Severe Storms

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

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

WW 0551 Status Updates
STATUS FOR WATCH 0551 HAS NOT BEEN ISSUED YET Read more

WW 0551 Status Updates
STATUS FOR WATCH 0551 HAS NOT BEEN ISSUED YET Read more

WW 0551 Status Updates
STATUS FOR WATCH 0551 HAS NOT BEEN ISSUED YET Read more

WW 0551 Status Updates
STATUS FOR WATCH 0551 HAS NOT BEEN ISSUED YET Read more

WW 0551 Status Updates
STATUS FOR WATCH 0551 HAS NOT BEEN ISSUED YET Read more

WW 551 SEVERE TSTM MT 281915Z - 290300Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 551 NWS Storm Prediction Center Norman OK 115 PM MDT Mon Jul 28 2025 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Central Montana * Effective this Monday afternoon and evening from 115 PM until 900 PM MDT. * Primary threats include... Scattered large hail and isolated very large hail events to 2.5 inches in diameter possible Scattered damaging wind gusts to 70 mph possible SUMMARY...Scattered thunderstorm development is expected through the afternoon, including the potential for a few supercells. Large hail of 1-2.5 inches in diameter will be possible, while severe outflow gusts of 60-70 mph will be possible with upscale growth into a cluster or two this evening. The severe thunderstorm watch area is approximately along and 60 statute miles north and south of a line from 35 miles northwest of Helena MT to 75 miles east of Lewistown MT. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU1). 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. && OTHER WATCH INFORMATION...CONTINUE...WW 550... AVIATION...A few severe thunderstorms with hail surface and aloft to 2.5 inches. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 450. Mean storm motion vector 28020. ...Thompson Read more

WW 0550 Status Updates
STATUS REPORT ON WW 550 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 20 S DIK TO 15 WNW BIS TO 45 WNW JMS TO 20 N JMS. ..KERR..07/28/25 ATTN...WFO...BIS... STATUS REPORT FOR WS 550 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS NDC001-015-029-037-041-043-047-051-059-085-281940- ND . NORTH DAKOTA COUNTIES INCLUDED ARE ADAMS BURLEIGH EMMONS GRANT HETTINGER KIDDER LOGAN MCINTOSH MORTON 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

MD 1822 CONCERNING SEVERE THUNDERSTORM WATCH 550... FOR SOUTHERN NORTH DAKOTA...ADJACENT NORTHERN SOUTH DAKOTA...SOUTHEASTERN MONTANA
Mesoscale Discussion 1822 NWS Storm Prediction Center Norman OK 1042 AM CDT Mon Jul 28 2025 Areas affected...southern North Dakota...adjacent northern South Dakota...southeastern Montana Concerning...Severe Thunderstorm Watch 550... Valid 281542Z - 281745Z The severe weather threat for Severe Thunderstorm Watch 550 continues. SUMMARY...Storms now spreading across south central North Dakota have undergone recent weakening. It is still possible that this activity could re-intensify while spreading eastward into early afternoon, but this remains uncertain. DISCUSSION...Strongest convection remains confined to a compact area, near an associated meso-beta scale cyclonic circulation which has been accompanied by a narrow swath of strong to severe gusts along its southwestern periphery. This is now passing near and to the southwest/through south of Bismarck, though it has undergone recently weakening based on radar trends. It appears that weakening may be in response to updraft inflow of more stable air. Objective analysis does indicate some downstream destabilization is underway, but forcing for convective development is weak, and there is potentially substantive mid-level inhibition near the northern periphery of a plume of very warm elevated mixed-layer air advecting northeast of the Rockies. This appears roughly delineated by the +12 to +14 isotherms around 700 mb, which is forecast to remain quasi-stationary to slowly shift north/east of the North/South Dakota states border area into this afternoon. Given these trends, persistence of upstream convection now spreading near/north of Baker MT into southwestern North Dakota also remains unclear. However, this activity appears more likely to remain rooted in warm advection, above boundary-layer air stabilized by convective outflow. ..Kerr.. 07/28/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...ABR...BIS...UNR...BYZ... LAT...LON 46710051 46589814 45709832 45680050 45530219 45700350 46030487 46530428 46470262 46710051 MOST PROBABLE PEAK WIND GUST...55-70 MPH MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1224 PM CDT Mon Jul 28 2025 Valid 291200Z - 301200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE NORTHERN HIGH PLAINS INTO THE MID-MISSOURI VALLEY... ...SUMMARY... Severe thunderstorms are possible from southern Montana into the central High Plains as well as parts of the Mid-Missouri and Mid-Mississippi Valleys on Tuesday. ...Synopsis... A belt of enhanced northwesterly flow aloft will extend from portions of the Dakotas into the Great Lakes on Tuesday. A somewhat complex surface pattern is forecast. A low will likely be located over the southwest NE/northwest KS/northeast CO vicinity. A front will extend from the low northeast into central MN/northern WI Tuesday morning. Outflow from a severe MCS in the Day 1/Monday period may be located across portions of the Mid-MS Valley, but this is uncertain. A very moist and unstable airmass will reside to the east of the low and in the vicinity of these surface boundaries, with the corridor of greatest instability expected to extend from northeast CO eastward across NE and into IA/northern MO/northeast KS. Behind the surface front across portions of WY/MT into the Dakotas, boundary layer moisture will be maintained with dewpoints in the mid 50s to low 60s. This will support weak to moderate instability by afternoon. ...Northeast CO into NE and the Mid-MO Valley/central IA... This region will be displaced to the south from the belt of stronger mid/upper northwesterly flow. Nevertheless, strong instability and low-level convergence will support thunderstorm development during the afternoon near the surface low and northeastward along the surface front. Vertically veering wind profiles will support effective shear magnitudes in the 25-40 kt range, with initial supercells possible. With time, clustering is expected. One or more line segments or possibly a severe MCS could develop and move east across central/eastern NE into western/central IA and vicinity. Severe/damaging wind gusts will be the main hazard, but isolated hail may also occur, especially early in thunderstorm evolution. ...MT/WY into western SD/NE Panhandle... Scattered thunderstorms will develop during the afternoon in the moist post-frontal upslope regime. These areas will experience better shear, with stronger mid/upper westerly flow compared to points further southeast. Forecast soundings across eastern WY indicated effective shear magnitudes greater than 40 kt will be possible, with elongated/straight hodographs also noted. Steep midlevel lapse rates large instability through the cold layer aloft, in combination with favorable shear profiles, suggests cells producing isolated large hail will be possible, particularly from eastern WY into adjacent parts of MT/SD/NE. Further northwest into southern MT, instability will be lower and storm coverage more isolated. Still any storms that do develop will pose a risk for marginal hail. Where stronger heating occurs across the region, steepening low-level lapse rates could also support strong to severe wind gusts. ..ND... Isolated thunderstorms are expected to develop as a shortwave impulse migrates through west/northwesterly flow aloft. Buoyancy will be fairly weak this far north with only modest boundary-layer moisture persisting behind the surface front and generally warm temperatures aloft through about 600 mb. Nevertheless, strong mid/upper flow will support organized cells. Elongated/straight hodographs and effective shear greater than 40 kt suggests isolated marginal hail will be possible with any storms that develop. ..Leitman.. 07/28/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1224 PM CDT Mon Jul 28 2025 Valid 291200Z - 301200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE NORTHERN HIGH PLAINS INTO THE MID-MISSOURI VALLEY... ...SUMMARY... Severe thunderstorms are possible from southern Montana into the central High Plains as well as parts of the Mid-Missouri and Mid-Mississippi Valleys on Tuesday. ...Synopsis... A belt of enhanced northwesterly flow aloft will extend from portions of the Dakotas into the Great Lakes on Tuesday. A somewhat complex surface pattern is forecast. A low will likely be located over the southwest NE/northwest KS/northeast CO vicinity. A front will extend from the low northeast into central MN/northern WI Tuesday morning. Outflow from a severe MCS in the Day 1/Monday period may be located across portions of the Mid-MS Valley, but this is uncertain. A very moist and unstable airmass will reside to the east of the low and in the vicinity of these surface boundaries, with the corridor of greatest instability expected to extend from northeast CO eastward across NE and into IA/northern MO/northeast KS. Behind the surface front across portions of WY/MT into the Dakotas, boundary layer moisture will be maintained with dewpoints in the mid 50s to low 60s. This will support weak to moderate instability by afternoon. ...Northeast CO into NE and the Mid-MO Valley/central IA... This region will be displaced to the south from the belt of stronger mid/upper northwesterly flow. Nevertheless, strong instability and low-level convergence will support thunderstorm development during the afternoon near the surface low and northeastward along the surface front. Vertically veering wind profiles will support effective shear magnitudes in the 25-40 kt range, with initial supercells possible. With time, clustering is expected. One or more line segments or possibly a severe MCS could develop and move east across central/eastern NE into western/central IA and vicinity. Severe/damaging wind gusts will be the main hazard, but isolated hail may also occur, especially early in thunderstorm evolution. ...MT/WY into western SD/NE Panhandle... Scattered thunderstorms will develop during the afternoon in the moist post-frontal upslope regime. These areas will experience better shear, with stronger mid/upper westerly flow compared to points further southeast. Forecast soundings across eastern WY indicated effective shear magnitudes greater than 40 kt will be possible, with elongated/straight hodographs also noted. Steep midlevel lapse rates large instability through the cold layer aloft, in combination with favorable shear profiles, suggests cells producing isolated large hail will be possible, particularly from eastern WY into adjacent parts of MT/SD/NE. Further northwest into southern MT, instability will be lower and storm coverage more isolated. Still any storms that do develop will pose a risk for marginal hail. Where stronger heating occurs across the region, steepening low-level lapse rates could also support strong to severe wind gusts. ..ND... Isolated thunderstorms are expected to develop as a shortwave impulse migrates through west/northwesterly flow aloft. Buoyancy will be fairly weak this far north with only modest boundary-layer moisture persisting behind the surface front and generally warm temperatures aloft through about 600 mb. Nevertheless, strong mid/upper flow will support organized cells. Elongated/straight hodographs and effective shear greater than 40 kt suggests isolated marginal hail will be possible with any storms that develop. ..Leitman.. 07/28/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1224 PM CDT Mon Jul 28 2025 Valid 291200Z - 301200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE NORTHERN HIGH PLAINS INTO THE MID-MISSOURI VALLEY... ...SUMMARY... Severe thunderstorms are possible from southern Montana into the central High Plains as well as parts of the Mid-Missouri and Mid-Mississippi Valleys on Tuesday. ...Synopsis... A belt of enhanced northwesterly flow aloft will extend from portions of the Dakotas into the Great Lakes on Tuesday. A somewhat complex surface pattern is forecast. A low will likely be located over the southwest NE/northwest KS/northeast CO vicinity. A front will extend from the low northeast into central MN/northern WI Tuesday morning. Outflow from a severe MCS in the Day 1/Monday period may be located across portions of the Mid-MS Valley, but this is uncertain. A very moist and unstable airmass will reside to the east of the low and in the vicinity of these surface boundaries, with the corridor of greatest instability expected to extend from northeast CO eastward across NE and into IA/northern MO/northeast KS. Behind the surface front across portions of WY/MT into the Dakotas, boundary layer moisture will be maintained with dewpoints in the mid 50s to low 60s. This will support weak to moderate instability by afternoon. ...Northeast CO into NE and the Mid-MO Valley/central IA... This region will be displaced to the south from the belt of stronger mid/upper northwesterly flow. Nevertheless, strong instability and low-level convergence will support thunderstorm development during the afternoon near the surface low and northeastward along the surface front. Vertically veering wind profiles will support effective shear magnitudes in the 25-40 kt range, with initial supercells possible. With time, clustering is expected. One or more line segments or possibly a severe MCS could develop and move east across central/eastern NE into western/central IA and vicinity. Severe/damaging wind gusts will be the main hazard, but isolated hail may also occur, especially early in thunderstorm evolution. ...MT/WY into western SD/NE Panhandle... Scattered thunderstorms will develop during the afternoon in the moist post-frontal upslope regime. These areas will experience better shear, with stronger mid/upper westerly flow compared to points further southeast. Forecast soundings across eastern WY indicated effective shear magnitudes greater than 40 kt will be possible, with elongated/straight hodographs also noted. Steep midlevel lapse rates large instability through the cold layer aloft, in combination with favorable shear profiles, suggests cells producing isolated large hail will be possible, particularly from eastern WY into adjacent parts of MT/SD/NE. Further northwest into southern MT, instability will be lower and storm coverage more isolated. Still any storms that do develop will pose a risk for marginal hail. Where stronger heating occurs across the region, steepening low-level lapse rates could also support strong to severe wind gusts. ..ND... Isolated thunderstorms are expected to develop as a shortwave impulse migrates through west/northwesterly flow aloft. Buoyancy will be fairly weak this far north with only modest boundary-layer moisture persisting behind the surface front and generally warm temperatures aloft through about 600 mb. Nevertheless, strong mid/upper flow will support organized cells. Elongated/straight hodographs and effective shear greater than 40 kt suggests isolated marginal hail will be possible with any storms that develop. ..Leitman.. 07/28/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1224 PM CDT Mon Jul 28 2025 Valid 291200Z - 301200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE NORTHERN HIGH PLAINS INTO THE MID-MISSOURI VALLEY... ...SUMMARY... Severe thunderstorms are possible from southern Montana into the central High Plains as well as parts of the Mid-Missouri and Mid-Mississippi Valleys on Tuesday. ...Synopsis... A belt of enhanced northwesterly flow aloft will extend from portions of the Dakotas into the Great Lakes on Tuesday. A somewhat complex surface pattern is forecast. A low will likely be located over the southwest NE/northwest KS/northeast CO vicinity. A front will extend from the low northeast into central MN/northern WI Tuesday morning. Outflow from a severe MCS in the Day 1/Monday period may be located across portions of the Mid-MS Valley, but this is uncertain. A very moist and unstable airmass will reside to the east of the low and in the vicinity of these surface boundaries, with the corridor of greatest instability expected to extend from northeast CO eastward across NE and into IA/northern MO/northeast KS. Behind the surface front across portions of WY/MT into the Dakotas, boundary layer moisture will be maintained with dewpoints in the mid 50s to low 60s. This will support weak to moderate instability by afternoon. ...Northeast CO into NE and the Mid-MO Valley/central IA... This region will be displaced to the south from the belt of stronger mid/upper northwesterly flow. Nevertheless, strong instability and low-level convergence will support thunderstorm development during the afternoon near the surface low and northeastward along the surface front. Vertically veering wind profiles will support effective shear magnitudes in the 25-40 kt range, with initial supercells possible. With time, clustering is expected. One or more line segments or possibly a severe MCS could develop and move east across central/eastern NE into western/central IA and vicinity. Severe/damaging wind gusts will be the main hazard, but isolated hail may also occur, especially early in thunderstorm evolution. ...MT/WY into western SD/NE Panhandle... Scattered thunderstorms will develop during the afternoon in the moist post-frontal upslope regime. These areas will experience better shear, with stronger mid/upper westerly flow compared to points further southeast. Forecast soundings across eastern WY indicated effective shear magnitudes greater than 40 kt will be possible, with elongated/straight hodographs also noted. Steep midlevel lapse rates large instability through the cold layer aloft, in combination with favorable shear profiles, suggests cells producing isolated large hail will be possible, particularly from eastern WY into adjacent parts of MT/SD/NE. Further northwest into southern MT, instability will be lower and storm coverage more isolated. Still any storms that do develop will pose a risk for marginal hail. Where stronger heating occurs across the region, steepening low-level lapse rates could also support strong to severe wind gusts. ..ND... Isolated thunderstorms are expected to develop as a shortwave impulse migrates through west/northwesterly flow aloft. Buoyancy will be fairly weak this far north with only modest boundary-layer moisture persisting behind the surface front and generally warm temperatures aloft through about 600 mb. Nevertheless, strong mid/upper flow will support organized cells. Elongated/straight hodographs and effective shear greater than 40 kt suggests isolated marginal hail will be possible with any storms that develop. ..Leitman.. 07/28/2025 Read more