Severe Storms

WW 0525 Status Updates
STATUS FOR WATCH 0525 HAS NOT BEEN ISSUED YET Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0347 AM CDT Sat Jul 19 2025 Valid 221200Z - 271200Z ...DISCUSSION... Medium-range guidance continues to indicate a belt of strengthening west-northwesterly flow across Ontario, Quebec and adjacent portions of the U.S. Upper Midwest/Great Lakes toward the St. Lawrence Valley and Northeast during the middle to latter portions of the coming work week. This is forecast to occur as a notable mid-level low, digging southeast of the Canadian Arctic latitudes over the next couple of days, accelerates east-southeast of the Canadian Northwest Territories through the Hudson Bay vicinity and northern Quebec, to the north of an increasingly prominent high becoming centered over the Ohio/Tennessee Valleys by next Wednesday/Thursday. Potential forcing for ascent associated with smaller-scale perturbations emerging from initial troughing across the Pacific Northwest, or other more subtle perturbations migrating around the northwestern periphery of the high, before progressing eastward along the southern periphery of this regime remain much more unclear. However, guidance remains suggestive that moistening beneath a plume of eastward advecting elevated mixed-layer air might become supportive of destabilization conducive to the evolution of progressive organized clusters of storms capable of producing swaths of strong to severe gusts, in the presence of favorable shear. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0347 AM CDT Sat Jul 19 2025 Valid 221200Z - 271200Z ...DISCUSSION... Medium-range guidance continues to indicate a belt of strengthening west-northwesterly flow across Ontario, Quebec and adjacent portions of the U.S. Upper Midwest/Great Lakes toward the St. Lawrence Valley and Northeast during the middle to latter portions of the coming work week. This is forecast to occur as a notable mid-level low, digging southeast of the Canadian Arctic latitudes over the next couple of days, accelerates east-southeast of the Canadian Northwest Territories through the Hudson Bay vicinity and northern Quebec, to the north of an increasingly prominent high becoming centered over the Ohio/Tennessee Valleys by next Wednesday/Thursday. Potential forcing for ascent associated with smaller-scale perturbations emerging from initial troughing across the Pacific Northwest, or other more subtle perturbations migrating around the northwestern periphery of the high, before progressing eastward along the southern periphery of this regime remain much more unclear. However, guidance remains suggestive that moistening beneath a plume of eastward advecting elevated mixed-layer air might become supportive of destabilization conducive to the evolution of progressive organized clusters of storms capable of producing swaths of strong to severe gusts, in the presence of favorable shear. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0347 AM CDT Sat Jul 19 2025 Valid 221200Z - 271200Z ...DISCUSSION... Medium-range guidance continues to indicate a belt of strengthening west-northwesterly flow across Ontario, Quebec and adjacent portions of the U.S. Upper Midwest/Great Lakes toward the St. Lawrence Valley and Northeast during the middle to latter portions of the coming work week. This is forecast to occur as a notable mid-level low, digging southeast of the Canadian Arctic latitudes over the next couple of days, accelerates east-southeast of the Canadian Northwest Territories through the Hudson Bay vicinity and northern Quebec, to the north of an increasingly prominent high becoming centered over the Ohio/Tennessee Valleys by next Wednesday/Thursday. Potential forcing for ascent associated with smaller-scale perturbations emerging from initial troughing across the Pacific Northwest, or other more subtle perturbations migrating around the northwestern periphery of the high, before progressing eastward along the southern periphery of this regime remain much more unclear. However, guidance remains suggestive that moistening beneath a plume of eastward advecting elevated mixed-layer air might become supportive of destabilization conducive to the evolution of progressive organized clusters of storms capable of producing swaths of strong to severe gusts, in the presence of favorable shear. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0347 AM CDT Sat Jul 19 2025 Valid 221200Z - 271200Z ...DISCUSSION... Medium-range guidance continues to indicate a belt of strengthening west-northwesterly flow across Ontario, Quebec and adjacent portions of the U.S. Upper Midwest/Great Lakes toward the St. Lawrence Valley and Northeast during the middle to latter portions of the coming work week. This is forecast to occur as a notable mid-level low, digging southeast of the Canadian Arctic latitudes over the next couple of days, accelerates east-southeast of the Canadian Northwest Territories through the Hudson Bay vicinity and northern Quebec, to the north of an increasingly prominent high becoming centered over the Ohio/Tennessee Valleys by next Wednesday/Thursday. Potential forcing for ascent associated with smaller-scale perturbations emerging from initial troughing across the Pacific Northwest, or other more subtle perturbations migrating around the northwestern periphery of the high, before progressing eastward along the southern periphery of this regime remain much more unclear. However, guidance remains suggestive that moistening beneath a plume of eastward advecting elevated mixed-layer air might become supportive of destabilization conducive to the evolution of progressive organized clusters of storms capable of producing swaths of strong to severe gusts, in the presence of favorable shear. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0347 AM CDT Sat Jul 19 2025 Valid 221200Z - 271200Z ...DISCUSSION... Medium-range guidance continues to indicate a belt of strengthening west-northwesterly flow across Ontario, Quebec and adjacent portions of the U.S. Upper Midwest/Great Lakes toward the St. Lawrence Valley and Northeast during the middle to latter portions of the coming work week. This is forecast to occur as a notable mid-level low, digging southeast of the Canadian Arctic latitudes over the next couple of days, accelerates east-southeast of the Canadian Northwest Territories through the Hudson Bay vicinity and northern Quebec, to the north of an increasingly prominent high becoming centered over the Ohio/Tennessee Valleys by next Wednesday/Thursday. Potential forcing for ascent associated with smaller-scale perturbations emerging from initial troughing across the Pacific Northwest, or other more subtle perturbations migrating around the northwestern periphery of the high, before progressing eastward along the southern periphery of this regime remain much more unclear. However, guidance remains suggestive that moistening beneath a plume of eastward advecting elevated mixed-layer air might become supportive of destabilization conducive to the evolution of progressive organized clusters of storms capable of producing swaths of strong to severe gusts, in the presence of favorable shear. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0347 AM CDT Sat Jul 19 2025 Valid 221200Z - 271200Z ...DISCUSSION... Medium-range guidance continues to indicate a belt of strengthening west-northwesterly flow across Ontario, Quebec and adjacent portions of the U.S. Upper Midwest/Great Lakes toward the St. Lawrence Valley and Northeast during the middle to latter portions of the coming work week. This is forecast to occur as a notable mid-level low, digging southeast of the Canadian Arctic latitudes over the next couple of days, accelerates east-southeast of the Canadian Northwest Territories through the Hudson Bay vicinity and northern Quebec, to the north of an increasingly prominent high becoming centered over the Ohio/Tennessee Valleys by next Wednesday/Thursday. Potential forcing for ascent associated with smaller-scale perturbations emerging from initial troughing across the Pacific Northwest, or other more subtle perturbations migrating around the northwestern periphery of the high, before progressing eastward along the southern periphery of this regime remain much more unclear. However, guidance remains suggestive that moistening beneath a plume of eastward advecting elevated mixed-layer air might become supportive of destabilization conducive to the evolution of progressive organized clusters of storms capable of producing swaths of strong to severe gusts, in the presence of favorable shear. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0347 AM CDT Sat Jul 19 2025 Valid 221200Z - 271200Z ...DISCUSSION... Medium-range guidance continues to indicate a belt of strengthening west-northwesterly flow across Ontario, Quebec and adjacent portions of the U.S. Upper Midwest/Great Lakes toward the St. Lawrence Valley and Northeast during the middle to latter portions of the coming work week. This is forecast to occur as a notable mid-level low, digging southeast of the Canadian Arctic latitudes over the next couple of days, accelerates east-southeast of the Canadian Northwest Territories through the Hudson Bay vicinity and northern Quebec, to the north of an increasingly prominent high becoming centered over the Ohio/Tennessee Valleys by next Wednesday/Thursday. Potential forcing for ascent associated with smaller-scale perturbations emerging from initial troughing across the Pacific Northwest, or other more subtle perturbations migrating around the northwestern periphery of the high, before progressing eastward along the southern periphery of this regime remain much more unclear. However, guidance remains suggestive that moistening beneath a plume of eastward advecting elevated mixed-layer air might become supportive of destabilization conducive to the evolution of progressive organized clusters of storms capable of producing swaths of strong to severe gusts, in the presence of favorable shear. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0347 AM CDT Sat Jul 19 2025 Valid 221200Z - 271200Z ...DISCUSSION... Medium-range guidance continues to indicate a belt of strengthening west-northwesterly flow across Ontario, Quebec and adjacent portions of the U.S. Upper Midwest/Great Lakes toward the St. Lawrence Valley and Northeast during the middle to latter portions of the coming work week. This is forecast to occur as a notable mid-level low, digging southeast of the Canadian Arctic latitudes over the next couple of days, accelerates east-southeast of the Canadian Northwest Territories through the Hudson Bay vicinity and northern Quebec, to the north of an increasingly prominent high becoming centered over the Ohio/Tennessee Valleys by next Wednesday/Thursday. Potential forcing for ascent associated with smaller-scale perturbations emerging from initial troughing across the Pacific Northwest, or other more subtle perturbations migrating around the northwestern periphery of the high, before progressing eastward along the southern periphery of this regime remain much more unclear. However, guidance remains suggestive that moistening beneath a plume of eastward advecting elevated mixed-layer air might become supportive of destabilization conducive to the evolution of progressive organized clusters of storms capable of producing swaths of strong to severe gusts, in the presence of favorable shear. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0347 AM CDT Sat Jul 19 2025 Valid 221200Z - 271200Z ...DISCUSSION... Medium-range guidance continues to indicate a belt of strengthening west-northwesterly flow across Ontario, Quebec and adjacent portions of the U.S. Upper Midwest/Great Lakes toward the St. Lawrence Valley and Northeast during the middle to latter portions of the coming work week. This is forecast to occur as a notable mid-level low, digging southeast of the Canadian Arctic latitudes over the next couple of days, accelerates east-southeast of the Canadian Northwest Territories through the Hudson Bay vicinity and northern Quebec, to the north of an increasingly prominent high becoming centered over the Ohio/Tennessee Valleys by next Wednesday/Thursday. Potential forcing for ascent associated with smaller-scale perturbations emerging from initial troughing across the Pacific Northwest, or other more subtle perturbations migrating around the northwestern periphery of the high, before progressing eastward along the southern periphery of this regime remain much more unclear. However, guidance remains suggestive that moistening beneath a plume of eastward advecting elevated mixed-layer air might become supportive of destabilization conducive to the evolution of progressive organized clusters of storms capable of producing swaths of strong to severe gusts, in the presence of favorable shear. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0347 AM CDT Sat Jul 19 2025 Valid 221200Z - 271200Z ...DISCUSSION... Medium-range guidance continues to indicate a belt of strengthening west-northwesterly flow across Ontario, Quebec and adjacent portions of the U.S. Upper Midwest/Great Lakes toward the St. Lawrence Valley and Northeast during the middle to latter portions of the coming work week. This is forecast to occur as a notable mid-level low, digging southeast of the Canadian Arctic latitudes over the next couple of days, accelerates east-southeast of the Canadian Northwest Territories through the Hudson Bay vicinity and northern Quebec, to the north of an increasingly prominent high becoming centered over the Ohio/Tennessee Valleys by next Wednesday/Thursday. Potential forcing for ascent associated with smaller-scale perturbations emerging from initial troughing across the Pacific Northwest, or other more subtle perturbations migrating around the northwestern periphery of the high, before progressing eastward along the southern periphery of this regime remain much more unclear. However, guidance remains suggestive that moistening beneath a plume of eastward advecting elevated mixed-layer air might become supportive of destabilization conducive to the evolution of progressive organized clusters of storms capable of producing swaths of strong to severe gusts, in the presence of favorable shear. Read more

MD 1717 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR MUCH OF NORTHERN...CENTRAL...AND EASTERN IOWA
Mesoscale Discussion 1717 NWS Storm Prediction Center Norman OK 0154 AM CDT Sat Jul 19 2025 Areas affected...much of northern...central...and eastern Iowa Concerning...Severe potential...Watch possible Valid 190654Z - 190830Z Probability of Watch Issuance...40 percent SUMMARY...A downstream severe thunderstorm watch is possible if a more organized storm cluster can develop. DISCUSSION...A cluster of storms across southern Minnesota has started to show some strengthening over the past hour. The environment downstream of this activity is still mostly uncapped with 1500 to 2000 J/kg MUCAPE and 35-40 knots of effective shear. Continued upscale growth along the synoptic boundary from southern Minnesota into northwest Iowa is expected. This may result in a more organized damaging wind threat persisting beyond 08Z and east of the current severe thunderstorm watch. This solution is supported by the HRRR/RRFS with more robust convection between 08Z and 12Z across northern/eastern Iowa. Convective trends will continue to be monitored and if a more organized/bowing lie segment develops, a downstream severe thunderstorm watch may need to be issued. ..Bentley/Gleason.. 07/19/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...DVN...ARX...DMX...FSD... LAT...LON 41269208 41619327 42029483 42619590 43269609 43459590 43499450 43479300 43319166 42639084 42229055 41759071 41409111 41259185 41269208 MOST PROBABLE PEAK TORNADO INTENSITY...85-115 MPH MOST PROBABLE PEAK WIND GUST...55-70 MPH MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN Read more

WW 0524 Status Updates
STATUS REPORT ON WW 524 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 35 ESE LBF TO 10 ESE ANW TO 30 SSE MHE TO 15 ENE OTG TO 30 SE MKT. ..BENTLEY..07/19/25 ATTN...WFO...FSD...MPX...OAX...LBF... STATUS REPORT FOR WS 524 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS IAC041-059-119-141-143-149-167-190840- IA . IOWA COUNTIES INCLUDED ARE CLAY DICKINSON LYON O'BRIEN OSCEOLA PLYMOUTH SIOUX MNC013-043-047-063-091-105-133-147-161-165-190840- MN . MINNESOTA COUNTIES INCLUDED ARE BLUE EARTH FARIBAULT FREEBORN JACKSON MARTIN NOBLES ROCK STEELE WASECA WATONWAN NEC003-009-015-027-041-051-071-089-107-115-139-149-179-183- 190840- NE Read more

WW 0524 Status Updates
STATUS REPORT ON WW 524 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 35 ESE LBF TO 10 ESE ANW TO 30 SSE MHE TO 15 ENE OTG TO 30 SE MKT. ..BENTLEY..07/19/25 ATTN...WFO...FSD...MPX...OAX...LBF... STATUS REPORT FOR WS 524 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS IAC041-059-119-141-143-149-167-190840- IA . IOWA COUNTIES INCLUDED ARE CLAY DICKINSON LYON O'BRIEN OSCEOLA PLYMOUTH SIOUX MNC013-043-047-063-091-105-133-147-161-165-190840- MN . MINNESOTA COUNTIES INCLUDED ARE BLUE EARTH FARIBAULT FREEBORN JACKSON MARTIN NOBLES ROCK STEELE WASECA WATONWAN NEC003-009-015-027-041-051-071-089-107-115-139-149-179-183- 190840- NE Read more

WW 0524 Status Updates
STATUS REPORT ON WW 524 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 35 ESE LBF TO 10 ESE ANW TO 30 SSE MHE TO 15 ENE OTG TO 30 SE MKT. ..BENTLEY..07/19/25 ATTN...WFO...FSD...MPX...OAX...LBF... STATUS REPORT FOR WS 524 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS IAC041-059-119-141-143-149-167-190840- IA . IOWA COUNTIES INCLUDED ARE CLAY DICKINSON LYON O'BRIEN OSCEOLA PLYMOUTH SIOUX MNC013-043-047-063-091-105-133-147-161-165-190840- MN . MINNESOTA COUNTIES INCLUDED ARE BLUE EARTH FARIBAULT FREEBORN JACKSON MARTIN NOBLES ROCK STEELE WASECA WATONWAN NEC003-009-015-027-041-051-071-089-107-115-139-149-179-183- 190840- NE Read more

WW 0524 Status Updates
STATUS REPORT ON WW 524 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 35 ESE LBF TO 10 ESE ANW TO 30 SSE MHE TO 15 ENE OTG TO 30 SE MKT. ..BENTLEY..07/19/25 ATTN...WFO...FSD...MPX...OAX...LBF... STATUS REPORT FOR WS 524 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS IAC041-059-119-141-143-149-167-190840- IA . IOWA COUNTIES INCLUDED ARE CLAY DICKINSON LYON O'BRIEN OSCEOLA PLYMOUTH SIOUX MNC013-043-047-063-091-105-133-147-161-165-190840- MN . MINNESOTA COUNTIES INCLUDED ARE BLUE EARTH FARIBAULT FREEBORN JACKSON MARTIN NOBLES ROCK STEELE WASECA WATONWAN NEC003-009-015-027-041-051-071-089-107-115-139-149-179-183- 190840- NE Read more

WW 524 SEVERE TSTM IA MN NE SD 190110Z - 190800Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 524 NWS Storm Prediction Center Norman OK 810 PM CDT Fri Jul 18 2025 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Northwest Iowa Southwest Minnesota Central and Northeast Nebraska Southeast South Dakota * Effective this Friday night and Saturday morning from 810 PM until 300 AM CDT. * Primary threats include... Scattered large hail and isolated very large hail events to 2 inches in diameter possible Scattered damaging wind gusts to 70 mph possible A tornado or two possible SUMMARY...Widely scattered intense thunderstorms including supercells will develop and track across the watch area into the overnight period. Large hail and damaging wind gusts are the primary concerns. The severe thunderstorm watch area is approximately along and 60 statute miles north and south of a line from 40 miles west northwest of North Platte NE to 45 miles north northeast of Fairmont MN. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU4). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A Severe Thunderstorm Watch means conditions are favorable for severe thunderstorms in and close to the watch area. Persons in these areas should be on the lookout for threatening weather conditions and listen for later statements and possible warnings. Severe thunderstorms can and occasionally do produce tornadoes. && AVIATION...A few severe thunderstorms with hail surface and aloft to 2 inches. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 29025. ...Hart Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0228 AM CDT Sat Jul 19 2025 Valid 211200Z - 221200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS MONDAY INTO MONDAY NIGHT ACROSS PARTS OF THE NORTHERN GREAT PLAINS AND THE TENNESSEE VALLEY INTO SOUTH ATLANTIC SEABOARD... ...SUMMARY... Strong thunderstorm development may pose at least some risk for severe wind and perhaps hail across parts of the northern Great Plains and parts of the Tennessee Valley into southern Atlantic Seaboard Monday through Monday night. ...Discussion... Models indicate at least some shearing of mid-level troughing near the Pacific coast during this period, between fairly prominent and persistent lower latitude ridging encompassing much of the interior U.S. and stronger higher latitude ridging centered over the northeastern Pacific. The interior U.S. ridging may tend to build a bit further northeastward through the Upper Midwest/Great Lakes vicinity, in the wake of significant mid-level troughing progressing offshore of the northern U.S. and Canadian Atlantic coast. In lower levels, a cold front is forecast to progress southward along the Atlantic Seaboard, to the lee of the southern Appalachians, while its western flank retreats northeastward and eastward across the northern Great Plains, Upper Midwest and lower Ohio Valleys. ...Dakotas into Minnesota... Beneath a plume of warm and capping elevated mixed-layer air, models indicate that a seasonably moist boundary layer will again become characterized by moderate to large potential instability with daytime heating across the mid Missouri Valley toward Upper Midwest. Forcing for ascent to support convective development remains unclear, but guidance is suggestive that one or two subtle perturbations progressing around the northern periphery of the stronger mid-level ridging may support the initiation of storms near the North and South Dakota state border vicinity by late Monday afternoon. Although deep-layer shear may be modest, this evolution may include a supercell or two before activity tends to grow upscale into an east/southeastward propagating cluster capable of producing strong to severe surface gusts. ...Tennessee Valley into southern Atlantic Seaboard... With the cold front generally advancing south of the westerlies, the extent of severe weather potential remains unclear. Convection allowing models and other guidance suggest that it might not be out of the question that a remnant cluster of storms, emerging from the lower Ohio Valley early Monday, may persist or re-intensify during the day, while propagating southeastward along the front toward the southern Appalachians, aided by inflow of moderately unstable air. Otherwise, destabilization in advance of the progressive portion of the front, across the Carolinas, may contribute to strong storms posing a risk for potentially damaging wind gusts. ..Kerr.. 07/19/2025 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0228 AM CDT Sat Jul 19 2025 Valid 211200Z - 221200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS MONDAY INTO MONDAY NIGHT ACROSS PARTS OF THE NORTHERN GREAT PLAINS AND THE TENNESSEE VALLEY INTO SOUTH ATLANTIC SEABOARD... ...SUMMARY... Strong thunderstorm development may pose at least some risk for severe wind and perhaps hail across parts of the northern Great Plains and parts of the Tennessee Valley into southern Atlantic Seaboard Monday through Monday night. ...Discussion... Models indicate at least some shearing of mid-level troughing near the Pacific coast during this period, between fairly prominent and persistent lower latitude ridging encompassing much of the interior U.S. and stronger higher latitude ridging centered over the northeastern Pacific. The interior U.S. ridging may tend to build a bit further northeastward through the Upper Midwest/Great Lakes vicinity, in the wake of significant mid-level troughing progressing offshore of the northern U.S. and Canadian Atlantic coast. In lower levels, a cold front is forecast to progress southward along the Atlantic Seaboard, to the lee of the southern Appalachians, while its western flank retreats northeastward and eastward across the northern Great Plains, Upper Midwest and lower Ohio Valleys. ...Dakotas into Minnesota... Beneath a plume of warm and capping elevated mixed-layer air, models indicate that a seasonably moist boundary layer will again become characterized by moderate to large potential instability with daytime heating across the mid Missouri Valley toward Upper Midwest. Forcing for ascent to support convective development remains unclear, but guidance is suggestive that one or two subtle perturbations progressing around the northern periphery of the stronger mid-level ridging may support the initiation of storms near the North and South Dakota state border vicinity by late Monday afternoon. Although deep-layer shear may be modest, this evolution may include a supercell or two before activity tends to grow upscale into an east/southeastward propagating cluster capable of producing strong to severe surface gusts. ...Tennessee Valley into southern Atlantic Seaboard... With the cold front generally advancing south of the westerlies, the extent of severe weather potential remains unclear. Convection allowing models and other guidance suggest that it might not be out of the question that a remnant cluster of storms, emerging from the lower Ohio Valley early Monday, may persist or re-intensify during the day, while propagating southeastward along the front toward the southern Appalachians, aided by inflow of moderately unstable air. Otherwise, destabilization in advance of the progressive portion of the front, across the Carolinas, may contribute to strong storms posing a risk for potentially damaging wind gusts. ..Kerr.. 07/19/2025 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0228 AM CDT Sat Jul 19 2025 Valid 211200Z - 221200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS MONDAY INTO MONDAY NIGHT ACROSS PARTS OF THE NORTHERN GREAT PLAINS AND THE TENNESSEE VALLEY INTO SOUTH ATLANTIC SEABOARD... ...SUMMARY... Strong thunderstorm development may pose at least some risk for severe wind and perhaps hail across parts of the northern Great Plains and parts of the Tennessee Valley into southern Atlantic Seaboard Monday through Monday night. ...Discussion... Models indicate at least some shearing of mid-level troughing near the Pacific coast during this period, between fairly prominent and persistent lower latitude ridging encompassing much of the interior U.S. and stronger higher latitude ridging centered over the northeastern Pacific. The interior U.S. ridging may tend to build a bit further northeastward through the Upper Midwest/Great Lakes vicinity, in the wake of significant mid-level troughing progressing offshore of the northern U.S. and Canadian Atlantic coast. In lower levels, a cold front is forecast to progress southward along the Atlantic Seaboard, to the lee of the southern Appalachians, while its western flank retreats northeastward and eastward across the northern Great Plains, Upper Midwest and lower Ohio Valleys. ...Dakotas into Minnesota... Beneath a plume of warm and capping elevated mixed-layer air, models indicate that a seasonably moist boundary layer will again become characterized by moderate to large potential instability with daytime heating across the mid Missouri Valley toward Upper Midwest. Forcing for ascent to support convective development remains unclear, but guidance is suggestive that one or two subtle perturbations progressing around the northern periphery of the stronger mid-level ridging may support the initiation of storms near the North and South Dakota state border vicinity by late Monday afternoon. Although deep-layer shear may be modest, this evolution may include a supercell or two before activity tends to grow upscale into an east/southeastward propagating cluster capable of producing strong to severe surface gusts. ...Tennessee Valley into southern Atlantic Seaboard... With the cold front generally advancing south of the westerlies, the extent of severe weather potential remains unclear. Convection allowing models and other guidance suggest that it might not be out of the question that a remnant cluster of storms, emerging from the lower Ohio Valley early Monday, may persist or re-intensify during the day, while propagating southeastward along the front toward the southern Appalachians, aided by inflow of moderately unstable air. Otherwise, destabilization in advance of the progressive portion of the front, across the Carolinas, may contribute to strong storms posing a risk for potentially damaging wind gusts. ..Kerr.. 07/19/2025 Read more