Severe Storms

MD 2061 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR PORTIONS OF NORTHERN NORTH DAKOTA
Mesoscale Discussion 2061 NWS Storm Prediction Center Norman OK 1011 PM CDT Thu Sep 11 2025 Areas affected...portions of northern North Dakota Concerning...Severe potential...Watch unlikely Valid 120311Z - 120515Z Probability of Watch Issuance...5 percent SUMMARY...A few more instances of severe hail may occur over the next few hours with any discrete supercells that form or persist. DISCUSSION...Isolated, splitting supercells have developed along or immediately north of a quasi-stationary baroclinic boundary, and have produced severe hail over the past hour. These storms are likely elevated amid an environment where MLCINH continues to increase. When also considering weak forcing for ascent, questions remain if additional storms will form, and if the ongoing supercells will persist. Nonetheless, 2000-3000 J/kg MLCAPE and 35+ kts of effective bulk shear will continue to support the potential for severe-hail-producing supercells for at least a couple more hours. ..Squitieri/Hart.. 09/12/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...FGF...BIS... LAT...LON 48560388 48830146 48709934 48309801 47859763 47459812 47359937 47390090 47580233 47900329 48080348 48560388 MOST PROBABLE PEAK WIND GUST...UP TO 60 MPH MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0802 PM CDT Thu Sep 11 2025 Valid 120100Z - 121200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE NORTHERN ROCKIES AND PLAINS... ...SUMMARY... A few widely spaced strong to severe storms remain possible from western Colorado into eastern Montana and the western Dakotas. Isolated hail or strong gusts are possible. ...Discussion... Scattered thunderstorms persist this evening from the Canadian border southward across the Rockies, beneath moderate southwest flow aloft. 00Z soundings from GJT to GGW show moderately steep lapse rates, with 500 to 1500 J/kg MUCAPE. Given little height falls overnight, most of these storms should diminish after sunset. Farther east across the northern High Plains, stronger instability exists with MLCAPE of 1500-2500 J/kg from UNR to BIS. However, minimal capping does exist. Conditionally, the environment supports large hail, though there is little focusing mechanism for any concentrated risk areas. As such, the Slight Risk has been removed, due to expected isolated nature of the cells. ..Jewell.. 09/12/2025 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0802 PM CDT Thu Sep 11 2025 Valid 120100Z - 121200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE NORTHERN ROCKIES AND PLAINS... ...SUMMARY... A few widely spaced strong to severe storms remain possible from western Colorado into eastern Montana and the western Dakotas. Isolated hail or strong gusts are possible. ...Discussion... Scattered thunderstorms persist this evening from the Canadian border southward across the Rockies, beneath moderate southwest flow aloft. 00Z soundings from GJT to GGW show moderately steep lapse rates, with 500 to 1500 J/kg MUCAPE. Given little height falls overnight, most of these storms should diminish after sunset. Farther east across the northern High Plains, stronger instability exists with MLCAPE of 1500-2500 J/kg from UNR to BIS. However, minimal capping does exist. Conditionally, the environment supports large hail, though there is little focusing mechanism for any concentrated risk areas. As such, the Slight Risk has been removed, due to expected isolated nature of the cells. ..Jewell.. 09/12/2025 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0802 PM CDT Thu Sep 11 2025 Valid 120100Z - 121200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE NORTHERN ROCKIES AND PLAINS... ...SUMMARY... A few widely spaced strong to severe storms remain possible from western Colorado into eastern Montana and the western Dakotas. Isolated hail or strong gusts are possible. ...Discussion... Scattered thunderstorms persist this evening from the Canadian border southward across the Rockies, beneath moderate southwest flow aloft. 00Z soundings from GJT to GGW show moderately steep lapse rates, with 500 to 1500 J/kg MUCAPE. Given little height falls overnight, most of these storms should diminish after sunset. Farther east across the northern High Plains, stronger instability exists with MLCAPE of 1500-2500 J/kg from UNR to BIS. However, minimal capping does exist. Conditionally, the environment supports large hail, though there is little focusing mechanism for any concentrated risk areas. As such, the Slight Risk has been removed, due to expected isolated nature of the cells. ..Jewell.. 09/12/2025 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0802 PM CDT Thu Sep 11 2025 Valid 120100Z - 121200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE NORTHERN ROCKIES AND PLAINS... ...SUMMARY... A few widely spaced strong to severe storms remain possible from western Colorado into eastern Montana and the western Dakotas. Isolated hail or strong gusts are possible. ...Discussion... Scattered thunderstorms persist this evening from the Canadian border southward across the Rockies, beneath moderate southwest flow aloft. 00Z soundings from GJT to GGW show moderately steep lapse rates, with 500 to 1500 J/kg MUCAPE. Given little height falls overnight, most of these storms should diminish after sunset. Farther east across the northern High Plains, stronger instability exists with MLCAPE of 1500-2500 J/kg from UNR to BIS. However, minimal capping does exist. Conditionally, the environment supports large hail, though there is little focusing mechanism for any concentrated risk areas. As such, the Slight Risk has been removed, due to expected isolated nature of the cells. ..Jewell.. 09/12/2025 Read more

No watches are valid as of Thu Sep 11 22:46:02 UTC 2025.

No Mesoscale Discussions are in effect as of Thu Sep 11 22:46:02 UTC 2025.

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0448 PM CDT Thu Sep 11 2025 Valid 131200Z - 191200Z ...Day 3-5/Saturday-Monday... A mid-level trough across the Intermountain West will pivot northeastward into the Central and Northern Plains in the Day 3-4/Saturday-Sunday period, shifting the bulk of shower and thunderstorm activity east of the Rockies. Higher forecast confidence now exists in a positively tilted mid-level short wave trough entering the Northwest on Day 4-5/Sunday-Monday after a brief warm and dry day on Day 3/Saturday. Cooler temperatures behind an associated cold front, influx of Pacific moisture and precipitation will mitigate fire weather concerns for the Pacific Northwest through Day 5/Monday. Meanwhile ridging across the Southern Plains into the Midwest will support dry conditions and well above normal temperatures through the weekend. ...Day 6-8/Tuesday-Thursday... Ridging will quickly build over the Pacific Northwest along with the development of a coastal thermal trough by Day 6/Tuesday. An offshore pressure gradient will support a drier east/northeast flow west of the Cascades on Tuesday. However, recent moisture and expected preceding rainfall along and west of the Cascades on Day 4/Sunday should lower fire weather concerns overall in advance of the potential offshore wind event. High pressure will continue to promote above normal temperatures and mainly dry conditions across much of the Midwest and lower Mississippi Valley through the Day 8/Thursday period, further drying fuels across the region. ..Williams.. 09/11/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0448 PM CDT Thu Sep 11 2025 Valid 131200Z - 191200Z ...Day 3-5/Saturday-Monday... A mid-level trough across the Intermountain West will pivot northeastward into the Central and Northern Plains in the Day 3-4/Saturday-Sunday period, shifting the bulk of shower and thunderstorm activity east of the Rockies. Higher forecast confidence now exists in a positively tilted mid-level short wave trough entering the Northwest on Day 4-5/Sunday-Monday after a brief warm and dry day on Day 3/Saturday. Cooler temperatures behind an associated cold front, influx of Pacific moisture and precipitation will mitigate fire weather concerns for the Pacific Northwest through Day 5/Monday. Meanwhile ridging across the Southern Plains into the Midwest will support dry conditions and well above normal temperatures through the weekend. ...Day 6-8/Tuesday-Thursday... Ridging will quickly build over the Pacific Northwest along with the development of a coastal thermal trough by Day 6/Tuesday. An offshore pressure gradient will support a drier east/northeast flow west of the Cascades on Tuesday. However, recent moisture and expected preceding rainfall along and west of the Cascades on Day 4/Sunday should lower fire weather concerns overall in advance of the potential offshore wind event. High pressure will continue to promote above normal temperatures and mainly dry conditions across much of the Midwest and lower Mississippi Valley through the Day 8/Thursday period, further drying fuels across the region. ..Williams.. 09/11/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0448 PM CDT Thu Sep 11 2025 Valid 131200Z - 191200Z ...Day 3-5/Saturday-Monday... A mid-level trough across the Intermountain West will pivot northeastward into the Central and Northern Plains in the Day 3-4/Saturday-Sunday period, shifting the bulk of shower and thunderstorm activity east of the Rockies. Higher forecast confidence now exists in a positively tilted mid-level short wave trough entering the Northwest on Day 4-5/Sunday-Monday after a brief warm and dry day on Day 3/Saturday. Cooler temperatures behind an associated cold front, influx of Pacific moisture and precipitation will mitigate fire weather concerns for the Pacific Northwest through Day 5/Monday. Meanwhile ridging across the Southern Plains into the Midwest will support dry conditions and well above normal temperatures through the weekend. ...Day 6-8/Tuesday-Thursday... Ridging will quickly build over the Pacific Northwest along with the development of a coastal thermal trough by Day 6/Tuesday. An offshore pressure gradient will support a drier east/northeast flow west of the Cascades on Tuesday. However, recent moisture and expected preceding rainfall along and west of the Cascades on Day 4/Sunday should lower fire weather concerns overall in advance of the potential offshore wind event. High pressure will continue to promote above normal temperatures and mainly dry conditions across much of the Midwest and lower Mississippi Valley through the Day 8/Thursday period, further drying fuels across the region. ..Williams.. 09/11/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0448 PM CDT Thu Sep 11 2025 Valid 131200Z - 191200Z ...Day 3-5/Saturday-Monday... A mid-level trough across the Intermountain West will pivot northeastward into the Central and Northern Plains in the Day 3-4/Saturday-Sunday period, shifting the bulk of shower and thunderstorm activity east of the Rockies. Higher forecast confidence now exists in a positively tilted mid-level short wave trough entering the Northwest on Day 4-5/Sunday-Monday after a brief warm and dry day on Day 3/Saturday. Cooler temperatures behind an associated cold front, influx of Pacific moisture and precipitation will mitigate fire weather concerns for the Pacific Northwest through Day 5/Monday. Meanwhile ridging across the Southern Plains into the Midwest will support dry conditions and well above normal temperatures through the weekend. ...Day 6-8/Tuesday-Thursday... Ridging will quickly build over the Pacific Northwest along with the development of a coastal thermal trough by Day 6/Tuesday. An offshore pressure gradient will support a drier east/northeast flow west of the Cascades on Tuesday. However, recent moisture and expected preceding rainfall along and west of the Cascades on Day 4/Sunday should lower fire weather concerns overall in advance of the potential offshore wind event. High pressure will continue to promote above normal temperatures and mainly dry conditions across much of the Midwest and lower Mississippi Valley through the Day 8/Thursday period, further drying fuels across the region. ..Williams.. 09/11/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

MD 2060 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR PARTS OF WESTERN SD/NE...FAR EASTERN WY...NORTHEAST CO
Mesoscale Discussion 2060 NWS Storm Prediction Center Norman OK 0347 PM CDT Thu Sep 11 2025 Areas affected...Parts of western SD/NE...far eastern WY...northeast CO Concerning...Severe potential...Watch unlikely Valid 112047Z - 112245Z Probability of Watch Issuance...20 percent SUMMARY...Isolated severe storms are possible this afternoon and evening. DISCUSSION...Storm development is underway this afternoon across parts of the CO Front Range into southeast WY. Farther north, strong heating has occurred from parts of the NE Panhandle into western SD. The strongest instability resides across parts of western SD, where the 18Z UNR sounding (modified for recent surface observations) depicts steep tropospheric lapse rates and MLCAPE above 2000 J/kg. Effective shear of 30-40 kt across this area is favorable for organized convection, though coverage of storms remains somewhat uncertain in the absence of stronger large-scale ascent. Any storm that can mature within this environment could pose a threat for both severe hail and wind, given the favorable lapse rates. Farther south, there is some potential for ongoing convection to intensify as it moves eastward into a somewhat more moist and unstable environment across northeast CO into the NE Panhandle, though MLCINH also increases with eastward extent. Sufficient deep-layer shear will support some potential for organized storms, including potential for isolated severe hail/wind. ..Dean/Guyer.. 09/11/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...ABR...LBF...UNR...GLD...BOU...CYS... LAT...LON 41020485 44830410 45740373 45780268 45820193 44360178 42660196 41670209 41040223 40040284 39630341 39580374 39540424 39640462 40160471 41020485 MOST PROBABLE PEAK WIND GUST...55-70 MPH MOST PROBABLE PEAK HAIL SIZE...1.50-2.50 IN Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK Issued by 15th OWS Scott Air Force Base IL 0237 PM CDT Thu Sep 11 2025 Valid 112000Z - 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 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK Issued by 15th OWS Scott Air Force Base IL 0237 PM CDT Thu Sep 11 2025 Valid 112000Z - 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 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK Issued by 15th OWS Scott Air Force Base IL 0237 PM CDT Thu Sep 11 2025 Valid 112000Z - 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 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK Issued by 15th OWS Scott Air Force Base IL 0237 PM CDT Thu Sep 11 2025 Valid 112000Z - 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 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK Issued by 15th OWS Scott Air Force Base IL 0237 PM CDT Thu Sep 11 2025 Valid 112000Z - 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 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK Issued by 15th OWS Scott Air Force Base IL 0237 PM CDT Thu Sep 11 2025 Valid 112000Z - 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 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0235 PM CDT Thu Sep 11 2025 Valid 121200Z - 131200Z ...NO CRITICAL AREAS... Mid-level flow ahead of an upper-level trough over the western U.S. will become more diffuse through the Day 2 period. This will aid in reducing daytime surface winds across portions of the Southwest and in particular Utah. Locally elevated fire weather conditions are still expected across northwestern Arizona and southern Utah Friday with southwest winds of up to 15 mph and relative humidity falling to around 15% by the afternoon. However, fuel dryness is lacking to allow for significant wildfire spread. ..Williams.. 09/11/2025 .PREV DISCUSSION... /ISSUED 0118 AM CDT Thu Sep 11 2025/ ...Synopsis... The western trough will broaden and the mid-level jet will lose definition on Friday. Though not overly intense, a surface low will move into the central Plains and help promote windier conditions for parts of the central/southern Plains. Recent rainfall and generally unreceptive fuels will mean very minimal fire risk. Dry conditions will persist in parts of the Great Basin and Southwest, but winds will be weaker than previous days. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0235 PM CDT Thu Sep 11 2025 Valid 121200Z - 131200Z ...NO CRITICAL AREAS... Mid-level flow ahead of an upper-level trough over the western U.S. will become more diffuse through the Day 2 period. This will aid in reducing daytime surface winds across portions of the Southwest and in particular Utah. Locally elevated fire weather conditions are still expected across northwestern Arizona and southern Utah Friday with southwest winds of up to 15 mph and relative humidity falling to around 15% by the afternoon. However, fuel dryness is lacking to allow for significant wildfire spread. ..Williams.. 09/11/2025 .PREV DISCUSSION... /ISSUED 0118 AM CDT Thu Sep 11 2025/ ...Synopsis... The western trough will broaden and the mid-level jet will lose definition on Friday. Though not overly intense, a surface low will move into the central Plains and help promote windier conditions for parts of the central/southern Plains. Recent rainfall and generally unreceptive fuels will mean very minimal fire risk. Dry conditions will persist in parts of the Great Basin and Southwest, but winds will be weaker than previous days. ...Please see www.spc.noaa.gov/fire for graphic product... Read more