Severe Storms

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1233 AM CDT Sun Aug 24 2025 Valid 251200Z - 261200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... The potential for severe storms is low across the continental U.S. on Monday and Monday night. ...DISCUSSION... A large-scale cyclonic flow pattern will be in place across much of the eastern two-thirds of the U.S. on Monday. At the surface, a large area of high pressure will remain in place from the Great Plains eastward to the Appalachians. Along this southern periphery of this airmass, post-frontal storms will be possible across parts of the central High Plains and southern Plains Monday afternoon. Within this airmass, any instability that develops is forecast to remain weak, suggesting that the potential for severe storms is low. Elsewhere across the continental U.S., a severe threat is not expected Monday and Monday night. ..Broyles.. 08/24/2025 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1233 AM CDT Sun Aug 24 2025 Valid 251200Z - 261200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... The potential for severe storms is low across the continental U.S. on Monday and Monday night. ...DISCUSSION... A large-scale cyclonic flow pattern will be in place across much of the eastern two-thirds of the U.S. on Monday. At the surface, a large area of high pressure will remain in place from the Great Plains eastward to the Appalachians. Along this southern periphery of this airmass, post-frontal storms will be possible across parts of the central High Plains and southern Plains Monday afternoon. Within this airmass, any instability that develops is forecast to remain weak, suggesting that the potential for severe storms is low. Elsewhere across the continental U.S., a severe threat is not expected Monday and Monday night. ..Broyles.. 08/24/2025 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1233 AM CDT Sun Aug 24 2025 Valid 251200Z - 261200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... The potential for severe storms is low across the continental U.S. on Monday and Monday night. ...DISCUSSION... A large-scale cyclonic flow pattern will be in place across much of the eastern two-thirds of the U.S. on Monday. At the surface, a large area of high pressure will remain in place from the Great Plains eastward to the Appalachians. Along this southern periphery of this airmass, post-frontal storms will be possible across parts of the central High Plains and southern Plains Monday afternoon. Within this airmass, any instability that develops is forecast to remain weak, suggesting that the potential for severe storms is low. Elsewhere across the continental U.S., a severe threat is not expected Monday and Monday night. ..Broyles.. 08/24/2025 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1240 AM CDT Sun Aug 24 2025 Valid 241200Z - 251200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF NEW YORK/PENNSYLVANIA AND FROM EASTERN COLORADO TO WESTERN OKLAHOMA... ...SUMMARY... A few storms may reach severe thresholds from eastern Colorado into western Oklahoma this afternoon and evening. Scattered strong-severe storms are possible across portions of Pennsylvania and New York. Hail or wind are the expected risks. ...NY/PA... Early-morning satellite imagery depicts a strong upper trough over ON/Great Lakes, shifting east-southeast in line with latest model guidance. Associated surface front is forecast to advance into western NY/PA by early afternoon before shifting into central portions of these states by 25/00z. Modest boundary-layer heating is expected to aid destabilization ahead of the front and convective temperatures are expected to be breached around 20-21z; although, deep-layer lapse rates are not expected to be particularly steep (0-6km values around 6.5 C/km). While CAMs support this with scattered frontal convection developing around mid afternoon. This activity could generate locally strong winds, and perhaps some hail. Main risk will be during the mid afternoon into early evening before the boundary layer cools after sunset. ...Eastern CO to western OK... Eastern periphery of Great Basin high will flatten as northwesterly flow becomes firmly established along the back side of Great Lakes/OH Valley trough. At the surface, pronounced surface anticyclone will settle into the northern Plains, ultimately forcing the leading edge of more continental air into the southern Plains by the end of the period. Net take is a corridor of low-level warm advection will become established from southern WY into western OK - coincident with northwest-southeast frontal orientation. It appears a few weak disturbances will top the ridge and dig southeast toward the southern Plains. Each of these features should encourage a response in the LLJ, which will aid convective development. Elevated convection may be ongoing at the start of the period across western NE into northwest KS. A substantial cluster/MCS should propagate southeast with renewed development later in the period. Rain-cooled boundary layer will ensure stronger heating is focused across southeast CO into western OK. Primary concern for isolated severe will be near this zone of stronger heating/instability. Hail and wind may accompany this more robust convection. ..Darrow/Weinman.. 08/24/2025 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1240 AM CDT Sun Aug 24 2025 Valid 241200Z - 251200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF NEW YORK/PENNSYLVANIA AND FROM EASTERN COLORADO TO WESTERN OKLAHOMA... ...SUMMARY... A few storms may reach severe thresholds from eastern Colorado into western Oklahoma this afternoon and evening. Scattered strong-severe storms are possible across portions of Pennsylvania and New York. Hail or wind are the expected risks. ...NY/PA... Early-morning satellite imagery depicts a strong upper trough over ON/Great Lakes, shifting east-southeast in line with latest model guidance. Associated surface front is forecast to advance into western NY/PA by early afternoon before shifting into central portions of these states by 25/00z. Modest boundary-layer heating is expected to aid destabilization ahead of the front and convective temperatures are expected to be breached around 20-21z; although, deep-layer lapse rates are not expected to be particularly steep (0-6km values around 6.5 C/km). While CAMs support this with scattered frontal convection developing around mid afternoon. This activity could generate locally strong winds, and perhaps some hail. Main risk will be during the mid afternoon into early evening before the boundary layer cools after sunset. ...Eastern CO to western OK... Eastern periphery of Great Basin high will flatten as northwesterly flow becomes firmly established along the back side of Great Lakes/OH Valley trough. At the surface, pronounced surface anticyclone will settle into the northern Plains, ultimately forcing the leading edge of more continental air into the southern Plains by the end of the period. Net take is a corridor of low-level warm advection will become established from southern WY into western OK - coincident with northwest-southeast frontal orientation. It appears a few weak disturbances will top the ridge and dig southeast toward the southern Plains. Each of these features should encourage a response in the LLJ, which will aid convective development. Elevated convection may be ongoing at the start of the period across western NE into northwest KS. A substantial cluster/MCS should propagate southeast with renewed development later in the period. Rain-cooled boundary layer will ensure stronger heating is focused across southeast CO into western OK. Primary concern for isolated severe will be near this zone of stronger heating/instability. Hail and wind may accompany this more robust convection. ..Darrow/Weinman.. 08/24/2025 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1240 AM CDT Sun Aug 24 2025 Valid 241200Z - 251200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF NEW YORK/PENNSYLVANIA AND FROM EASTERN COLORADO TO WESTERN OKLAHOMA... ...SUMMARY... A few storms may reach severe thresholds from eastern Colorado into western Oklahoma this afternoon and evening. Scattered strong-severe storms are possible across portions of Pennsylvania and New York. Hail or wind are the expected risks. ...NY/PA... Early-morning satellite imagery depicts a strong upper trough over ON/Great Lakes, shifting east-southeast in line with latest model guidance. Associated surface front is forecast to advance into western NY/PA by early afternoon before shifting into central portions of these states by 25/00z. Modest boundary-layer heating is expected to aid destabilization ahead of the front and convective temperatures are expected to be breached around 20-21z; although, deep-layer lapse rates are not expected to be particularly steep (0-6km values around 6.5 C/km). While CAMs support this with scattered frontal convection developing around mid afternoon. This activity could generate locally strong winds, and perhaps some hail. Main risk will be during the mid afternoon into early evening before the boundary layer cools after sunset. ...Eastern CO to western OK... Eastern periphery of Great Basin high will flatten as northwesterly flow becomes firmly established along the back side of Great Lakes/OH Valley trough. At the surface, pronounced surface anticyclone will settle into the northern Plains, ultimately forcing the leading edge of more continental air into the southern Plains by the end of the period. Net take is a corridor of low-level warm advection will become established from southern WY into western OK - coincident with northwest-southeast frontal orientation. It appears a few weak disturbances will top the ridge and dig southeast toward the southern Plains. Each of these features should encourage a response in the LLJ, which will aid convective development. Elevated convection may be ongoing at the start of the period across western NE into northwest KS. A substantial cluster/MCS should propagate southeast with renewed development later in the period. Rain-cooled boundary layer will ensure stronger heating is focused across southeast CO into western OK. Primary concern for isolated severe will be near this zone of stronger heating/instability. Hail and wind may accompany this more robust convection. ..Darrow/Weinman.. 08/24/2025 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0740 PM CDT Sat Aug 23 2025 Valid 240100Z - 241200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ALONG THE CENTRAL ROCKIES FRONT RANGE... ...SUMMARY... Isolated severe thunderstorms remain possible near the Colorado/Wyoming Front Range and central High Plains this evening. ...01z Update... Great Basin upper ridge is gradually building north across the Interior West early this evening. As a result, northwesterly flow remains firmly established across eastern WY/CO. Scattered convection has developed beneath this feature with the eastern-most thunderstorms noted along the CO Front Range. Latest diagnostic data continues to depict a narrow corridor of modest instability along the Front Range from southeast WY into northeast NM. A few robust thunderstorms are noted along this corridor but MRMS data suggests any hail with this activity is likely marginally severe at best. Will maintain MRGL Risk for isolated-scattered thunderstorms this evening as cloud-layer shear is more than strong enough for organized updrafts. Southeast Lower Michigan: Scattered thunderstorms have developed along the cold front across southern ON into southeast MI. While gusty winds, and perhaps some marginally severe hail, may be noted with these storms for the next hour or so, this activity will quickly shift into ON. Severe probabilities will not be introduced for these reasons. ..Darrow.. 08/24/2025 Read more

No watches are valid as of Sat Aug 23 22:34:01 UTC 2025.

MD 2007 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR FRONT RANGE OF COLORADO
Mesoscale Discussion 2007 NWS Storm Prediction Center Norman OK 0523 PM CDT Sat Aug 23 2025 Areas affected...Front Range of Colorado Concerning...Severe potential...Watch unlikely Valid 232223Z - 240000Z Probability of Watch Issuance...20 percent SUMMARY...Isolated large hail (1-1.75 inches in diameter) will be possible the next few hours, but a watch is not anticipated. DISCUSSION...A couple of supercells have formed along the Front Range of CO, roughly 25-45 mi west and southwest of the Denver. Boundary-layer dewpoints in the low 50s have spread into the foothills with upslope flow, and moderate buoyancy is in place just east of the high terrain. Though large-scale forcing for ascent is weak at best, the northwest flow regime favors at least isolated, southward-moving supercells through this evening. Sufficiently long hodographs and steep midlevel lapse rates will favor the potential for isolated large hail, potentially in the 1-1.75 inch diameter range. Given the isolated storm coverage and the likelihood that storms will remain tied largely to the east slopes of the higher terrain, a watch is not anticipated. ..Thompson/Smith.. 08/23/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...PUB...BOU... LAT...LON 39650564 39890546 39910522 39730502 39080485 39080482 38700493 38660530 39040557 39650564 MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN Read more

No Mesoscale Discussions are in effect as of Sat Aug 23 21:27:01 UTC 2025.

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0230 PM CDT Sat Aug 23 2025 Valid 251200Z - 311200Z Upper ridging will prevail across the western and central CONUS through much of the upcoming week, before a mid-level trough attempts to impinge on the West Coast by next weekend. Through much of the period, deep-layer mid-level moisture will continue to progress northwestward across the northern Great Basin and eventually toward the Pacific Northwest. The chances of isolated to scattered thunderstorms will increase across these regions through early next week. However, there are uncertainties pertaining to the efficiency of lightning-based ignitions given the degree of available moisture (i.e. potentially greater than 1 inch precipitable water values) and appreciable rainfall accumulations from thunderstorms in the Days 1-2 time frame. Isolated dry thunderstorm probabilities have been withheld, though dry thunderstorm highlights cannot be completely ruled out by early next week. ..Squitieri.. 08/23/2025 ...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 0230 PM CDT Sat Aug 23 2025 Valid 251200Z - 311200Z Upper ridging will prevail across the western and central CONUS through much of the upcoming week, before a mid-level trough attempts to impinge on the West Coast by next weekend. Through much of the period, deep-layer mid-level moisture will continue to progress northwestward across the northern Great Basin and eventually toward the Pacific Northwest. The chances of isolated to scattered thunderstorms will increase across these regions through early next week. However, there are uncertainties pertaining to the efficiency of lightning-based ignitions given the degree of available moisture (i.e. potentially greater than 1 inch precipitable water values) and appreciable rainfall accumulations from thunderstorms in the Days 1-2 time frame. Isolated dry thunderstorm probabilities have been withheld, though dry thunderstorm highlights cannot be completely ruled out by early next week. ..Squitieri.. 08/23/2025 ...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 0230 PM CDT Sat Aug 23 2025 Valid 251200Z - 311200Z Upper ridging will prevail across the western and central CONUS through much of the upcoming week, before a mid-level trough attempts to impinge on the West Coast by next weekend. Through much of the period, deep-layer mid-level moisture will continue to progress northwestward across the northern Great Basin and eventually toward the Pacific Northwest. The chances of isolated to scattered thunderstorms will increase across these regions through early next week. However, there are uncertainties pertaining to the efficiency of lightning-based ignitions given the degree of available moisture (i.e. potentially greater than 1 inch precipitable water values) and appreciable rainfall accumulations from thunderstorms in the Days 1-2 time frame. Isolated dry thunderstorm probabilities have been withheld, though dry thunderstorm highlights cannot be completely ruled out by early next week. ..Squitieri.. 08/23/2025 ...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 0230 PM CDT Sat Aug 23 2025 Valid 251200Z - 311200Z Upper ridging will prevail across the western and central CONUS through much of the upcoming week, before a mid-level trough attempts to impinge on the West Coast by next weekend. Through much of the period, deep-layer mid-level moisture will continue to progress northwestward across the northern Great Basin and eventually toward the Pacific Northwest. The chances of isolated to scattered thunderstorms will increase across these regions through early next week. However, there are uncertainties pertaining to the efficiency of lightning-based ignitions given the degree of available moisture (i.e. potentially greater than 1 inch precipitable water values) and appreciable rainfall accumulations from thunderstorms in the Days 1-2 time frame. Isolated dry thunderstorm probabilities have been withheld, though dry thunderstorm highlights cannot be completely ruled out by early next week. ..Squitieri.. 08/23/2025 ...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 0230 PM CDT Sat Aug 23 2025 Valid 251200Z - 311200Z Upper ridging will prevail across the western and central CONUS through much of the upcoming week, before a mid-level trough attempts to impinge on the West Coast by next weekend. Through much of the period, deep-layer mid-level moisture will continue to progress northwestward across the northern Great Basin and eventually toward the Pacific Northwest. The chances of isolated to scattered thunderstorms will increase across these regions through early next week. However, there are uncertainties pertaining to the efficiency of lightning-based ignitions given the degree of available moisture (i.e. potentially greater than 1 inch precipitable water values) and appreciable rainfall accumulations from thunderstorms in the Days 1-2 time frame. Isolated dry thunderstorm probabilities have been withheld, though dry thunderstorm highlights cannot be completely ruled out by early next week. ..Squitieri.. 08/23/2025 ...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 0230 PM CDT Sat Aug 23 2025 Valid 251200Z - 311200Z Upper ridging will prevail across the western and central CONUS through much of the upcoming week, before a mid-level trough attempts to impinge on the West Coast by next weekend. Through much of the period, deep-layer mid-level moisture will continue to progress northwestward across the northern Great Basin and eventually toward the Pacific Northwest. The chances of isolated to scattered thunderstorms will increase across these regions through early next week. However, there are uncertainties pertaining to the efficiency of lightning-based ignitions given the degree of available moisture (i.e. potentially greater than 1 inch precipitable water values) and appreciable rainfall accumulations from thunderstorms in the Days 1-2 time frame. Isolated dry thunderstorm probabilities have been withheld, though dry thunderstorm highlights cannot be completely ruled out by early next week. ..Squitieri.. 08/23/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

MD 2006 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR FAR SOUTHEAST WYOMING INTO CENTRAL COLORADO
Mesoscale Discussion 2006 NWS Storm Prediction Center Norman OK 0221 PM CDT Sat Aug 23 2025 Areas affected...Far southeast Wyoming into central Colorado Concerning...Severe potential...Watch unlikely Valid 231921Z - 232115Z Probability of Watch Issuance...20 percent SUMMARY...Isolated thunderstorms, including a supercell or two, may pose a large hail threat across northern and central Colorado through early evening. This threat should remain sufficiently isolated to preclude watch issuance. DISCUSSION...GOES visible imagery and lightning data show a gradual uptick in deep convection across much of the central Rockies as temperatures slowly warm into the 70s and low 80s along the Front Range and within the higher elevation. Although lingering cloud cover continues to modulate daytime heating to some degree, latest RAP mesoanalysis estimates suggest that even this modest heating is sufficient to support MLCAPE values of around 1000 J/kg - especially across north-central CO where a pocket of somewhat richer moisture is noted in surface observations (upper 50s to low 60s dewpoints). Additionally, recent VWP observations from KCYS sampled northwesterly mid-level winds at about 40 knots. Given weak east/southeasterly low-level flow within a diffuse frontal zone, this should yield deep-layer bulk shear values of around 40-45 knots with somewhat elongated/straight hodographs. A recent split of a shallow convective cell north of the CO/WY border confirms a favorable kinematic environment is in place for splitting cells. Convective intensity will likely increase through late afternoon as daytime heating continues, and the favorable wind profile will likely promote splitting supercells with an attendant threat for large hail. That said, limited forcing for ascent away from the terrain and less favorable thermodynamic conditions with southeastward extent should limit the overall coverage of intense convection. ..Moore/Gleason.. 08/23/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...PUB...BOU...CYS...GJT... LAT...LON 38960597 40770657 41100661 41360638 41450603 41410572 40280385 39880383 39510395 39280416 39030453 38880498 38800547 38960597 MOST PROBABLE PEAK WIND GUST...UP TO 60 MPH MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0227 PM CDT Sat Aug 23 2025 Valid 251200Z - 261200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe storms are not forecast on Monday. ...Synopsis... An upper low will progress eastward into Quebec, with a large area of cyclonic flow aloft over much of the eastern CONUS on Monday. West of this trough, and upper ridge will remain from the Four Corners states into western TX. At the surface, an expansive area of high pressure will result in relatively stable/dry conditions over much of the central and eastern CONUS. The leading cold front and bulk of associated thunderstorm activity will stretch from the western Atlantic into the northern Gulf. Western portions of the front will extend into central TX, where southerly winds will maintain a moist and marginally unstable air mass. Early day activity may exist over KS into OK where southerly 850 mb flow may yield elevated instability atop the surface front. Additional storm development is possible south of any such activity into northwest TX, but poor lapse rates and shear aloft will limit severe potential. Otherwise, scattered afternoon thunderstorms are likely over much of the Intermountain West as areas of midlevel moisture persist. ..Jewell.. 08/23/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0227 PM CDT Sat Aug 23 2025 Valid 251200Z - 261200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe storms are not forecast on Monday. ...Synopsis... An upper low will progress eastward into Quebec, with a large area of cyclonic flow aloft over much of the eastern CONUS on Monday. West of this trough, and upper ridge will remain from the Four Corners states into western TX. At the surface, an expansive area of high pressure will result in relatively stable/dry conditions over much of the central and eastern CONUS. The leading cold front and bulk of associated thunderstorm activity will stretch from the western Atlantic into the northern Gulf. Western portions of the front will extend into central TX, where southerly winds will maintain a moist and marginally unstable air mass. Early day activity may exist over KS into OK where southerly 850 mb flow may yield elevated instability atop the surface front. Additional storm development is possible south of any such activity into northwest TX, but poor lapse rates and shear aloft will limit severe potential. Otherwise, scattered afternoon thunderstorms are likely over much of the Intermountain West as areas of midlevel moisture persist. ..Jewell.. 08/23/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0227 PM CDT Sat Aug 23 2025 Valid 251200Z - 261200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe storms are not forecast on Monday. ...Synopsis... An upper low will progress eastward into Quebec, with a large area of cyclonic flow aloft over much of the eastern CONUS on Monday. West of this trough, and upper ridge will remain from the Four Corners states into western TX. At the surface, an expansive area of high pressure will result in relatively stable/dry conditions over much of the central and eastern CONUS. The leading cold front and bulk of associated thunderstorm activity will stretch from the western Atlantic into the northern Gulf. Western portions of the front will extend into central TX, where southerly winds will maintain a moist and marginally unstable air mass. Early day activity may exist over KS into OK where southerly 850 mb flow may yield elevated instability atop the surface front. Additional storm development is possible south of any such activity into northwest TX, but poor lapse rates and shear aloft will limit severe potential. Otherwise, scattered afternoon thunderstorms are likely over much of the Intermountain West as areas of midlevel moisture persist. ..Jewell.. 08/23/2025 Read more