Severe Storms

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1200 PM CDT Thu Jul 03 2025 Valid 031700Z - 041200Z ...Central California... An approaching mid-level short wave trough will promote enhanced dry downslope winds along and leeward of the Diablo Range into the San Joaquin Valley this afternoon. West-northwest winds of 10-15 mph with locally sustained 20 mph combined with relative humidity as low as 10% will support a few hours of elevated fire weather conditions amid dry fuels. ...Northern Great Basin and Upper-Colorado River Basin... Isolated dry thunderstorm threat was expanded into south-central OR and north-central NV with latest model guidance and observed soundings indicating precipitable water values holding in the 0.50-0.80 inch range for this afternoon. The advancing short-wave trough will support faster storm motions particularly across southeastern OR. In addition, falling 500 DM heights and mid-level jet support will keep a nocturnal thunderstorm threat for southeastern OR and southern Idaho through 12Z Friday. Otherwise, a mix of wet/dry thunderstorms across the Upper CO River Basin and central Mountains of UT could support new ignitions in pockets of existing dry fuels. ..Williams.. 07/03/2025 .PREV DISCUSSION... /ISSUED 0211 AM CDT Thu Jul 03 2025/ ...Synopsis... A compact shortwave trough moving across northern CA will accompany 40-50 kt westerly flow across the northern Great Basin. This will encourage dry downslope flow across parts of western NV and the northern Great Basin. At the same time, continued monsoon moisture will allow scattered showers and thunderstorms over the Intermountain West with isolated lightning. ...Northern Great Basin... Dry and breezy conditions are expected today and tonight in the lee of the Sierra and northern Great Basin ahead of the shortwave trough. Sustained 15-20 mph surface winds are expected from the west/southwest through the day. A dry and deep boundary layer will also support RH below 15-20%. Despite some recent rainfall, area fuels remain receptive across much of NV and the northern Great Basin. Widespread elevated and locally critical fire-weather conditions are likely. ...Dry Thunder... As the upper trough moves into the West, monsoon moisture will be shunted eastward compared to the last several days. Still, PWATS around 0.6-0.8 inches across western CO and into the northern Rockies will be sufficient to support scattered showers and thunderstorms this afternoon and evening. Fuel receptiveness has decreased with multiple rounds of showers and storms this week. Still, drier pockets remain and lightning outside of the heavier precipitation cores will be capable of ignitions. This appears most likely over parts of northern CO to eastern ID, where less rainfall has been observed. Will maintain IsoDryT highlights for occasional lighting strikes within receptive fuels. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1200 PM CDT Thu Jul 03 2025 Valid 031700Z - 041200Z ...Central California... An approaching mid-level short wave trough will promote enhanced dry downslope winds along and leeward of the Diablo Range into the San Joaquin Valley this afternoon. West-northwest winds of 10-15 mph with locally sustained 20 mph combined with relative humidity as low as 10% will support a few hours of elevated fire weather conditions amid dry fuels. ...Northern Great Basin and Upper-Colorado River Basin... Isolated dry thunderstorm threat was expanded into south-central OR and north-central NV with latest model guidance and observed soundings indicating precipitable water values holding in the 0.50-0.80 inch range for this afternoon. The advancing short-wave trough will support faster storm motions particularly across southeastern OR. In addition, falling 500 DM heights and mid-level jet support will keep a nocturnal thunderstorm threat for southeastern OR and southern Idaho through 12Z Friday. Otherwise, a mix of wet/dry thunderstorms across the Upper CO River Basin and central Mountains of UT could support new ignitions in pockets of existing dry fuels. ..Williams.. 07/03/2025 .PREV DISCUSSION... /ISSUED 0211 AM CDT Thu Jul 03 2025/ ...Synopsis... A compact shortwave trough moving across northern CA will accompany 40-50 kt westerly flow across the northern Great Basin. This will encourage dry downslope flow across parts of western NV and the northern Great Basin. At the same time, continued monsoon moisture will allow scattered showers and thunderstorms over the Intermountain West with isolated lightning. ...Northern Great Basin... Dry and breezy conditions are expected today and tonight in the lee of the Sierra and northern Great Basin ahead of the shortwave trough. Sustained 15-20 mph surface winds are expected from the west/southwest through the day. A dry and deep boundary layer will also support RH below 15-20%. Despite some recent rainfall, area fuels remain receptive across much of NV and the northern Great Basin. Widespread elevated and locally critical fire-weather conditions are likely. ...Dry Thunder... As the upper trough moves into the West, monsoon moisture will be shunted eastward compared to the last several days. Still, PWATS around 0.6-0.8 inches across western CO and into the northern Rockies will be sufficient to support scattered showers and thunderstorms this afternoon and evening. Fuel receptiveness has decreased with multiple rounds of showers and storms this week. Still, drier pockets remain and lightning outside of the heavier precipitation cores will be capable of ignitions. This appears most likely over parts of northern CO to eastern ID, where less rainfall has been observed. Will maintain IsoDryT highlights for occasional lighting strikes within receptive fuels. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1200 PM CDT Thu Jul 03 2025 Valid 031700Z - 041200Z ...Central California... An approaching mid-level short wave trough will promote enhanced dry downslope winds along and leeward of the Diablo Range into the San Joaquin Valley this afternoon. West-northwest winds of 10-15 mph with locally sustained 20 mph combined with relative humidity as low as 10% will support a few hours of elevated fire weather conditions amid dry fuels. ...Northern Great Basin and Upper-Colorado River Basin... Isolated dry thunderstorm threat was expanded into south-central OR and north-central NV with latest model guidance and observed soundings indicating precipitable water values holding in the 0.50-0.80 inch range for this afternoon. The advancing short-wave trough will support faster storm motions particularly across southeastern OR. In addition, falling 500 DM heights and mid-level jet support will keep a nocturnal thunderstorm threat for southeastern OR and southern Idaho through 12Z Friday. Otherwise, a mix of wet/dry thunderstorms across the Upper CO River Basin and central Mountains of UT could support new ignitions in pockets of existing dry fuels. ..Williams.. 07/03/2025 .PREV DISCUSSION... /ISSUED 0211 AM CDT Thu Jul 03 2025/ ...Synopsis... A compact shortwave trough moving across northern CA will accompany 40-50 kt westerly flow across the northern Great Basin. This will encourage dry downslope flow across parts of western NV and the northern Great Basin. At the same time, continued monsoon moisture will allow scattered showers and thunderstorms over the Intermountain West with isolated lightning. ...Northern Great Basin... Dry and breezy conditions are expected today and tonight in the lee of the Sierra and northern Great Basin ahead of the shortwave trough. Sustained 15-20 mph surface winds are expected from the west/southwest through the day. A dry and deep boundary layer will also support RH below 15-20%. Despite some recent rainfall, area fuels remain receptive across much of NV and the northern Great Basin. Widespread elevated and locally critical fire-weather conditions are likely. ...Dry Thunder... As the upper trough moves into the West, monsoon moisture will be shunted eastward compared to the last several days. Still, PWATS around 0.6-0.8 inches across western CO and into the northern Rockies will be sufficient to support scattered showers and thunderstorms this afternoon and evening. Fuel receptiveness has decreased with multiple rounds of showers and storms this week. Still, drier pockets remain and lightning outside of the heavier precipitation cores will be capable of ignitions. This appears most likely over parts of northern CO to eastern ID, where less rainfall has been observed. Will maintain IsoDryT highlights for occasional lighting strikes within receptive fuels. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1200 PM CDT Thu Jul 03 2025 Valid 031700Z - 041200Z ...Central California... An approaching mid-level short wave trough will promote enhanced dry downslope winds along and leeward of the Diablo Range into the San Joaquin Valley this afternoon. West-northwest winds of 10-15 mph with locally sustained 20 mph combined with relative humidity as low as 10% will support a few hours of elevated fire weather conditions amid dry fuels. ...Northern Great Basin and Upper-Colorado River Basin... Isolated dry thunderstorm threat was expanded into south-central OR and north-central NV with latest model guidance and observed soundings indicating precipitable water values holding in the 0.50-0.80 inch range for this afternoon. The advancing short-wave trough will support faster storm motions particularly across southeastern OR. In addition, falling 500 DM heights and mid-level jet support will keep a nocturnal thunderstorm threat for southeastern OR and southern Idaho through 12Z Friday. Otherwise, a mix of wet/dry thunderstorms across the Upper CO River Basin and central Mountains of UT could support new ignitions in pockets of existing dry fuels. ..Williams.. 07/03/2025 .PREV DISCUSSION... /ISSUED 0211 AM CDT Thu Jul 03 2025/ ...Synopsis... A compact shortwave trough moving across northern CA will accompany 40-50 kt westerly flow across the northern Great Basin. This will encourage dry downslope flow across parts of western NV and the northern Great Basin. At the same time, continued monsoon moisture will allow scattered showers and thunderstorms over the Intermountain West with isolated lightning. ...Northern Great Basin... Dry and breezy conditions are expected today and tonight in the lee of the Sierra and northern Great Basin ahead of the shortwave trough. Sustained 15-20 mph surface winds are expected from the west/southwest through the day. A dry and deep boundary layer will also support RH below 15-20%. Despite some recent rainfall, area fuels remain receptive across much of NV and the northern Great Basin. Widespread elevated and locally critical fire-weather conditions are likely. ...Dry Thunder... As the upper trough moves into the West, monsoon moisture will be shunted eastward compared to the last several days. Still, PWATS around 0.6-0.8 inches across western CO and into the northern Rockies will be sufficient to support scattered showers and thunderstorms this afternoon and evening. Fuel receptiveness has decreased with multiple rounds of showers and storms this week. Still, drier pockets remain and lightning outside of the heavier precipitation cores will be capable of ignitions. This appears most likely over parts of northern CO to eastern ID, where less rainfall has been observed. Will maintain IsoDryT highlights for occasional lighting strikes within receptive fuels. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

WW 0483 Status Updates
STATUS REPORT ON WW 483 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 1547. ..GRAMS..07/03/25 ATTN...WFO...GYX...CAR... STATUS REPORT FOR WS 483 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS MEC001-003-005-007-009-011-013-015-017-019-021-023-025-027-029- 031-031740- ME . MAINE COUNTIES INCLUDED ARE ANDROSCOGGIN AROOSTOOK CUMBERLAND FRANKLIN HANCOCK KENNEBEC KNOX LINCOLN OXFORD PENOBSCOT PISCATAQUIS SAGADAHOC SOMERSET WALDO WASHINGTON YORK NHC001-003-005-007-009-011-013-015-017-019-031740- NH . NEW HAMPSHIRE COUNTIES INCLUDED ARE BELKNAP CARROLL CHESHIRE COOS GRAFTON HILLSBOROUGH MERRIMACK ROCKINGHAM STRAFFORD SULLIVAN Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1120 AM CDT Thu Jul 03 2025 Valid 031630Z - 041200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR NORTH DAKOTA AND MUCH OF THE NORTHEAST... ...SUMMARY... Scattered severe thunderstorms capable of producing severe/damaging winds and large hail are forecast across parts of the Northeast and northern Plains today. ...Northeast... Recent satellite imagery shows a well-defined cyclone over northern QC and a shortwave trough embedded within the southern periphery of this cyclone progressing through the Lower Great Lakes. An attendant cold front is in place just ahead of this shortwave. Expectation is for this shortwave to continue quickly eastward into the Northeast, with the cold front progressing eastward/southeastward as well. The leading edge of the stronger large-scale forcing for ascent has already reached ME and NH, contributing to thunderstorm development where the preceding airmass has already destabilized. Continued destabilization is anticipated, likely resulting in a nearly continuous line of storms. In addition to moderate buoyancy, moderate vertical shear is in place as well. This combination of buoyancy and shear is expected to result in organized storms capable of large hail (more probable during the early-stage cellular mode) and damaging gusts (more probable later with later-stage linear modes). This ongoing development is well ahead of the primary cold front, so the potential exists for additional development across NY this afternoon, continuing into southern New England during the late afternoon and evening. Environmental conditions will be similar to those farther north and east, with large hail and damaging gusts possible with these storms as well. ...Northern Plains... Low-level moisture will continue to advect northwestward into the region today, helping to offset some of the anticipated mixing and keeping dewpoints in the upper 60s/70s later this afternoon/evening. This favorable low-level moisture beneath steep mid-level lapse rates will promote a very unstable airmass, with MLCAPE from 2000 to 3000 J/kg across ND this evening. Subtle ascent attendant to a modest vorticity maximum rounding the northwestern periphery of the central CONUS upper ridging will begin interacting with the westernmost edge of this moist and unstable airmass around 21Z-00Z. Initial cellular development is anticipated across northeast WY and far southeast MT, before expanding northeastward into more of ND over time. A risk for very large hail and perhaps a tornado would accompany initial supercells before storm outflow and mergers lead to upscale growth into an eastward-moving cluster during the evening. Once this upscale growth occurs, a quick northeastward progression is anticipated across ND with some severe wind gusts possible. An instance or two of gusts around 75 mph are possible. ...Southeastern ND/Northeast SD into the Upper Midwest... Recent regional radar imagery shows an MCV tracking east-northeastward over south-central ND. The airmass downstream from southeast ND/northeast SD into southern MN and northern IA is destabilizing amid strong heating and ample low-level moisture. As a result, there is a low-probability chance for thunderstorm redevelopment/reintensification early this afternoon in the vicinity of the MCV. If this occurs, isolated damaging gusts are possible. A more probable scenario is for this MCV to continue rounding the ridge and provide the impetus for thunderstorm development farther east across the Upper Midwest later this evening. Weak warm-air advection could augment ascent across the region as well. Moderate to strong buoyancy and moderate deep-layer vertical shear will be in place, supporting strong updrafts capable of large hail, particularly with initial development. Storms should continue throughout much of the night, with an isolated hail risk. ..Mosier/Karstens.. 07/03/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1120 AM CDT Thu Jul 03 2025 Valid 031630Z - 041200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR NORTH DAKOTA AND MUCH OF THE NORTHEAST... ...SUMMARY... Scattered severe thunderstorms capable of producing severe/damaging winds and large hail are forecast across parts of the Northeast and northern Plains today. ...Northeast... Recent satellite imagery shows a well-defined cyclone over northern QC and a shortwave trough embedded within the southern periphery of this cyclone progressing through the Lower Great Lakes. An attendant cold front is in place just ahead of this shortwave. Expectation is for this shortwave to continue quickly eastward into the Northeast, with the cold front progressing eastward/southeastward as well. The leading edge of the stronger large-scale forcing for ascent has already reached ME and NH, contributing to thunderstorm development where the preceding airmass has already destabilized. Continued destabilization is anticipated, likely resulting in a nearly continuous line of storms. In addition to moderate buoyancy, moderate vertical shear is in place as well. This combination of buoyancy and shear is expected to result in organized storms capable of large hail (more probable during the early-stage cellular mode) and damaging gusts (more probable later with later-stage linear modes). This ongoing development is well ahead of the primary cold front, so the potential exists for additional development across NY this afternoon, continuing into southern New England during the late afternoon and evening. Environmental conditions will be similar to those farther north and east, with large hail and damaging gusts possible with these storms as well. ...Northern Plains... Low-level moisture will continue to advect northwestward into the region today, helping to offset some of the anticipated mixing and keeping dewpoints in the upper 60s/70s later this afternoon/evening. This favorable low-level moisture beneath steep mid-level lapse rates will promote a very unstable airmass, with MLCAPE from 2000 to 3000 J/kg across ND this evening. Subtle ascent attendant to a modest vorticity maximum rounding the northwestern periphery of the central CONUS upper ridging will begin interacting with the westernmost edge of this moist and unstable airmass around 21Z-00Z. Initial cellular development is anticipated across northeast WY and far southeast MT, before expanding northeastward into more of ND over time. A risk for very large hail and perhaps a tornado would accompany initial supercells before storm outflow and mergers lead to upscale growth into an eastward-moving cluster during the evening. Once this upscale growth occurs, a quick northeastward progression is anticipated across ND with some severe wind gusts possible. An instance or two of gusts around 75 mph are possible. ...Southeastern ND/Northeast SD into the Upper Midwest... Recent regional radar imagery shows an MCV tracking east-northeastward over south-central ND. The airmass downstream from southeast ND/northeast SD into southern MN and northern IA is destabilizing amid strong heating and ample low-level moisture. As a result, there is a low-probability chance for thunderstorm redevelopment/reintensification early this afternoon in the vicinity of the MCV. If this occurs, isolated damaging gusts are possible. A more probable scenario is for this MCV to continue rounding the ridge and provide the impetus for thunderstorm development farther east across the Upper Midwest later this evening. Weak warm-air advection could augment ascent across the region as well. Moderate to strong buoyancy and moderate deep-layer vertical shear will be in place, supporting strong updrafts capable of large hail, particularly with initial development. Storms should continue throughout much of the night, with an isolated hail risk. ..Mosier/Karstens.. 07/03/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1120 AM CDT Thu Jul 03 2025 Valid 031630Z - 041200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR NORTH DAKOTA AND MUCH OF THE NORTHEAST... ...SUMMARY... Scattered severe thunderstorms capable of producing severe/damaging winds and large hail are forecast across parts of the Northeast and northern Plains today. ...Northeast... Recent satellite imagery shows a well-defined cyclone over northern QC and a shortwave trough embedded within the southern periphery of this cyclone progressing through the Lower Great Lakes. An attendant cold front is in place just ahead of this shortwave. Expectation is for this shortwave to continue quickly eastward into the Northeast, with the cold front progressing eastward/southeastward as well. The leading edge of the stronger large-scale forcing for ascent has already reached ME and NH, contributing to thunderstorm development where the preceding airmass has already destabilized. Continued destabilization is anticipated, likely resulting in a nearly continuous line of storms. In addition to moderate buoyancy, moderate vertical shear is in place as well. This combination of buoyancy and shear is expected to result in organized storms capable of large hail (more probable during the early-stage cellular mode) and damaging gusts (more probable later with later-stage linear modes). This ongoing development is well ahead of the primary cold front, so the potential exists for additional development across NY this afternoon, continuing into southern New England during the late afternoon and evening. Environmental conditions will be similar to those farther north and east, with large hail and damaging gusts possible with these storms as well. ...Northern Plains... Low-level moisture will continue to advect northwestward into the region today, helping to offset some of the anticipated mixing and keeping dewpoints in the upper 60s/70s later this afternoon/evening. This favorable low-level moisture beneath steep mid-level lapse rates will promote a very unstable airmass, with MLCAPE from 2000 to 3000 J/kg across ND this evening. Subtle ascent attendant to a modest vorticity maximum rounding the northwestern periphery of the central CONUS upper ridging will begin interacting with the westernmost edge of this moist and unstable airmass around 21Z-00Z. Initial cellular development is anticipated across northeast WY and far southeast MT, before expanding northeastward into more of ND over time. A risk for very large hail and perhaps a tornado would accompany initial supercells before storm outflow and mergers lead to upscale growth into an eastward-moving cluster during the evening. Once this upscale growth occurs, a quick northeastward progression is anticipated across ND with some severe wind gusts possible. An instance or two of gusts around 75 mph are possible. ...Southeastern ND/Northeast SD into the Upper Midwest... Recent regional radar imagery shows an MCV tracking east-northeastward over south-central ND. The airmass downstream from southeast ND/northeast SD into southern MN and northern IA is destabilizing amid strong heating and ample low-level moisture. As a result, there is a low-probability chance for thunderstorm redevelopment/reintensification early this afternoon in the vicinity of the MCV. If this occurs, isolated damaging gusts are possible. A more probable scenario is for this MCV to continue rounding the ridge and provide the impetus for thunderstorm development farther east across the Upper Midwest later this evening. Weak warm-air advection could augment ascent across the region as well. Moderate to strong buoyancy and moderate deep-layer vertical shear will be in place, supporting strong updrafts capable of large hail, particularly with initial development. Storms should continue throughout much of the night, with an isolated hail risk. ..Mosier/Karstens.. 07/03/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1120 AM CDT Thu Jul 03 2025 Valid 031630Z - 041200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR NORTH DAKOTA AND MUCH OF THE NORTHEAST... ...SUMMARY... Scattered severe thunderstorms capable of producing severe/damaging winds and large hail are forecast across parts of the Northeast and northern Plains today. ...Northeast... Recent satellite imagery shows a well-defined cyclone over northern QC and a shortwave trough embedded within the southern periphery of this cyclone progressing through the Lower Great Lakes. An attendant cold front is in place just ahead of this shortwave. Expectation is for this shortwave to continue quickly eastward into the Northeast, with the cold front progressing eastward/southeastward as well. The leading edge of the stronger large-scale forcing for ascent has already reached ME and NH, contributing to thunderstorm development where the preceding airmass has already destabilized. Continued destabilization is anticipated, likely resulting in a nearly continuous line of storms. In addition to moderate buoyancy, moderate vertical shear is in place as well. This combination of buoyancy and shear is expected to result in organized storms capable of large hail (more probable during the early-stage cellular mode) and damaging gusts (more probable later with later-stage linear modes). This ongoing development is well ahead of the primary cold front, so the potential exists for additional development across NY this afternoon, continuing into southern New England during the late afternoon and evening. Environmental conditions will be similar to those farther north and east, with large hail and damaging gusts possible with these storms as well. ...Northern Plains... Low-level moisture will continue to advect northwestward into the region today, helping to offset some of the anticipated mixing and keeping dewpoints in the upper 60s/70s later this afternoon/evening. This favorable low-level moisture beneath steep mid-level lapse rates will promote a very unstable airmass, with MLCAPE from 2000 to 3000 J/kg across ND this evening. Subtle ascent attendant to a modest vorticity maximum rounding the northwestern periphery of the central CONUS upper ridging will begin interacting with the westernmost edge of this moist and unstable airmass around 21Z-00Z. Initial cellular development is anticipated across northeast WY and far southeast MT, before expanding northeastward into more of ND over time. A risk for very large hail and perhaps a tornado would accompany initial supercells before storm outflow and mergers lead to upscale growth into an eastward-moving cluster during the evening. Once this upscale growth occurs, a quick northeastward progression is anticipated across ND with some severe wind gusts possible. An instance or two of gusts around 75 mph are possible. ...Southeastern ND/Northeast SD into the Upper Midwest... Recent regional radar imagery shows an MCV tracking east-northeastward over south-central ND. The airmass downstream from southeast ND/northeast SD into southern MN and northern IA is destabilizing amid strong heating and ample low-level moisture. As a result, there is a low-probability chance for thunderstorm redevelopment/reintensification early this afternoon in the vicinity of the MCV. If this occurs, isolated damaging gusts are possible. A more probable scenario is for this MCV to continue rounding the ridge and provide the impetus for thunderstorm development farther east across the Upper Midwest later this evening. Weak warm-air advection could augment ascent across the region as well. Moderate to strong buoyancy and moderate deep-layer vertical shear will be in place, supporting strong updrafts capable of large hail, particularly with initial development. Storms should continue throughout much of the night, with an isolated hail risk. ..Mosier/Karstens.. 07/03/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1120 AM CDT Thu Jul 03 2025 Valid 031630Z - 041200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR NORTH DAKOTA AND MUCH OF THE NORTHEAST... ...SUMMARY... Scattered severe thunderstorms capable of producing severe/damaging winds and large hail are forecast across parts of the Northeast and northern Plains today. ...Northeast... Recent satellite imagery shows a well-defined cyclone over northern QC and a shortwave trough embedded within the southern periphery of this cyclone progressing through the Lower Great Lakes. An attendant cold front is in place just ahead of this shortwave. Expectation is for this shortwave to continue quickly eastward into the Northeast, with the cold front progressing eastward/southeastward as well. The leading edge of the stronger large-scale forcing for ascent has already reached ME and NH, contributing to thunderstorm development where the preceding airmass has already destabilized. Continued destabilization is anticipated, likely resulting in a nearly continuous line of storms. In addition to moderate buoyancy, moderate vertical shear is in place as well. This combination of buoyancy and shear is expected to result in organized storms capable of large hail (more probable during the early-stage cellular mode) and damaging gusts (more probable later with later-stage linear modes). This ongoing development is well ahead of the primary cold front, so the potential exists for additional development across NY this afternoon, continuing into southern New England during the late afternoon and evening. Environmental conditions will be similar to those farther north and east, with large hail and damaging gusts possible with these storms as well. ...Northern Plains... Low-level moisture will continue to advect northwestward into the region today, helping to offset some of the anticipated mixing and keeping dewpoints in the upper 60s/70s later this afternoon/evening. This favorable low-level moisture beneath steep mid-level lapse rates will promote a very unstable airmass, with MLCAPE from 2000 to 3000 J/kg across ND this evening. Subtle ascent attendant to a modest vorticity maximum rounding the northwestern periphery of the central CONUS upper ridging will begin interacting with the westernmost edge of this moist and unstable airmass around 21Z-00Z. Initial cellular development is anticipated across northeast WY and far southeast MT, before expanding northeastward into more of ND over time. A risk for very large hail and perhaps a tornado would accompany initial supercells before storm outflow and mergers lead to upscale growth into an eastward-moving cluster during the evening. Once this upscale growth occurs, a quick northeastward progression is anticipated across ND with some severe wind gusts possible. An instance or two of gusts around 75 mph are possible. ...Southeastern ND/Northeast SD into the Upper Midwest... Recent regional radar imagery shows an MCV tracking east-northeastward over south-central ND. The airmass downstream from southeast ND/northeast SD into southern MN and northern IA is destabilizing amid strong heating and ample low-level moisture. As a result, there is a low-probability chance for thunderstorm redevelopment/reintensification early this afternoon in the vicinity of the MCV. If this occurs, isolated damaging gusts are possible. A more probable scenario is for this MCV to continue rounding the ridge and provide the impetus for thunderstorm development farther east across the Upper Midwest later this evening. Weak warm-air advection could augment ascent across the region as well. Moderate to strong buoyancy and moderate deep-layer vertical shear will be in place, supporting strong updrafts capable of large hail, particularly with initial development. Storms should continue throughout much of the night, with an isolated hail risk. ..Mosier/Karstens.. 07/03/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1120 AM CDT Thu Jul 03 2025 Valid 031630Z - 041200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR NORTH DAKOTA AND MUCH OF THE NORTHEAST... ...SUMMARY... Scattered severe thunderstorms capable of producing severe/damaging winds and large hail are forecast across parts of the Northeast and northern Plains today. ...Northeast... Recent satellite imagery shows a well-defined cyclone over northern QC and a shortwave trough embedded within the southern periphery of this cyclone progressing through the Lower Great Lakes. An attendant cold front is in place just ahead of this shortwave. Expectation is for this shortwave to continue quickly eastward into the Northeast, with the cold front progressing eastward/southeastward as well. The leading edge of the stronger large-scale forcing for ascent has already reached ME and NH, contributing to thunderstorm development where the preceding airmass has already destabilized. Continued destabilization is anticipated, likely resulting in a nearly continuous line of storms. In addition to moderate buoyancy, moderate vertical shear is in place as well. This combination of buoyancy and shear is expected to result in organized storms capable of large hail (more probable during the early-stage cellular mode) and damaging gusts (more probable later with later-stage linear modes). This ongoing development is well ahead of the primary cold front, so the potential exists for additional development across NY this afternoon, continuing into southern New England during the late afternoon and evening. Environmental conditions will be similar to those farther north and east, with large hail and damaging gusts possible with these storms as well. ...Northern Plains... Low-level moisture will continue to advect northwestward into the region today, helping to offset some of the anticipated mixing and keeping dewpoints in the upper 60s/70s later this afternoon/evening. This favorable low-level moisture beneath steep mid-level lapse rates will promote a very unstable airmass, with MLCAPE from 2000 to 3000 J/kg across ND this evening. Subtle ascent attendant to a modest vorticity maximum rounding the northwestern periphery of the central CONUS upper ridging will begin interacting with the westernmost edge of this moist and unstable airmass around 21Z-00Z. Initial cellular development is anticipated across northeast WY and far southeast MT, before expanding northeastward into more of ND over time. A risk for very large hail and perhaps a tornado would accompany initial supercells before storm outflow and mergers lead to upscale growth into an eastward-moving cluster during the evening. Once this upscale growth occurs, a quick northeastward progression is anticipated across ND with some severe wind gusts possible. An instance or two of gusts around 75 mph are possible. ...Southeastern ND/Northeast SD into the Upper Midwest... Recent regional radar imagery shows an MCV tracking east-northeastward over south-central ND. The airmass downstream from southeast ND/northeast SD into southern MN and northern IA is destabilizing amid strong heating and ample low-level moisture. As a result, there is a low-probability chance for thunderstorm redevelopment/reintensification early this afternoon in the vicinity of the MCV. If this occurs, isolated damaging gusts are possible. A more probable scenario is for this MCV to continue rounding the ridge and provide the impetus for thunderstorm development farther east across the Upper Midwest later this evening. Weak warm-air advection could augment ascent across the region as well. Moderate to strong buoyancy and moderate deep-layer vertical shear will be in place, supporting strong updrafts capable of large hail, particularly with initial development. Storms should continue throughout much of the night, with an isolated hail risk. ..Mosier/Karstens.. 07/03/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1120 AM CDT Thu Jul 03 2025 Valid 031630Z - 041200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR NORTH DAKOTA AND MUCH OF THE NORTHEAST... ...SUMMARY... Scattered severe thunderstorms capable of producing severe/damaging winds and large hail are forecast across parts of the Northeast and northern Plains today. ...Northeast... Recent satellite imagery shows a well-defined cyclone over northern QC and a shortwave trough embedded within the southern periphery of this cyclone progressing through the Lower Great Lakes. An attendant cold front is in place just ahead of this shortwave. Expectation is for this shortwave to continue quickly eastward into the Northeast, with the cold front progressing eastward/southeastward as well. The leading edge of the stronger large-scale forcing for ascent has already reached ME and NH, contributing to thunderstorm development where the preceding airmass has already destabilized. Continued destabilization is anticipated, likely resulting in a nearly continuous line of storms. In addition to moderate buoyancy, moderate vertical shear is in place as well. This combination of buoyancy and shear is expected to result in organized storms capable of large hail (more probable during the early-stage cellular mode) and damaging gusts (more probable later with later-stage linear modes). This ongoing development is well ahead of the primary cold front, so the potential exists for additional development across NY this afternoon, continuing into southern New England during the late afternoon and evening. Environmental conditions will be similar to those farther north and east, with large hail and damaging gusts possible with these storms as well. ...Northern Plains... Low-level moisture will continue to advect northwestward into the region today, helping to offset some of the anticipated mixing and keeping dewpoints in the upper 60s/70s later this afternoon/evening. This favorable low-level moisture beneath steep mid-level lapse rates will promote a very unstable airmass, with MLCAPE from 2000 to 3000 J/kg across ND this evening. Subtle ascent attendant to a modest vorticity maximum rounding the northwestern periphery of the central CONUS upper ridging will begin interacting with the westernmost edge of this moist and unstable airmass around 21Z-00Z. Initial cellular development is anticipated across northeast WY and far southeast MT, before expanding northeastward into more of ND over time. A risk for very large hail and perhaps a tornado would accompany initial supercells before storm outflow and mergers lead to upscale growth into an eastward-moving cluster during the evening. Once this upscale growth occurs, a quick northeastward progression is anticipated across ND with some severe wind gusts possible. An instance or two of gusts around 75 mph are possible. ...Southeastern ND/Northeast SD into the Upper Midwest... Recent regional radar imagery shows an MCV tracking east-northeastward over south-central ND. The airmass downstream from southeast ND/northeast SD into southern MN and northern IA is destabilizing amid strong heating and ample low-level moisture. As a result, there is a low-probability chance for thunderstorm redevelopment/reintensification early this afternoon in the vicinity of the MCV. If this occurs, isolated damaging gusts are possible. A more probable scenario is for this MCV to continue rounding the ridge and provide the impetus for thunderstorm development farther east across the Upper Midwest later this evening. Weak warm-air advection could augment ascent across the region as well. Moderate to strong buoyancy and moderate deep-layer vertical shear will be in place, supporting strong updrafts capable of large hail, particularly with initial development. Storms should continue throughout much of the night, with an isolated hail risk. ..Mosier/Karstens.. 07/03/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1120 AM CDT Thu Jul 03 2025 Valid 031630Z - 041200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR NORTH DAKOTA AND MUCH OF THE NORTHEAST... ...SUMMARY... Scattered severe thunderstorms capable of producing severe/damaging winds and large hail are forecast across parts of the Northeast and northern Plains today. ...Northeast... Recent satellite imagery shows a well-defined cyclone over northern QC and a shortwave trough embedded within the southern periphery of this cyclone progressing through the Lower Great Lakes. An attendant cold front is in place just ahead of this shortwave. Expectation is for this shortwave to continue quickly eastward into the Northeast, with the cold front progressing eastward/southeastward as well. The leading edge of the stronger large-scale forcing for ascent has already reached ME and NH, contributing to thunderstorm development where the preceding airmass has already destabilized. Continued destabilization is anticipated, likely resulting in a nearly continuous line of storms. In addition to moderate buoyancy, moderate vertical shear is in place as well. This combination of buoyancy and shear is expected to result in organized storms capable of large hail (more probable during the early-stage cellular mode) and damaging gusts (more probable later with later-stage linear modes). This ongoing development is well ahead of the primary cold front, so the potential exists for additional development across NY this afternoon, continuing into southern New England during the late afternoon and evening. Environmental conditions will be similar to those farther north and east, with large hail and damaging gusts possible with these storms as well. ...Northern Plains... Low-level moisture will continue to advect northwestward into the region today, helping to offset some of the anticipated mixing and keeping dewpoints in the upper 60s/70s later this afternoon/evening. This favorable low-level moisture beneath steep mid-level lapse rates will promote a very unstable airmass, with MLCAPE from 2000 to 3000 J/kg across ND this evening. Subtle ascent attendant to a modest vorticity maximum rounding the northwestern periphery of the central CONUS upper ridging will begin interacting with the westernmost edge of this moist and unstable airmass around 21Z-00Z. Initial cellular development is anticipated across northeast WY and far southeast MT, before expanding northeastward into more of ND over time. A risk for very large hail and perhaps a tornado would accompany initial supercells before storm outflow and mergers lead to upscale growth into an eastward-moving cluster during the evening. Once this upscale growth occurs, a quick northeastward progression is anticipated across ND with some severe wind gusts possible. An instance or two of gusts around 75 mph are possible. ...Southeastern ND/Northeast SD into the Upper Midwest... Recent regional radar imagery shows an MCV tracking east-northeastward over south-central ND. The airmass downstream from southeast ND/northeast SD into southern MN and northern IA is destabilizing amid strong heating and ample low-level moisture. As a result, there is a low-probability chance for thunderstorm redevelopment/reintensification early this afternoon in the vicinity of the MCV. If this occurs, isolated damaging gusts are possible. A more probable scenario is for this MCV to continue rounding the ridge and provide the impetus for thunderstorm development farther east across the Upper Midwest later this evening. Weak warm-air advection could augment ascent across the region as well. Moderate to strong buoyancy and moderate deep-layer vertical shear will be in place, supporting strong updrafts capable of large hail, particularly with initial development. Storms should continue throughout much of the night, with an isolated hail risk. ..Mosier/Karstens.. 07/03/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1120 AM CDT Thu Jul 03 2025 Valid 031630Z - 041200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR NORTH DAKOTA AND MUCH OF THE NORTHEAST... ...SUMMARY... Scattered severe thunderstorms capable of producing severe/damaging winds and large hail are forecast across parts of the Northeast and northern Plains today. ...Northeast... Recent satellite imagery shows a well-defined cyclone over northern QC and a shortwave trough embedded within the southern periphery of this cyclone progressing through the Lower Great Lakes. An attendant cold front is in place just ahead of this shortwave. Expectation is for this shortwave to continue quickly eastward into the Northeast, with the cold front progressing eastward/southeastward as well. The leading edge of the stronger large-scale forcing for ascent has already reached ME and NH, contributing to thunderstorm development where the preceding airmass has already destabilized. Continued destabilization is anticipated, likely resulting in a nearly continuous line of storms. In addition to moderate buoyancy, moderate vertical shear is in place as well. This combination of buoyancy and shear is expected to result in organized storms capable of large hail (more probable during the early-stage cellular mode) and damaging gusts (more probable later with later-stage linear modes). This ongoing development is well ahead of the primary cold front, so the potential exists for additional development across NY this afternoon, continuing into southern New England during the late afternoon and evening. Environmental conditions will be similar to those farther north and east, with large hail and damaging gusts possible with these storms as well. ...Northern Plains... Low-level moisture will continue to advect northwestward into the region today, helping to offset some of the anticipated mixing and keeping dewpoints in the upper 60s/70s later this afternoon/evening. This favorable low-level moisture beneath steep mid-level lapse rates will promote a very unstable airmass, with MLCAPE from 2000 to 3000 J/kg across ND this evening. Subtle ascent attendant to a modest vorticity maximum rounding the northwestern periphery of the central CONUS upper ridging will begin interacting with the westernmost edge of this moist and unstable airmass around 21Z-00Z. Initial cellular development is anticipated across northeast WY and far southeast MT, before expanding northeastward into more of ND over time. A risk for very large hail and perhaps a tornado would accompany initial supercells before storm outflow and mergers lead to upscale growth into an eastward-moving cluster during the evening. Once this upscale growth occurs, a quick northeastward progression is anticipated across ND with some severe wind gusts possible. An instance or two of gusts around 75 mph are possible. ...Southeastern ND/Northeast SD into the Upper Midwest... Recent regional radar imagery shows an MCV tracking east-northeastward over south-central ND. The airmass downstream from southeast ND/northeast SD into southern MN and northern IA is destabilizing amid strong heating and ample low-level moisture. As a result, there is a low-probability chance for thunderstorm redevelopment/reintensification early this afternoon in the vicinity of the MCV. If this occurs, isolated damaging gusts are possible. A more probable scenario is for this MCV to continue rounding the ridge and provide the impetus for thunderstorm development farther east across the Upper Midwest later this evening. Weak warm-air advection could augment ascent across the region as well. Moderate to strong buoyancy and moderate deep-layer vertical shear will be in place, supporting strong updrafts capable of large hail, particularly with initial development. Storms should continue throughout much of the night, with an isolated hail risk. ..Mosier/Karstens.. 07/03/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1120 AM CDT Thu Jul 03 2025 Valid 031630Z - 041200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR NORTH DAKOTA AND MUCH OF THE NORTHEAST... ...SUMMARY... Scattered severe thunderstorms capable of producing severe/damaging winds and large hail are forecast across parts of the Northeast and northern Plains today. ...Northeast... Recent satellite imagery shows a well-defined cyclone over northern QC and a shortwave trough embedded within the southern periphery of this cyclone progressing through the Lower Great Lakes. An attendant cold front is in place just ahead of this shortwave. Expectation is for this shortwave to continue quickly eastward into the Northeast, with the cold front progressing eastward/southeastward as well. The leading edge of the stronger large-scale forcing for ascent has already reached ME and NH, contributing to thunderstorm development where the preceding airmass has already destabilized. Continued destabilization is anticipated, likely resulting in a nearly continuous line of storms. In addition to moderate buoyancy, moderate vertical shear is in place as well. This combination of buoyancy and shear is expected to result in organized storms capable of large hail (more probable during the early-stage cellular mode) and damaging gusts (more probable later with later-stage linear modes). This ongoing development is well ahead of the primary cold front, so the potential exists for additional development across NY this afternoon, continuing into southern New England during the late afternoon and evening. Environmental conditions will be similar to those farther north and east, with large hail and damaging gusts possible with these storms as well. ...Northern Plains... Low-level moisture will continue to advect northwestward into the region today, helping to offset some of the anticipated mixing and keeping dewpoints in the upper 60s/70s later this afternoon/evening. This favorable low-level moisture beneath steep mid-level lapse rates will promote a very unstable airmass, with MLCAPE from 2000 to 3000 J/kg across ND this evening. Subtle ascent attendant to a modest vorticity maximum rounding the northwestern periphery of the central CONUS upper ridging will begin interacting with the westernmost edge of this moist and unstable airmass around 21Z-00Z. Initial cellular development is anticipated across northeast WY and far southeast MT, before expanding northeastward into more of ND over time. A risk for very large hail and perhaps a tornado would accompany initial supercells before storm outflow and mergers lead to upscale growth into an eastward-moving cluster during the evening. Once this upscale growth occurs, a quick northeastward progression is anticipated across ND with some severe wind gusts possible. An instance or two of gusts around 75 mph are possible. ...Southeastern ND/Northeast SD into the Upper Midwest... Recent regional radar imagery shows an MCV tracking east-northeastward over south-central ND. The airmass downstream from southeast ND/northeast SD into southern MN and northern IA is destabilizing amid strong heating and ample low-level moisture. As a result, there is a low-probability chance for thunderstorm redevelopment/reintensification early this afternoon in the vicinity of the MCV. If this occurs, isolated damaging gusts are possible. A more probable scenario is for this MCV to continue rounding the ridge and provide the impetus for thunderstorm development farther east across the Upper Midwest later this evening. Weak warm-air advection could augment ascent across the region as well. Moderate to strong buoyancy and moderate deep-layer vertical shear will be in place, supporting strong updrafts capable of large hail, particularly with initial development. Storms should continue throughout much of the night, with an isolated hail risk. ..Mosier/Karstens.. 07/03/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1120 AM CDT Thu Jul 03 2025 Valid 031630Z - 041200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR NORTH DAKOTA AND MUCH OF THE NORTHEAST... ...SUMMARY... Scattered severe thunderstorms capable of producing severe/damaging winds and large hail are forecast across parts of the Northeast and northern Plains today. ...Northeast... Recent satellite imagery shows a well-defined cyclone over northern QC and a shortwave trough embedded within the southern periphery of this cyclone progressing through the Lower Great Lakes. An attendant cold front is in place just ahead of this shortwave. Expectation is for this shortwave to continue quickly eastward into the Northeast, with the cold front progressing eastward/southeastward as well. The leading edge of the stronger large-scale forcing for ascent has already reached ME and NH, contributing to thunderstorm development where the preceding airmass has already destabilized. Continued destabilization is anticipated, likely resulting in a nearly continuous line of storms. In addition to moderate buoyancy, moderate vertical shear is in place as well. This combination of buoyancy and shear is expected to result in organized storms capable of large hail (more probable during the early-stage cellular mode) and damaging gusts (more probable later with later-stage linear modes). This ongoing development is well ahead of the primary cold front, so the potential exists for additional development across NY this afternoon, continuing into southern New England during the late afternoon and evening. Environmental conditions will be similar to those farther north and east, with large hail and damaging gusts possible with these storms as well. ...Northern Plains... Low-level moisture will continue to advect northwestward into the region today, helping to offset some of the anticipated mixing and keeping dewpoints in the upper 60s/70s later this afternoon/evening. This favorable low-level moisture beneath steep mid-level lapse rates will promote a very unstable airmass, with MLCAPE from 2000 to 3000 J/kg across ND this evening. Subtle ascent attendant to a modest vorticity maximum rounding the northwestern periphery of the central CONUS upper ridging will begin interacting with the westernmost edge of this moist and unstable airmass around 21Z-00Z. Initial cellular development is anticipated across northeast WY and far southeast MT, before expanding northeastward into more of ND over time. A risk for very large hail and perhaps a tornado would accompany initial supercells before storm outflow and mergers lead to upscale growth into an eastward-moving cluster during the evening. Once this upscale growth occurs, a quick northeastward progression is anticipated across ND with some severe wind gusts possible. An instance or two of gusts around 75 mph are possible. ...Southeastern ND/Northeast SD into the Upper Midwest... Recent regional radar imagery shows an MCV tracking east-northeastward over south-central ND. The airmass downstream from southeast ND/northeast SD into southern MN and northern IA is destabilizing amid strong heating and ample low-level moisture. As a result, there is a low-probability chance for thunderstorm redevelopment/reintensification early this afternoon in the vicinity of the MCV. If this occurs, isolated damaging gusts are possible. A more probable scenario is for this MCV to continue rounding the ridge and provide the impetus for thunderstorm development farther east across the Upper Midwest later this evening. Weak warm-air advection could augment ascent across the region as well. Moderate to strong buoyancy and moderate deep-layer vertical shear will be in place, supporting strong updrafts capable of large hail, particularly with initial development. Storms should continue throughout much of the night, with an isolated hail risk. ..Mosier/Karstens.. 07/03/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1120 AM CDT Thu Jul 03 2025 Valid 031630Z - 041200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR NORTH DAKOTA AND MUCH OF THE NORTHEAST... ...SUMMARY... Scattered severe thunderstorms capable of producing severe/damaging winds and large hail are forecast across parts of the Northeast and northern Plains today. ...Northeast... Recent satellite imagery shows a well-defined cyclone over northern QC and a shortwave trough embedded within the southern periphery of this cyclone progressing through the Lower Great Lakes. An attendant cold front is in place just ahead of this shortwave. Expectation is for this shortwave to continue quickly eastward into the Northeast, with the cold front progressing eastward/southeastward as well. The leading edge of the stronger large-scale forcing for ascent has already reached ME and NH, contributing to thunderstorm development where the preceding airmass has already destabilized. Continued destabilization is anticipated, likely resulting in a nearly continuous line of storms. In addition to moderate buoyancy, moderate vertical shear is in place as well. This combination of buoyancy and shear is expected to result in organized storms capable of large hail (more probable during the early-stage cellular mode) and damaging gusts (more probable later with later-stage linear modes). This ongoing development is well ahead of the primary cold front, so the potential exists for additional development across NY this afternoon, continuing into southern New England during the late afternoon and evening. Environmental conditions will be similar to those farther north and east, with large hail and damaging gusts possible with these storms as well. ...Northern Plains... Low-level moisture will continue to advect northwestward into the region today, helping to offset some of the anticipated mixing and keeping dewpoints in the upper 60s/70s later this afternoon/evening. This favorable low-level moisture beneath steep mid-level lapse rates will promote a very unstable airmass, with MLCAPE from 2000 to 3000 J/kg across ND this evening. Subtle ascent attendant to a modest vorticity maximum rounding the northwestern periphery of the central CONUS upper ridging will begin interacting with the westernmost edge of this moist and unstable airmass around 21Z-00Z. Initial cellular development is anticipated across northeast WY and far southeast MT, before expanding northeastward into more of ND over time. A risk for very large hail and perhaps a tornado would accompany initial supercells before storm outflow and mergers lead to upscale growth into an eastward-moving cluster during the evening. Once this upscale growth occurs, a quick northeastward progression is anticipated across ND with some severe wind gusts possible. An instance or two of gusts around 75 mph are possible. ...Southeastern ND/Northeast SD into the Upper Midwest... Recent regional radar imagery shows an MCV tracking east-northeastward over south-central ND. The airmass downstream from southeast ND/northeast SD into southern MN and northern IA is destabilizing amid strong heating and ample low-level moisture. As a result, there is a low-probability chance for thunderstorm redevelopment/reintensification early this afternoon in the vicinity of the MCV. If this occurs, isolated damaging gusts are possible. A more probable scenario is for this MCV to continue rounding the ridge and provide the impetus for thunderstorm development farther east across the Upper Midwest later this evening. Weak warm-air advection could augment ascent across the region as well. Moderate to strong buoyancy and moderate deep-layer vertical shear will be in place, supporting strong updrafts capable of large hail, particularly with initial development. Storms should continue throughout much of the night, with an isolated hail risk. ..Mosier/Karstens.. 07/03/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1120 AM CDT Thu Jul 03 2025 Valid 031630Z - 041200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR NORTH DAKOTA AND MUCH OF THE NORTHEAST... ...SUMMARY... Scattered severe thunderstorms capable of producing severe/damaging winds and large hail are forecast across parts of the Northeast and northern Plains today. ...Northeast... Recent satellite imagery shows a well-defined cyclone over northern QC and a shortwave trough embedded within the southern periphery of this cyclone progressing through the Lower Great Lakes. An attendant cold front is in place just ahead of this shortwave. Expectation is for this shortwave to continue quickly eastward into the Northeast, with the cold front progressing eastward/southeastward as well. The leading edge of the stronger large-scale forcing for ascent has already reached ME and NH, contributing to thunderstorm development where the preceding airmass has already destabilized. Continued destabilization is anticipated, likely resulting in a nearly continuous line of storms. In addition to moderate buoyancy, moderate vertical shear is in place as well. This combination of buoyancy and shear is expected to result in organized storms capable of large hail (more probable during the early-stage cellular mode) and damaging gusts (more probable later with later-stage linear modes). This ongoing development is well ahead of the primary cold front, so the potential exists for additional development across NY this afternoon, continuing into southern New England during the late afternoon and evening. Environmental conditions will be similar to those farther north and east, with large hail and damaging gusts possible with these storms as well. ...Northern Plains... Low-level moisture will continue to advect northwestward into the region today, helping to offset some of the anticipated mixing and keeping dewpoints in the upper 60s/70s later this afternoon/evening. This favorable low-level moisture beneath steep mid-level lapse rates will promote a very unstable airmass, with MLCAPE from 2000 to 3000 J/kg across ND this evening. Subtle ascent attendant to a modest vorticity maximum rounding the northwestern periphery of the central CONUS upper ridging will begin interacting with the westernmost edge of this moist and unstable airmass around 21Z-00Z. Initial cellular development is anticipated across northeast WY and far southeast MT, before expanding northeastward into more of ND over time. A risk for very large hail and perhaps a tornado would accompany initial supercells before storm outflow and mergers lead to upscale growth into an eastward-moving cluster during the evening. Once this upscale growth occurs, a quick northeastward progression is anticipated across ND with some severe wind gusts possible. An instance or two of gusts around 75 mph are possible. ...Southeastern ND/Northeast SD into the Upper Midwest... Recent regional radar imagery shows an MCV tracking east-northeastward over south-central ND. The airmass downstream from southeast ND/northeast SD into southern MN and northern IA is destabilizing amid strong heating and ample low-level moisture. As a result, there is a low-probability chance for thunderstorm redevelopment/reintensification early this afternoon in the vicinity of the MCV. If this occurs, isolated damaging gusts are possible. A more probable scenario is for this MCV to continue rounding the ridge and provide the impetus for thunderstorm development farther east across the Upper Midwest later this evening. Weak warm-air advection could augment ascent across the region as well. Moderate to strong buoyancy and moderate deep-layer vertical shear will be in place, supporting strong updrafts capable of large hail, particularly with initial development. Storms should continue throughout much of the night, with an isolated hail risk. ..Mosier/Karstens.. 07/03/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1120 AM CDT Thu Jul 03 2025 Valid 031630Z - 041200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR NORTH DAKOTA AND MUCH OF THE NORTHEAST... ...SUMMARY... Scattered severe thunderstorms capable of producing severe/damaging winds and large hail are forecast across parts of the Northeast and northern Plains today. ...Northeast... Recent satellite imagery shows a well-defined cyclone over northern QC and a shortwave trough embedded within the southern periphery of this cyclone progressing through the Lower Great Lakes. An attendant cold front is in place just ahead of this shortwave. Expectation is for this shortwave to continue quickly eastward into the Northeast, with the cold front progressing eastward/southeastward as well. The leading edge of the stronger large-scale forcing for ascent has already reached ME and NH, contributing to thunderstorm development where the preceding airmass has already destabilized. Continued destabilization is anticipated, likely resulting in a nearly continuous line of storms. In addition to moderate buoyancy, moderate vertical shear is in place as well. This combination of buoyancy and shear is expected to result in organized storms capable of large hail (more probable during the early-stage cellular mode) and damaging gusts (more probable later with later-stage linear modes). This ongoing development is well ahead of the primary cold front, so the potential exists for additional development across NY this afternoon, continuing into southern New England during the late afternoon and evening. Environmental conditions will be similar to those farther north and east, with large hail and damaging gusts possible with these storms as well. ...Northern Plains... Low-level moisture will continue to advect northwestward into the region today, helping to offset some of the anticipated mixing and keeping dewpoints in the upper 60s/70s later this afternoon/evening. This favorable low-level moisture beneath steep mid-level lapse rates will promote a very unstable airmass, with MLCAPE from 2000 to 3000 J/kg across ND this evening. Subtle ascent attendant to a modest vorticity maximum rounding the northwestern periphery of the central CONUS upper ridging will begin interacting with the westernmost edge of this moist and unstable airmass around 21Z-00Z. Initial cellular development is anticipated across northeast WY and far southeast MT, before expanding northeastward into more of ND over time. A risk for very large hail and perhaps a tornado would accompany initial supercells before storm outflow and mergers lead to upscale growth into an eastward-moving cluster during the evening. Once this upscale growth occurs, a quick northeastward progression is anticipated across ND with some severe wind gusts possible. An instance or two of gusts around 75 mph are possible. ...Southeastern ND/Northeast SD into the Upper Midwest... Recent regional radar imagery shows an MCV tracking east-northeastward over south-central ND. The airmass downstream from southeast ND/northeast SD into southern MN and northern IA is destabilizing amid strong heating and ample low-level moisture. As a result, there is a low-probability chance for thunderstorm redevelopment/reintensification early this afternoon in the vicinity of the MCV. If this occurs, isolated damaging gusts are possible. A more probable scenario is for this MCV to continue rounding the ridge and provide the impetus for thunderstorm development farther east across the Upper Midwest later this evening. Weak warm-air advection could augment ascent across the region as well. Moderate to strong buoyancy and moderate deep-layer vertical shear will be in place, supporting strong updrafts capable of large hail, particularly with initial development. Storms should continue throughout much of the night, with an isolated hail risk. ..Mosier/Karstens.. 07/03/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1120 AM CDT Thu Jul 03 2025 Valid 031630Z - 041200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR NORTH DAKOTA AND MUCH OF THE NORTHEAST... ...SUMMARY... Scattered severe thunderstorms capable of producing severe/damaging winds and large hail are forecast across parts of the Northeast and northern Plains today. ...Northeast... Recent satellite imagery shows a well-defined cyclone over northern QC and a shortwave trough embedded within the southern periphery of this cyclone progressing through the Lower Great Lakes. An attendant cold front is in place just ahead of this shortwave. Expectation is for this shortwave to continue quickly eastward into the Northeast, with the cold front progressing eastward/southeastward as well. The leading edge of the stronger large-scale forcing for ascent has already reached ME and NH, contributing to thunderstorm development where the preceding airmass has already destabilized. Continued destabilization is anticipated, likely resulting in a nearly continuous line of storms. In addition to moderate buoyancy, moderate vertical shear is in place as well. This combination of buoyancy and shear is expected to result in organized storms capable of large hail (more probable during the early-stage cellular mode) and damaging gusts (more probable later with later-stage linear modes). This ongoing development is well ahead of the primary cold front, so the potential exists for additional development across NY this afternoon, continuing into southern New England during the late afternoon and evening. Environmental conditions will be similar to those farther north and east, with large hail and damaging gusts possible with these storms as well. ...Northern Plains... Low-level moisture will continue to advect northwestward into the region today, helping to offset some of the anticipated mixing and keeping dewpoints in the upper 60s/70s later this afternoon/evening. This favorable low-level moisture beneath steep mid-level lapse rates will promote a very unstable airmass, with MLCAPE from 2000 to 3000 J/kg across ND this evening. Subtle ascent attendant to a modest vorticity maximum rounding the northwestern periphery of the central CONUS upper ridging will begin interacting with the westernmost edge of this moist and unstable airmass around 21Z-00Z. Initial cellular development is anticipated across northeast WY and far southeast MT, before expanding northeastward into more of ND over time. A risk for very large hail and perhaps a tornado would accompany initial supercells before storm outflow and mergers lead to upscale growth into an eastward-moving cluster during the evening. Once this upscale growth occurs, a quick northeastward progression is anticipated across ND with some severe wind gusts possible. An instance or two of gusts around 75 mph are possible. ...Southeastern ND/Northeast SD into the Upper Midwest... Recent regional radar imagery shows an MCV tracking east-northeastward over south-central ND. The airmass downstream from southeast ND/northeast SD into southern MN and northern IA is destabilizing amid strong heating and ample low-level moisture. As a result, there is a low-probability chance for thunderstorm redevelopment/reintensification early this afternoon in the vicinity of the MCV. If this occurs, isolated damaging gusts are possible. A more probable scenario is for this MCV to continue rounding the ridge and provide the impetus for thunderstorm development farther east across the Upper Midwest later this evening. Weak warm-air advection could augment ascent across the region as well. Moderate to strong buoyancy and moderate deep-layer vertical shear will be in place, supporting strong updrafts capable of large hail, particularly with initial development. Storms should continue throughout much of the night, with an isolated hail risk. ..Mosier/Karstens.. 07/03/2025 Read more