Severe Storms

No Mesoscale Discussions are in effect as of Fri Sep 12 22:23:01 UTC 2025.

MD 2067 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR CENTRAL MONTANA INTO NORTHEASTERN WYOMING AND FAR WESTERN SOUTH DAKOTA
Mesoscale Discussion 2067 NWS Storm Prediction Center Norman OK 0232 PM CDT Fri Sep 12 2025 Areas affected...central Montana into northeastern Wyoming and far western South Dakota Concerning...Severe potential...Watch possible Valid 121932Z - 122200Z Probability of Watch Issuance...40 percent SUMMARY...Thunderstorm development is expected to continue across the high terrain and adjacent areas in central Montana, northeastern Wyoming, and far western South Dakota. An isolated wind and hail risk will be possible before more widespread severe storms develop this evening. DISCUSSION...A couple of areas of thunderstorm development are noted near the Big Horns in Wyoming, central Montana mountains, and near the Black Hills in South Dakota. The more prominent upper-level forcing for ascent remains across portions of AZ/CO, which will likely keep the risk somewhat initially isolated and tied to the terrain. Given the weakening MLCIN and heating/destabilization amid deep layer shear around 30-40 kts, these thunderstorms will be capable of a few instances of strong to severe wind and marginally severe hail. As the upper-level wave approaches this evening, further cooling aloft and forcing for ascent should promote more broader scale air mass destabilization, increasing shear, and increase in thunderstorm activity moving off the terrain posing an increased risk for large hail and damaging wind. ..Thornton/Guyer.. 09/12/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...UNR...CYS...BYZ...GGW...RIW...TFX... LAT...LON 46121051 47181056 48970846 48870574 43810321 43050395 43180562 46121051 MOST PROBABLE PEAK WIND GUST...UP TO 60 MPH MOST PROBABLE PEAK HAIL SIZE...1.50-2.50 IN Read more

MD 2066 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR EASTERN UTAH AND ADJACENT PORTIONS OF WESTERN COLORADO
Mesoscale Discussion 2066 NWS Storm Prediction Center Norman OK 0224 PM CDT Fri Sep 12 2025 Areas affected...Eastern Utah and adjacent portions of western Colorado Concerning...Severe potential...Watch unlikely Valid 121924Z - 122200Z Probability of Watch Issuance...20 percent SUMMARY...Thunderstorms posing an isolated threat of hail and damaging winds will continue through the afternoon across the area. DISCUSSION...A narrow axis of clearing and destabilization has developed across the area. As a result, storms have reinvigorated across eastern Utah ahead of a midlevel impulse swinging north-northeastward across the southern Great Basin. While instability is limited (~500 J/kg MLCAPE), strong deep-layer shear (over 50 knots per 18Z GJT sounding) and forcing for ascent are aiding in storm organization. Furthermore, long, straight hodographs will favor storm splitting. Consequently, large hail and damaging winds may be possible from the strongest storms this afternoon. The severe threat is expected to be too isolated to warrant a severe thunderstorm watch. ..Jirak/Guyer.. 09/12/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...GJT...SLC... LAT...LON 37221013 38931024 40110983 40370934 40370892 40290870 40020842 39040842 38270837 37240876 37080928 37221013 MOST PROBABLE PEAK WIND GUST...UP TO 60 MPH MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0422 PM CDT Fri Sep 12 2025 Valid 141200Z - 201200Z ...Pacific Northwest... A mid-level trough and attendant cold front entering Washington/Oregon Coast on Day 3/Sunday will usher in a cooler, moist air mass as well as wetting rains to portions of the Pacific Northwest. A quick eastward translation of the trough commences Sunday night into Day 4/Monday with an amplifying mid-level ridge building over the region through Monday night. Surface high pressure settling into the Northern Rockies and development of thermal trough along the coast will promote a dry, offshore flow across the Cascades, including poor to moderate overnight RH recoveries, early in the Day 5/Tuesday period. Expected rainfall across the Cascades on Day 3/Sunday as well as lack of very dry fuels could mitigate overall impact of this offshore wind event. ...California and Southwest... The cold front associated with the Pacific Northwest trough will bring dry, north/northeast flow to the Sacramento Valley Sunday night into Day 4/Monday but lack of drier fuels should lessen fire weather impact of wind event. Residual moisture from tropical storm Mario could bring showers and thunderstorms, including high-based thunderstorms on the periphery of deeper subtropical moisture, into portions of southern California and the Southwest late next week (Day 7-8/Thursday-Friday). However, uncertainty regarding the evolution of the moisture plume and subdued fuel receptiveness precludes introduction of dry thunderstorm probabilities at this time. ...Midwest and Lower Mississippi Valley... Hot and dry conditions under a mid-level ridge will persist across the Midwest and lower Mississippi Valley through much of next week. Primary impact will be continued drying of fuels, where ERC values in some areas reach into 80-90th percentile. However, generally light winds attributed to weak pressure gradients will keep fire weather concerns somewhat benign through the middle of next week. ..Williams.. 09/12/2025 ...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 0422 PM CDT Fri Sep 12 2025 Valid 141200Z - 201200Z ...Pacific Northwest... A mid-level trough and attendant cold front entering Washington/Oregon Coast on Day 3/Sunday will usher in a cooler, moist air mass as well as wetting rains to portions of the Pacific Northwest. A quick eastward translation of the trough commences Sunday night into Day 4/Monday with an amplifying mid-level ridge building over the region through Monday night. Surface high pressure settling into the Northern Rockies and development of thermal trough along the coast will promote a dry, offshore flow across the Cascades, including poor to moderate overnight RH recoveries, early in the Day 5/Tuesday period. Expected rainfall across the Cascades on Day 3/Sunday as well as lack of very dry fuels could mitigate overall impact of this offshore wind event. ...California and Southwest... The cold front associated with the Pacific Northwest trough will bring dry, north/northeast flow to the Sacramento Valley Sunday night into Day 4/Monday but lack of drier fuels should lessen fire weather impact of wind event. Residual moisture from tropical storm Mario could bring showers and thunderstorms, including high-based thunderstorms on the periphery of deeper subtropical moisture, into portions of southern California and the Southwest late next week (Day 7-8/Thursday-Friday). However, uncertainty regarding the evolution of the moisture plume and subdued fuel receptiveness precludes introduction of dry thunderstorm probabilities at this time. ...Midwest and Lower Mississippi Valley... Hot and dry conditions under a mid-level ridge will persist across the Midwest and lower Mississippi Valley through much of next week. Primary impact will be continued drying of fuels, where ERC values in some areas reach into 80-90th percentile. However, generally light winds attributed to weak pressure gradients will keep fire weather concerns somewhat benign through the middle of next week. ..Williams.. 09/12/2025 ...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 0422 PM CDT Fri Sep 12 2025 Valid 141200Z - 201200Z ...Pacific Northwest... A mid-level trough and attendant cold front entering Washington/Oregon Coast on Day 3/Sunday will usher in a cooler, moist air mass as well as wetting rains to portions of the Pacific Northwest. A quick eastward translation of the trough commences Sunday night into Day 4/Monday with an amplifying mid-level ridge building over the region through Monday night. Surface high pressure settling into the Northern Rockies and development of thermal trough along the coast will promote a dry, offshore flow across the Cascades, including poor to moderate overnight RH recoveries, early in the Day 5/Tuesday period. Expected rainfall across the Cascades on Day 3/Sunday as well as lack of very dry fuels could mitigate overall impact of this offshore wind event. ...California and Southwest... The cold front associated with the Pacific Northwest trough will bring dry, north/northeast flow to the Sacramento Valley Sunday night into Day 4/Monday but lack of drier fuels should lessen fire weather impact of wind event. Residual moisture from tropical storm Mario could bring showers and thunderstorms, including high-based thunderstorms on the periphery of deeper subtropical moisture, into portions of southern California and the Southwest late next week (Day 7-8/Thursday-Friday). However, uncertainty regarding the evolution of the moisture plume and subdued fuel receptiveness precludes introduction of dry thunderstorm probabilities at this time. ...Midwest and Lower Mississippi Valley... Hot and dry conditions under a mid-level ridge will persist across the Midwest and lower Mississippi Valley through much of next week. Primary impact will be continued drying of fuels, where ERC values in some areas reach into 80-90th percentile. However, generally light winds attributed to weak pressure gradients will keep fire weather concerns somewhat benign through the middle of next week. ..Williams.. 09/12/2025 ...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 0422 PM CDT Fri Sep 12 2025 Valid 141200Z - 201200Z ...Pacific Northwest... A mid-level trough and attendant cold front entering Washington/Oregon Coast on Day 3/Sunday will usher in a cooler, moist air mass as well as wetting rains to portions of the Pacific Northwest. A quick eastward translation of the trough commences Sunday night into Day 4/Monday with an amplifying mid-level ridge building over the region through Monday night. Surface high pressure settling into the Northern Rockies and development of thermal trough along the coast will promote a dry, offshore flow across the Cascades, including poor to moderate overnight RH recoveries, early in the Day 5/Tuesday period. Expected rainfall across the Cascades on Day 3/Sunday as well as lack of very dry fuels could mitigate overall impact of this offshore wind event. ...California and Southwest... The cold front associated with the Pacific Northwest trough will bring dry, north/northeast flow to the Sacramento Valley Sunday night into Day 4/Monday but lack of drier fuels should lessen fire weather impact of wind event. Residual moisture from tropical storm Mario could bring showers and thunderstorms, including high-based thunderstorms on the periphery of deeper subtropical moisture, into portions of southern California and the Southwest late next week (Day 7-8/Thursday-Friday). However, uncertainty regarding the evolution of the moisture plume and subdued fuel receptiveness precludes introduction of dry thunderstorm probabilities at this time. ...Midwest and Lower Mississippi Valley... Hot and dry conditions under a mid-level ridge will persist across the Midwest and lower Mississippi Valley through much of next week. Primary impact will be continued drying of fuels, where ERC values in some areas reach into 80-90th percentile. However, generally light winds attributed to weak pressure gradients will keep fire weather concerns somewhat benign through the middle of next week. ..Williams.. 09/12/2025 ...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 0422 PM CDT Fri Sep 12 2025 Valid 141200Z - 201200Z ...Pacific Northwest... A mid-level trough and attendant cold front entering Washington/Oregon Coast on Day 3/Sunday will usher in a cooler, moist air mass as well as wetting rains to portions of the Pacific Northwest. A quick eastward translation of the trough commences Sunday night into Day 4/Monday with an amplifying mid-level ridge building over the region through Monday night. Surface high pressure settling into the Northern Rockies and development of thermal trough along the coast will promote a dry, offshore flow across the Cascades, including poor to moderate overnight RH recoveries, early in the Day 5/Tuesday period. Expected rainfall across the Cascades on Day 3/Sunday as well as lack of very dry fuels could mitigate overall impact of this offshore wind event. ...California and Southwest... The cold front associated with the Pacific Northwest trough will bring dry, north/northeast flow to the Sacramento Valley Sunday night into Day 4/Monday but lack of drier fuels should lessen fire weather impact of wind event. Residual moisture from tropical storm Mario could bring showers and thunderstorms, including high-based thunderstorms on the periphery of deeper subtropical moisture, into portions of southern California and the Southwest late next week (Day 7-8/Thursday-Friday). However, uncertainty regarding the evolution of the moisture plume and subdued fuel receptiveness precludes introduction of dry thunderstorm probabilities at this time. ...Midwest and Lower Mississippi Valley... Hot and dry conditions under a mid-level ridge will persist across the Midwest and lower Mississippi Valley through much of next week. Primary impact will be continued drying of fuels, where ERC values in some areas reach into 80-90th percentile. However, generally light winds attributed to weak pressure gradients will keep fire weather concerns somewhat benign through the middle of next week. ..Williams.. 09/12/2025 ...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 0422 PM CDT Fri Sep 12 2025 Valid 141200Z - 201200Z ...Pacific Northwest... A mid-level trough and attendant cold front entering Washington/Oregon Coast on Day 3/Sunday will usher in a cooler, moist air mass as well as wetting rains to portions of the Pacific Northwest. A quick eastward translation of the trough commences Sunday night into Day 4/Monday with an amplifying mid-level ridge building over the region through Monday night. Surface high pressure settling into the Northern Rockies and development of thermal trough along the coast will promote a dry, offshore flow across the Cascades, including poor to moderate overnight RH recoveries, early in the Day 5/Tuesday period. Expected rainfall across the Cascades on Day 3/Sunday as well as lack of very dry fuels could mitigate overall impact of this offshore wind event. ...California and Southwest... The cold front associated with the Pacific Northwest trough will bring dry, north/northeast flow to the Sacramento Valley Sunday night into Day 4/Monday but lack of drier fuels should lessen fire weather impact of wind event. Residual moisture from tropical storm Mario could bring showers and thunderstorms, including high-based thunderstorms on the periphery of deeper subtropical moisture, into portions of southern California and the Southwest late next week (Day 7-8/Thursday-Friday). However, uncertainty regarding the evolution of the moisture plume and subdued fuel receptiveness precludes introduction of dry thunderstorm probabilities at this time. ...Midwest and Lower Mississippi Valley... Hot and dry conditions under a mid-level ridge will persist across the Midwest and lower Mississippi Valley through much of next week. Primary impact will be continued drying of fuels, where ERC values in some areas reach into 80-90th percentile. However, generally light winds attributed to weak pressure gradients will keep fire weather concerns somewhat benign through the middle of next week. ..Williams.. 09/12/2025 ...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 0422 PM CDT Fri Sep 12 2025 Valid 141200Z - 201200Z ...Pacific Northwest... A mid-level trough and attendant cold front entering Washington/Oregon Coast on Day 3/Sunday will usher in a cooler, moist air mass as well as wetting rains to portions of the Pacific Northwest. A quick eastward translation of the trough commences Sunday night into Day 4/Monday with an amplifying mid-level ridge building over the region through Monday night. Surface high pressure settling into the Northern Rockies and development of thermal trough along the coast will promote a dry, offshore flow across the Cascades, including poor to moderate overnight RH recoveries, early in the Day 5/Tuesday period. Expected rainfall across the Cascades on Day 3/Sunday as well as lack of very dry fuels could mitigate overall impact of this offshore wind event. ...California and Southwest... The cold front associated with the Pacific Northwest trough will bring dry, north/northeast flow to the Sacramento Valley Sunday night into Day 4/Monday but lack of drier fuels should lessen fire weather impact of wind event. Residual moisture from tropical storm Mario could bring showers and thunderstorms, including high-based thunderstorms on the periphery of deeper subtropical moisture, into portions of southern California and the Southwest late next week (Day 7-8/Thursday-Friday). However, uncertainty regarding the evolution of the moisture plume and subdued fuel receptiveness precludes introduction of dry thunderstorm probabilities at this time. ...Midwest and Lower Mississippi Valley... Hot and dry conditions under a mid-level ridge will persist across the Midwest and lower Mississippi Valley through much of next week. Primary impact will be continued drying of fuels, where ERC values in some areas reach into 80-90th percentile. However, generally light winds attributed to weak pressure gradients will keep fire weather concerns somewhat benign through the middle of next week. ..Williams.. 09/12/2025 ...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 0422 PM CDT Fri Sep 12 2025 Valid 141200Z - 201200Z ...Pacific Northwest... A mid-level trough and attendant cold front entering Washington/Oregon Coast on Day 3/Sunday will usher in a cooler, moist air mass as well as wetting rains to portions of the Pacific Northwest. A quick eastward translation of the trough commences Sunday night into Day 4/Monday with an amplifying mid-level ridge building over the region through Monday night. Surface high pressure settling into the Northern Rockies and development of thermal trough along the coast will promote a dry, offshore flow across the Cascades, including poor to moderate overnight RH recoveries, early in the Day 5/Tuesday period. Expected rainfall across the Cascades on Day 3/Sunday as well as lack of very dry fuels could mitigate overall impact of this offshore wind event. ...California and Southwest... The cold front associated with the Pacific Northwest trough will bring dry, north/northeast flow to the Sacramento Valley Sunday night into Day 4/Monday but lack of drier fuels should lessen fire weather impact of wind event. Residual moisture from tropical storm Mario could bring showers and thunderstorms, including high-based thunderstorms on the periphery of deeper subtropical moisture, into portions of southern California and the Southwest late next week (Day 7-8/Thursday-Friday). However, uncertainty regarding the evolution of the moisture plume and subdued fuel receptiveness precludes introduction of dry thunderstorm probabilities at this time. ...Midwest and Lower Mississippi Valley... Hot and dry conditions under a mid-level ridge will persist across the Midwest and lower Mississippi Valley through much of next week. Primary impact will be continued drying of fuels, where ERC values in some areas reach into 80-90th percentile. However, generally light winds attributed to weak pressure gradients will keep fire weather concerns somewhat benign through the middle of next week. ..Williams.. 09/12/2025 ...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 0422 PM CDT Fri Sep 12 2025 Valid 141200Z - 201200Z ...Pacific Northwest... A mid-level trough and attendant cold front entering Washington/Oregon Coast on Day 3/Sunday will usher in a cooler, moist air mass as well as wetting rains to portions of the Pacific Northwest. A quick eastward translation of the trough commences Sunday night into Day 4/Monday with an amplifying mid-level ridge building over the region through Monday night. Surface high pressure settling into the Northern Rockies and development of thermal trough along the coast will promote a dry, offshore flow across the Cascades, including poor to moderate overnight RH recoveries, early in the Day 5/Tuesday period. Expected rainfall across the Cascades on Day 3/Sunday as well as lack of very dry fuels could mitigate overall impact of this offshore wind event. ...California and Southwest... The cold front associated with the Pacific Northwest trough will bring dry, north/northeast flow to the Sacramento Valley Sunday night into Day 4/Monday but lack of drier fuels should lessen fire weather impact of wind event. Residual moisture from tropical storm Mario could bring showers and thunderstorms, including high-based thunderstorms on the periphery of deeper subtropical moisture, into portions of southern California and the Southwest late next week (Day 7-8/Thursday-Friday). However, uncertainty regarding the evolution of the moisture plume and subdued fuel receptiveness precludes introduction of dry thunderstorm probabilities at this time. ...Midwest and Lower Mississippi Valley... Hot and dry conditions under a mid-level ridge will persist across the Midwest and lower Mississippi Valley through much of next week. Primary impact will be continued drying of fuels, where ERC values in some areas reach into 80-90th percentile. However, generally light winds attributed to weak pressure gradients will keep fire weather concerns somewhat benign through the middle of next week. ..Williams.. 09/12/2025 ...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 0422 PM CDT Fri Sep 12 2025 Valid 141200Z - 201200Z ...Pacific Northwest... A mid-level trough and attendant cold front entering Washington/Oregon Coast on Day 3/Sunday will usher in a cooler, moist air mass as well as wetting rains to portions of the Pacific Northwest. A quick eastward translation of the trough commences Sunday night into Day 4/Monday with an amplifying mid-level ridge building over the region through Monday night. Surface high pressure settling into the Northern Rockies and development of thermal trough along the coast will promote a dry, offshore flow across the Cascades, including poor to moderate overnight RH recoveries, early in the Day 5/Tuesday period. Expected rainfall across the Cascades on Day 3/Sunday as well as lack of very dry fuels could mitigate overall impact of this offshore wind event. ...California and Southwest... The cold front associated with the Pacific Northwest trough will bring dry, north/northeast flow to the Sacramento Valley Sunday night into Day 4/Monday but lack of drier fuels should lessen fire weather impact of wind event. Residual moisture from tropical storm Mario could bring showers and thunderstorms, including high-based thunderstorms on the periphery of deeper subtropical moisture, into portions of southern California and the Southwest late next week (Day 7-8/Thursday-Friday). However, uncertainty regarding the evolution of the moisture plume and subdued fuel receptiveness precludes introduction of dry thunderstorm probabilities at this time. ...Midwest and Lower Mississippi Valley... Hot and dry conditions under a mid-level ridge will persist across the Midwest and lower Mississippi Valley through much of next week. Primary impact will be continued drying of fuels, where ERC values in some areas reach into 80-90th percentile. However, generally light winds attributed to weak pressure gradients will keep fire weather concerns somewhat benign through the middle of next week. ..Williams.. 09/12/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0300 PM CDT Fri Sep 12 2025 Valid 122000Z - 131200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE FOUR CORNERS VICINITY AND ALSO ACROSS THE NORTHERN HIGH PLAINS... ...SUMMARY... Isolated severe storms remain possible this afternoon across the Four Corners area and central Rockies, with an increasing risk for severe storms into late afternoon and tonight across the northern Plains. ...Four Corners vicinity into the Southwest... The Slight Risk has been expanded westward into parts of southeast/east-central UT, where favorable deep-layer shear and modest but sufficient instability remains in place this afternoon. Occasional small supercells will continue to be possible, with a threat of hail and localized strong/severe gusts. See MCD 2066 for more details. The Marginal Risk has been expanded slightly westward across southeast AZ, based on trends on visible satellite. The 18Z TUS depicted a favorable conditional environment for severe storms, with moderate MLCAPE and deep-layer shear. While the threat should generally remain rather isolated, a supercell or two will be possible, with an attendant threat of hail and localized severe gusts. See MCD 2065 for more information. ...Northern High Plains vicinity... Only modest adjustments have been made to the Marginal Risk across the northern High Plains vicinity, with no changes to the Slight Risk. An isolated threat for hail and strong/severe gusts may develop later this afternoon, with some increase in coverage of the severe threat expected into this evening. See MCD 2067 and the previous discussion below for more details. ...East-central MN into northwest WI... Much of the Marginal Risk across MN and northwest WI has been removed. An earlier cluster of storms has generally weakened this afternoon across east-central MN, though modestly steep midlevel lapse rates and relatively favorable effective shear could still support a threat for small to near-severe hail and locally gusty winds as these storms move into northwest WI. Additional elevated convection may develop later tonight across the same general region, but severe potential with the later storms appears limited at this time. ..Dean.. 09/12/2025 .PREV DISCUSSION... /ISSUED 1139 AM CDT Fri Sep 12 2025/ ...Four Corners Region/central Rockies... Ahead of the prominent upper trough centered over the Great Basin and Lower Colorado River Valley, a lead mid-level impulse and related height falls and a strengthening of cyclonic flow aloft will influence the region. Cooling mid-level temperatures and a modestly warming boundary layer will further steepen lapse rates diurnally, with strong to severe storms expected to further develop into the afternoon. Relatively strong flow aloft with 40+ kt effective shear will support some supercell structures, with a related enhanced potential for severe hail, aside from locally gusty thunderstorm winds. More severe-favorable ingredients and a somewhat higher potential for severe storms appears to exist across the Four Corners vicinity including northwest New Mexico across western Colorado through the afternoon. ...Northern Plains including Eastern Montana/western Dakotas... Thunderstorm development/intensification is expected by late afternoon, initially on an isolated basis across central/eastern portions of Montana and Wyoming. Cooling mid-level temperatures and surface dew points in the 50s F will contribute to 500-1000 J/kg MLCAPE. Southwesterly deep-layer shear averaging 20-35 kt will be favorable for isolated storms with hail potential. Storm coverage should steadily increase into the evening toward the western Dakotas, aided by the arriving influence of greater forcing for ascent as located over the central Rockies early today. Hail potential will become more common this evening, with localized severe wind potential also modestly increasing. Strong/locally severe storms will potentially persist overnight across the western and central Dakotas. ...Northern/central Minnesota to northwest Wisconsin... Very isolated elevated severe storms, with hail as the most probable hazard, may continue east-southeastward today, semi-focused by elevated moisture transport well to the north of a warm front. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0300 PM CDT Fri Sep 12 2025 Valid 122000Z - 131200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE FOUR CORNERS VICINITY AND ALSO ACROSS THE NORTHERN HIGH PLAINS... ...SUMMARY... Isolated severe storms remain possible this afternoon across the Four Corners area and central Rockies, with an increasing risk for severe storms into late afternoon and tonight across the northern Plains. ...Four Corners vicinity into the Southwest... The Slight Risk has been expanded westward into parts of southeast/east-central UT, where favorable deep-layer shear and modest but sufficient instability remains in place this afternoon. Occasional small supercells will continue to be possible, with a threat of hail and localized strong/severe gusts. See MCD 2066 for more details. The Marginal Risk has been expanded slightly westward across southeast AZ, based on trends on visible satellite. The 18Z TUS depicted a favorable conditional environment for severe storms, with moderate MLCAPE and deep-layer shear. While the threat should generally remain rather isolated, a supercell or two will be possible, with an attendant threat of hail and localized severe gusts. See MCD 2065 for more information. ...Northern High Plains vicinity... Only modest adjustments have been made to the Marginal Risk across the northern High Plains vicinity, with no changes to the Slight Risk. An isolated threat for hail and strong/severe gusts may develop later this afternoon, with some increase in coverage of the severe threat expected into this evening. See MCD 2067 and the previous discussion below for more details. ...East-central MN into northwest WI... Much of the Marginal Risk across MN and northwest WI has been removed. An earlier cluster of storms has generally weakened this afternoon across east-central MN, though modestly steep midlevel lapse rates and relatively favorable effective shear could still support a threat for small to near-severe hail and locally gusty winds as these storms move into northwest WI. Additional elevated convection may develop later tonight across the same general region, but severe potential with the later storms appears limited at this time. ..Dean.. 09/12/2025 .PREV DISCUSSION... /ISSUED 1139 AM CDT Fri Sep 12 2025/ ...Four Corners Region/central Rockies... Ahead of the prominent upper trough centered over the Great Basin and Lower Colorado River Valley, a lead mid-level impulse and related height falls and a strengthening of cyclonic flow aloft will influence the region. Cooling mid-level temperatures and a modestly warming boundary layer will further steepen lapse rates diurnally, with strong to severe storms expected to further develop into the afternoon. Relatively strong flow aloft with 40+ kt effective shear will support some supercell structures, with a related enhanced potential for severe hail, aside from locally gusty thunderstorm winds. More severe-favorable ingredients and a somewhat higher potential for severe storms appears to exist across the Four Corners vicinity including northwest New Mexico across western Colorado through the afternoon. ...Northern Plains including Eastern Montana/western Dakotas... Thunderstorm development/intensification is expected by late afternoon, initially on an isolated basis across central/eastern portions of Montana and Wyoming. Cooling mid-level temperatures and surface dew points in the 50s F will contribute to 500-1000 J/kg MLCAPE. Southwesterly deep-layer shear averaging 20-35 kt will be favorable for isolated storms with hail potential. Storm coverage should steadily increase into the evening toward the western Dakotas, aided by the arriving influence of greater forcing for ascent as located over the central Rockies early today. Hail potential will become more common this evening, with localized severe wind potential also modestly increasing. Strong/locally severe storms will potentially persist overnight across the western and central Dakotas. ...Northern/central Minnesota to northwest Wisconsin... Very isolated elevated severe storms, with hail as the most probable hazard, may continue east-southeastward today, semi-focused by elevated moisture transport well to the north of a warm front. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0300 PM CDT Fri Sep 12 2025 Valid 122000Z - 131200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE FOUR CORNERS VICINITY AND ALSO ACROSS THE NORTHERN HIGH PLAINS... ...SUMMARY... Isolated severe storms remain possible this afternoon across the Four Corners area and central Rockies, with an increasing risk for severe storms into late afternoon and tonight across the northern Plains. ...Four Corners vicinity into the Southwest... The Slight Risk has been expanded westward into parts of southeast/east-central UT, where favorable deep-layer shear and modest but sufficient instability remains in place this afternoon. Occasional small supercells will continue to be possible, with a threat of hail and localized strong/severe gusts. See MCD 2066 for more details. The Marginal Risk has been expanded slightly westward across southeast AZ, based on trends on visible satellite. The 18Z TUS depicted a favorable conditional environment for severe storms, with moderate MLCAPE and deep-layer shear. While the threat should generally remain rather isolated, a supercell or two will be possible, with an attendant threat of hail and localized severe gusts. See MCD 2065 for more information. ...Northern High Plains vicinity... Only modest adjustments have been made to the Marginal Risk across the northern High Plains vicinity, with no changes to the Slight Risk. An isolated threat for hail and strong/severe gusts may develop later this afternoon, with some increase in coverage of the severe threat expected into this evening. See MCD 2067 and the previous discussion below for more details. ...East-central MN into northwest WI... Much of the Marginal Risk across MN and northwest WI has been removed. An earlier cluster of storms has generally weakened this afternoon across east-central MN, though modestly steep midlevel lapse rates and relatively favorable effective shear could still support a threat for small to near-severe hail and locally gusty winds as these storms move into northwest WI. Additional elevated convection may develop later tonight across the same general region, but severe potential with the later storms appears limited at this time. ..Dean.. 09/12/2025 .PREV DISCUSSION... /ISSUED 1139 AM CDT Fri Sep 12 2025/ ...Four Corners Region/central Rockies... Ahead of the prominent upper trough centered over the Great Basin and Lower Colorado River Valley, a lead mid-level impulse and related height falls and a strengthening of cyclonic flow aloft will influence the region. Cooling mid-level temperatures and a modestly warming boundary layer will further steepen lapse rates diurnally, with strong to severe storms expected to further develop into the afternoon. Relatively strong flow aloft with 40+ kt effective shear will support some supercell structures, with a related enhanced potential for severe hail, aside from locally gusty thunderstorm winds. More severe-favorable ingredients and a somewhat higher potential for severe storms appears to exist across the Four Corners vicinity including northwest New Mexico across western Colorado through the afternoon. ...Northern Plains including Eastern Montana/western Dakotas... Thunderstorm development/intensification is expected by late afternoon, initially on an isolated basis across central/eastern portions of Montana and Wyoming. Cooling mid-level temperatures and surface dew points in the 50s F will contribute to 500-1000 J/kg MLCAPE. Southwesterly deep-layer shear averaging 20-35 kt will be favorable for isolated storms with hail potential. Storm coverage should steadily increase into the evening toward the western Dakotas, aided by the arriving influence of greater forcing for ascent as located over the central Rockies early today. Hail potential will become more common this evening, with localized severe wind potential also modestly increasing. Strong/locally severe storms will potentially persist overnight across the western and central Dakotas. ...Northern/central Minnesota to northwest Wisconsin... Very isolated elevated severe storms, with hail as the most probable hazard, may continue east-southeastward today, semi-focused by elevated moisture transport well to the north of a warm front. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0300 PM CDT Fri Sep 12 2025 Valid 122000Z - 131200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE FOUR CORNERS VICINITY AND ALSO ACROSS THE NORTHERN HIGH PLAINS... ...SUMMARY... Isolated severe storms remain possible this afternoon across the Four Corners area and central Rockies, with an increasing risk for severe storms into late afternoon and tonight across the northern Plains. ...Four Corners vicinity into the Southwest... The Slight Risk has been expanded westward into parts of southeast/east-central UT, where favorable deep-layer shear and modest but sufficient instability remains in place this afternoon. Occasional small supercells will continue to be possible, with a threat of hail and localized strong/severe gusts. See MCD 2066 for more details. The Marginal Risk has been expanded slightly westward across southeast AZ, based on trends on visible satellite. The 18Z TUS depicted a favorable conditional environment for severe storms, with moderate MLCAPE and deep-layer shear. While the threat should generally remain rather isolated, a supercell or two will be possible, with an attendant threat of hail and localized severe gusts. See MCD 2065 for more information. ...Northern High Plains vicinity... Only modest adjustments have been made to the Marginal Risk across the northern High Plains vicinity, with no changes to the Slight Risk. An isolated threat for hail and strong/severe gusts may develop later this afternoon, with some increase in coverage of the severe threat expected into this evening. See MCD 2067 and the previous discussion below for more details. ...East-central MN into northwest WI... Much of the Marginal Risk across MN and northwest WI has been removed. An earlier cluster of storms has generally weakened this afternoon across east-central MN, though modestly steep midlevel lapse rates and relatively favorable effective shear could still support a threat for small to near-severe hail and locally gusty winds as these storms move into northwest WI. Additional elevated convection may develop later tonight across the same general region, but severe potential with the later storms appears limited at this time. ..Dean.. 09/12/2025 .PREV DISCUSSION... /ISSUED 1139 AM CDT Fri Sep 12 2025/ ...Four Corners Region/central Rockies... Ahead of the prominent upper trough centered over the Great Basin and Lower Colorado River Valley, a lead mid-level impulse and related height falls and a strengthening of cyclonic flow aloft will influence the region. Cooling mid-level temperatures and a modestly warming boundary layer will further steepen lapse rates diurnally, with strong to severe storms expected to further develop into the afternoon. Relatively strong flow aloft with 40+ kt effective shear will support some supercell structures, with a related enhanced potential for severe hail, aside from locally gusty thunderstorm winds. More severe-favorable ingredients and a somewhat higher potential for severe storms appears to exist across the Four Corners vicinity including northwest New Mexico across western Colorado through the afternoon. ...Northern Plains including Eastern Montana/western Dakotas... Thunderstorm development/intensification is expected by late afternoon, initially on an isolated basis across central/eastern portions of Montana and Wyoming. Cooling mid-level temperatures and surface dew points in the 50s F will contribute to 500-1000 J/kg MLCAPE. Southwesterly deep-layer shear averaging 20-35 kt will be favorable for isolated storms with hail potential. Storm coverage should steadily increase into the evening toward the western Dakotas, aided by the arriving influence of greater forcing for ascent as located over the central Rockies early today. Hail potential will become more common this evening, with localized severe wind potential also modestly increasing. Strong/locally severe storms will potentially persist overnight across the western and central Dakotas. ...Northern/central Minnesota to northwest Wisconsin... Very isolated elevated severe storms, with hail as the most probable hazard, may continue east-southeastward today, semi-focused by elevated moisture transport well to the north of a warm front. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0300 PM CDT Fri Sep 12 2025 Valid 122000Z - 131200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE FOUR CORNERS VICINITY AND ALSO ACROSS THE NORTHERN HIGH PLAINS... ...SUMMARY... Isolated severe storms remain possible this afternoon across the Four Corners area and central Rockies, with an increasing risk for severe storms into late afternoon and tonight across the northern Plains. ...Four Corners vicinity into the Southwest... The Slight Risk has been expanded westward into parts of southeast/east-central UT, where favorable deep-layer shear and modest but sufficient instability remains in place this afternoon. Occasional small supercells will continue to be possible, with a threat of hail and localized strong/severe gusts. See MCD 2066 for more details. The Marginal Risk has been expanded slightly westward across southeast AZ, based on trends on visible satellite. The 18Z TUS depicted a favorable conditional environment for severe storms, with moderate MLCAPE and deep-layer shear. While the threat should generally remain rather isolated, a supercell or two will be possible, with an attendant threat of hail and localized severe gusts. See MCD 2065 for more information. ...Northern High Plains vicinity... Only modest adjustments have been made to the Marginal Risk across the northern High Plains vicinity, with no changes to the Slight Risk. An isolated threat for hail and strong/severe gusts may develop later this afternoon, with some increase in coverage of the severe threat expected into this evening. See MCD 2067 and the previous discussion below for more details. ...East-central MN into northwest WI... Much of the Marginal Risk across MN and northwest WI has been removed. An earlier cluster of storms has generally weakened this afternoon across east-central MN, though modestly steep midlevel lapse rates and relatively favorable effective shear could still support a threat for small to near-severe hail and locally gusty winds as these storms move into northwest WI. Additional elevated convection may develop later tonight across the same general region, but severe potential with the later storms appears limited at this time. ..Dean.. 09/12/2025 .PREV DISCUSSION... /ISSUED 1139 AM CDT Fri Sep 12 2025/ ...Four Corners Region/central Rockies... Ahead of the prominent upper trough centered over the Great Basin and Lower Colorado River Valley, a lead mid-level impulse and related height falls and a strengthening of cyclonic flow aloft will influence the region. Cooling mid-level temperatures and a modestly warming boundary layer will further steepen lapse rates diurnally, with strong to severe storms expected to further develop into the afternoon. Relatively strong flow aloft with 40+ kt effective shear will support some supercell structures, with a related enhanced potential for severe hail, aside from locally gusty thunderstorm winds. More severe-favorable ingredients and a somewhat higher potential for severe storms appears to exist across the Four Corners vicinity including northwest New Mexico across western Colorado through the afternoon. ...Northern Plains including Eastern Montana/western Dakotas... Thunderstorm development/intensification is expected by late afternoon, initially on an isolated basis across central/eastern portions of Montana and Wyoming. Cooling mid-level temperatures and surface dew points in the 50s F will contribute to 500-1000 J/kg MLCAPE. Southwesterly deep-layer shear averaging 20-35 kt will be favorable for isolated storms with hail potential. Storm coverage should steadily increase into the evening toward the western Dakotas, aided by the arriving influence of greater forcing for ascent as located over the central Rockies early today. Hail potential will become more common this evening, with localized severe wind potential also modestly increasing. Strong/locally severe storms will potentially persist overnight across the western and central Dakotas. ...Northern/central Minnesota to northwest Wisconsin... Very isolated elevated severe storms, with hail as the most probable hazard, may continue east-southeastward today, semi-focused by elevated moisture transport well to the north of a warm front. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0300 PM CDT Fri Sep 12 2025 Valid 122000Z - 131200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE FOUR CORNERS VICINITY AND ALSO ACROSS THE NORTHERN HIGH PLAINS... ...SUMMARY... Isolated severe storms remain possible this afternoon across the Four Corners area and central Rockies, with an increasing risk for severe storms into late afternoon and tonight across the northern Plains. ...Four Corners vicinity into the Southwest... The Slight Risk has been expanded westward into parts of southeast/east-central UT, where favorable deep-layer shear and modest but sufficient instability remains in place this afternoon. Occasional small supercells will continue to be possible, with a threat of hail and localized strong/severe gusts. See MCD 2066 for more details. The Marginal Risk has been expanded slightly westward across southeast AZ, based on trends on visible satellite. The 18Z TUS depicted a favorable conditional environment for severe storms, with moderate MLCAPE and deep-layer shear. While the threat should generally remain rather isolated, a supercell or two will be possible, with an attendant threat of hail and localized severe gusts. See MCD 2065 for more information. ...Northern High Plains vicinity... Only modest adjustments have been made to the Marginal Risk across the northern High Plains vicinity, with no changes to the Slight Risk. An isolated threat for hail and strong/severe gusts may develop later this afternoon, with some increase in coverage of the severe threat expected into this evening. See MCD 2067 and the previous discussion below for more details. ...East-central MN into northwest WI... Much of the Marginal Risk across MN and northwest WI has been removed. An earlier cluster of storms has generally weakened this afternoon across east-central MN, though modestly steep midlevel lapse rates and relatively favorable effective shear could still support a threat for small to near-severe hail and locally gusty winds as these storms move into northwest WI. Additional elevated convection may develop later tonight across the same general region, but severe potential with the later storms appears limited at this time. ..Dean.. 09/12/2025 .PREV DISCUSSION... /ISSUED 1139 AM CDT Fri Sep 12 2025/ ...Four Corners Region/central Rockies... Ahead of the prominent upper trough centered over the Great Basin and Lower Colorado River Valley, a lead mid-level impulse and related height falls and a strengthening of cyclonic flow aloft will influence the region. Cooling mid-level temperatures and a modestly warming boundary layer will further steepen lapse rates diurnally, with strong to severe storms expected to further develop into the afternoon. Relatively strong flow aloft with 40+ kt effective shear will support some supercell structures, with a related enhanced potential for severe hail, aside from locally gusty thunderstorm winds. More severe-favorable ingredients and a somewhat higher potential for severe storms appears to exist across the Four Corners vicinity including northwest New Mexico across western Colorado through the afternoon. ...Northern Plains including Eastern Montana/western Dakotas... Thunderstorm development/intensification is expected by late afternoon, initially on an isolated basis across central/eastern portions of Montana and Wyoming. Cooling mid-level temperatures and surface dew points in the 50s F will contribute to 500-1000 J/kg MLCAPE. Southwesterly deep-layer shear averaging 20-35 kt will be favorable for isolated storms with hail potential. Storm coverage should steadily increase into the evening toward the western Dakotas, aided by the arriving influence of greater forcing for ascent as located over the central Rockies early today. Hail potential will become more common this evening, with localized severe wind potential also modestly increasing. Strong/locally severe storms will potentially persist overnight across the western and central Dakotas. ...Northern/central Minnesota to northwest Wisconsin... Very isolated elevated severe storms, with hail as the most probable hazard, may continue east-southeastward today, semi-focused by elevated moisture transport well to the north of a warm front. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0300 PM CDT Fri Sep 12 2025 Valid 122000Z - 131200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE FOUR CORNERS VICINITY AND ALSO ACROSS THE NORTHERN HIGH PLAINS... ...SUMMARY... Isolated severe storms remain possible this afternoon across the Four Corners area and central Rockies, with an increasing risk for severe storms into late afternoon and tonight across the northern Plains. ...Four Corners vicinity into the Southwest... The Slight Risk has been expanded westward into parts of southeast/east-central UT, where favorable deep-layer shear and modest but sufficient instability remains in place this afternoon. Occasional small supercells will continue to be possible, with a threat of hail and localized strong/severe gusts. See MCD 2066 for more details. The Marginal Risk has been expanded slightly westward across southeast AZ, based on trends on visible satellite. The 18Z TUS depicted a favorable conditional environment for severe storms, with moderate MLCAPE and deep-layer shear. While the threat should generally remain rather isolated, a supercell or two will be possible, with an attendant threat of hail and localized severe gusts. See MCD 2065 for more information. ...Northern High Plains vicinity... Only modest adjustments have been made to the Marginal Risk across the northern High Plains vicinity, with no changes to the Slight Risk. An isolated threat for hail and strong/severe gusts may develop later this afternoon, with some increase in coverage of the severe threat expected into this evening. See MCD 2067 and the previous discussion below for more details. ...East-central MN into northwest WI... Much of the Marginal Risk across MN and northwest WI has been removed. An earlier cluster of storms has generally weakened this afternoon across east-central MN, though modestly steep midlevel lapse rates and relatively favorable effective shear could still support a threat for small to near-severe hail and locally gusty winds as these storms move into northwest WI. Additional elevated convection may develop later tonight across the same general region, but severe potential with the later storms appears limited at this time. ..Dean.. 09/12/2025 .PREV DISCUSSION... /ISSUED 1139 AM CDT Fri Sep 12 2025/ ...Four Corners Region/central Rockies... Ahead of the prominent upper trough centered over the Great Basin and Lower Colorado River Valley, a lead mid-level impulse and related height falls and a strengthening of cyclonic flow aloft will influence the region. Cooling mid-level temperatures and a modestly warming boundary layer will further steepen lapse rates diurnally, with strong to severe storms expected to further develop into the afternoon. Relatively strong flow aloft with 40+ kt effective shear will support some supercell structures, with a related enhanced potential for severe hail, aside from locally gusty thunderstorm winds. More severe-favorable ingredients and a somewhat higher potential for severe storms appears to exist across the Four Corners vicinity including northwest New Mexico across western Colorado through the afternoon. ...Northern Plains including Eastern Montana/western Dakotas... Thunderstorm development/intensification is expected by late afternoon, initially on an isolated basis across central/eastern portions of Montana and Wyoming. Cooling mid-level temperatures and surface dew points in the 50s F will contribute to 500-1000 J/kg MLCAPE. Southwesterly deep-layer shear averaging 20-35 kt will be favorable for isolated storms with hail potential. Storm coverage should steadily increase into the evening toward the western Dakotas, aided by the arriving influence of greater forcing for ascent as located over the central Rockies early today. Hail potential will become more common this evening, with localized severe wind potential also modestly increasing. Strong/locally severe storms will potentially persist overnight across the western and central Dakotas. ...Northern/central Minnesota to northwest Wisconsin... Very isolated elevated severe storms, with hail as the most probable hazard, may continue east-southeastward today, semi-focused by elevated moisture transport well to the north of a warm front. Read more