Severe Storms

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0250 PM CDT Mon Jul 28 2025 Valid 291200Z - 301200Z ...20z update... The previous outlooks remains valid with only minor adjustments for the latest model guidance. Widely scattered showers and thunderstorms, with isolated dry strikes, are likely over much of the Northwest Tuesday. While several rounds of storms have resulted in some precipitation accumulation and wetting of fuels, widely scattered storms with limited precipitation efficiency will still pose a risk for ignitions over parts of the southern Cascades and northern CA. A few storms may continue overnight into early D3/Wednesday with isolated lightning possible. ..Lyons.. 07/28/2025 .PREV DISCUSSION... /ISSUED 0153 AM CDT Mon Jul 28 2025/ ...Synopsis... Similar to Day 1, an upper ridge will remain in place over the CONUS, with mid-level moisture continuing to pivot around the ridge across the Pacific Northwest into the Northern Rockies. A dry boundary layer will develop during the afternoon and support a mix of wet and dry thunderstorms. As in Day 1, isolated dry thunderstorm highlights have been introduced given the presence of dry fuels. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0250 PM CDT Mon Jul 28 2025 Valid 291200Z - 301200Z ...20z update... The previous outlooks remains valid with only minor adjustments for the latest model guidance. Widely scattered showers and thunderstorms, with isolated dry strikes, are likely over much of the Northwest Tuesday. While several rounds of storms have resulted in some precipitation accumulation and wetting of fuels, widely scattered storms with limited precipitation efficiency will still pose a risk for ignitions over parts of the southern Cascades and northern CA. A few storms may continue overnight into early D3/Wednesday with isolated lightning possible. ..Lyons.. 07/28/2025 .PREV DISCUSSION... /ISSUED 0153 AM CDT Mon Jul 28 2025/ ...Synopsis... Similar to Day 1, an upper ridge will remain in place over the CONUS, with mid-level moisture continuing to pivot around the ridge across the Pacific Northwest into the Northern Rockies. A dry boundary layer will develop during the afternoon and support a mix of wet and dry thunderstorms. As in Day 1, isolated dry thunderstorm highlights have been introduced given the presence of dry fuels. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0250 PM CDT Mon Jul 28 2025 Valid 291200Z - 301200Z ...20z update... The previous outlooks remains valid with only minor adjustments for the latest model guidance. Widely scattered showers and thunderstorms, with isolated dry strikes, are likely over much of the Northwest Tuesday. While several rounds of storms have resulted in some precipitation accumulation and wetting of fuels, widely scattered storms with limited precipitation efficiency will still pose a risk for ignitions over parts of the southern Cascades and northern CA. A few storms may continue overnight into early D3/Wednesday with isolated lightning possible. ..Lyons.. 07/28/2025 .PREV DISCUSSION... /ISSUED 0153 AM CDT Mon Jul 28 2025/ ...Synopsis... Similar to Day 1, an upper ridge will remain in place over the CONUS, with mid-level moisture continuing to pivot around the ridge across the Pacific Northwest into the Northern Rockies. A dry boundary layer will develop during the afternoon and support a mix of wet and dry thunderstorms. As in Day 1, isolated dry thunderstorm highlights have been introduced given the presence of dry fuels. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0250 PM CDT Mon Jul 28 2025 Valid 291200Z - 301200Z ...20z update... The previous outlooks remains valid with only minor adjustments for the latest model guidance. Widely scattered showers and thunderstorms, with isolated dry strikes, are likely over much of the Northwest Tuesday. While several rounds of storms have resulted in some precipitation accumulation and wetting of fuels, widely scattered storms with limited precipitation efficiency will still pose a risk for ignitions over parts of the southern Cascades and northern CA. A few storms may continue overnight into early D3/Wednesday with isolated lightning possible. ..Lyons.. 07/28/2025 .PREV DISCUSSION... /ISSUED 0153 AM CDT Mon Jul 28 2025/ ...Synopsis... Similar to Day 1, an upper ridge will remain in place over the CONUS, with mid-level moisture continuing to pivot around the ridge across the Pacific Northwest into the Northern Rockies. A dry boundary layer will develop during the afternoon and support a mix of wet and dry thunderstorms. As in Day 1, isolated dry thunderstorm highlights have been introduced given the presence of dry fuels. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0250 PM CDT Mon Jul 28 2025 Valid 291200Z - 301200Z ...20z update... The previous outlooks remains valid with only minor adjustments for the latest model guidance. Widely scattered showers and thunderstorms, with isolated dry strikes, are likely over much of the Northwest Tuesday. While several rounds of storms have resulted in some precipitation accumulation and wetting of fuels, widely scattered storms with limited precipitation efficiency will still pose a risk for ignitions over parts of the southern Cascades and northern CA. A few storms may continue overnight into early D3/Wednesday with isolated lightning possible. ..Lyons.. 07/28/2025 .PREV DISCUSSION... /ISSUED 0153 AM CDT Mon Jul 28 2025/ ...Synopsis... Similar to Day 1, an upper ridge will remain in place over the CONUS, with mid-level moisture continuing to pivot around the ridge across the Pacific Northwest into the Northern Rockies. A dry boundary layer will develop during the afternoon and support a mix of wet and dry thunderstorms. As in Day 1, isolated dry thunderstorm highlights have been introduced given the presence of dry fuels. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0250 PM CDT Mon Jul 28 2025 Valid 291200Z - 301200Z ...20z update... The previous outlooks remains valid with only minor adjustments for the latest model guidance. Widely scattered showers and thunderstorms, with isolated dry strikes, are likely over much of the Northwest Tuesday. While several rounds of storms have resulted in some precipitation accumulation and wetting of fuels, widely scattered storms with limited precipitation efficiency will still pose a risk for ignitions over parts of the southern Cascades and northern CA. A few storms may continue overnight into early D3/Wednesday with isolated lightning possible. ..Lyons.. 07/28/2025 .PREV DISCUSSION... /ISSUED 0153 AM CDT Mon Jul 28 2025/ ...Synopsis... Similar to Day 1, an upper ridge will remain in place over the CONUS, with mid-level moisture continuing to pivot around the ridge across the Pacific Northwest into the Northern Rockies. A dry boundary layer will develop during the afternoon and support a mix of wet and dry thunderstorms. As in Day 1, isolated dry thunderstorm highlights have been introduced given the presence of dry fuels. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0250 PM CDT Mon Jul 28 2025 Valid 291200Z - 301200Z ...20z update... The previous outlooks remains valid with only minor adjustments for the latest model guidance. Widely scattered showers and thunderstorms, with isolated dry strikes, are likely over much of the Northwest Tuesday. While several rounds of storms have resulted in some precipitation accumulation and wetting of fuels, widely scattered storms with limited precipitation efficiency will still pose a risk for ignitions over parts of the southern Cascades and northern CA. A few storms may continue overnight into early D3/Wednesday with isolated lightning possible. ..Lyons.. 07/28/2025 .PREV DISCUSSION... /ISSUED 0153 AM CDT Mon Jul 28 2025/ ...Synopsis... Similar to Day 1, an upper ridge will remain in place over the CONUS, with mid-level moisture continuing to pivot around the ridge across the Pacific Northwest into the Northern Rockies. A dry boundary layer will develop during the afternoon and support a mix of wet and dry thunderstorms. As in Day 1, isolated dry thunderstorm highlights have been introduced given the presence of dry fuels. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0250 PM CDT Mon Jul 28 2025 Valid 291200Z - 301200Z ...20z update... The previous outlooks remains valid with only minor adjustments for the latest model guidance. Widely scattered showers and thunderstorms, with isolated dry strikes, are likely over much of the Northwest Tuesday. While several rounds of storms have resulted in some precipitation accumulation and wetting of fuels, widely scattered storms with limited precipitation efficiency will still pose a risk for ignitions over parts of the southern Cascades and northern CA. A few storms may continue overnight into early D3/Wednesday with isolated lightning possible. ..Lyons.. 07/28/2025 .PREV DISCUSSION... /ISSUED 0153 AM CDT Mon Jul 28 2025/ ...Synopsis... Similar to Day 1, an upper ridge will remain in place over the CONUS, with mid-level moisture continuing to pivot around the ridge across the Pacific Northwest into the Northern Rockies. A dry boundary layer will develop during the afternoon and support a mix of wet and dry thunderstorms. As in Day 1, isolated dry thunderstorm highlights have been introduced given the presence of dry fuels. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

WW 0550 Status Updates
STATUS REPORT ON WW 550 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 25 E Y22 TO JMS. REMAINING VALID PORTION OF WW COULD BE CANCELLED EARLY. ..KERR..07/28/25 ATTN...WFO...BIS... STATUS REPORT FOR WS 550 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS NDC029-047-051-085-282040- ND . NORTH DAKOTA COUNTIES INCLUDED ARE EMMONS LOGAN MCINTOSH SIOUX THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE REFER TO WATCH COUNTY NOTIFICATION STATEMENTS FOR OFFICIAL INFORMATION ON COUNTIES...INDEPENDENT CITIES AND MARINE ZONES CLEARED FROM SEVERE THUNDERSTORM AND TORNADO WATCHES. Read more

WW 0550 Status Updates
STATUS REPORT ON WW 550 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 25 E Y22 TO JMS. REMAINING VALID PORTION OF WW COULD BE CANCELLED EARLY. ..KERR..07/28/25 ATTN...WFO...BIS... STATUS REPORT FOR WS 550 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS NDC029-047-051-085-282040- ND . NORTH DAKOTA COUNTIES INCLUDED ARE EMMONS LOGAN MCINTOSH SIOUX THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE REFER TO WATCH COUNTY NOTIFICATION STATEMENTS FOR OFFICIAL INFORMATION ON COUNTIES...INDEPENDENT CITIES AND MARINE ZONES CLEARED FROM SEVERE THUNDERSTORM AND TORNADO WATCHES. Read more

WW 0550 Status Updates
STATUS REPORT ON WW 550 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 25 E Y22 TO JMS. REMAINING VALID PORTION OF WW COULD BE CANCELLED EARLY. ..KERR..07/28/25 ATTN...WFO...BIS... STATUS REPORT FOR WS 550 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS NDC029-047-051-085-282040- ND . NORTH DAKOTA COUNTIES INCLUDED ARE EMMONS LOGAN MCINTOSH SIOUX THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE REFER TO WATCH COUNTY NOTIFICATION STATEMENTS FOR OFFICIAL INFORMATION ON COUNTIES...INDEPENDENT CITIES AND MARINE ZONES CLEARED FROM SEVERE THUNDERSTORM AND TORNADO WATCHES. Read more

WW 0550 Status Updates
STATUS REPORT ON WW 550 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 25 E Y22 TO JMS. REMAINING VALID PORTION OF WW COULD BE CANCELLED EARLY. ..KERR..07/28/25 ATTN...WFO...BIS... STATUS REPORT FOR WS 550 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS NDC029-047-051-085-282040- ND . NORTH DAKOTA COUNTIES INCLUDED ARE EMMONS LOGAN MCINTOSH SIOUX THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE REFER TO WATCH COUNTY NOTIFICATION STATEMENTS FOR OFFICIAL INFORMATION ON COUNTIES...INDEPENDENT CITIES AND MARINE ZONES CLEARED FROM SEVERE THUNDERSTORM AND TORNADO WATCHES. Read more

WW 0550 Status Updates
STATUS REPORT ON WW 550 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 25 E Y22 TO JMS. REMAINING VALID PORTION OF WW COULD BE CANCELLED EARLY. ..KERR..07/28/25 ATTN...WFO...BIS... STATUS REPORT FOR WS 550 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS NDC029-047-051-085-282040- ND . NORTH DAKOTA COUNTIES INCLUDED ARE EMMONS LOGAN MCINTOSH SIOUX THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE REFER TO WATCH COUNTY NOTIFICATION STATEMENTS FOR OFFICIAL INFORMATION ON COUNTIES...INDEPENDENT CITIES AND MARINE ZONES CLEARED FROM SEVERE THUNDERSTORM AND TORNADO WATCHES. Read more

WW 0550 Status Updates
STATUS REPORT ON WW 550 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 25 E Y22 TO JMS. REMAINING VALID PORTION OF WW COULD BE CANCELLED EARLY. ..KERR..07/28/25 ATTN...WFO...BIS... STATUS REPORT FOR WS 550 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS NDC029-047-051-085-282040- ND . NORTH DAKOTA COUNTIES INCLUDED ARE EMMONS LOGAN MCINTOSH SIOUX THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE REFER TO WATCH COUNTY NOTIFICATION STATEMENTS FOR OFFICIAL INFORMATION ON COUNTIES...INDEPENDENT CITIES AND MARINE ZONES CLEARED FROM SEVERE THUNDERSTORM AND TORNADO WATCHES. Read more

WW 550 SEVERE TSTM ND 281325Z - 282100Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 550 NWS Storm Prediction Center Norman OK 825 AM CDT Mon Jul 28 2025 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Southwest and south central North Dakota * Effective this Monday morning and afternoon from 825 AM until 400 PM CDT. * Primary threats include... Scattered damaging winds and isolated significant gusts to 75 mph likely Scattered large hail events to 1.5 inches in diameter possible SUMMARY...A storm cluster in southwest North Dakota will likely persist and spread eastward through the morning and into the afternoon. Damaging outflow gusts of 60-75 mph will be the main threat, along with large hail up to 1.5 inches in diameter with the strongest embedded storms. The severe thunderstorm watch area is approximately along and 45 statute miles north and south of a line from 10 miles south of Dickinson ND to 25 miles south of Jamestown ND. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU0). 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 1.5 inches. Extreme turbulence and surface wind gusts to 65 knots. A few cumulonimbi with maximum tops to 550. Mean storm motion vector 28035. ...Thompson Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0226 PM CDT Mon Jul 28 2025 Valid 301200Z - 311200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE NORTHERN/CENTRAL HIGH PLAINS...ACROSS THE MID-MISSISSIPPI VALLEY...AND OVER PORTIONS OF THE NORTHEAST... ...SUMMARY... Severe thunderstorms are possible in the Mid-Missouri/Mississippi Valley vicinity, parts of the Mid-Atlantic/southern New England, and the northern/central High Plains on Wednesday. ...Synopsis... A belt of enhanced mid/upper westerly flow on the southern periphery of the eastern Canada upper cyclone will overlap portions of the Great Lakes to the Northeast. A surface cold front is forecast to move south/southeast across portions of OK/TX into the Ohio Valley and Northeast on Wednesday. Ahead of the front, a seasonally moist airmass will be in place. The corridor of greatest instability will reside from the Ozarks to the Ohio Valley and into the northern Mid-Atlantic, coincident with stronger boundary layer moisture and stronger heating. The better boundary layer moisture/instability corridor will remain displaced to the south of the stronger mid/upper flow. Nevertheless, a few corridors of strong to severe thunderstorm potential appear possible. ...Lower-MO/Mid-MS Valley vicinity... A decaying MCS from the Day 2/Tuesday period may be located over IA. Associated outflow and any MCV could move across parts of the Mid-MS Valley and become a focus for more organized storm development within the modestly sheared environment. This scenario is uncertain and depends on how convection develops late in the Day 2 period into early Day 3/Wednesday. Any storms that develop will do so within a very moist (70s dewpoints) and strongly unstable airmass. A risk for damaging/severe gusts would accompany this activity. ...Northeast... A moist boundary layer will be in place ahead of the south/southeast moving cold front. Midlevel lapse rates will be weak, limiting stronger destabilization. The corridor of greatest instability will likely remain confined to the northern Mid-Atlantic vicinity with more modest moisture/instability with northward extent into ME. Nevertheless, stronger vertical shear will reside across the region. Vertically veering wind profiles and effective shear values greater than 40 kt suggest supercells may be possible, though shear profiles are forecast to remain weak through 1-2 km. Where strong heating occurs and allows for steep low-level lapse rates, strong/locally damaging gusts may occur. ...Northern/Central High Plains... Easterly low-level flow will maintain modest boundary layer moisture (mid 50s to low 60s dewpoints) across the region beneath steep midlevel lapse rates. This will support development of moderate instability during the afternoon within the upslope flow regime. Initial thunderstorms will develop over higher terrain and generally migrate east. While low-level flow through around 2-3 km will remain very weak, vertically veering wind profiles and rapidly increasing westerlies above 500 mb will support effective shear magnitudes around 25-35 kt, allowing for some storm organization. Isolated hail and gusty winds will be possible with these storms. ...Oregon... A weak upper shortwave trough is forecast to move across OR during the afternoon or evening. Sufficient midlevel moisture will be present amid steep midlevel lapse rates to support isolated thunderstorm development associated with this feature. MLCAPE values to around 500-1000 J/kg over a relatively confined area near the Cascades will be possible. Low to midlevel flow will remain weak, with increasing winds above 3 km, resulting in sufficient effective shear magnitudes for a couple of briefly organized cells. Inverted-v sub-cloud thermodynamic profiles could support sporadic strong gusts. A Marginal risk (level 1 of 5) could be needed at some point in the coming day if confidence increases in storm timing and coverage. ..Leitman.. 07/28/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0226 PM CDT Mon Jul 28 2025 Valid 301200Z - 311200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE NORTHERN/CENTRAL HIGH PLAINS...ACROSS THE MID-MISSISSIPPI VALLEY...AND OVER PORTIONS OF THE NORTHEAST... ...SUMMARY... Severe thunderstorms are possible in the Mid-Missouri/Mississippi Valley vicinity, parts of the Mid-Atlantic/southern New England, and the northern/central High Plains on Wednesday. ...Synopsis... A belt of enhanced mid/upper westerly flow on the southern periphery of the eastern Canada upper cyclone will overlap portions of the Great Lakes to the Northeast. A surface cold front is forecast to move south/southeast across portions of OK/TX into the Ohio Valley and Northeast on Wednesday. Ahead of the front, a seasonally moist airmass will be in place. The corridor of greatest instability will reside from the Ozarks to the Ohio Valley and into the northern Mid-Atlantic, coincident with stronger boundary layer moisture and stronger heating. The better boundary layer moisture/instability corridor will remain displaced to the south of the stronger mid/upper flow. Nevertheless, a few corridors of strong to severe thunderstorm potential appear possible. ...Lower-MO/Mid-MS Valley vicinity... A decaying MCS from the Day 2/Tuesday period may be located over IA. Associated outflow and any MCV could move across parts of the Mid-MS Valley and become a focus for more organized storm development within the modestly sheared environment. This scenario is uncertain and depends on how convection develops late in the Day 2 period into early Day 3/Wednesday. Any storms that develop will do so within a very moist (70s dewpoints) and strongly unstable airmass. A risk for damaging/severe gusts would accompany this activity. ...Northeast... A moist boundary layer will be in place ahead of the south/southeast moving cold front. Midlevel lapse rates will be weak, limiting stronger destabilization. The corridor of greatest instability will likely remain confined to the northern Mid-Atlantic vicinity with more modest moisture/instability with northward extent into ME. Nevertheless, stronger vertical shear will reside across the region. Vertically veering wind profiles and effective shear values greater than 40 kt suggest supercells may be possible, though shear profiles are forecast to remain weak through 1-2 km. Where strong heating occurs and allows for steep low-level lapse rates, strong/locally damaging gusts may occur. ...Northern/Central High Plains... Easterly low-level flow will maintain modest boundary layer moisture (mid 50s to low 60s dewpoints) across the region beneath steep midlevel lapse rates. This will support development of moderate instability during the afternoon within the upslope flow regime. Initial thunderstorms will develop over higher terrain and generally migrate east. While low-level flow through around 2-3 km will remain very weak, vertically veering wind profiles and rapidly increasing westerlies above 500 mb will support effective shear magnitudes around 25-35 kt, allowing for some storm organization. Isolated hail and gusty winds will be possible with these storms. ...Oregon... A weak upper shortwave trough is forecast to move across OR during the afternoon or evening. Sufficient midlevel moisture will be present amid steep midlevel lapse rates to support isolated thunderstorm development associated with this feature. MLCAPE values to around 500-1000 J/kg over a relatively confined area near the Cascades will be possible. Low to midlevel flow will remain weak, with increasing winds above 3 km, resulting in sufficient effective shear magnitudes for a couple of briefly organized cells. Inverted-v sub-cloud thermodynamic profiles could support sporadic strong gusts. A Marginal risk (level 1 of 5) could be needed at some point in the coming day if confidence increases in storm timing and coverage. ..Leitman.. 07/28/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0226 PM CDT Mon Jul 28 2025 Valid 301200Z - 311200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE NORTHERN/CENTRAL HIGH PLAINS...ACROSS THE MID-MISSISSIPPI VALLEY...AND OVER PORTIONS OF THE NORTHEAST... ...SUMMARY... Severe thunderstorms are possible in the Mid-Missouri/Mississippi Valley vicinity, parts of the Mid-Atlantic/southern New England, and the northern/central High Plains on Wednesday. ...Synopsis... A belt of enhanced mid/upper westerly flow on the southern periphery of the eastern Canada upper cyclone will overlap portions of the Great Lakes to the Northeast. A surface cold front is forecast to move south/southeast across portions of OK/TX into the Ohio Valley and Northeast on Wednesday. Ahead of the front, a seasonally moist airmass will be in place. The corridor of greatest instability will reside from the Ozarks to the Ohio Valley and into the northern Mid-Atlantic, coincident with stronger boundary layer moisture and stronger heating. The better boundary layer moisture/instability corridor will remain displaced to the south of the stronger mid/upper flow. Nevertheless, a few corridors of strong to severe thunderstorm potential appear possible. ...Lower-MO/Mid-MS Valley vicinity... A decaying MCS from the Day 2/Tuesday period may be located over IA. Associated outflow and any MCV could move across parts of the Mid-MS Valley and become a focus for more organized storm development within the modestly sheared environment. This scenario is uncertain and depends on how convection develops late in the Day 2 period into early Day 3/Wednesday. Any storms that develop will do so within a very moist (70s dewpoints) and strongly unstable airmass. A risk for damaging/severe gusts would accompany this activity. ...Northeast... A moist boundary layer will be in place ahead of the south/southeast moving cold front. Midlevel lapse rates will be weak, limiting stronger destabilization. The corridor of greatest instability will likely remain confined to the northern Mid-Atlantic vicinity with more modest moisture/instability with northward extent into ME. Nevertheless, stronger vertical shear will reside across the region. Vertically veering wind profiles and effective shear values greater than 40 kt suggest supercells may be possible, though shear profiles are forecast to remain weak through 1-2 km. Where strong heating occurs and allows for steep low-level lapse rates, strong/locally damaging gusts may occur. ...Northern/Central High Plains... Easterly low-level flow will maintain modest boundary layer moisture (mid 50s to low 60s dewpoints) across the region beneath steep midlevel lapse rates. This will support development of moderate instability during the afternoon within the upslope flow regime. Initial thunderstorms will develop over higher terrain and generally migrate east. While low-level flow through around 2-3 km will remain very weak, vertically veering wind profiles and rapidly increasing westerlies above 500 mb will support effective shear magnitudes around 25-35 kt, allowing for some storm organization. Isolated hail and gusty winds will be possible with these storms. ...Oregon... A weak upper shortwave trough is forecast to move across OR during the afternoon or evening. Sufficient midlevel moisture will be present amid steep midlevel lapse rates to support isolated thunderstorm development associated with this feature. MLCAPE values to around 500-1000 J/kg over a relatively confined area near the Cascades will be possible. Low to midlevel flow will remain weak, with increasing winds above 3 km, resulting in sufficient effective shear magnitudes for a couple of briefly organized cells. Inverted-v sub-cloud thermodynamic profiles could support sporadic strong gusts. A Marginal risk (level 1 of 5) could be needed at some point in the coming day if confidence increases in storm timing and coverage. ..Leitman.. 07/28/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0226 PM CDT Mon Jul 28 2025 Valid 301200Z - 311200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE NORTHERN/CENTRAL HIGH PLAINS...ACROSS THE MID-MISSISSIPPI VALLEY...AND OVER PORTIONS OF THE NORTHEAST... ...SUMMARY... Severe thunderstorms are possible in the Mid-Missouri/Mississippi Valley vicinity, parts of the Mid-Atlantic/southern New England, and the northern/central High Plains on Wednesday. ...Synopsis... A belt of enhanced mid/upper westerly flow on the southern periphery of the eastern Canada upper cyclone will overlap portions of the Great Lakes to the Northeast. A surface cold front is forecast to move south/southeast across portions of OK/TX into the Ohio Valley and Northeast on Wednesday. Ahead of the front, a seasonally moist airmass will be in place. The corridor of greatest instability will reside from the Ozarks to the Ohio Valley and into the northern Mid-Atlantic, coincident with stronger boundary layer moisture and stronger heating. The better boundary layer moisture/instability corridor will remain displaced to the south of the stronger mid/upper flow. Nevertheless, a few corridors of strong to severe thunderstorm potential appear possible. ...Lower-MO/Mid-MS Valley vicinity... A decaying MCS from the Day 2/Tuesday period may be located over IA. Associated outflow and any MCV could move across parts of the Mid-MS Valley and become a focus for more organized storm development within the modestly sheared environment. This scenario is uncertain and depends on how convection develops late in the Day 2 period into early Day 3/Wednesday. Any storms that develop will do so within a very moist (70s dewpoints) and strongly unstable airmass. A risk for damaging/severe gusts would accompany this activity. ...Northeast... A moist boundary layer will be in place ahead of the south/southeast moving cold front. Midlevel lapse rates will be weak, limiting stronger destabilization. The corridor of greatest instability will likely remain confined to the northern Mid-Atlantic vicinity with more modest moisture/instability with northward extent into ME. Nevertheless, stronger vertical shear will reside across the region. Vertically veering wind profiles and effective shear values greater than 40 kt suggest supercells may be possible, though shear profiles are forecast to remain weak through 1-2 km. Where strong heating occurs and allows for steep low-level lapse rates, strong/locally damaging gusts may occur. ...Northern/Central High Plains... Easterly low-level flow will maintain modest boundary layer moisture (mid 50s to low 60s dewpoints) across the region beneath steep midlevel lapse rates. This will support development of moderate instability during the afternoon within the upslope flow regime. Initial thunderstorms will develop over higher terrain and generally migrate east. While low-level flow through around 2-3 km will remain very weak, vertically veering wind profiles and rapidly increasing westerlies above 500 mb will support effective shear magnitudes around 25-35 kt, allowing for some storm organization. Isolated hail and gusty winds will be possible with these storms. ...Oregon... A weak upper shortwave trough is forecast to move across OR during the afternoon or evening. Sufficient midlevel moisture will be present amid steep midlevel lapse rates to support isolated thunderstorm development associated with this feature. MLCAPE values to around 500-1000 J/kg over a relatively confined area near the Cascades will be possible. Low to midlevel flow will remain weak, with increasing winds above 3 km, resulting in sufficient effective shear magnitudes for a couple of briefly organized cells. Inverted-v sub-cloud thermodynamic profiles could support sporadic strong gusts. A Marginal risk (level 1 of 5) could be needed at some point in the coming day if confidence increases in storm timing and coverage. ..Leitman.. 07/28/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0226 PM CDT Mon Jul 28 2025 Valid 301200Z - 311200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE NORTHERN/CENTRAL HIGH PLAINS...ACROSS THE MID-MISSISSIPPI VALLEY...AND OVER PORTIONS OF THE NORTHEAST... ...SUMMARY... Severe thunderstorms are possible in the Mid-Missouri/Mississippi Valley vicinity, parts of the Mid-Atlantic/southern New England, and the northern/central High Plains on Wednesday. ...Synopsis... A belt of enhanced mid/upper westerly flow on the southern periphery of the eastern Canada upper cyclone will overlap portions of the Great Lakes to the Northeast. A surface cold front is forecast to move south/southeast across portions of OK/TX into the Ohio Valley and Northeast on Wednesday. Ahead of the front, a seasonally moist airmass will be in place. The corridor of greatest instability will reside from the Ozarks to the Ohio Valley and into the northern Mid-Atlantic, coincident with stronger boundary layer moisture and stronger heating. The better boundary layer moisture/instability corridor will remain displaced to the south of the stronger mid/upper flow. Nevertheless, a few corridors of strong to severe thunderstorm potential appear possible. ...Lower-MO/Mid-MS Valley vicinity... A decaying MCS from the Day 2/Tuesday period may be located over IA. Associated outflow and any MCV could move across parts of the Mid-MS Valley and become a focus for more organized storm development within the modestly sheared environment. This scenario is uncertain and depends on how convection develops late in the Day 2 period into early Day 3/Wednesday. Any storms that develop will do so within a very moist (70s dewpoints) and strongly unstable airmass. A risk for damaging/severe gusts would accompany this activity. ...Northeast... A moist boundary layer will be in place ahead of the south/southeast moving cold front. Midlevel lapse rates will be weak, limiting stronger destabilization. The corridor of greatest instability will likely remain confined to the northern Mid-Atlantic vicinity with more modest moisture/instability with northward extent into ME. Nevertheless, stronger vertical shear will reside across the region. Vertically veering wind profiles and effective shear values greater than 40 kt suggest supercells may be possible, though shear profiles are forecast to remain weak through 1-2 km. Where strong heating occurs and allows for steep low-level lapse rates, strong/locally damaging gusts may occur. ...Northern/Central High Plains... Easterly low-level flow will maintain modest boundary layer moisture (mid 50s to low 60s dewpoints) across the region beneath steep midlevel lapse rates. This will support development of moderate instability during the afternoon within the upslope flow regime. Initial thunderstorms will develop over higher terrain and generally migrate east. While low-level flow through around 2-3 km will remain very weak, vertically veering wind profiles and rapidly increasing westerlies above 500 mb will support effective shear magnitudes around 25-35 kt, allowing for some storm organization. Isolated hail and gusty winds will be possible with these storms. ...Oregon... A weak upper shortwave trough is forecast to move across OR during the afternoon or evening. Sufficient midlevel moisture will be present amid steep midlevel lapse rates to support isolated thunderstorm development associated with this feature. MLCAPE values to around 500-1000 J/kg over a relatively confined area near the Cascades will be possible. Low to midlevel flow will remain weak, with increasing winds above 3 km, resulting in sufficient effective shear magnitudes for a couple of briefly organized cells. Inverted-v sub-cloud thermodynamic profiles could support sporadic strong gusts. A Marginal risk (level 1 of 5) could be needed at some point in the coming day if confidence increases in storm timing and coverage. ..Leitman.. 07/28/2025 Read more