Severe Storms

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1159 AM CDT Thu Jul 17 2025 Valid 171700Z - 181200Z ...Dry Thunderstorms... Southerly flow on the eastern fringe of a mid-level low entering southern California will aid in northward transport of monsoon moisture into the Desert Southwest and Four Corners region. Isolated dry thunderstorms are expected on the northern periphery of the deeper moisture now across AZ and NM, where surface dewpoints are in the upper 40s to 60s. The isolated dry thunderstorm threat was contracted overall across the Great Basin, UT and western CO/southwestern WY owing to latest model guidance, current position of the monsoon moisture plume, alignment of remaining receptive fuels as well as to account for recent precipitation footprints over the last 48 hours. ..Williams.. 07/17/2025 .PREV DISCUSSION... /ISSUED 1257 AM CDT Thu Jul 17 2025/ ...Synopsis... A shortwave trough will glance the Pacific Northwest bringing an increase of westerly flow aloft across the Cascades into the Cascade Gaps. As a result, areas of increased westerly downslope flow can be expected along and just east of the Cascades in the Columbia River Basin. Sustained winds 10-15 mph (locally higher in the Cascade Gaps) overlap with afternoon relative humidity reductions to around 10-20 percent. An Elevated delineation was added with this outlook to support this potential. ...Dry Thunderstorms... A closed low off the coast of Baja California will bring moisture northward across portions of the Southwest into the Great Basin. On the fringe of this deeper moisture, isolated dry thunderstorm potential will continue across portions of western Colorado into western Wyoming, Utah, far southern Idaho and eastern Nevada. Here precipitable water values drop to around 0.50" or less with more limited coverage. Some mix of wet/dry thunderstorms will be possible in central Utah and west-central Colorado but storm motions around 15-20 kts will likely yield little measurable precipitation. ...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 1159 AM CDT Thu Jul 17 2025 Valid 171700Z - 181200Z ...Dry Thunderstorms... Southerly flow on the eastern fringe of a mid-level low entering southern California will aid in northward transport of monsoon moisture into the Desert Southwest and Four Corners region. Isolated dry thunderstorms are expected on the northern periphery of the deeper moisture now across AZ and NM, where surface dewpoints are in the upper 40s to 60s. The isolated dry thunderstorm threat was contracted overall across the Great Basin, UT and western CO/southwestern WY owing to latest model guidance, current position of the monsoon moisture plume, alignment of remaining receptive fuels as well as to account for recent precipitation footprints over the last 48 hours. ..Williams.. 07/17/2025 .PREV DISCUSSION... /ISSUED 1257 AM CDT Thu Jul 17 2025/ ...Synopsis... A shortwave trough will glance the Pacific Northwest bringing an increase of westerly flow aloft across the Cascades into the Cascade Gaps. As a result, areas of increased westerly downslope flow can be expected along and just east of the Cascades in the Columbia River Basin. Sustained winds 10-15 mph (locally higher in the Cascade Gaps) overlap with afternoon relative humidity reductions to around 10-20 percent. An Elevated delineation was added with this outlook to support this potential. ...Dry Thunderstorms... A closed low off the coast of Baja California will bring moisture northward across portions of the Southwest into the Great Basin. On the fringe of this deeper moisture, isolated dry thunderstorm potential will continue across portions of western Colorado into western Wyoming, Utah, far southern Idaho and eastern Nevada. Here precipitable water values drop to around 0.50" or less with more limited coverage. Some mix of wet/dry thunderstorms will be possible in central Utah and west-central Colorado but storm motions around 15-20 kts will likely yield little measurable precipitation. ...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 1159 AM CDT Thu Jul 17 2025 Valid 171700Z - 181200Z ...Dry Thunderstorms... Southerly flow on the eastern fringe of a mid-level low entering southern California will aid in northward transport of monsoon moisture into the Desert Southwest and Four Corners region. Isolated dry thunderstorms are expected on the northern periphery of the deeper moisture now across AZ and NM, where surface dewpoints are in the upper 40s to 60s. The isolated dry thunderstorm threat was contracted overall across the Great Basin, UT and western CO/southwestern WY owing to latest model guidance, current position of the monsoon moisture plume, alignment of remaining receptive fuels as well as to account for recent precipitation footprints over the last 48 hours. ..Williams.. 07/17/2025 .PREV DISCUSSION... /ISSUED 1257 AM CDT Thu Jul 17 2025/ ...Synopsis... A shortwave trough will glance the Pacific Northwest bringing an increase of westerly flow aloft across the Cascades into the Cascade Gaps. As a result, areas of increased westerly downslope flow can be expected along and just east of the Cascades in the Columbia River Basin. Sustained winds 10-15 mph (locally higher in the Cascade Gaps) overlap with afternoon relative humidity reductions to around 10-20 percent. An Elevated delineation was added with this outlook to support this potential. ...Dry Thunderstorms... A closed low off the coast of Baja California will bring moisture northward across portions of the Southwest into the Great Basin. On the fringe of this deeper moisture, isolated dry thunderstorm potential will continue across portions of western Colorado into western Wyoming, Utah, far southern Idaho and eastern Nevada. Here precipitable water values drop to around 0.50" or less with more limited coverage. Some mix of wet/dry thunderstorms will be possible in central Utah and west-central Colorado but storm motions around 15-20 kts will likely yield little measurable precipitation. ...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 1159 AM CDT Thu Jul 17 2025 Valid 171700Z - 181200Z ...Dry Thunderstorms... Southerly flow on the eastern fringe of a mid-level low entering southern California will aid in northward transport of monsoon moisture into the Desert Southwest and Four Corners region. Isolated dry thunderstorms are expected on the northern periphery of the deeper moisture now across AZ and NM, where surface dewpoints are in the upper 40s to 60s. The isolated dry thunderstorm threat was contracted overall across the Great Basin, UT and western CO/southwestern WY owing to latest model guidance, current position of the monsoon moisture plume, alignment of remaining receptive fuels as well as to account for recent precipitation footprints over the last 48 hours. ..Williams.. 07/17/2025 .PREV DISCUSSION... /ISSUED 1257 AM CDT Thu Jul 17 2025/ ...Synopsis... A shortwave trough will glance the Pacific Northwest bringing an increase of westerly flow aloft across the Cascades into the Cascade Gaps. As a result, areas of increased westerly downslope flow can be expected along and just east of the Cascades in the Columbia River Basin. Sustained winds 10-15 mph (locally higher in the Cascade Gaps) overlap with afternoon relative humidity reductions to around 10-20 percent. An Elevated delineation was added with this outlook to support this potential. ...Dry Thunderstorms... A closed low off the coast of Baja California will bring moisture northward across portions of the Southwest into the Great Basin. On the fringe of this deeper moisture, isolated dry thunderstorm potential will continue across portions of western Colorado into western Wyoming, Utah, far southern Idaho and eastern Nevada. Here precipitable water values drop to around 0.50" or less with more limited coverage. Some mix of wet/dry thunderstorms will be possible in central Utah and west-central Colorado but storm motions around 15-20 kts will likely yield little measurable precipitation. ...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 1159 AM CDT Thu Jul 17 2025 Valid 171700Z - 181200Z ...Dry Thunderstorms... Southerly flow on the eastern fringe of a mid-level low entering southern California will aid in northward transport of monsoon moisture into the Desert Southwest and Four Corners region. Isolated dry thunderstorms are expected on the northern periphery of the deeper moisture now across AZ and NM, where surface dewpoints are in the upper 40s to 60s. The isolated dry thunderstorm threat was contracted overall across the Great Basin, UT and western CO/southwestern WY owing to latest model guidance, current position of the monsoon moisture plume, alignment of remaining receptive fuels as well as to account for recent precipitation footprints over the last 48 hours. ..Williams.. 07/17/2025 .PREV DISCUSSION... /ISSUED 1257 AM CDT Thu Jul 17 2025/ ...Synopsis... A shortwave trough will glance the Pacific Northwest bringing an increase of westerly flow aloft across the Cascades into the Cascade Gaps. As a result, areas of increased westerly downslope flow can be expected along and just east of the Cascades in the Columbia River Basin. Sustained winds 10-15 mph (locally higher in the Cascade Gaps) overlap with afternoon relative humidity reductions to around 10-20 percent. An Elevated delineation was added with this outlook to support this potential. ...Dry Thunderstorms... A closed low off the coast of Baja California will bring moisture northward across portions of the Southwest into the Great Basin. On the fringe of this deeper moisture, isolated dry thunderstorm potential will continue across portions of western Colorado into western Wyoming, Utah, far southern Idaho and eastern Nevada. Here precipitable water values drop to around 0.50" or less with more limited coverage. Some mix of wet/dry thunderstorms will be possible in central Utah and west-central Colorado but storm motions around 15-20 kts will likely yield little measurable precipitation. ...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 1159 AM CDT Thu Jul 17 2025 Valid 171700Z - 181200Z ...Dry Thunderstorms... Southerly flow on the eastern fringe of a mid-level low entering southern California will aid in northward transport of monsoon moisture into the Desert Southwest and Four Corners region. Isolated dry thunderstorms are expected on the northern periphery of the deeper moisture now across AZ and NM, where surface dewpoints are in the upper 40s to 60s. The isolated dry thunderstorm threat was contracted overall across the Great Basin, UT and western CO/southwestern WY owing to latest model guidance, current position of the monsoon moisture plume, alignment of remaining receptive fuels as well as to account for recent precipitation footprints over the last 48 hours. ..Williams.. 07/17/2025 .PREV DISCUSSION... /ISSUED 1257 AM CDT Thu Jul 17 2025/ ...Synopsis... A shortwave trough will glance the Pacific Northwest bringing an increase of westerly flow aloft across the Cascades into the Cascade Gaps. As a result, areas of increased westerly downslope flow can be expected along and just east of the Cascades in the Columbia River Basin. Sustained winds 10-15 mph (locally higher in the Cascade Gaps) overlap with afternoon relative humidity reductions to around 10-20 percent. An Elevated delineation was added with this outlook to support this potential. ...Dry Thunderstorms... A closed low off the coast of Baja California will bring moisture northward across portions of the Southwest into the Great Basin. On the fringe of this deeper moisture, isolated dry thunderstorm potential will continue across portions of western Colorado into western Wyoming, Utah, far southern Idaho and eastern Nevada. Here precipitable water values drop to around 0.50" or less with more limited coverage. Some mix of wet/dry thunderstorms will be possible in central Utah and west-central Colorado but storm motions around 15-20 kts will likely yield little measurable precipitation. ...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 1159 AM CDT Thu Jul 17 2025 Valid 171700Z - 181200Z ...Dry Thunderstorms... Southerly flow on the eastern fringe of a mid-level low entering southern California will aid in northward transport of monsoon moisture into the Desert Southwest and Four Corners region. Isolated dry thunderstorms are expected on the northern periphery of the deeper moisture now across AZ and NM, where surface dewpoints are in the upper 40s to 60s. The isolated dry thunderstorm threat was contracted overall across the Great Basin, UT and western CO/southwestern WY owing to latest model guidance, current position of the monsoon moisture plume, alignment of remaining receptive fuels as well as to account for recent precipitation footprints over the last 48 hours. ..Williams.. 07/17/2025 .PREV DISCUSSION... /ISSUED 1257 AM CDT Thu Jul 17 2025/ ...Synopsis... A shortwave trough will glance the Pacific Northwest bringing an increase of westerly flow aloft across the Cascades into the Cascade Gaps. As a result, areas of increased westerly downslope flow can be expected along and just east of the Cascades in the Columbia River Basin. Sustained winds 10-15 mph (locally higher in the Cascade Gaps) overlap with afternoon relative humidity reductions to around 10-20 percent. An Elevated delineation was added with this outlook to support this potential. ...Dry Thunderstorms... A closed low off the coast of Baja California will bring moisture northward across portions of the Southwest into the Great Basin. On the fringe of this deeper moisture, isolated dry thunderstorm potential will continue across portions of western Colorado into western Wyoming, Utah, far southern Idaho and eastern Nevada. Here precipitable water values drop to around 0.50" or less with more limited coverage. Some mix of wet/dry thunderstorms will be possible in central Utah and west-central Colorado but storm motions around 15-20 kts will likely yield little measurable precipitation. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1125 AM CDT Thu Jul 17 2025 Valid 171630Z - 181200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS NORTHERN NEW ENGLAND AND THE NORTHERN HIGH PLAINS... ...SUMMARY... Scattered damaging winds and a tornado are possible across northern New England this afternoon. A confined corridor of large hail and severe gusts appears possible from north-central Montana to southwest North Dakota this evening. ...Northeast... Midday visible-satellite imagery shows cloud breaks and surface observations show warming temperatures which imply a destabilizing airmass. A lead, convectively enhanced disturbance evident in radar/satellite imagery, is moving east across southern Quebec, while an upstream larger-scale mid-level trough continues eastward across Ontario and into Quebec later today. A cyclone will develop northeast from eastern Ontario into eastern Quebec while a cold front pushes through the Lower Great Lakes and through much of the Northeast through mid evening. The deep moisture through much of the troposphere and weak lapse rate profiles, which were sampled by the 12 UTC Buffalo and Albany, NY raobs, will undergo moderate destabilization by early to mid afternoon. Although forcing for ascent will favor Quebec into northern New England, scattered thunderstorms will likely develop from Maine southward into southern New England. The greatest potential for some organized storms will favor northern New England where stronger effective shear (30-40 kt) and adequate buoyancy will promote a wind-damage threat with the stronger storms. Forecast sounding over northern Maine show enlarged hodographs for a few hours, which may aid in low-level mesocyclone development and perhaps a risk for a tornado. Lower coverage of severe is forecast farther south where weaker shear will tend to limit storm intensity. The severe activity will likely diminish by the early to mid evening. ...Northern High Plains... Model guidance continues to show a focused corridor of supercell thunderstorm potential from north-central MT to southwest ND, mainly this evening. Water-vapor imagery shows a mid-level shortwave trough rotating southeastward across the southern part of the Canadian Rockies moving towards the northern High Plains. Forecast soundings this afternoon show elongated hodographs amidst modest buoyancy, which would support the development of a supercell or two during the evening. Large hail is the primary hazard with this activity but severe gusts may occur on a localized basis. An isolated hail/wind risk may persist along the ND/SD border vicinity overnight. ...Mid-Atlantic to the Southern High Plains... A surface front draped over the south-central Plains east-northeastward into the mid MS/OH Valleys will focus scattered thunderstorm activity this afternoon. The eastern part of this broader region over the Mid-Atlantic into the OH Valley will be displaced from the mid-level trough over influencing storm activity over the Northeast. A remnant MCV and outflow from overnight storms in the MO/KS/OK vicinity will aid in developing storms and perhaps localized threats for sporadic hail/wind mainly this afternoon. Isolated damaging winds may also occur with thunderstorms that develop east of the central Appalachians this afternoon, even though coverage should be somewhat less. ..Smith/Lyons.. 07/17/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1125 AM CDT Thu Jul 17 2025 Valid 171630Z - 181200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS NORTHERN NEW ENGLAND AND THE NORTHERN HIGH PLAINS... ...SUMMARY... Scattered damaging winds and a tornado are possible across northern New England this afternoon. A confined corridor of large hail and severe gusts appears possible from north-central Montana to southwest North Dakota this evening. ...Northeast... Midday visible-satellite imagery shows cloud breaks and surface observations show warming temperatures which imply a destabilizing airmass. A lead, convectively enhanced disturbance evident in radar/satellite imagery, is moving east across southern Quebec, while an upstream larger-scale mid-level trough continues eastward across Ontario and into Quebec later today. A cyclone will develop northeast from eastern Ontario into eastern Quebec while a cold front pushes through the Lower Great Lakes and through much of the Northeast through mid evening. The deep moisture through much of the troposphere and weak lapse rate profiles, which were sampled by the 12 UTC Buffalo and Albany, NY raobs, will undergo moderate destabilization by early to mid afternoon. Although forcing for ascent will favor Quebec into northern New England, scattered thunderstorms will likely develop from Maine southward into southern New England. The greatest potential for some organized storms will favor northern New England where stronger effective shear (30-40 kt) and adequate buoyancy will promote a wind-damage threat with the stronger storms. Forecast sounding over northern Maine show enlarged hodographs for a few hours, which may aid in low-level mesocyclone development and perhaps a risk for a tornado. Lower coverage of severe is forecast farther south where weaker shear will tend to limit storm intensity. The severe activity will likely diminish by the early to mid evening. ...Northern High Plains... Model guidance continues to show a focused corridor of supercell thunderstorm potential from north-central MT to southwest ND, mainly this evening. Water-vapor imagery shows a mid-level shortwave trough rotating southeastward across the southern part of the Canadian Rockies moving towards the northern High Plains. Forecast soundings this afternoon show elongated hodographs amidst modest buoyancy, which would support the development of a supercell or two during the evening. Large hail is the primary hazard with this activity but severe gusts may occur on a localized basis. An isolated hail/wind risk may persist along the ND/SD border vicinity overnight. ...Mid-Atlantic to the Southern High Plains... A surface front draped over the south-central Plains east-northeastward into the mid MS/OH Valleys will focus scattered thunderstorm activity this afternoon. The eastern part of this broader region over the Mid-Atlantic into the OH Valley will be displaced from the mid-level trough over influencing storm activity over the Northeast. A remnant MCV and outflow from overnight storms in the MO/KS/OK vicinity will aid in developing storms and perhaps localized threats for sporadic hail/wind mainly this afternoon. Isolated damaging winds may also occur with thunderstorms that develop east of the central Appalachians this afternoon, even though coverage should be somewhat less. ..Smith/Lyons.. 07/17/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1125 AM CDT Thu Jul 17 2025 Valid 171630Z - 181200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS NORTHERN NEW ENGLAND AND THE NORTHERN HIGH PLAINS... ...SUMMARY... Scattered damaging winds and a tornado are possible across northern New England this afternoon. A confined corridor of large hail and severe gusts appears possible from north-central Montana to southwest North Dakota this evening. ...Northeast... Midday visible-satellite imagery shows cloud breaks and surface observations show warming temperatures which imply a destabilizing airmass. A lead, convectively enhanced disturbance evident in radar/satellite imagery, is moving east across southern Quebec, while an upstream larger-scale mid-level trough continues eastward across Ontario and into Quebec later today. A cyclone will develop northeast from eastern Ontario into eastern Quebec while a cold front pushes through the Lower Great Lakes and through much of the Northeast through mid evening. The deep moisture through much of the troposphere and weak lapse rate profiles, which were sampled by the 12 UTC Buffalo and Albany, NY raobs, will undergo moderate destabilization by early to mid afternoon. Although forcing for ascent will favor Quebec into northern New England, scattered thunderstorms will likely develop from Maine southward into southern New England. The greatest potential for some organized storms will favor northern New England where stronger effective shear (30-40 kt) and adequate buoyancy will promote a wind-damage threat with the stronger storms. Forecast sounding over northern Maine show enlarged hodographs for a few hours, which may aid in low-level mesocyclone development and perhaps a risk for a tornado. Lower coverage of severe is forecast farther south where weaker shear will tend to limit storm intensity. The severe activity will likely diminish by the early to mid evening. ...Northern High Plains... Model guidance continues to show a focused corridor of supercell thunderstorm potential from north-central MT to southwest ND, mainly this evening. Water-vapor imagery shows a mid-level shortwave trough rotating southeastward across the southern part of the Canadian Rockies moving towards the northern High Plains. Forecast soundings this afternoon show elongated hodographs amidst modest buoyancy, which would support the development of a supercell or two during the evening. Large hail is the primary hazard with this activity but severe gusts may occur on a localized basis. An isolated hail/wind risk may persist along the ND/SD border vicinity overnight. ...Mid-Atlantic to the Southern High Plains... A surface front draped over the south-central Plains east-northeastward into the mid MS/OH Valleys will focus scattered thunderstorm activity this afternoon. The eastern part of this broader region over the Mid-Atlantic into the OH Valley will be displaced from the mid-level trough over influencing storm activity over the Northeast. A remnant MCV and outflow from overnight storms in the MO/KS/OK vicinity will aid in developing storms and perhaps localized threats for sporadic hail/wind mainly this afternoon. Isolated damaging winds may also occur with thunderstorms that develop east of the central Appalachians this afternoon, even though coverage should be somewhat less. ..Smith/Lyons.. 07/17/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1125 AM CDT Thu Jul 17 2025 Valid 171630Z - 181200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS NORTHERN NEW ENGLAND AND THE NORTHERN HIGH PLAINS... ...SUMMARY... Scattered damaging winds and a tornado are possible across northern New England this afternoon. A confined corridor of large hail and severe gusts appears possible from north-central Montana to southwest North Dakota this evening. ...Northeast... Midday visible-satellite imagery shows cloud breaks and surface observations show warming temperatures which imply a destabilizing airmass. A lead, convectively enhanced disturbance evident in radar/satellite imagery, is moving east across southern Quebec, while an upstream larger-scale mid-level trough continues eastward across Ontario and into Quebec later today. A cyclone will develop northeast from eastern Ontario into eastern Quebec while a cold front pushes through the Lower Great Lakes and through much of the Northeast through mid evening. The deep moisture through much of the troposphere and weak lapse rate profiles, which were sampled by the 12 UTC Buffalo and Albany, NY raobs, will undergo moderate destabilization by early to mid afternoon. Although forcing for ascent will favor Quebec into northern New England, scattered thunderstorms will likely develop from Maine southward into southern New England. The greatest potential for some organized storms will favor northern New England where stronger effective shear (30-40 kt) and adequate buoyancy will promote a wind-damage threat with the stronger storms. Forecast sounding over northern Maine show enlarged hodographs for a few hours, which may aid in low-level mesocyclone development and perhaps a risk for a tornado. Lower coverage of severe is forecast farther south where weaker shear will tend to limit storm intensity. The severe activity will likely diminish by the early to mid evening. ...Northern High Plains... Model guidance continues to show a focused corridor of supercell thunderstorm potential from north-central MT to southwest ND, mainly this evening. Water-vapor imagery shows a mid-level shortwave trough rotating southeastward across the southern part of the Canadian Rockies moving towards the northern High Plains. Forecast soundings this afternoon show elongated hodographs amidst modest buoyancy, which would support the development of a supercell or two during the evening. Large hail is the primary hazard with this activity but severe gusts may occur on a localized basis. An isolated hail/wind risk may persist along the ND/SD border vicinity overnight. ...Mid-Atlantic to the Southern High Plains... A surface front draped over the south-central Plains east-northeastward into the mid MS/OH Valleys will focus scattered thunderstorm activity this afternoon. The eastern part of this broader region over the Mid-Atlantic into the OH Valley will be displaced from the mid-level trough over influencing storm activity over the Northeast. A remnant MCV and outflow from overnight storms in the MO/KS/OK vicinity will aid in developing storms and perhaps localized threats for sporadic hail/wind mainly this afternoon. Isolated damaging winds may also occur with thunderstorms that develop east of the central Appalachians this afternoon, even though coverage should be somewhat less. ..Smith/Lyons.. 07/17/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1125 AM CDT Thu Jul 17 2025 Valid 171630Z - 181200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS NORTHERN NEW ENGLAND AND THE NORTHERN HIGH PLAINS... ...SUMMARY... Scattered damaging winds and a tornado are possible across northern New England this afternoon. A confined corridor of large hail and severe gusts appears possible from north-central Montana to southwest North Dakota this evening. ...Northeast... Midday visible-satellite imagery shows cloud breaks and surface observations show warming temperatures which imply a destabilizing airmass. A lead, convectively enhanced disturbance evident in radar/satellite imagery, is moving east across southern Quebec, while an upstream larger-scale mid-level trough continues eastward across Ontario and into Quebec later today. A cyclone will develop northeast from eastern Ontario into eastern Quebec while a cold front pushes through the Lower Great Lakes and through much of the Northeast through mid evening. The deep moisture through much of the troposphere and weak lapse rate profiles, which were sampled by the 12 UTC Buffalo and Albany, NY raobs, will undergo moderate destabilization by early to mid afternoon. Although forcing for ascent will favor Quebec into northern New England, scattered thunderstorms will likely develop from Maine southward into southern New England. The greatest potential for some organized storms will favor northern New England where stronger effective shear (30-40 kt) and adequate buoyancy will promote a wind-damage threat with the stronger storms. Forecast sounding over northern Maine show enlarged hodographs for a few hours, which may aid in low-level mesocyclone development and perhaps a risk for a tornado. Lower coverage of severe is forecast farther south where weaker shear will tend to limit storm intensity. The severe activity will likely diminish by the early to mid evening. ...Northern High Plains... Model guidance continues to show a focused corridor of supercell thunderstorm potential from north-central MT to southwest ND, mainly this evening. Water-vapor imagery shows a mid-level shortwave trough rotating southeastward across the southern part of the Canadian Rockies moving towards the northern High Plains. Forecast soundings this afternoon show elongated hodographs amidst modest buoyancy, which would support the development of a supercell or two during the evening. Large hail is the primary hazard with this activity but severe gusts may occur on a localized basis. An isolated hail/wind risk may persist along the ND/SD border vicinity overnight. ...Mid-Atlantic to the Southern High Plains... A surface front draped over the south-central Plains east-northeastward into the mid MS/OH Valleys will focus scattered thunderstorm activity this afternoon. The eastern part of this broader region over the Mid-Atlantic into the OH Valley will be displaced from the mid-level trough over influencing storm activity over the Northeast. A remnant MCV and outflow from overnight storms in the MO/KS/OK vicinity will aid in developing storms and perhaps localized threats for sporadic hail/wind mainly this afternoon. Isolated damaging winds may also occur with thunderstorms that develop east of the central Appalachians this afternoon, even though coverage should be somewhat less. ..Smith/Lyons.. 07/17/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1125 AM CDT Thu Jul 17 2025 Valid 171630Z - 181200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS NORTHERN NEW ENGLAND AND THE NORTHERN HIGH PLAINS... ...SUMMARY... Scattered damaging winds and a tornado are possible across northern New England this afternoon. A confined corridor of large hail and severe gusts appears possible from north-central Montana to southwest North Dakota this evening. ...Northeast... Midday visible-satellite imagery shows cloud breaks and surface observations show warming temperatures which imply a destabilizing airmass. A lead, convectively enhanced disturbance evident in radar/satellite imagery, is moving east across southern Quebec, while an upstream larger-scale mid-level trough continues eastward across Ontario and into Quebec later today. A cyclone will develop northeast from eastern Ontario into eastern Quebec while a cold front pushes through the Lower Great Lakes and through much of the Northeast through mid evening. The deep moisture through much of the troposphere and weak lapse rate profiles, which were sampled by the 12 UTC Buffalo and Albany, NY raobs, will undergo moderate destabilization by early to mid afternoon. Although forcing for ascent will favor Quebec into northern New England, scattered thunderstorms will likely develop from Maine southward into southern New England. The greatest potential for some organized storms will favor northern New England where stronger effective shear (30-40 kt) and adequate buoyancy will promote a wind-damage threat with the stronger storms. Forecast sounding over northern Maine show enlarged hodographs for a few hours, which may aid in low-level mesocyclone development and perhaps a risk for a tornado. Lower coverage of severe is forecast farther south where weaker shear will tend to limit storm intensity. The severe activity will likely diminish by the early to mid evening. ...Northern High Plains... Model guidance continues to show a focused corridor of supercell thunderstorm potential from north-central MT to southwest ND, mainly this evening. Water-vapor imagery shows a mid-level shortwave trough rotating southeastward across the southern part of the Canadian Rockies moving towards the northern High Plains. Forecast soundings this afternoon show elongated hodographs amidst modest buoyancy, which would support the development of a supercell or two during the evening. Large hail is the primary hazard with this activity but severe gusts may occur on a localized basis. An isolated hail/wind risk may persist along the ND/SD border vicinity overnight. ...Mid-Atlantic to the Southern High Plains... A surface front draped over the south-central Plains east-northeastward into the mid MS/OH Valleys will focus scattered thunderstorm activity this afternoon. The eastern part of this broader region over the Mid-Atlantic into the OH Valley will be displaced from the mid-level trough over influencing storm activity over the Northeast. A remnant MCV and outflow from overnight storms in the MO/KS/OK vicinity will aid in developing storms and perhaps localized threats for sporadic hail/wind mainly this afternoon. Isolated damaging winds may also occur with thunderstorms that develop east of the central Appalachians this afternoon, even though coverage should be somewhat less. ..Smith/Lyons.. 07/17/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1125 AM CDT Thu Jul 17 2025 Valid 171630Z - 181200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS NORTHERN NEW ENGLAND AND THE NORTHERN HIGH PLAINS... ...SUMMARY... Scattered damaging winds and a tornado are possible across northern New England this afternoon. A confined corridor of large hail and severe gusts appears possible from north-central Montana to southwest North Dakota this evening. ...Northeast... Midday visible-satellite imagery shows cloud breaks and surface observations show warming temperatures which imply a destabilizing airmass. A lead, convectively enhanced disturbance evident in radar/satellite imagery, is moving east across southern Quebec, while an upstream larger-scale mid-level trough continues eastward across Ontario and into Quebec later today. A cyclone will develop northeast from eastern Ontario into eastern Quebec while a cold front pushes through the Lower Great Lakes and through much of the Northeast through mid evening. The deep moisture through much of the troposphere and weak lapse rate profiles, which were sampled by the 12 UTC Buffalo and Albany, NY raobs, will undergo moderate destabilization by early to mid afternoon. Although forcing for ascent will favor Quebec into northern New England, scattered thunderstorms will likely develop from Maine southward into southern New England. The greatest potential for some organized storms will favor northern New England where stronger effective shear (30-40 kt) and adequate buoyancy will promote a wind-damage threat with the stronger storms. Forecast sounding over northern Maine show enlarged hodographs for a few hours, which may aid in low-level mesocyclone development and perhaps a risk for a tornado. Lower coverage of severe is forecast farther south where weaker shear will tend to limit storm intensity. The severe activity will likely diminish by the early to mid evening. ...Northern High Plains... Model guidance continues to show a focused corridor of supercell thunderstorm potential from north-central MT to southwest ND, mainly this evening. Water-vapor imagery shows a mid-level shortwave trough rotating southeastward across the southern part of the Canadian Rockies moving towards the northern High Plains. Forecast soundings this afternoon show elongated hodographs amidst modest buoyancy, which would support the development of a supercell or two during the evening. Large hail is the primary hazard with this activity but severe gusts may occur on a localized basis. An isolated hail/wind risk may persist along the ND/SD border vicinity overnight. ...Mid-Atlantic to the Southern High Plains... A surface front draped over the south-central Plains east-northeastward into the mid MS/OH Valleys will focus scattered thunderstorm activity this afternoon. The eastern part of this broader region over the Mid-Atlantic into the OH Valley will be displaced from the mid-level trough over influencing storm activity over the Northeast. A remnant MCV and outflow from overnight storms in the MO/KS/OK vicinity will aid in developing storms and perhaps localized threats for sporadic hail/wind mainly this afternoon. Isolated damaging winds may also occur with thunderstorms that develop east of the central Appalachians this afternoon, even though coverage should be somewhat less. ..Smith/Lyons.. 07/17/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1125 AM CDT Thu Jul 17 2025 Valid 171630Z - 181200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS NORTHERN NEW ENGLAND AND THE NORTHERN HIGH PLAINS... ...SUMMARY... Scattered damaging winds and a tornado are possible across northern New England this afternoon. A confined corridor of large hail and severe gusts appears possible from north-central Montana to southwest North Dakota this evening. ...Northeast... Midday visible-satellite imagery shows cloud breaks and surface observations show warming temperatures which imply a destabilizing airmass. A lead, convectively enhanced disturbance evident in radar/satellite imagery, is moving east across southern Quebec, while an upstream larger-scale mid-level trough continues eastward across Ontario and into Quebec later today. A cyclone will develop northeast from eastern Ontario into eastern Quebec while a cold front pushes through the Lower Great Lakes and through much of the Northeast through mid evening. The deep moisture through much of the troposphere and weak lapse rate profiles, which were sampled by the 12 UTC Buffalo and Albany, NY raobs, will undergo moderate destabilization by early to mid afternoon. Although forcing for ascent will favor Quebec into northern New England, scattered thunderstorms will likely develop from Maine southward into southern New England. The greatest potential for some organized storms will favor northern New England where stronger effective shear (30-40 kt) and adequate buoyancy will promote a wind-damage threat with the stronger storms. Forecast sounding over northern Maine show enlarged hodographs for a few hours, which may aid in low-level mesocyclone development and perhaps a risk for a tornado. Lower coverage of severe is forecast farther south where weaker shear will tend to limit storm intensity. The severe activity will likely diminish by the early to mid evening. ...Northern High Plains... Model guidance continues to show a focused corridor of supercell thunderstorm potential from north-central MT to southwest ND, mainly this evening. Water-vapor imagery shows a mid-level shortwave trough rotating southeastward across the southern part of the Canadian Rockies moving towards the northern High Plains. Forecast soundings this afternoon show elongated hodographs amidst modest buoyancy, which would support the development of a supercell or two during the evening. Large hail is the primary hazard with this activity but severe gusts may occur on a localized basis. An isolated hail/wind risk may persist along the ND/SD border vicinity overnight. ...Mid-Atlantic to the Southern High Plains... A surface front draped over the south-central Plains east-northeastward into the mid MS/OH Valleys will focus scattered thunderstorm activity this afternoon. The eastern part of this broader region over the Mid-Atlantic into the OH Valley will be displaced from the mid-level trough over influencing storm activity over the Northeast. A remnant MCV and outflow from overnight storms in the MO/KS/OK vicinity will aid in developing storms and perhaps localized threats for sporadic hail/wind mainly this afternoon. Isolated damaging winds may also occur with thunderstorms that develop east of the central Appalachians this afternoon, even though coverage should be somewhat less. ..Smith/Lyons.. 07/17/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1125 AM CDT Thu Jul 17 2025 Valid 171630Z - 181200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS NORTHERN NEW ENGLAND AND THE NORTHERN HIGH PLAINS... ...SUMMARY... Scattered damaging winds and a tornado are possible across northern New England this afternoon. A confined corridor of large hail and severe gusts appears possible from north-central Montana to southwest North Dakota this evening. ...Northeast... Midday visible-satellite imagery shows cloud breaks and surface observations show warming temperatures which imply a destabilizing airmass. A lead, convectively enhanced disturbance evident in radar/satellite imagery, is moving east across southern Quebec, while an upstream larger-scale mid-level trough continues eastward across Ontario and into Quebec later today. A cyclone will develop northeast from eastern Ontario into eastern Quebec while a cold front pushes through the Lower Great Lakes and through much of the Northeast through mid evening. The deep moisture through much of the troposphere and weak lapse rate profiles, which were sampled by the 12 UTC Buffalo and Albany, NY raobs, will undergo moderate destabilization by early to mid afternoon. Although forcing for ascent will favor Quebec into northern New England, scattered thunderstorms will likely develop from Maine southward into southern New England. The greatest potential for some organized storms will favor northern New England where stronger effective shear (30-40 kt) and adequate buoyancy will promote a wind-damage threat with the stronger storms. Forecast sounding over northern Maine show enlarged hodographs for a few hours, which may aid in low-level mesocyclone development and perhaps a risk for a tornado. Lower coverage of severe is forecast farther south where weaker shear will tend to limit storm intensity. The severe activity will likely diminish by the early to mid evening. ...Northern High Plains... Model guidance continues to show a focused corridor of supercell thunderstorm potential from north-central MT to southwest ND, mainly this evening. Water-vapor imagery shows a mid-level shortwave trough rotating southeastward across the southern part of the Canadian Rockies moving towards the northern High Plains. Forecast soundings this afternoon show elongated hodographs amidst modest buoyancy, which would support the development of a supercell or two during the evening. Large hail is the primary hazard with this activity but severe gusts may occur on a localized basis. An isolated hail/wind risk may persist along the ND/SD border vicinity overnight. ...Mid-Atlantic to the Southern High Plains... A surface front draped over the south-central Plains east-northeastward into the mid MS/OH Valleys will focus scattered thunderstorm activity this afternoon. The eastern part of this broader region over the Mid-Atlantic into the OH Valley will be displaced from the mid-level trough over influencing storm activity over the Northeast. A remnant MCV and outflow from overnight storms in the MO/KS/OK vicinity will aid in developing storms and perhaps localized threats for sporadic hail/wind mainly this afternoon. Isolated damaging winds may also occur with thunderstorms that develop east of the central Appalachians this afternoon, even though coverage should be somewhat less. ..Smith/Lyons.. 07/17/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1125 AM CDT Thu Jul 17 2025 Valid 171630Z - 181200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS NORTHERN NEW ENGLAND AND THE NORTHERN HIGH PLAINS... ...SUMMARY... Scattered damaging winds and a tornado are possible across northern New England this afternoon. A confined corridor of large hail and severe gusts appears possible from north-central Montana to southwest North Dakota this evening. ...Northeast... Midday visible-satellite imagery shows cloud breaks and surface observations show warming temperatures which imply a destabilizing airmass. A lead, convectively enhanced disturbance evident in radar/satellite imagery, is moving east across southern Quebec, while an upstream larger-scale mid-level trough continues eastward across Ontario and into Quebec later today. A cyclone will develop northeast from eastern Ontario into eastern Quebec while a cold front pushes through the Lower Great Lakes and through much of the Northeast through mid evening. The deep moisture through much of the troposphere and weak lapse rate profiles, which were sampled by the 12 UTC Buffalo and Albany, NY raobs, will undergo moderate destabilization by early to mid afternoon. Although forcing for ascent will favor Quebec into northern New England, scattered thunderstorms will likely develop from Maine southward into southern New England. The greatest potential for some organized storms will favor northern New England where stronger effective shear (30-40 kt) and adequate buoyancy will promote a wind-damage threat with the stronger storms. Forecast sounding over northern Maine show enlarged hodographs for a few hours, which may aid in low-level mesocyclone development and perhaps a risk for a tornado. Lower coverage of severe is forecast farther south where weaker shear will tend to limit storm intensity. The severe activity will likely diminish by the early to mid evening. ...Northern High Plains... Model guidance continues to show a focused corridor of supercell thunderstorm potential from north-central MT to southwest ND, mainly this evening. Water-vapor imagery shows a mid-level shortwave trough rotating southeastward across the southern part of the Canadian Rockies moving towards the northern High Plains. Forecast soundings this afternoon show elongated hodographs amidst modest buoyancy, which would support the development of a supercell or two during the evening. Large hail is the primary hazard with this activity but severe gusts may occur on a localized basis. An isolated hail/wind risk may persist along the ND/SD border vicinity overnight. ...Mid-Atlantic to the Southern High Plains... A surface front draped over the south-central Plains east-northeastward into the mid MS/OH Valleys will focus scattered thunderstorm activity this afternoon. The eastern part of this broader region over the Mid-Atlantic into the OH Valley will be displaced from the mid-level trough over influencing storm activity over the Northeast. A remnant MCV and outflow from overnight storms in the MO/KS/OK vicinity will aid in developing storms and perhaps localized threats for sporadic hail/wind mainly this afternoon. Isolated damaging winds may also occur with thunderstorms that develop east of the central Appalachians this afternoon, even though coverage should be somewhat less. ..Smith/Lyons.. 07/17/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1125 AM CDT Thu Jul 17 2025 Valid 171630Z - 181200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS NORTHERN NEW ENGLAND AND THE NORTHERN HIGH PLAINS... ...SUMMARY... Scattered damaging winds and a tornado are possible across northern New England this afternoon. A confined corridor of large hail and severe gusts appears possible from north-central Montana to southwest North Dakota this evening. ...Northeast... Midday visible-satellite imagery shows cloud breaks and surface observations show warming temperatures which imply a destabilizing airmass. A lead, convectively enhanced disturbance evident in radar/satellite imagery, is moving east across southern Quebec, while an upstream larger-scale mid-level trough continues eastward across Ontario and into Quebec later today. A cyclone will develop northeast from eastern Ontario into eastern Quebec while a cold front pushes through the Lower Great Lakes and through much of the Northeast through mid evening. The deep moisture through much of the troposphere and weak lapse rate profiles, which were sampled by the 12 UTC Buffalo and Albany, NY raobs, will undergo moderate destabilization by early to mid afternoon. Although forcing for ascent will favor Quebec into northern New England, scattered thunderstorms will likely develop from Maine southward into southern New England. The greatest potential for some organized storms will favor northern New England where stronger effective shear (30-40 kt) and adequate buoyancy will promote a wind-damage threat with the stronger storms. Forecast sounding over northern Maine show enlarged hodographs for a few hours, which may aid in low-level mesocyclone development and perhaps a risk for a tornado. Lower coverage of severe is forecast farther south where weaker shear will tend to limit storm intensity. The severe activity will likely diminish by the early to mid evening. ...Northern High Plains... Model guidance continues to show a focused corridor of supercell thunderstorm potential from north-central MT to southwest ND, mainly this evening. Water-vapor imagery shows a mid-level shortwave trough rotating southeastward across the southern part of the Canadian Rockies moving towards the northern High Plains. Forecast soundings this afternoon show elongated hodographs amidst modest buoyancy, which would support the development of a supercell or two during the evening. Large hail is the primary hazard with this activity but severe gusts may occur on a localized basis. An isolated hail/wind risk may persist along the ND/SD border vicinity overnight. ...Mid-Atlantic to the Southern High Plains... A surface front draped over the south-central Plains east-northeastward into the mid MS/OH Valleys will focus scattered thunderstorm activity this afternoon. The eastern part of this broader region over the Mid-Atlantic into the OH Valley will be displaced from the mid-level trough over influencing storm activity over the Northeast. A remnant MCV and outflow from overnight storms in the MO/KS/OK vicinity will aid in developing storms and perhaps localized threats for sporadic hail/wind mainly this afternoon. Isolated damaging winds may also occur with thunderstorms that develop east of the central Appalachians this afternoon, even though coverage should be somewhat less. ..Smith/Lyons.. 07/17/2025 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0735 AM CDT Thu Jul 17 2025 Valid 171300Z - 181200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHEAST AND NORTHERN HIGH PLAINS... ...SUMMARY... Scattered damaging winds and a brief tornado are possible across northern New England this afternoon. Isolated/sporadic damaging winds may also occur across a broad swath of the Northeast/Mid-Atlantic to the southern High Plains. A confined corridor of large hail and severe gusts appears possible from north-central Montana to southwest North Dakota this evening. ...Northeast... The Slight Risk has been maintained across this region with no changes. A shortwave trough will move northeastward from the Upper Great Lakes to the Ontario/Quebec border vicinity by this evening. A broad swath of enhanced 850-700 mb west-southwesterly winds is forecast from PA/NJ northward into New England. Further weakening of already poor mid-level lapse rates is anticipated across parts of southern NY into southern New England. This may tend to limit convective coverage across the northern Mid-Atlantic to southern New England vicinity. But, farther north and in closer proximity to ascent associated with the approaching mid-level shortwave trough, scattered robust convection is anticipated this afternoon along the Quebec border across northern New England. Sufficient instability and deep-layer shear are forecast across this region to support a mix of multicells and perhaps marginal supercells. Given the enhanced low/mid-level flow, scattered damaging winds should be the main threat with this activity as it moves generally east-northeastward through the early evening, before eventually weakening as it approaches the coast. Enough low-level hodograph enlargement/curvature may also be present to support some risk for a tornado or two. ...Mid-Atlantic to the Southern High Plains... Extensive convection is ongoing this morning across south-central/southeast KS into MO. This activity should generally remain sub-severe, but it will help reinforce a front that is expected to gradually sag southward and eventually stall across the mid MS Valley to southern Plains today. Scattered to numerous thunderstorms are expected to develop west of the Appalachians along this boundary later this afternoon as diurnal heating occurs. Moderate to strong instability amid steepened low-level rates along/south of the outflow/front should support sporadic wet microbursts. Isolated hail will be possible with thunderstorms in the post-frontal upslope flow regime across parts of the southern High Plains. But, modest deep-layer shear and warm temperatures aloft across all these regions should temper the overall intensity/coverage of severe convection. Isolated damaging winds may also occur with thunderstorms that develop east of the central Appalachians this afternoon, even though coverage should be somewhat less. ...Northern Plains... A narrow corridor of supercell potential remains evident across north-central MT to southwest ND, mainly this evening. A positively tilted mid-level shortwave trough over the southern Canadian Rockies will progress eastward along the international border with MT/ND today. Mid to late afternoon convective initiation should occur over parts of southwest Alberta in association with this feature. A confined plume of weak buoyancy ahead of this activity should initially temper updraft intensity as it spreads east-southeastward into north-central MT by late afternoon. But, favorably timed strengthening of a 500-mb westerly jet over MT will aid in hodograph elongation at mid/upper levels this evening. This could support a long-lived supercell or two during the evening, impinging on the nose of moderate instability that should be present across southeast MT. Large hail should be the main threat with these supercells if they can be maintained. An isolated hail/wind risk may persist along the ND/SD border vicinity overnight. ..Gleason/Bentley.. 07/17/2025 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0735 AM CDT Thu Jul 17 2025 Valid 171300Z - 181200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHEAST AND NORTHERN HIGH PLAINS... ...SUMMARY... Scattered damaging winds and a brief tornado are possible across northern New England this afternoon. Isolated/sporadic damaging winds may also occur across a broad swath of the Northeast/Mid-Atlantic to the southern High Plains. A confined corridor of large hail and severe gusts appears possible from north-central Montana to southwest North Dakota this evening. ...Northeast... The Slight Risk has been maintained across this region with no changes. A shortwave trough will move northeastward from the Upper Great Lakes to the Ontario/Quebec border vicinity by this evening. A broad swath of enhanced 850-700 mb west-southwesterly winds is forecast from PA/NJ northward into New England. Further weakening of already poor mid-level lapse rates is anticipated across parts of southern NY into southern New England. This may tend to limit convective coverage across the northern Mid-Atlantic to southern New England vicinity. But, farther north and in closer proximity to ascent associated with the approaching mid-level shortwave trough, scattered robust convection is anticipated this afternoon along the Quebec border across northern New England. Sufficient instability and deep-layer shear are forecast across this region to support a mix of multicells and perhaps marginal supercells. Given the enhanced low/mid-level flow, scattered damaging winds should be the main threat with this activity as it moves generally east-northeastward through the early evening, before eventually weakening as it approaches the coast. Enough low-level hodograph enlargement/curvature may also be present to support some risk for a tornado or two. ...Mid-Atlantic to the Southern High Plains... Extensive convection is ongoing this morning across south-central/southeast KS into MO. This activity should generally remain sub-severe, but it will help reinforce a front that is expected to gradually sag southward and eventually stall across the mid MS Valley to southern Plains today. Scattered to numerous thunderstorms are expected to develop west of the Appalachians along this boundary later this afternoon as diurnal heating occurs. Moderate to strong instability amid steepened low-level rates along/south of the outflow/front should support sporadic wet microbursts. Isolated hail will be possible with thunderstorms in the post-frontal upslope flow regime across parts of the southern High Plains. But, modest deep-layer shear and warm temperatures aloft across all these regions should temper the overall intensity/coverage of severe convection. Isolated damaging winds may also occur with thunderstorms that develop east of the central Appalachians this afternoon, even though coverage should be somewhat less. ...Northern Plains... A narrow corridor of supercell potential remains evident across north-central MT to southwest ND, mainly this evening. A positively tilted mid-level shortwave trough over the southern Canadian Rockies will progress eastward along the international border with MT/ND today. Mid to late afternoon convective initiation should occur over parts of southwest Alberta in association with this feature. A confined plume of weak buoyancy ahead of this activity should initially temper updraft intensity as it spreads east-southeastward into north-central MT by late afternoon. But, favorably timed strengthening of a 500-mb westerly jet over MT will aid in hodograph elongation at mid/upper levels this evening. This could support a long-lived supercell or two during the evening, impinging on the nose of moderate instability that should be present across southeast MT. Large hail should be the main threat with these supercells if they can be maintained. An isolated hail/wind risk may persist along the ND/SD border vicinity overnight. ..Gleason/Bentley.. 07/17/2025 Read more