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SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook RESENT 1 NWS Storm Prediction Center Norman OK 1221 PM CDT Thu Sep 11 2025 Valid 111630Z - 121200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM EASTERN MONTANA INTO WESTERN NORTH DAKOTA... CORRECTED FOR PROB GRAPHICS ...SUMMARY... Scattered severe thunderstorms are expected over eastern Montana into western North Dakota late this afternoon through the evening. The primary hazards are severe wind gusts and large hail. ...Synopsis... Water-vapor imagery shows a large cyclone over the West with a downstream ridge over the Great Plains, and a trough centered over the Lower Great Lakes. Southwesterly mid to high-level flow extends from the base of the larger-scale western U.S. trough northeastward through the Great Basin and into the northern Great Plains. A mid-level disturbance implied in water-vapor imagery over western WY, is forecast to move northeast into eastern MT/western ND towards this evening. In the low levels, a plume of seasonably rich moisture will protrude northward from the central Plains into the Dakotas and eastern MT. A lee trough will extend southward from a surface low over the northern High Plains. ...Rockies into the northern Plains... An ongoing cluster of thunderstorms associated with warm-air advection near the ND/Manitoba border will continue to move east-northeastward into southern Canada ahead of a pair of MCVs over western ND/eastern MT. Diurnal heating over the higher terrain from near the Four Corners northward into southern MT will favor scattered thunderstorms developing during the midday into the early afternoon. Storm coverage will increase further over the central Rockies during the afternoon, with the stronger storms capable of an isolated hail/wind threat. As the airmass destabilizes over the plains, particularly across eastern MT within the moist plume primarily north of the surface low, isolated to scattered storms are forecast by mid to late afternoon. This initial activity will probably develop near the MT/WY border with upscale growth into a cluster possible during the evening. Deep-layer shear supporting organized storm modes coupled with steep lapse rates, will combine to aid in several stronger storms capable of a hail/wind threat. The wind threat will probably continue into ND during the evening within the terminus region of a 35-40 kt southerly LLJ. A gradual transition to increasingly elevated convection is expected late as convective inhibition increases and the overall severe risk lessens. ..15_ows.. 09/11/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook RESENT 1 NWS Storm Prediction Center Norman OK 1221 PM CDT Thu Sep 11 2025 Valid 111630Z - 121200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM EASTERN MONTANA INTO WESTERN NORTH DAKOTA... CORRECTED FOR PROB GRAPHICS ...SUMMARY... Scattered severe thunderstorms are expected over eastern Montana into western North Dakota late this afternoon through the evening. The primary hazards are severe wind gusts and large hail. ...Synopsis... Water-vapor imagery shows a large cyclone over the West with a downstream ridge over the Great Plains, and a trough centered over the Lower Great Lakes. Southwesterly mid to high-level flow extends from the base of the larger-scale western U.S. trough northeastward through the Great Basin and into the northern Great Plains. A mid-level disturbance implied in water-vapor imagery over western WY, is forecast to move northeast into eastern MT/western ND towards this evening. In the low levels, a plume of seasonably rich moisture will protrude northward from the central Plains into the Dakotas and eastern MT. A lee trough will extend southward from a surface low over the northern High Plains. ...Rockies into the northern Plains... An ongoing cluster of thunderstorms associated with warm-air advection near the ND/Manitoba border will continue to move east-northeastward into southern Canada ahead of a pair of MCVs over western ND/eastern MT. Diurnal heating over the higher terrain from near the Four Corners northward into southern MT will favor scattered thunderstorms developing during the midday into the early afternoon. Storm coverage will increase further over the central Rockies during the afternoon, with the stronger storms capable of an isolated hail/wind threat. As the airmass destabilizes over the plains, particularly across eastern MT within the moist plume primarily north of the surface low, isolated to scattered storms are forecast by mid to late afternoon. This initial activity will probably develop near the MT/WY border with upscale growth into a cluster possible during the evening. Deep-layer shear supporting organized storm modes coupled with steep lapse rates, will combine to aid in several stronger storms capable of a hail/wind threat. The wind threat will probably continue into ND during the evening within the terminus region of a 35-40 kt southerly LLJ. A gradual transition to increasingly elevated convection is expected late as convective inhibition increases and the overall severe risk lessens. ..15_ows.. 09/11/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook RESENT 1 NWS Storm Prediction Center Norman OK 1221 PM CDT Thu Sep 11 2025 Valid 111630Z - 121200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM EASTERN MONTANA INTO WESTERN NORTH DAKOTA... CORRECTED FOR PROB GRAPHICS ...SUMMARY... Scattered severe thunderstorms are expected over eastern Montana into western North Dakota late this afternoon through the evening. The primary hazards are severe wind gusts and large hail. ...Synopsis... Water-vapor imagery shows a large cyclone over the West with a downstream ridge over the Great Plains, and a trough centered over the Lower Great Lakes. Southwesterly mid to high-level flow extends from the base of the larger-scale western U.S. trough northeastward through the Great Basin and into the northern Great Plains. A mid-level disturbance implied in water-vapor imagery over western WY, is forecast to move northeast into eastern MT/western ND towards this evening. In the low levels, a plume of seasonably rich moisture will protrude northward from the central Plains into the Dakotas and eastern MT. A lee trough will extend southward from a surface low over the northern High Plains. ...Rockies into the northern Plains... An ongoing cluster of thunderstorms associated with warm-air advection near the ND/Manitoba border will continue to move east-northeastward into southern Canada ahead of a pair of MCVs over western ND/eastern MT. Diurnal heating over the higher terrain from near the Four Corners northward into southern MT will favor scattered thunderstorms developing during the midday into the early afternoon. Storm coverage will increase further over the central Rockies during the afternoon, with the stronger storms capable of an isolated hail/wind threat. As the airmass destabilizes over the plains, particularly across eastern MT within the moist plume primarily north of the surface low, isolated to scattered storms are forecast by mid to late afternoon. This initial activity will probably develop near the MT/WY border with upscale growth into a cluster possible during the evening. Deep-layer shear supporting organized storm modes coupled with steep lapse rates, will combine to aid in several stronger storms capable of a hail/wind threat. The wind threat will probably continue into ND during the evening within the terminus region of a 35-40 kt southerly LLJ. A gradual transition to increasingly elevated convection is expected late as convective inhibition increases and the overall severe risk lessens. ..15_ows.. 09/11/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK Issued by 15th OWS Scott Air Force Base IL 1105 AM CDT Thu Sep 11 2025 Valid 111630Z - 121200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM EASTERN MONTANA INTO WESTERN NORTH DAKOTA... ...SUMMARY... Scattered severe thunderstorms are expected over eastern Montana into western North Dakota late this afternoon through the evening. The primary hazards are severe wind gusts and large hail. ...Synopsis... Water-vapor imagery shows a large cyclone over the West with a downstream ridge over the Great Plains, and a trough centered over the Lower Great Lakes. Southwesterly mid to high-level flow extends from the base of the larger-scale western U.S. trough northeastward through the Great Basin and into the northern Great Plains. A mid-level disturbance implied in water-vapor imagery over western WY, is forecast to move northeast into eastern MT/western ND towards this evening. In the low levels, a plume of seasonably rich moisture will protrude northward from the central Plains into the Dakotas and eastern MT. A lee trough will extend southward from a surface low over the northern High Plains. ...Rockies into the northern Plains... An ongoing cluster of thunderstorms associated with warm-air advection near the ND/Manitoba border will continue to move east-northeastward into southern Canada ahead of a pair of MCVs over western ND/eastern MT. Diurnal heating over the higher terrain from near the Four Corners northward into southern MT will favor scattered thunderstorms developing during the midday into the early afternoon. Storm coverage will increase further over the central Rockies during the afternoon, with the stronger storms capable of an isolated hail/wind threat. As the airmass destabilizes over the plains, particularly across eastern MT within the moist plume primarily north of the surface low, isolated to scattered storms are forecast by mid to late afternoon. This initial activity will probably develop near the MT/WY border with upscale growth into a cluster possible during the evening. Deep-layer shear supporting organized storm modes coupled with steep lapse rates, will combine to aid in several stronger storms capable of a hail/wind threat. The wind threat will probably continue into ND during the evening within the terminus region of a 35-40 kt southerly LLJ. A gradual transition to increasingly elevated convection is expected late as convective inhibition increases and the overall severe risk lessens. ..15_ows.. 09/11/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK Issued by 15th OWS Scott Air Force Base IL 1105 AM CDT Thu Sep 11 2025 Valid 111630Z - 121200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM EASTERN MONTANA INTO WESTERN NORTH DAKOTA... ...SUMMARY... Scattered severe thunderstorms are expected over eastern Montana into western North Dakota late this afternoon through the evening. The primary hazards are severe wind gusts and large hail. ...Synopsis... Water-vapor imagery shows a large cyclone over the West with a downstream ridge over the Great Plains, and a trough centered over the Lower Great Lakes. Southwesterly mid to high-level flow extends from the base of the larger-scale western U.S. trough northeastward through the Great Basin and into the northern Great Plains. A mid-level disturbance implied in water-vapor imagery over western WY, is forecast to move northeast into eastern MT/western ND towards this evening. In the low levels, a plume of seasonably rich moisture will protrude northward from the central Plains into the Dakotas and eastern MT. A lee trough will extend southward from a surface low over the northern High Plains. ...Rockies into the northern Plains... An ongoing cluster of thunderstorms associated with warm-air advection near the ND/Manitoba border will continue to move east-northeastward into southern Canada ahead of a pair of MCVs over western ND/eastern MT. Diurnal heating over the higher terrain from near the Four Corners northward into southern MT will favor scattered thunderstorms developing during the midday into the early afternoon. Storm coverage will increase further over the central Rockies during the afternoon, with the stronger storms capable of an isolated hail/wind threat. As the airmass destabilizes over the plains, particularly across eastern MT within the moist plume primarily north of the surface low, isolated to scattered storms are forecast by mid to late afternoon. This initial activity will probably develop near the MT/WY border with upscale growth into a cluster possible during the evening. Deep-layer shear supporting organized storm modes coupled with steep lapse rates, will combine to aid in several stronger storms capable of a hail/wind threat. The wind threat will probably continue into ND during the evening within the terminus region of a 35-40 kt southerly LLJ. A gradual transition to increasingly elevated convection is expected late as convective inhibition increases and the overall severe risk lessens. ..15_ows.. 09/11/2025 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1135 AM CDT Thu Sep 11 2025 Valid 111700Z - 121200Z ...Western Utah... Strong southwest mid-level flow atop a well-mixed boundary layer will support gusty surface winds this afternoon across western Utah as daytime heating progresses under mostly clear skies. Sustained southwest winds of up to 20 mph combined with relative humidity close to 15% will result in Elevated fire weather conditions for portions of western Utah this afternoon. The overall fire weather threat has shifted slightly northeastward based on latest model guidance but remains largely on track. ..Williams.. 09/11/2025 .PREV DISCUSSION... /ISSUED 0117 AM CDT Thu Sep 11 2025/ ...Synopsis... The upper-level trough in the Great Basin will move marginally eastward today. The mid-level dry slot will move over western Utah during the afternoon. Though the mid-level jet will be weakening through the period, there should be enough flow across parts of the eastern Great Basin to promote at least pockets of locally elevated fire weather. With locally stronger winds and drier surface conditions in western Utah, sustained elevated conditions are most likely here. Surface winds of 15-20 mph and RH of 15-20% by the afternoon are expected. ...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 1135 AM CDT Thu Sep 11 2025 Valid 111700Z - 121200Z ...Western Utah... Strong southwest mid-level flow atop a well-mixed boundary layer will support gusty surface winds this afternoon across western Utah as daytime heating progresses under mostly clear skies. Sustained southwest winds of up to 20 mph combined with relative humidity close to 15% will result in Elevated fire weather conditions for portions of western Utah this afternoon. The overall fire weather threat has shifted slightly northeastward based on latest model guidance but remains largely on track. ..Williams.. 09/11/2025 .PREV DISCUSSION... /ISSUED 0117 AM CDT Thu Sep 11 2025/ ...Synopsis... The upper-level trough in the Great Basin will move marginally eastward today. The mid-level dry slot will move over western Utah during the afternoon. Though the mid-level jet will be weakening through the period, there should be enough flow across parts of the eastern Great Basin to promote at least pockets of locally elevated fire weather. With locally stronger winds and drier surface conditions in western Utah, sustained elevated conditions are most likely here. Surface winds of 15-20 mph and RH of 15-20% by the afternoon are expected. ...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 1135 AM CDT Thu Sep 11 2025 Valid 111700Z - 121200Z ...Western Utah... Strong southwest mid-level flow atop a well-mixed boundary layer will support gusty surface winds this afternoon across western Utah as daytime heating progresses under mostly clear skies. Sustained southwest winds of up to 20 mph combined with relative humidity close to 15% will result in Elevated fire weather conditions for portions of western Utah this afternoon. The overall fire weather threat has shifted slightly northeastward based on latest model guidance but remains largely on track. ..Williams.. 09/11/2025 .PREV DISCUSSION... /ISSUED 0117 AM CDT Thu Sep 11 2025/ ...Synopsis... The upper-level trough in the Great Basin will move marginally eastward today. The mid-level dry slot will move over western Utah during the afternoon. Though the mid-level jet will be weakening through the period, there should be enough flow across parts of the eastern Great Basin to promote at least pockets of locally elevated fire weather. With locally stronger winds and drier surface conditions in western Utah, sustained elevated conditions are most likely here. Surface winds of 15-20 mph and RH of 15-20% by the afternoon are expected. ...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 1135 AM CDT Thu Sep 11 2025 Valid 111700Z - 121200Z ...Western Utah... Strong southwest mid-level flow atop a well-mixed boundary layer will support gusty surface winds this afternoon across western Utah as daytime heating progresses under mostly clear skies. Sustained southwest winds of up to 20 mph combined with relative humidity close to 15% will result in Elevated fire weather conditions for portions of western Utah this afternoon. The overall fire weather threat has shifted slightly northeastward based on latest model guidance but remains largely on track. ..Williams.. 09/11/2025 .PREV DISCUSSION... /ISSUED 0117 AM CDT Thu Sep 11 2025/ ...Synopsis... The upper-level trough in the Great Basin will move marginally eastward today. The mid-level dry slot will move over western Utah during the afternoon. Though the mid-level jet will be weakening through the period, there should be enough flow across parts of the eastern Great Basin to promote at least pockets of locally elevated fire weather. With locally stronger winds and drier surface conditions in western Utah, sustained elevated conditions are most likely here. Surface winds of 15-20 mph and RH of 15-20% by the afternoon are expected. ...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 1135 AM CDT Thu Sep 11 2025 Valid 111700Z - 121200Z ...Western Utah... Strong southwest mid-level flow atop a well-mixed boundary layer will support gusty surface winds this afternoon across western Utah as daytime heating progresses under mostly clear skies. Sustained southwest winds of up to 20 mph combined with relative humidity close to 15% will result in Elevated fire weather conditions for portions of western Utah this afternoon. The overall fire weather threat has shifted slightly northeastward based on latest model guidance but remains largely on track. ..Williams.. 09/11/2025 .PREV DISCUSSION... /ISSUED 0117 AM CDT Thu Sep 11 2025/ ...Synopsis... The upper-level trough in the Great Basin will move marginally eastward today. The mid-level dry slot will move over western Utah during the afternoon. Though the mid-level jet will be weakening through the period, there should be enough flow across parts of the eastern Great Basin to promote at least pockets of locally elevated fire weather. With locally stronger winds and drier surface conditions in western Utah, sustained elevated conditions are most likely here. Surface winds of 15-20 mph and RH of 15-20% by the afternoon are expected. ...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 1135 AM CDT Thu Sep 11 2025 Valid 111700Z - 121200Z ...Western Utah... Strong southwest mid-level flow atop a well-mixed boundary layer will support gusty surface winds this afternoon across western Utah as daytime heating progresses under mostly clear skies. Sustained southwest winds of up to 20 mph combined with relative humidity close to 15% will result in Elevated fire weather conditions for portions of western Utah this afternoon. The overall fire weather threat has shifted slightly northeastward based on latest model guidance but remains largely on track. ..Williams.. 09/11/2025 .PREV DISCUSSION... /ISSUED 0117 AM CDT Thu Sep 11 2025/ ...Synopsis... The upper-level trough in the Great Basin will move marginally eastward today. The mid-level dry slot will move over western Utah during the afternoon. Though the mid-level jet will be weakening through the period, there should be enough flow across parts of the eastern Great Basin to promote at least pockets of locally elevated fire weather. With locally stronger winds and drier surface conditions in western Utah, sustained elevated conditions are most likely here. Surface winds of 15-20 mph and RH of 15-20% by the afternoon are expected. ...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 1135 AM CDT Thu Sep 11 2025 Valid 111700Z - 121200Z ...Western Utah... Strong southwest mid-level flow atop a well-mixed boundary layer will support gusty surface winds this afternoon across western Utah as daytime heating progresses under mostly clear skies. Sustained southwest winds of up to 20 mph combined with relative humidity close to 15% will result in Elevated fire weather conditions for portions of western Utah this afternoon. The overall fire weather threat has shifted slightly northeastward based on latest model guidance but remains largely on track. ..Williams.. 09/11/2025 .PREV DISCUSSION... /ISSUED 0117 AM CDT Thu Sep 11 2025/ ...Synopsis... The upper-level trough in the Great Basin will move marginally eastward today. The mid-level dry slot will move over western Utah during the afternoon. Though the mid-level jet will be weakening through the period, there should be enough flow across parts of the eastern Great Basin to promote at least pockets of locally elevated fire weather. With locally stronger winds and drier surface conditions in western Utah, sustained elevated conditions are most likely here. Surface winds of 15-20 mph and RH of 15-20% by the afternoon are expected. ...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 1135 AM CDT Thu Sep 11 2025 Valid 111700Z - 121200Z ...Western Utah... Strong southwest mid-level flow atop a well-mixed boundary layer will support gusty surface winds this afternoon across western Utah as daytime heating progresses under mostly clear skies. Sustained southwest winds of up to 20 mph combined with relative humidity close to 15% will result in Elevated fire weather conditions for portions of western Utah this afternoon. The overall fire weather threat has shifted slightly northeastward based on latest model guidance but remains largely on track. ..Williams.. 09/11/2025 .PREV DISCUSSION... /ISSUED 0117 AM CDT Thu Sep 11 2025/ ...Synopsis... The upper-level trough in the Great Basin will move marginally eastward today. The mid-level dry slot will move over western Utah during the afternoon. Though the mid-level jet will be weakening through the period, there should be enough flow across parts of the eastern Great Basin to promote at least pockets of locally elevated fire weather. With locally stronger winds and drier surface conditions in western Utah, sustained elevated conditions are most likely here. Surface winds of 15-20 mph and RH of 15-20% by the afternoon are expected. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

Unincorporated portions of Warrick County were in an open fire emergency for seven days starting September 10 as drought heightened the fire danger. WBKR-FM (Owensboro, Ky.), Sep 11, 2025

Heat and drought permitted bluetongue and epizootic hemorrhagic disease to spread among deer in eastern Washington, according to state wildlife officials. The viral infections are caused by biting gnats and can kill deer swiftly. The Washington Department of Fish and Wildlife began receiving calls the first week of September from people who observed sick or dying deer primarily in Stevens and Spokane counties, and that the calls increased significantly on Monday, September 8. As of September 10, wildlife officials had counted at least 31 cases in Stevens County, 35 in Spokane County and three apiece in Walla Walla and Whitman counties. WDFW was still waiting for test results from the Washington Animal Disease Diagnostic Laboratory to confirm the outbreaks, but officials were confident that the diseases were present due to the time of year, weather conditions and reports of deer with telltale symptoms – deer acting disoriented, being unresponsive to humans and foaming at the mouth. In August, the Idaho Department of Fish and Game announced that it had found deer infected with EHD southeast of Lewiston. The Spokesman-Review (Spokane, Wash.), Sep 10, 2025

Water shutoffs took place earlier than usual for some irrigators in the Yakima River Basin as reservoir levels were the lowest since 1971. Non-senior water rights holders in the Yakima basin expected to receive 40% of their allotment this year, while senior water rights holders received a full allotment. As of September 1, reservoir storage was 20% of capacity with 218,000 acre-feet of water, or 44% of average. The manager of the Roza Irrigation District estimated deliveries would end on Sept. 23, about a month earlier than usual. The Kittitas Reclamation District shut off on Aug. 13, about two months early, because of the lack of water. The Ellensburg-based district supplies water for hay and tree fruit growers. Washington State Standard (Olympia, Wash.), Sep 8, 2025

A burn ban was in effect for Trigg County as drought caused the fire danger to rise. All open burning was prohibited within the county, including bonfires, burning of leaves, brush or trash. The public was advised to be especially cautious using grills and other outdoor cooking equipment. WHOP-AM (Hopkinsville, Ky.), Sep 10, 2025

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0705 AM CDT Thu Sep 11 2025 Valid 111300Z - 121200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM EASTERN MONTANA INTO WESTERN NORTH DAKOTA... ...SUMMARY... Scattered severe thunderstorms are possible over eastern Montana into western North Dakota late this afternoon through the evening. The primary hazards are severe gusts and large hail. ...Synopsis... Water-vapor imagery shows a large cyclone over the West with a downstream ridge over the Great Plains, and a trough centered over the Lower Great Lakes. Southwesterly mid to high-level flow extends from the base of the larger-scale western U.S. trough northeastward through the Great Basin and into the northern Great Plains. A mid-level disturbance implied in morning water-vapor imagery over western WY, is forecast to move northeast into eastern MT/western ND towards this evening. In the low levels, a plume of seasonably rich moisture will protrude northward from the central Plains into the Dakotas and eastern MT. A lee trough will extend southward from a surface low over the northern High Plains. ...Rockies into the northern Plains... An ongoing cluster of weak thunderstorms associated with warm-air advection near the ND/Manitoba border will continue to move east-northeastward into southern Canada ahead of a pair of MCVs over western ND/eastern MT. Diurnal heating over the higher terrain from near the Four Corners northward into southern MT will favor scattered thunderstorms developing during the midday into the early afternoon. Storm coverage will probably increase further over the central Rockies during the afternoon, with the stronger storms capable of an isolated hail/wind threat. As the airmass destabilizes over the plains, particularly across eastern MT within the moist plume primarily north of the surface low, isolated to scattered storms are forecast by mid to late afternoon. This initial activity will probably develop near the MT/WY border with upscale growth into a cluster possible during the evening. Deep-layer shear supporting organized storm modes coupled with steep lapse rates, will combine to aid in several stronger storms capable of a hail/wind threat. The wind threat will probably continue into ND during the evening within the terminus region of a 35-40 kt southerly LLJ. A gradual transition to increasingly elevated convection is expected late as convective inhibition increases and the overall severe risk lessens. ..Smith/Broyles.. 09/11/2025 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0705 AM CDT Thu Sep 11 2025 Valid 111300Z - 121200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM EASTERN MONTANA INTO WESTERN NORTH DAKOTA... ...SUMMARY... Scattered severe thunderstorms are possible over eastern Montana into western North Dakota late this afternoon through the evening. The primary hazards are severe gusts and large hail. ...Synopsis... Water-vapor imagery shows a large cyclone over the West with a downstream ridge over the Great Plains, and a trough centered over the Lower Great Lakes. Southwesterly mid to high-level flow extends from the base of the larger-scale western U.S. trough northeastward through the Great Basin and into the northern Great Plains. A mid-level disturbance implied in morning water-vapor imagery over western WY, is forecast to move northeast into eastern MT/western ND towards this evening. In the low levels, a plume of seasonably rich moisture will protrude northward from the central Plains into the Dakotas and eastern MT. A lee trough will extend southward from a surface low over the northern High Plains. ...Rockies into the northern Plains... An ongoing cluster of weak thunderstorms associated with warm-air advection near the ND/Manitoba border will continue to move east-northeastward into southern Canada ahead of a pair of MCVs over western ND/eastern MT. Diurnal heating over the higher terrain from near the Four Corners northward into southern MT will favor scattered thunderstorms developing during the midday into the early afternoon. Storm coverage will probably increase further over the central Rockies during the afternoon, with the stronger storms capable of an isolated hail/wind threat. As the airmass destabilizes over the plains, particularly across eastern MT within the moist plume primarily north of the surface low, isolated to scattered storms are forecast by mid to late afternoon. This initial activity will probably develop near the MT/WY border with upscale growth into a cluster possible during the evening. Deep-layer shear supporting organized storm modes coupled with steep lapse rates, will combine to aid in several stronger storms capable of a hail/wind threat. The wind threat will probably continue into ND during the evening within the terminus region of a 35-40 kt southerly LLJ. A gradual transition to increasingly elevated convection is expected late as convective inhibition increases and the overall severe risk lessens. ..Smith/Broyles.. 09/11/2025 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0705 AM CDT Thu Sep 11 2025 Valid 111300Z - 121200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM EASTERN MONTANA INTO WESTERN NORTH DAKOTA... ...SUMMARY... Scattered severe thunderstorms are possible over eastern Montana into western North Dakota late this afternoon through the evening. The primary hazards are severe gusts and large hail. ...Synopsis... Water-vapor imagery shows a large cyclone over the West with a downstream ridge over the Great Plains, and a trough centered over the Lower Great Lakes. Southwesterly mid to high-level flow extends from the base of the larger-scale western U.S. trough northeastward through the Great Basin and into the northern Great Plains. A mid-level disturbance implied in morning water-vapor imagery over western WY, is forecast to move northeast into eastern MT/western ND towards this evening. In the low levels, a plume of seasonably rich moisture will protrude northward from the central Plains into the Dakotas and eastern MT. A lee trough will extend southward from a surface low over the northern High Plains. ...Rockies into the northern Plains... An ongoing cluster of weak thunderstorms associated with warm-air advection near the ND/Manitoba border will continue to move east-northeastward into southern Canada ahead of a pair of MCVs over western ND/eastern MT. Diurnal heating over the higher terrain from near the Four Corners northward into southern MT will favor scattered thunderstorms developing during the midday into the early afternoon. Storm coverage will probably increase further over the central Rockies during the afternoon, with the stronger storms capable of an isolated hail/wind threat. As the airmass destabilizes over the plains, particularly across eastern MT within the moist plume primarily north of the surface low, isolated to scattered storms are forecast by mid to late afternoon. This initial activity will probably develop near the MT/WY border with upscale growth into a cluster possible during the evening. Deep-layer shear supporting organized storm modes coupled with steep lapse rates, will combine to aid in several stronger storms capable of a hail/wind threat. The wind threat will probably continue into ND during the evening within the terminus region of a 35-40 kt southerly LLJ. A gradual transition to increasingly elevated convection is expected late as convective inhibition increases and the overall severe risk lessens. ..Smith/Broyles.. 09/11/2025 Read more