdown of upper-level ridge over the Northern Rockies along with sufficient mid-level moisture/instability will aid in high-based thunderstorm development across the higher terrain of western MT, moving into eastern MT by evening. Fast east-northeastward thunderstorm trajectories on the order of 25-30 knots will limit rainfall (in addition to gusty/erratic outflow winds) over dry fuels, supporting an increased wildfire spread potential for portions of central and eastern MT where isolated dry thunderstorm highlights were added. Otherwise, previous forecast (see below) for additional fire weather threats across the Western U.S. remains on track with minimal changes. ..Williams.. 07/09/2025 .PREV DISCUSSION... /ISSUED 0156 AM CDT Wed Jul 09 2025/ ...Synopsis... A compact midlevel trough will advance eastward across the northern Great Basin during the day. At the same time, a separate large-scale trough will move eastward across western Canada. ...Great Basin... Preceding the compact midlevel trough, moderate deep-layer southwesterly flow will overspread the Great Basin during peak heating. Deep boundary-layer mixing into this strengthening flow aloft will result in an expansive area of lower-teens RH and 20-25 mph sustained west-southwesterly surface winds. Given increasingly dry fuels across the region, critical fire-weather conditions are expected from central NV into western UT (with elevated conditions surrounding this area across the Great Basin). ...Northwest... Large-scale ascent accompanying the compact midlevel trough will aid in isolated to widely scattered thunderstorm development over southeastern OR, southwestern ID, and far northeastern CA during the afternoon/evening hours. Deep inverted-V soundings and 0.5-0.7 inch PW will favor dry thunderstorms -- with a risk of lightning-induced ignitions and strong/erratic outflow winds. Additionally, strong westerly flow in the base of the large-scale trough moving across western Canada will persist across the Cascades. Despite slightly higher RH than previous days, strong downslope/westerly surface winds will favor elevated to locally critical fire-weather conditions in the Columbia Basin. ...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 1157 AM CDT Wed Jul 09 2025 Valid 091700Z - 101200Z ...CRITICAL FIRE WEATHER AREA FOR EASTERN NEVADA AND FAR WESTERN UTAH... ...Montana... A mid-level trough translating east across the Canada/U.S. border and subsequent breakdown of upper-level ridge over the Northern Rockies along with sufficient mid-level moisture/instability will aid in high-based thunderstorm development across the higher terrain of western MT, moving into eastern MT by evening. Fast east-northeastward thunderstorm trajectories on the order of 25-30 knots will limit rainfall (in addition to gusty/erratic outflow winds) over dry fuels, supporting an increased wildfire spread potential for portions of central and eastern MT where isolated dry thunderstorm highlights were added. Otherwise, previous forecast (see below) for additional fire weather threats across the Western U.S. remains on track with minimal changes. ..Williams.. 07/09/2025 .PREV DISCUSSION... /ISSUED 0156 AM CDT Wed Jul 09 2025/ ...Synopsis... A compact midlevel trough will advance eastward across the northern Great Basin during the day. At the same time, a separate large-scale trough will move eastward across western Canada. ...Great Basin... Preceding the compact midlevel trough, moderate deep-layer southwesterly flow will overspread the Great Basin during peak heating. Deep boundary-layer mixing into this strengthening flow aloft will result in an expansive area of lower-teens RH and 20-25 mph sustained west-southwesterly surface winds. Given increasingly dry fuels across the region, critical fire-weather conditions are expected from central NV into western UT (with elevated conditions surrounding this area across the Great Basin). ...Northwest... Large-scale ascent accompanying the compact midlevel trough will aid in isolated to widely scattered thunderstorm development over southeastern OR, southwestern ID, and far northeastern CA during the afternoon/evening hours. Deep inverted-V soundings and 0.5-0.7 inch PW will favor dry thunderstorms -- with a risk of lightning-induced ignitions and strong/erratic outflow winds. Additionally, strong westerly flow in the base of the large-scale trough moving across western Canada will persist across the Cascades. Despite slightly higher RH than previous days, strong downslope/westerly surface winds will favor elevated to locally critical fire-weather conditions in the Columbia Basin. ...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 1157 AM CDT Wed Jul 09 2025 Valid 091700Z - 101200Z ...CRITICAL FIRE WEATHER AREA FOR EASTERN NEVADA AND FAR WESTERN UTAH... ...Montana... A mid-level trough translating east across the Canada/U.S. border and subsequent breakdown of upper-level ridge over the Northern Rockies along with sufficient mid-level moisture/instability will aid in high-based thunderstorm development across the higher terrain of western MT, moving into eastern MT by evening. Fast east-northeastward thunderstorm trajectories on the order of 25-30 knots will limit rainfall (in addition to gusty/erratic outflow winds) over dry fuels, supporting an increased wildfire spread potential for portions of central and eastern MT where isolated dry thunderstorm highlights were added. Otherwise, previous forecast (see below) for additional fire weather threats across the Western U.S. remains on track with minimal changes. ..Williams.. 07/09/2025 .PREV DISCUSSION... /ISSUED 0156 AM CDT Wed Jul 09 2025/ ...Synopsis... A compact midlevel trough will advance eastward across the northern Great Basin during the day. At the same time, a separate large-scale trough will move eastward across western Canada. ...Great Basin... Preceding the compact midlevel trough, moderate deep-layer southwesterly flow will overspread the Great Basin during peak heating. Deep boundary-layer mixing into this strengthening flow aloft will result in an expansive area of lower-teens RH and 20-25 mph sustained west-southwesterly surface winds. Given increasingly dry fuels across the region, critical fire-weather conditions are expected from central NV into western UT (with elevated conditions surrounding this area across the Great Basin). ...Northwest... Large-scale ascent accompanying the compact midlevel trough will aid in isolated to widely scattered thunderstorm development over southeastern OR, southwestern ID, and far northeastern CA during the afternoon/evening hours. Deep inverted-V soundings and 0.5-0.7 inch PW will favor dry thunderstorms -- with a risk of lightning-induced ignitions and strong/erratic outflow winds. Additionally, strong westerly flow in the base of the large-scale trough moving across western Canada will persist across the Cascades. Despite slightly higher RH than previous days, strong downslope/westerly surface winds will favor elevated to locally critical fire-weather conditions in the Columbia Basin. ...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 1157 AM CDT Wed Jul 09 2025 Valid 091700Z - 101200Z ...CRITICAL FIRE WEATHER AREA FOR EASTERN NEVADA AND FAR WESTERN UTAH... ...Montana... A mid-level trough translating east across the Canada/U.S. border and subsequent breakdown of upper-level ridge over the Northern Rockies along with sufficient mid-level moisture/instability will aid in high-based thunderstorm development across the higher terrain of western MT, moving into eastern MT by evening. Fast east-northeastward thunderstorm trajectories on the order of 25-30 knots will limit rainfall (in addition to gusty/erratic outflow winds) over dry fuels, supporting an increased wildfire spread potential for portions of central and eastern MT where isolated dry thunderstorm highlights were added. Otherwise, previous forecast (see below) for additional fire weather threats across the Western U.S. remains on track with minimal changes. ..Williams.. 07/09/2025 .PREV DISCUSSION... /ISSUED 0156 AM CDT Wed Jul 09 2025/ ...Synopsis... A compact midlevel trough will advance eastward across the northern Great Basin during the day. At the same time, a separate large-scale trough will move eastward across western Canada. ...Great Basin... Preceding the compact midlevel trough, moderate deep-layer southwesterly flow will overspread the Great Basin during peak heating. Deep boundary-layer mixing into this strengthening flow aloft will result in an expansive area of lower-teens RH and 20-25 mph sustained west-southwesterly surface winds. Given increasingly dry fuels across the region, critical fire-weather conditions are expected from central NV into western UT (with elevated conditions surrounding this area across the Great Basin). ...Northwest... Large-scale ascent accompanying the compact midlevel trough will aid in isolated to widely scattered thunderstorm development over southeastern OR, southwestern ID, and far northeastern CA during the afternoon/evening hours. Deep inverted-V soundings and 0.5-0.7 inch PW will favor dry thunderstorms -- with a risk of lightning-induced ignitions and strong/erratic outflow winds. Additionally, strong westerly flow in the base of the large-scale trough moving across western Canada will persist across the Cascades. Despite slightly higher RH than previous days, strong downslope/westerly surface winds will favor elevated to locally critical fire-weather conditions in the Columbia Basin. ...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 1157 AM CDT Wed Jul 09 2025 Valid 091700Z - 101200Z ...CRITICAL FIRE WEATHER AREA FOR EASTERN NEVADA AND FAR WESTERN UTAH... ...Montana... A mid-level trough translating east across the Canada/U.S. border and subsequent breakdown of upper-level ridge over the Northern Rockies along with sufficient mid-level moisture/instability will aid in high-based thunderstorm development across the higher terrain of western MT, moving into eastern MT by evening. Fast east-northeastward thunderstorm trajectories on the order of 25-30 knots will limit rainfall (in addition to gusty/erratic outflow winds) over dry fuels, supporting an increased wildfire spread potential for portions of central and eastern MT where isolated dry thunderstorm highlights were added. Otherwise, previous forecast (see below) for additional fire weather threats across the Western U.S. remains on track with minimal changes. ..Williams.. 07/09/2025 .PREV DISCUSSION... /ISSUED 0156 AM CDT Wed Jul 09 2025/ ...Synopsis... A compact midlevel trough will advance eastward across the northern Great Basin during the day. At the same time, a separate large-scale trough will move eastward across western Canada. ...Great Basin... Preceding the compact midlevel trough, moderate deep-layer southwesterly flow will overspread the Great Basin during peak heating. Deep boundary-layer mixing into this strengthening flow aloft will result in an expansive area of lower-teens RH and 20-25 mph sustained west-southwesterly surface winds. Given increasingly dry fuels across the region, critical fire-weather conditions are expected from central NV into western UT (with elevated conditions surrounding this area across the Great Basin). ...Northwest... Large-scale ascent accompanying the compact midlevel trough will aid in isolated to widely scattered thunderstorm development over southeastern OR, southwestern ID, and far northeastern CA during the afternoon/evening hours. Deep inverted-V soundings and 0.5-0.7 inch PW will favor dry thunderstorms -- with a risk of lightning-induced ignitions and strong/erratic outflow winds. Additionally, strong westerly flow in the base of the large-scale trough moving across western Canada will persist across the Cascades. Despite slightly higher RH than previous days, strong downslope/westerly surface winds will favor elevated to locally critical fire-weather conditions in the Columbia Basin. ...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 1157 AM CDT Wed Jul 09 2025 Valid 091700Z - 101200Z ...CRITICAL FIRE WEATHER AREA FOR EASTERN NEVADA AND FAR WESTERN UTAH... ...Montana... A mid-level trough translating east across the Canada/U.S. border and subsequent breakdown of upper-level ridge over the Northern Rockies along with sufficient mid-level moisture/instability will aid in high-based thunderstorm development across the higher terrain of western MT, moving into eastern MT by evening. Fast east-northeastward thunderstorm trajectories on the order of 25-30 knots will limit rainfall (in addition to gusty/erratic outflow winds) over dry fuels, supporting an increased wildfire spread potential for portions of central and eastern MT where isolated dry thunderstorm highlights were added. Otherwise, previous forecast (see below) for additional fire weather threats across the Western U.S. remains on track with minimal changes. ..Williams.. 07/09/2025 .PREV DISCUSSION... /ISSUED 0156 AM CDT Wed Jul 09 2025/ ...Synopsis... A compact midlevel trough will advance eastward across the northern Great Basin during the day. At the same time, a separate large-scale trough will move eastward across western Canada. ...Great Basin... Preceding the compact midlevel trough, moderate deep-layer southwesterly flow will overspread the Great Basin during peak heating. Deep boundary-layer mixing into this strengthening flow aloft will result in an expansive area of lower-teens RH and 20-25 mph sustained west-southwesterly surface winds. Given increasingly dry fuels across the region, critical fire-weather conditions are expected from central NV into western UT (with elevated conditions surrounding this area across the Great Basin). ...Northwest... Large-scale ascent accompanying the compact midlevel trough will aid in isolated to widely scattered thunderstorm development over southeastern OR, southwestern ID, and far northeastern CA during the afternoon/evening hours. Deep inverted-V soundings and 0.5-0.7 inch PW will favor dry thunderstorms -- with a risk of lightning-induced ignitions and strong/erratic outflow winds. Additionally, strong westerly flow in the base of the large-scale trough moving across western Canada will persist across the Cascades. Despite slightly higher RH than previous days, strong downslope/westerly surface winds will favor elevated to locally critical fire-weather conditions in the Columbia Basin. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

MD 1612 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR PORTIONS OF EXTREME NORTHEAST NORTH CAROLINA INTO CENTRAL AND EASTERN WEST VIRGINIA...WESTERN VIRGINIA...AND WESTERN MARYLAND
Mesoscale Discussion 1612 NWS Storm Prediction Center Norman OK 1030 AM CDT Wed Jul 09 2025 Areas affected...Portions of extreme northeast North Carolina into central and eastern West Virginia...western Virginia...and western Maryland Concerning...Severe potential...Watch possible Valid 091530Z - 091700Z Probability of Watch Issuance...40 percent SUMMARY...Storms should increase in coverage and intensity through early afternoon. Damaging gusts should be the main threat, though a few instances of severe hail are also possible. DISCUSSION...Thunderstorms have gradually intensified over the past couple of hours, with MRMS mosaic radar imagery showing 40 dBZ echoes already approaching 30 kft. Ahead of the storms, temperatures have already reached 80 F in spots, with 70 F dewpoints helping to boost MLCAPE to around 1000 J/kg amid rapidly eroding MLCINH. Furthermore, stronger mid-level southwesterly flow overspreading the region is contributing to straight hodographs and up to 35 kts of effective bulk shear. With continued boundary layer destabilization, multicells and perhaps a transient supercell will be the most likely storm modes, capable of damaging gusts and perhaps an instance or two of severe hail. ..Squitieri/Mosier.. 07/09/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...LWX...RNK...PBZ...RLX...MRX... LAT...LON 36728197 38058184 38728166 38958147 39218119 39358086 39677960 39687898 39677864 39577821 39297804 38827807 38447827 38097917 37578005 36848058 36218106 36148145 36248186 36728197 MOST PROBABLE PEAK WIND GUST...55-70 MPH MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1131 AM CDT Wed Jul 09 2025 Valid 091630Z - 101200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS CENTRAL SD AND FAR NORTH-CENTRAL NE AND SOUTH-CENTRAL MT... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE MID-ATLANTIC STATES AND CAROLINAS... ...SUMMARY... Severe wind gusts and isolated large hail are possible across parts of the northern/central Plains late this afternoon into evening. Scattered damaging winds are possible this afternoon to early evening from parts of the Carolinas to the Mid-Atlantic as well as over central Montana. ...Northern/Central Plains... A reservoir of ample low-level moisture currently exists from the central Plains back northwestward into eastern MT, with upper 60s dewpoints in NE and mid 60s dewpoints as far northwest as DIK in southwest ND. Steep mid-level lapse rates extend over the westernmost portions of this greater low-level moisture, which will support the development of strong to very strong buoyancy later this afternoon. Thunderstorms are not expected to develop within this area of strong buoyancy, but instead will likely initiate farther west (from southeast MT/northeast WY into the NE Panhandle) amid a combination of weak lee troughing and subtle ascent attendant to low-amplitude shortwave trough. Here, modest buoyancy, high cloud bases, and moderate westerly flow aloft will result in outflow-dominant storm structures which will quickly move into the more buoyant airmass downstream. Given the ample buoyancy and moderate vertical shear, updrafts should persist along this fast-moving outflow, resulting in more progressive convective clusters. Severe gusts will be possible as these clusters move eastward/southeastward, with some potential for gusts over 75 mph. Recent guidance has provided more confidence in higher severe wind coverage, meriting the introduction of 30% wind probabilities and southeastward expansion of the 15% wind probabilities past the MO River in NE/IA. ...Mid-Atlantic/Southeast States... Recent satellite imagery shows a shortwave trough extending from southern Ontario through the Lower OH Valley. Morning soundings and recent mesoanalysis both show moderate mid-level flow (i.e. 30 to 40 kt at 500 mb) throughout the base of this shortwave. Expectation is for this wave to continue eastward/northeastward through the OH Valley, reaching the Mid-Atlantic by late afternoon. The airmass preceding this wave across the Mid-Atlantic is very moist, with dewpoints ranging from the upper 60s/low 70s from eastern PA/NJ to the mid 70s across the eastern Carolina. This ample low-level moisture will result in quick airmass destabilization amid strong daytime heating. Limited remaining convective inhibition on recent mesoanalysis indicates this destabilization is already firmly underway. Large-scale lift attendant to the approaching shortwave (augmented by orographic ascent) coupled with airmass destabilization will result in scattered to numerous thunderstorms development this afternoon over the southern Appalachians and Blue Ridge Mountains. This initial, more cellular development could produce isolated hail. These storms should then spread eastward towards the coast with some increasing coverage possible. The strongest mid-level flow (and greatest vertical shear) this afternoon will extend from WV across northern VA/southern PA and NJ. The greatest buoyancy will be farther south, across the Carolinas and GA. Even with this displacement, there is enough overlap between the buoyancy and shear to support loosely organized strong to severe storms. The highest concentration of severe storms is anticipated from southeast PA/southern NJ southward across central VA and the Delmarva into central NC. In this region, numerous thunderstorms coupled with moderate shear should result in several cold-pool-dominated, forward-propagating convective clusters. Damaging gusts will be the primary risk within this more linear activity. ...Northern Intermountain West/Rockies and Northern Great Basin... A shortwave trough is currently moving through northern CA. An elongated belt of enhanced southwesterly mid-level flow exists from the base of this shortwave (over northern CA/northwest NV) northeastward across the northern Great Basin/Rockies. Scattered thunderstorm development is anticipated within this favorable flow regime. Daytime heating and steepened low-level lapse rates coupled with this enhanced mid-level flow should support a strong to severe wind gusts from parts of eastern Oregon into Idaho/Montana and possibly northern Utah. Highest coverage is expected over south-central MT. ...Lower Michigan to northwest Ohio... Scattered thunderstorms are forecast develop this afternoon beneath a weak upper trough across parts of Lower Michigan and northwest Ohio. A modest combination of instability and deep-layer shear will support isolated/marginally severe hail and locally damaging winds with the strongest updrafts. ..Mosier/Moore.. 07/09/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1131 AM CDT Wed Jul 09 2025 Valid 091630Z - 101200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS CENTRAL SD AND FAR NORTH-CENTRAL NE AND SOUTH-CENTRAL MT... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE MID-ATLANTIC STATES AND CAROLINAS... ...SUMMARY... Severe wind gusts and isolated large hail are possible across parts of the northern/central Plains late this afternoon into evening. Scattered damaging winds are possible this afternoon to early evening from parts of the Carolinas to the Mid-Atlantic as well as over central Montana. ...Northern/Central Plains... A reservoir of ample low-level moisture currently exists from the central Plains back northwestward into eastern MT, with upper 60s dewpoints in NE and mid 60s dewpoints as far northwest as DIK in southwest ND. Steep mid-level lapse rates extend over the westernmost portions of this greater low-level moisture, which will support the development of strong to very strong buoyancy later this afternoon. Thunderstorms are not expected to develop within this area of strong buoyancy, but instead will likely initiate farther west (from southeast MT/northeast WY into the NE Panhandle) amid a combination of weak lee troughing and subtle ascent attendant to low-amplitude shortwave trough. Here, modest buoyancy, high cloud bases, and moderate westerly flow aloft will result in outflow-dominant storm structures which will quickly move into the more buoyant airmass downstream. Given the ample buoyancy and moderate vertical shear, updrafts should persist along this fast-moving outflow, resulting in more progressive convective clusters. Severe gusts will be possible as these clusters move eastward/southeastward, with some potential for gusts over 75 mph. Recent guidance has provided more confidence in higher severe wind coverage, meriting the introduction of 30% wind probabilities and southeastward expansion of the 15% wind probabilities past the MO River in NE/IA. ...Mid-Atlantic/Southeast States... Recent satellite imagery shows a shortwave trough extending from southern Ontario through the Lower OH Valley. Morning soundings and recent mesoanalysis both show moderate mid-level flow (i.e. 30 to 40 kt at 500 mb) throughout the base of this shortwave. Expectation is for this wave to continue eastward/northeastward through the OH Valley, reaching the Mid-Atlantic by late afternoon. The airmass preceding this wave across the Mid-Atlantic is very moist, with dewpoints ranging from the upper 60s/low 70s from eastern PA/NJ to the mid 70s across the eastern Carolina. This ample low-level moisture will result in quick airmass destabilization amid strong daytime heating. Limited remaining convective inhibition on recent mesoanalysis indicates this destabilization is already firmly underway. Large-scale lift attendant to the approaching shortwave (augmented by orographic ascent) coupled with airmass destabilization will result in scattered to numerous thunderstorms development this afternoon over the southern Appalachians and Blue Ridge Mountains. This initial, more cellular development could produce isolated hail. These storms should then spread eastward towards the coast with some increasing coverage possible. The strongest mid-level flow (and greatest vertical shear) this afternoon will extend from WV across northern VA/southern PA and NJ. The greatest buoyancy will be farther south, across the Carolinas and GA. Even with this displacement, there is enough overlap between the buoyancy and shear to support loosely organized strong to severe storms. The highest concentration of severe storms is anticipated from southeast PA/southern NJ southward across central VA and the Delmarva into central NC. In this region, numerous thunderstorms coupled with moderate shear should result in several cold-pool-dominated, forward-propagating convective clusters. Damaging gusts will be the primary risk within this more linear activity. ...Northern Intermountain West/Rockies and Northern Great Basin... A shortwave trough is currently moving through northern CA. An elongated belt of enhanced southwesterly mid-level flow exists from the base of this shortwave (over northern CA/northwest NV) northeastward across the northern Great Basin/Rockies. Scattered thunderstorm development is anticipated within this favorable flow regime. Daytime heating and steepened low-level lapse rates coupled with this enhanced mid-level flow should support a strong to severe wind gusts from parts of eastern Oregon into Idaho/Montana and possibly northern Utah. Highest coverage is expected over south-central MT. ...Lower Michigan to northwest Ohio... Scattered thunderstorms are forecast develop this afternoon beneath a weak upper trough across parts of Lower Michigan and northwest Ohio. A modest combination of instability and deep-layer shear will support isolated/marginally severe hail and locally damaging winds with the strongest updrafts. ..Mosier/Moore.. 07/09/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1131 AM CDT Wed Jul 09 2025 Valid 091630Z - 101200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS CENTRAL SD AND FAR NORTH-CENTRAL NE AND SOUTH-CENTRAL MT... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE MID-ATLANTIC STATES AND CAROLINAS... ...SUMMARY... Severe wind gusts and isolated large hail are possible across parts of the northern/central Plains late this afternoon into evening. Scattered damaging winds are possible this afternoon to early evening from parts of the Carolinas to the Mid-Atlantic as well as over central Montana. ...Northern/Central Plains... A reservoir of ample low-level moisture currently exists from the central Plains back northwestward into eastern MT, with upper 60s dewpoints in NE and mid 60s dewpoints as far northwest as DIK in southwest ND. Steep mid-level lapse rates extend over the westernmost portions of this greater low-level moisture, which will support the development of strong to very strong buoyancy later this afternoon. Thunderstorms are not expected to develop within this area of strong buoyancy, but instead will likely initiate farther west (from southeast MT/northeast WY into the NE Panhandle) amid a combination of weak lee troughing and subtle ascent attendant to low-amplitude shortwave trough. Here, modest buoyancy, high cloud bases, and moderate westerly flow aloft will result in outflow-dominant storm structures which will quickly move into the more buoyant airmass downstream. Given the ample buoyancy and moderate vertical shear, updrafts should persist along this fast-moving outflow, resulting in more progressive convective clusters. Severe gusts will be possible as these clusters move eastward/southeastward, with some potential for gusts over 75 mph. Recent guidance has provided more confidence in higher severe wind coverage, meriting the introduction of 30% wind probabilities and southeastward expansion of the 15% wind probabilities past the MO River in NE/IA. ...Mid-Atlantic/Southeast States... Recent satellite imagery shows a shortwave trough extending from southern Ontario through the Lower OH Valley. Morning soundings and recent mesoanalysis both show moderate mid-level flow (i.e. 30 to 40 kt at 500 mb) throughout the base of this shortwave. Expectation is for this wave to continue eastward/northeastward through the OH Valley, reaching the Mid-Atlantic by late afternoon. The airmass preceding this wave across the Mid-Atlantic is very moist, with dewpoints ranging from the upper 60s/low 70s from eastern PA/NJ to the mid 70s across the eastern Carolina. This ample low-level moisture will result in quick airmass destabilization amid strong daytime heating. Limited remaining convective inhibition on recent mesoanalysis indicates this destabilization is already firmly underway. Large-scale lift attendant to the approaching shortwave (augmented by orographic ascent) coupled with airmass destabilization will result in scattered to numerous thunderstorms development this afternoon over the southern Appalachians and Blue Ridge Mountains. This initial, more cellular development could produce isolated hail. These storms should then spread eastward towards the coast with some increasing coverage possible. The strongest mid-level flow (and greatest vertical shear) this afternoon will extend from WV across northern VA/southern PA and NJ. The greatest buoyancy will be farther south, across the Carolinas and GA. Even with this displacement, there is enough overlap between the buoyancy and shear to support loosely organized strong to severe storms. The highest concentration of severe storms is anticipated from southeast PA/southern NJ southward across central VA and the Delmarva into central NC. In this region, numerous thunderstorms coupled with moderate shear should result in several cold-pool-dominated, forward-propagating convective clusters. Damaging gusts will be the primary risk within this more linear activity. ...Northern Intermountain West/Rockies and Northern Great Basin... A shortwave trough is currently moving through northern CA. An elongated belt of enhanced southwesterly mid-level flow exists from the base of this shortwave (over northern CA/northwest NV) northeastward across the northern Great Basin/Rockies. Scattered thunderstorm development is anticipated within this favorable flow regime. Daytime heating and steepened low-level lapse rates coupled with this enhanced mid-level flow should support a strong to severe wind gusts from parts of eastern Oregon into Idaho/Montana and possibly northern Utah. Highest coverage is expected over south-central MT. ...Lower Michigan to northwest Ohio... Scattered thunderstorms are forecast develop this afternoon beneath a weak upper trough across parts of Lower Michigan and northwest Ohio. A modest combination of instability and deep-layer shear will support isolated/marginally severe hail and locally damaging winds with the strongest updrafts. ..Mosier/Moore.. 07/09/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1131 AM CDT Wed Jul 09 2025 Valid 091630Z - 101200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS CENTRAL SD AND FAR NORTH-CENTRAL NE AND SOUTH-CENTRAL MT... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE MID-ATLANTIC STATES AND CAROLINAS... ...SUMMARY... Severe wind gusts and isolated large hail are possible across parts of the northern/central Plains late this afternoon into evening. Scattered damaging winds are possible this afternoon to early evening from parts of the Carolinas to the Mid-Atlantic as well as over central Montana. ...Northern/Central Plains... A reservoir of ample low-level moisture currently exists from the central Plains back northwestward into eastern MT, with upper 60s dewpoints in NE and mid 60s dewpoints as far northwest as DIK in southwest ND. Steep mid-level lapse rates extend over the westernmost portions of this greater low-level moisture, which will support the development of strong to very strong buoyancy later this afternoon. Thunderstorms are not expected to develop within this area of strong buoyancy, but instead will likely initiate farther west (from southeast MT/northeast WY into the NE Panhandle) amid a combination of weak lee troughing and subtle ascent attendant to low-amplitude shortwave trough. Here, modest buoyancy, high cloud bases, and moderate westerly flow aloft will result in outflow-dominant storm structures which will quickly move into the more buoyant airmass downstream. Given the ample buoyancy and moderate vertical shear, updrafts should persist along this fast-moving outflow, resulting in more progressive convective clusters. Severe gusts will be possible as these clusters move eastward/southeastward, with some potential for gusts over 75 mph. Recent guidance has provided more confidence in higher severe wind coverage, meriting the introduction of 30% wind probabilities and southeastward expansion of the 15% wind probabilities past the MO River in NE/IA. ...Mid-Atlantic/Southeast States... Recent satellite imagery shows a shortwave trough extending from southern Ontario through the Lower OH Valley. Morning soundings and recent mesoanalysis both show moderate mid-level flow (i.e. 30 to 40 kt at 500 mb) throughout the base of this shortwave. Expectation is for this wave to continue eastward/northeastward through the OH Valley, reaching the Mid-Atlantic by late afternoon. The airmass preceding this wave across the Mid-Atlantic is very moist, with dewpoints ranging from the upper 60s/low 70s from eastern PA/NJ to the mid 70s across the eastern Carolina. This ample low-level moisture will result in quick airmass destabilization amid strong daytime heating. Limited remaining convective inhibition on recent mesoanalysis indicates this destabilization is already firmly underway. Large-scale lift attendant to the approaching shortwave (augmented by orographic ascent) coupled with airmass destabilization will result in scattered to numerous thunderstorms development this afternoon over the southern Appalachians and Blue Ridge Mountains. This initial, more cellular development could produce isolated hail. These storms should then spread eastward towards the coast with some increasing coverage possible. The strongest mid-level flow (and greatest vertical shear) this afternoon will extend from WV across northern VA/southern PA and NJ. The greatest buoyancy will be farther south, across the Carolinas and GA. Even with this displacement, there is enough overlap between the buoyancy and shear to support loosely organized strong to severe storms. The highest concentration of severe storms is anticipated from southeast PA/southern NJ southward across central VA and the Delmarva into central NC. In this region, numerous thunderstorms coupled with moderate shear should result in several cold-pool-dominated, forward-propagating convective clusters. Damaging gusts will be the primary risk within this more linear activity. ...Northern Intermountain West/Rockies and Northern Great Basin... A shortwave trough is currently moving through northern CA. An elongated belt of enhanced southwesterly mid-level flow exists from the base of this shortwave (over northern CA/northwest NV) northeastward across the northern Great Basin/Rockies. Scattered thunderstorm development is anticipated within this favorable flow regime. Daytime heating and steepened low-level lapse rates coupled with this enhanced mid-level flow should support a strong to severe wind gusts from parts of eastern Oregon into Idaho/Montana and possibly northern Utah. Highest coverage is expected over south-central MT. ...Lower Michigan to northwest Ohio... Scattered thunderstorms are forecast develop this afternoon beneath a weak upper trough across parts of Lower Michigan and northwest Ohio. A modest combination of instability and deep-layer shear will support isolated/marginally severe hail and locally damaging winds with the strongest updrafts. ..Mosier/Moore.. 07/09/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1131 AM CDT Wed Jul 09 2025 Valid 091630Z - 101200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS CENTRAL SD AND FAR NORTH-CENTRAL NE AND SOUTH-CENTRAL MT... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE MID-ATLANTIC STATES AND CAROLINAS... ...SUMMARY... Severe wind gusts and isolated large hail are possible across parts of the northern/central Plains late this afternoon into evening. Scattered damaging winds are possible this afternoon to early evening from parts of the Carolinas to the Mid-Atlantic as well as over central Montana. ...Northern/Central Plains... A reservoir of ample low-level moisture currently exists from the central Plains back northwestward into eastern MT, with upper 60s dewpoints in NE and mid 60s dewpoints as far northwest as DIK in southwest ND. Steep mid-level lapse rates extend over the westernmost portions of this greater low-level moisture, which will support the development of strong to very strong buoyancy later this afternoon. Thunderstorms are not expected to develop within this area of strong buoyancy, but instead will likely initiate farther west (from southeast MT/northeast WY into the NE Panhandle) amid a combination of weak lee troughing and subtle ascent attendant to low-amplitude shortwave trough. Here, modest buoyancy, high cloud bases, and moderate westerly flow aloft will result in outflow-dominant storm structures which will quickly move into the more buoyant airmass downstream. Given the ample buoyancy and moderate vertical shear, updrafts should persist along this fast-moving outflow, resulting in more progressive convective clusters. Severe gusts will be possible as these clusters move eastward/southeastward, with some potential for gusts over 75 mph. Recent guidance has provided more confidence in higher severe wind coverage, meriting the introduction of 30% wind probabilities and southeastward expansion of the 15% wind probabilities past the MO River in NE/IA. ...Mid-Atlantic/Southeast States... Recent satellite imagery shows a shortwave trough extending from southern Ontario through the Lower OH Valley. Morning soundings and recent mesoanalysis both show moderate mid-level flow (i.e. 30 to 40 kt at 500 mb) throughout the base of this shortwave. Expectation is for this wave to continue eastward/northeastward through the OH Valley, reaching the Mid-Atlantic by late afternoon. The airmass preceding this wave across the Mid-Atlantic is very moist, with dewpoints ranging from the upper 60s/low 70s from eastern PA/NJ to the mid 70s across the eastern Carolina. This ample low-level moisture will result in quick airmass destabilization amid strong daytime heating. Limited remaining convective inhibition on recent mesoanalysis indicates this destabilization is already firmly underway. Large-scale lift attendant to the approaching shortwave (augmented by orographic ascent) coupled with airmass destabilization will result in scattered to numerous thunderstorms development this afternoon over the southern Appalachians and Blue Ridge Mountains. This initial, more cellular development could produce isolated hail. These storms should then spread eastward towards the coast with some increasing coverage possible. The strongest mid-level flow (and greatest vertical shear) this afternoon will extend from WV across northern VA/southern PA and NJ. The greatest buoyancy will be farther south, across the Carolinas and GA. Even with this displacement, there is enough overlap between the buoyancy and shear to support loosely organized strong to severe storms. The highest concentration of severe storms is anticipated from southeast PA/southern NJ southward across central VA and the Delmarva into central NC. In this region, numerous thunderstorms coupled with moderate shear should result in several cold-pool-dominated, forward-propagating convective clusters. Damaging gusts will be the primary risk within this more linear activity. ...Northern Intermountain West/Rockies and Northern Great Basin... A shortwave trough is currently moving through northern CA. An elongated belt of enhanced southwesterly mid-level flow exists from the base of this shortwave (over northern CA/northwest NV) northeastward across the northern Great Basin/Rockies. Scattered thunderstorm development is anticipated within this favorable flow regime. Daytime heating and steepened low-level lapse rates coupled with this enhanced mid-level flow should support a strong to severe wind gusts from parts of eastern Oregon into Idaho/Montana and possibly northern Utah. Highest coverage is expected over south-central MT. ...Lower Michigan to northwest Ohio... Scattered thunderstorms are forecast develop this afternoon beneath a weak upper trough across parts of Lower Michigan and northwest Ohio. A modest combination of instability and deep-layer shear will support isolated/marginally severe hail and locally damaging winds with the strongest updrafts. ..Mosier/Moore.. 07/09/2025 Read more