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SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1150 AM CDT Sun Jun 30 2024 Valid 301700Z - 011200Z ...CRITICAL FIRE WEATHER AREA FOR PARTS OF EASTERN NV AND WESTERN UT... ...17z Update... The ISODRYT area was adjusted south and east for the latest hi-res guidance. Isolated storms should develop late this afternoon with little to no wetting rainfall over far northeast CA, southeast OR and northern NV. A very isolated storm will remain possible over the southern Cascades, though coverage is too limited for higher thunder probabilities. Weak CAPE should support intermittent cloud to ground lightning and the potential for ignitions through this evening. Otherwise, minimal changes were made to the current outlook. Critically dry and windy conditions are expected this afternoon over the eastern Great Basin. See the previous discussion for more information. ..Lyons.. 06/30/2024 .PREV DISCUSSION... /ISSUED 0157 AM CDT Sun Jun 30 2024/ ...Synopsis... An upper ridge will remain in place over the central CONUS as a mid-level trough traverses the Interior west today. A surface cyclone will become established across the Great Basin, with dry and breezy conditions expected ahead of an approaching cold front during the afternoon. Widespread 20+ mph sustained southwesterly surface winds will coincide with 5-15 percent RH for much of the Great Basin into the central Rockies. Critical highlights have been maintained where these surface conditions will overlap with fuels that are most favorable for supporting wildfire-spread potential. Meanwhile, thunderstorms are expected to form immediately ahead of the cold front across portions of the Pacific Northwest. These storms are expected to be high-based since the boundary layer is expected to mix up to at least 600 mb. With fuels drying across the region, lightning strikes away from precipitation cores may support ignitions, warranting the maintenance of isolated dry thunderstorm highlights. ...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 1150 AM CDT Sun Jun 30 2024 Valid 301700Z - 011200Z ...CRITICAL FIRE WEATHER AREA FOR PARTS OF EASTERN NV AND WESTERN UT... ...17z Update... The ISODRYT area was adjusted south and east for the latest hi-res guidance. Isolated storms should develop late this afternoon with little to no wetting rainfall over far northeast CA, southeast OR and northern NV. A very isolated storm will remain possible over the southern Cascades, though coverage is too limited for higher thunder probabilities. Weak CAPE should support intermittent cloud to ground lightning and the potential for ignitions through this evening. Otherwise, minimal changes were made to the current outlook. Critically dry and windy conditions are expected this afternoon over the eastern Great Basin. See the previous discussion for more information. ..Lyons.. 06/30/2024 .PREV DISCUSSION... /ISSUED 0157 AM CDT Sun Jun 30 2024/ ...Synopsis... An upper ridge will remain in place over the central CONUS as a mid-level trough traverses the Interior west today. A surface cyclone will become established across the Great Basin, with dry and breezy conditions expected ahead of an approaching cold front during the afternoon. Widespread 20+ mph sustained southwesterly surface winds will coincide with 5-15 percent RH for much of the Great Basin into the central Rockies. Critical highlights have been maintained where these surface conditions will overlap with fuels that are most favorable for supporting wildfire-spread potential. Meanwhile, thunderstorms are expected to form immediately ahead of the cold front across portions of the Pacific Northwest. These storms are expected to be high-based since the boundary layer is expected to mix up to at least 600 mb. With fuels drying across the region, lightning strikes away from precipitation cores may support ignitions, warranting the maintenance of isolated dry thunderstorm highlights. ...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 1150 AM CDT Sun Jun 30 2024 Valid 301700Z - 011200Z ...CRITICAL FIRE WEATHER AREA FOR PARTS OF EASTERN NV AND WESTERN UT... ...17z Update... The ISODRYT area was adjusted south and east for the latest hi-res guidance. Isolated storms should develop late this afternoon with little to no wetting rainfall over far northeast CA, southeast OR and northern NV. A very isolated storm will remain possible over the southern Cascades, though coverage is too limited for higher thunder probabilities. Weak CAPE should support intermittent cloud to ground lightning and the potential for ignitions through this evening. Otherwise, minimal changes were made to the current outlook. Critically dry and windy conditions are expected this afternoon over the eastern Great Basin. See the previous discussion for more information. ..Lyons.. 06/30/2024 .PREV DISCUSSION... /ISSUED 0157 AM CDT Sun Jun 30 2024/ ...Synopsis... An upper ridge will remain in place over the central CONUS as a mid-level trough traverses the Interior west today. A surface cyclone will become established across the Great Basin, with dry and breezy conditions expected ahead of an approaching cold front during the afternoon. Widespread 20+ mph sustained southwesterly surface winds will coincide with 5-15 percent RH for much of the Great Basin into the central Rockies. Critical highlights have been maintained where these surface conditions will overlap with fuels that are most favorable for supporting wildfire-spread potential. Meanwhile, thunderstorms are expected to form immediately ahead of the cold front across portions of the Pacific Northwest. These storms are expected to be high-based since the boundary layer is expected to mix up to at least 600 mb. With fuels drying across the region, lightning strikes away from precipitation cores may support ignitions, warranting the maintenance of isolated dry thunderstorm highlights. ...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 1150 AM CDT Sun Jun 30 2024 Valid 301700Z - 011200Z ...CRITICAL FIRE WEATHER AREA FOR PARTS OF EASTERN NV AND WESTERN UT... ...17z Update... The ISODRYT area was adjusted south and east for the latest hi-res guidance. Isolated storms should develop late this afternoon with little to no wetting rainfall over far northeast CA, southeast OR and northern NV. A very isolated storm will remain possible over the southern Cascades, though coverage is too limited for higher thunder probabilities. Weak CAPE should support intermittent cloud to ground lightning and the potential for ignitions through this evening. Otherwise, minimal changes were made to the current outlook. Critically dry and windy conditions are expected this afternoon over the eastern Great Basin. See the previous discussion for more information. ..Lyons.. 06/30/2024 .PREV DISCUSSION... /ISSUED 0157 AM CDT Sun Jun 30 2024/ ...Synopsis... An upper ridge will remain in place over the central CONUS as a mid-level trough traverses the Interior west today. A surface cyclone will become established across the Great Basin, with dry and breezy conditions expected ahead of an approaching cold front during the afternoon. Widespread 20+ mph sustained southwesterly surface winds will coincide with 5-15 percent RH for much of the Great Basin into the central Rockies. Critical highlights have been maintained where these surface conditions will overlap with fuels that are most favorable for supporting wildfire-spread potential. Meanwhile, thunderstorms are expected to form immediately ahead of the cold front across portions of the Pacific Northwest. These storms are expected to be high-based since the boundary layer is expected to mix up to at least 600 mb. With fuels drying across the region, lightning strikes away from precipitation cores may support ignitions, warranting the maintenance of isolated dry thunderstorm highlights. ...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 1150 AM CDT Sun Jun 30 2024 Valid 301700Z - 011200Z ...CRITICAL FIRE WEATHER AREA FOR PARTS OF EASTERN NV AND WESTERN UT... ...17z Update... The ISODRYT area was adjusted south and east for the latest hi-res guidance. Isolated storms should develop late this afternoon with little to no wetting rainfall over far northeast CA, southeast OR and northern NV. A very isolated storm will remain possible over the southern Cascades, though coverage is too limited for higher thunder probabilities. Weak CAPE should support intermittent cloud to ground lightning and the potential for ignitions through this evening. Otherwise, minimal changes were made to the current outlook. Critically dry and windy conditions are expected this afternoon over the eastern Great Basin. See the previous discussion for more information. ..Lyons.. 06/30/2024 .PREV DISCUSSION... /ISSUED 0157 AM CDT Sun Jun 30 2024/ ...Synopsis... An upper ridge will remain in place over the central CONUS as a mid-level trough traverses the Interior west today. A surface cyclone will become established across the Great Basin, with dry and breezy conditions expected ahead of an approaching cold front during the afternoon. Widespread 20+ mph sustained southwesterly surface winds will coincide with 5-15 percent RH for much of the Great Basin into the central Rockies. Critical highlights have been maintained where these surface conditions will overlap with fuels that are most favorable for supporting wildfire-spread potential. Meanwhile, thunderstorms are expected to form immediately ahead of the cold front across portions of the Pacific Northwest. These storms are expected to be high-based since the boundary layer is expected to mix up to at least 600 mb. With fuels drying across the region, lightning strikes away from precipitation cores may support ignitions, warranting the maintenance of isolated dry thunderstorm highlights. ...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 1150 AM CDT Sun Jun 30 2024 Valid 301700Z - 011200Z ...CRITICAL FIRE WEATHER AREA FOR PARTS OF EASTERN NV AND WESTERN UT... ...17z Update... The ISODRYT area was adjusted south and east for the latest hi-res guidance. Isolated storms should develop late this afternoon with little to no wetting rainfall over far northeast CA, southeast OR and northern NV. A very isolated storm will remain possible over the southern Cascades, though coverage is too limited for higher thunder probabilities. Weak CAPE should support intermittent cloud to ground lightning and the potential for ignitions through this evening. Otherwise, minimal changes were made to the current outlook. Critically dry and windy conditions are expected this afternoon over the eastern Great Basin. See the previous discussion for more information. ..Lyons.. 06/30/2024 .PREV DISCUSSION... /ISSUED 0157 AM CDT Sun Jun 30 2024/ ...Synopsis... An upper ridge will remain in place over the central CONUS as a mid-level trough traverses the Interior west today. A surface cyclone will become established across the Great Basin, with dry and breezy conditions expected ahead of an approaching cold front during the afternoon. Widespread 20+ mph sustained southwesterly surface winds will coincide with 5-15 percent RH for much of the Great Basin into the central Rockies. Critical highlights have been maintained where these surface conditions will overlap with fuels that are most favorable for supporting wildfire-spread potential. Meanwhile, thunderstorms are expected to form immediately ahead of the cold front across portions of the Pacific Northwest. These storms are expected to be high-based since the boundary layer is expected to mix up to at least 600 mb. With fuels drying across the region, lightning strikes away from precipitation cores may support ignitions, warranting the maintenance of isolated dry thunderstorm highlights. ...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 1150 AM CDT Sun Jun 30 2024 Valid 301700Z - 011200Z ...CRITICAL FIRE WEATHER AREA FOR PARTS OF EASTERN NV AND WESTERN UT... ...17z Update... The ISODRYT area was adjusted south and east for the latest hi-res guidance. Isolated storms should develop late this afternoon with little to no wetting rainfall over far northeast CA, southeast OR and northern NV. A very isolated storm will remain possible over the southern Cascades, though coverage is too limited for higher thunder probabilities. Weak CAPE should support intermittent cloud to ground lightning and the potential for ignitions through this evening. Otherwise, minimal changes were made to the current outlook. Critically dry and windy conditions are expected this afternoon over the eastern Great Basin. See the previous discussion for more information. ..Lyons.. 06/30/2024 .PREV DISCUSSION... /ISSUED 0157 AM CDT Sun Jun 30 2024/ ...Synopsis... An upper ridge will remain in place over the central CONUS as a mid-level trough traverses the Interior west today. A surface cyclone will become established across the Great Basin, with dry and breezy conditions expected ahead of an approaching cold front during the afternoon. Widespread 20+ mph sustained southwesterly surface winds will coincide with 5-15 percent RH for much of the Great Basin into the central Rockies. Critical highlights have been maintained where these surface conditions will overlap with fuels that are most favorable for supporting wildfire-spread potential. Meanwhile, thunderstorms are expected to form immediately ahead of the cold front across portions of the Pacific Northwest. These storms are expected to be high-based since the boundary layer is expected to mix up to at least 600 mb. With fuels drying across the region, lightning strikes away from precipitation cores may support ignitions, warranting the maintenance of isolated dry thunderstorm highlights. ...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 1150 AM CDT Sun Jun 30 2024 Valid 301700Z - 011200Z ...CRITICAL FIRE WEATHER AREA FOR PARTS OF EASTERN NV AND WESTERN UT... ...17z Update... The ISODRYT area was adjusted south and east for the latest hi-res guidance. Isolated storms should develop late this afternoon with little to no wetting rainfall over far northeast CA, southeast OR and northern NV. A very isolated storm will remain possible over the southern Cascades, though coverage is too limited for higher thunder probabilities. Weak CAPE should support intermittent cloud to ground lightning and the potential for ignitions through this evening. Otherwise, minimal changes were made to the current outlook. Critically dry and windy conditions are expected this afternoon over the eastern Great Basin. See the previous discussion for more information. ..Lyons.. 06/30/2024 .PREV DISCUSSION... /ISSUED 0157 AM CDT Sun Jun 30 2024/ ...Synopsis... An upper ridge will remain in place over the central CONUS as a mid-level trough traverses the Interior west today. A surface cyclone will become established across the Great Basin, with dry and breezy conditions expected ahead of an approaching cold front during the afternoon. Widespread 20+ mph sustained southwesterly surface winds will coincide with 5-15 percent RH for much of the Great Basin into the central Rockies. Critical highlights have been maintained where these surface conditions will overlap with fuels that are most favorable for supporting wildfire-spread potential. Meanwhile, thunderstorms are expected to form immediately ahead of the cold front across portions of the Pacific Northwest. These storms are expected to be high-based since the boundary layer is expected to mix up to at least 600 mb. With fuels drying across the region, lightning strikes away from precipitation cores may support ignitions, warranting the maintenance of isolated dry thunderstorm highlights. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

WW 0490 Status Updates
STATUS FOR WATCH 0490 HAS NOT BEEN ISSUED YET Read more

WW 0489 Status Updates
STATUS REPORT ON WW 489 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. ..LEITMAN..06/30/24 ATTN...WFO...OKX...BOX...ALY...PHI...BGM...CTP... STATUS REPORT FOR WS 489 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS CTC001-003-005-007-009-011-013-015-301740- CT . CONNECTICUT COUNTIES INCLUDED ARE FAIRFIELD HARTFORD LITCHFIELD MIDDLESEX NEW HAVEN NEW LONDON TOLLAND WINDHAM DEC003-301740- DE . DELAWARE COUNTIES INCLUDED ARE NEW CASTLE MAC003-005-009-011-013-015-017-021-023-025-027-301740- MA . MASSACHUSETTS COUNTIES INCLUDED ARE BERKSHIRE BRISTOL ESSEX FRANKLIN HAMPDEN HAMPSHIRE MIDDLESEX NORFOLK PLYMOUTH Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Sun Jun 30 2024 Valid 301630Z - 011200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF SOUTHERN NEW ENGLAND AND THE EASTERN MID-ATLANTIC... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHERN HIGH PLAINS... ...SUMMARY... Scattered to numerous damaging wind gusts are likely across parts of the Northeast and Mid-Atlantic States this afternoon and evening. Large hail and severe/damaging winds should also occur from southern Montana into western North Dakota. ...Northeast/Mid-Atlantic into the Carolinas... A mid-level trough over the Great Lakes and eastern Canada will continue moving eastward through the period. An associated cold front will likewise advance east-southeastward across New England and much of the Mid-Atlantic through this evening. Based on area 12Z soundings and recent surface observations, a very moist airmass is in place ahead of the front, with surface dewpoints generally in the low to mid 70s. Filtered daytime heating with broken cloud cover will support weak to moderate instability through late this afternoon, with most guidance continuing to suggest a narrow corridor of 1000-2000 J/kg MLCAPE will be in place along/near the I-95 corridor from southern New England to the eastern Mid-Atlantic. Mid-level flow will increase through the day in tandem with the upper trough, which will foster strong deep-layer shear and organized convection. Expectations are for thunderstorms to continue increasing in coverage and intensity this afternoon, both along/ahead of the cold front and a pre-frontal surface trough. Multiple rounds of intense convection appear possible. Given a rather favorable thermodynamic and kinematic parameter space, swaths of severe/damaging winds generally 60-70 mph will likely occur as a mix of bowing line segments/clusters and a few supercells sweep eastward through the afternoon/evening. No changes have been made to the Enhanced Risk across parts of southern New England into the Mid-Atlantic, where the greatest concentration of damaging winds is still anticipated. Isolated hail and perhaps a tornado may also occur with any sustained supercell, although poor mid-level lapse rates and modest/veered low-level flow should hinder both of these threats, respectively. Deep-layer shear will be weaker with southward extent across the Mid-Atlantic into the Carolinas. Convective mode should also tend to be mainly multicellular across these regions. Even so, steepened low-level lapse rates and ample instability should support a threat for scattered damaging winds as thunderstorms develop and spread eastward to the Atlantic Coast this afternoon/evening. ...Northern/Central High Plains... A mid-level shortwave trough evident over the Northwest this morning will progress eastward across the northern Rockies and adjacent High Plains through tonight. A surface lee cyclone is forecast to deepen and consolidate over northern WY/southeast MT by this evening, as large-scale ascent preceding the upper trough overspreads the northern High Plains. Even though low-level moisture is expected to remain rather limited across this area, steep lapse rates and daytime heating will contribute to at least weak instability developing by late afternoon. Moderate to strong deep-layer shear will support updraft organization. Cellular convection that initially develops over the higher terrain of southwest MT and vicinity should quickly grow upscale into a small bowing cluster as it moves east-northeastward across central/eastern MT this evening. Large hail may occur initially, but a transition to mainly a severe/damaging wind threat appears likely as this mode transition occurs. Isolated significant severe wind gusts (75-80 mph) appear possible given the very steep/favorable low/mid-level lapse rates expected. This wind threat may continue into parts of western ND and vicinity tonight before convection eventually weakens. Farther south, isolated to scattered thunderstorms should develop along/east of the higher terrain from WY into CO. Various NAM/RAP forecast soundings across this area show favorable shear for organized convection, including the potential for a mix of multicells and perhaps a couple of supercells. The southern fringe of the stronger mid-level flow and the northwest edge of the monsoonal moisture may overlap enough in western CO to support an isolated threat for severe wind gusts. ...Arizona... Low/mid-level moisture should gradually increase through the period on the western periphery of a mid/upper-level high centered over the southern Plains. Diurnal heating in the wake of overnight convection should occur across the higher terrain of eastern/southeast AZ through this afternoon, which will aid in the development of weak to moderate instability. Expectations are for thunderstorms to initially form over the higher terrain, and then slowly westward late this afternoon and evening in response to around 15-20 kt of east-southeasterly mid-level flow. A very well mixed boundary layer, with steep lapse rates through much of the troposphere, should support a threat for isolated strong to severe wind gusts with this high-based convection. ..Gleason/Thornton.. 06/30/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Sun Jun 30 2024 Valid 301630Z - 011200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF SOUTHERN NEW ENGLAND AND THE EASTERN MID-ATLANTIC... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHERN HIGH PLAINS... ...SUMMARY... Scattered to numerous damaging wind gusts are likely across parts of the Northeast and Mid-Atlantic States this afternoon and evening. Large hail and severe/damaging winds should also occur from southern Montana into western North Dakota. ...Northeast/Mid-Atlantic into the Carolinas... A mid-level trough over the Great Lakes and eastern Canada will continue moving eastward through the period. An associated cold front will likewise advance east-southeastward across New England and much of the Mid-Atlantic through this evening. Based on area 12Z soundings and recent surface observations, a very moist airmass is in place ahead of the front, with surface dewpoints generally in the low to mid 70s. Filtered daytime heating with broken cloud cover will support weak to moderate instability through late this afternoon, with most guidance continuing to suggest a narrow corridor of 1000-2000 J/kg MLCAPE will be in place along/near the I-95 corridor from southern New England to the eastern Mid-Atlantic. Mid-level flow will increase through the day in tandem with the upper trough, which will foster strong deep-layer shear and organized convection. Expectations are for thunderstorms to continue increasing in coverage and intensity this afternoon, both along/ahead of the cold front and a pre-frontal surface trough. Multiple rounds of intense convection appear possible. Given a rather favorable thermodynamic and kinematic parameter space, swaths of severe/damaging winds generally 60-70 mph will likely occur as a mix of bowing line segments/clusters and a few supercells sweep eastward through the afternoon/evening. No changes have been made to the Enhanced Risk across parts of southern New England into the Mid-Atlantic, where the greatest concentration of damaging winds is still anticipated. Isolated hail and perhaps a tornado may also occur with any sustained supercell, although poor mid-level lapse rates and modest/veered low-level flow should hinder both of these threats, respectively. Deep-layer shear will be weaker with southward extent across the Mid-Atlantic into the Carolinas. Convective mode should also tend to be mainly multicellular across these regions. Even so, steepened low-level lapse rates and ample instability should support a threat for scattered damaging winds as thunderstorms develop and spread eastward to the Atlantic Coast this afternoon/evening. ...Northern/Central High Plains... A mid-level shortwave trough evident over the Northwest this morning will progress eastward across the northern Rockies and adjacent High Plains through tonight. A surface lee cyclone is forecast to deepen and consolidate over northern WY/southeast MT by this evening, as large-scale ascent preceding the upper trough overspreads the northern High Plains. Even though low-level moisture is expected to remain rather limited across this area, steep lapse rates and daytime heating will contribute to at least weak instability developing by late afternoon. Moderate to strong deep-layer shear will support updraft organization. Cellular convection that initially develops over the higher terrain of southwest MT and vicinity should quickly grow upscale into a small bowing cluster as it moves east-northeastward across central/eastern MT this evening. Large hail may occur initially, but a transition to mainly a severe/damaging wind threat appears likely as this mode transition occurs. Isolated significant severe wind gusts (75-80 mph) appear possible given the very steep/favorable low/mid-level lapse rates expected. This wind threat may continue into parts of western ND and vicinity tonight before convection eventually weakens. Farther south, isolated to scattered thunderstorms should develop along/east of the higher terrain from WY into CO. Various NAM/RAP forecast soundings across this area show favorable shear for organized convection, including the potential for a mix of multicells and perhaps a couple of supercells. The southern fringe of the stronger mid-level flow and the northwest edge of the monsoonal moisture may overlap enough in western CO to support an isolated threat for severe wind gusts. ...Arizona... Low/mid-level moisture should gradually increase through the period on the western periphery of a mid/upper-level high centered over the southern Plains. Diurnal heating in the wake of overnight convection should occur across the higher terrain of eastern/southeast AZ through this afternoon, which will aid in the development of weak to moderate instability. Expectations are for thunderstorms to initially form over the higher terrain, and then slowly westward late this afternoon and evening in response to around 15-20 kt of east-southeasterly mid-level flow. A very well mixed boundary layer, with steep lapse rates through much of the troposphere, should support a threat for isolated strong to severe wind gusts with this high-based convection. ..Gleason/Thornton.. 06/30/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Sun Jun 30 2024 Valid 301630Z - 011200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF SOUTHERN NEW ENGLAND AND THE EASTERN MID-ATLANTIC... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHERN HIGH PLAINS... ...SUMMARY... Scattered to numerous damaging wind gusts are likely across parts of the Northeast and Mid-Atlantic States this afternoon and evening. Large hail and severe/damaging winds should also occur from southern Montana into western North Dakota. ...Northeast/Mid-Atlantic into the Carolinas... A mid-level trough over the Great Lakes and eastern Canada will continue moving eastward through the period. An associated cold front will likewise advance east-southeastward across New England and much of the Mid-Atlantic through this evening. Based on area 12Z soundings and recent surface observations, a very moist airmass is in place ahead of the front, with surface dewpoints generally in the low to mid 70s. Filtered daytime heating with broken cloud cover will support weak to moderate instability through late this afternoon, with most guidance continuing to suggest a narrow corridor of 1000-2000 J/kg MLCAPE will be in place along/near the I-95 corridor from southern New England to the eastern Mid-Atlantic. Mid-level flow will increase through the day in tandem with the upper trough, which will foster strong deep-layer shear and organized convection. Expectations are for thunderstorms to continue increasing in coverage and intensity this afternoon, both along/ahead of the cold front and a pre-frontal surface trough. Multiple rounds of intense convection appear possible. Given a rather favorable thermodynamic and kinematic parameter space, swaths of severe/damaging winds generally 60-70 mph will likely occur as a mix of bowing line segments/clusters and a few supercells sweep eastward through the afternoon/evening. No changes have been made to the Enhanced Risk across parts of southern New England into the Mid-Atlantic, where the greatest concentration of damaging winds is still anticipated. Isolated hail and perhaps a tornado may also occur with any sustained supercell, although poor mid-level lapse rates and modest/veered low-level flow should hinder both of these threats, respectively. Deep-layer shear will be weaker with southward extent across the Mid-Atlantic into the Carolinas. Convective mode should also tend to be mainly multicellular across these regions. Even so, steepened low-level lapse rates and ample instability should support a threat for scattered damaging winds as thunderstorms develop and spread eastward to the Atlantic Coast this afternoon/evening. ...Northern/Central High Plains... A mid-level shortwave trough evident over the Northwest this morning will progress eastward across the northern Rockies and adjacent High Plains through tonight. A surface lee cyclone is forecast to deepen and consolidate over northern WY/southeast MT by this evening, as large-scale ascent preceding the upper trough overspreads the northern High Plains. Even though low-level moisture is expected to remain rather limited across this area, steep lapse rates and daytime heating will contribute to at least weak instability developing by late afternoon. Moderate to strong deep-layer shear will support updraft organization. Cellular convection that initially develops over the higher terrain of southwest MT and vicinity should quickly grow upscale into a small bowing cluster as it moves east-northeastward across central/eastern MT this evening. Large hail may occur initially, but a transition to mainly a severe/damaging wind threat appears likely as this mode transition occurs. Isolated significant severe wind gusts (75-80 mph) appear possible given the very steep/favorable low/mid-level lapse rates expected. This wind threat may continue into parts of western ND and vicinity tonight before convection eventually weakens. Farther south, isolated to scattered thunderstorms should develop along/east of the higher terrain from WY into CO. Various NAM/RAP forecast soundings across this area show favorable shear for organized convection, including the potential for a mix of multicells and perhaps a couple of supercells. The southern fringe of the stronger mid-level flow and the northwest edge of the monsoonal moisture may overlap enough in western CO to support an isolated threat for severe wind gusts. ...Arizona... Low/mid-level moisture should gradually increase through the period on the western periphery of a mid/upper-level high centered over the southern Plains. Diurnal heating in the wake of overnight convection should occur across the higher terrain of eastern/southeast AZ through this afternoon, which will aid in the development of weak to moderate instability. Expectations are for thunderstorms to initially form over the higher terrain, and then slowly westward late this afternoon and evening in response to around 15-20 kt of east-southeasterly mid-level flow. A very well mixed boundary layer, with steep lapse rates through much of the troposphere, should support a threat for isolated strong to severe wind gusts with this high-based convection. ..Gleason/Thornton.. 06/30/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Sun Jun 30 2024 Valid 301630Z - 011200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF SOUTHERN NEW ENGLAND AND THE EASTERN MID-ATLANTIC... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHERN HIGH PLAINS... ...SUMMARY... Scattered to numerous damaging wind gusts are likely across parts of the Northeast and Mid-Atlantic States this afternoon and evening. Large hail and severe/damaging winds should also occur from southern Montana into western North Dakota. ...Northeast/Mid-Atlantic into the Carolinas... A mid-level trough over the Great Lakes and eastern Canada will continue moving eastward through the period. An associated cold front will likewise advance east-southeastward across New England and much of the Mid-Atlantic through this evening. Based on area 12Z soundings and recent surface observations, a very moist airmass is in place ahead of the front, with surface dewpoints generally in the low to mid 70s. Filtered daytime heating with broken cloud cover will support weak to moderate instability through late this afternoon, with most guidance continuing to suggest a narrow corridor of 1000-2000 J/kg MLCAPE will be in place along/near the I-95 corridor from southern New England to the eastern Mid-Atlantic. Mid-level flow will increase through the day in tandem with the upper trough, which will foster strong deep-layer shear and organized convection. Expectations are for thunderstorms to continue increasing in coverage and intensity this afternoon, both along/ahead of the cold front and a pre-frontal surface trough. Multiple rounds of intense convection appear possible. Given a rather favorable thermodynamic and kinematic parameter space, swaths of severe/damaging winds generally 60-70 mph will likely occur as a mix of bowing line segments/clusters and a few supercells sweep eastward through the afternoon/evening. No changes have been made to the Enhanced Risk across parts of southern New England into the Mid-Atlantic, where the greatest concentration of damaging winds is still anticipated. Isolated hail and perhaps a tornado may also occur with any sustained supercell, although poor mid-level lapse rates and modest/veered low-level flow should hinder both of these threats, respectively. Deep-layer shear will be weaker with southward extent across the Mid-Atlantic into the Carolinas. Convective mode should also tend to be mainly multicellular across these regions. Even so, steepened low-level lapse rates and ample instability should support a threat for scattered damaging winds as thunderstorms develop and spread eastward to the Atlantic Coast this afternoon/evening. ...Northern/Central High Plains... A mid-level shortwave trough evident over the Northwest this morning will progress eastward across the northern Rockies and adjacent High Plains through tonight. A surface lee cyclone is forecast to deepen and consolidate over northern WY/southeast MT by this evening, as large-scale ascent preceding the upper trough overspreads the northern High Plains. Even though low-level moisture is expected to remain rather limited across this area, steep lapse rates and daytime heating will contribute to at least weak instability developing by late afternoon. Moderate to strong deep-layer shear will support updraft organization. Cellular convection that initially develops over the higher terrain of southwest MT and vicinity should quickly grow upscale into a small bowing cluster as it moves east-northeastward across central/eastern MT this evening. Large hail may occur initially, but a transition to mainly a severe/damaging wind threat appears likely as this mode transition occurs. Isolated significant severe wind gusts (75-80 mph) appear possible given the very steep/favorable low/mid-level lapse rates expected. This wind threat may continue into parts of western ND and vicinity tonight before convection eventually weakens. Farther south, isolated to scattered thunderstorms should develop along/east of the higher terrain from WY into CO. Various NAM/RAP forecast soundings across this area show favorable shear for organized convection, including the potential for a mix of multicells and perhaps a couple of supercells. The southern fringe of the stronger mid-level flow and the northwest edge of the monsoonal moisture may overlap enough in western CO to support an isolated threat for severe wind gusts. ...Arizona... Low/mid-level moisture should gradually increase through the period on the western periphery of a mid/upper-level high centered over the southern Plains. Diurnal heating in the wake of overnight convection should occur across the higher terrain of eastern/southeast AZ through this afternoon, which will aid in the development of weak to moderate instability. Expectations are for thunderstorms to initially form over the higher terrain, and then slowly westward late this afternoon and evening in response to around 15-20 kt of east-southeasterly mid-level flow. A very well mixed boundary layer, with steep lapse rates through much of the troposphere, should support a threat for isolated strong to severe wind gusts with this high-based convection. ..Gleason/Thornton.. 06/30/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Sun Jun 30 2024 Valid 301630Z - 011200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF SOUTHERN NEW ENGLAND AND THE EASTERN MID-ATLANTIC... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHERN HIGH PLAINS... ...SUMMARY... Scattered to numerous damaging wind gusts are likely across parts of the Northeast and Mid-Atlantic States this afternoon and evening. Large hail and severe/damaging winds should also occur from southern Montana into western North Dakota. ...Northeast/Mid-Atlantic into the Carolinas... A mid-level trough over the Great Lakes and eastern Canada will continue moving eastward through the period. An associated cold front will likewise advance east-southeastward across New England and much of the Mid-Atlantic through this evening. Based on area 12Z soundings and recent surface observations, a very moist airmass is in place ahead of the front, with surface dewpoints generally in the low to mid 70s. Filtered daytime heating with broken cloud cover will support weak to moderate instability through late this afternoon, with most guidance continuing to suggest a narrow corridor of 1000-2000 J/kg MLCAPE will be in place along/near the I-95 corridor from southern New England to the eastern Mid-Atlantic. Mid-level flow will increase through the day in tandem with the upper trough, which will foster strong deep-layer shear and organized convection. Expectations are for thunderstorms to continue increasing in coverage and intensity this afternoon, both along/ahead of the cold front and a pre-frontal surface trough. Multiple rounds of intense convection appear possible. Given a rather favorable thermodynamic and kinematic parameter space, swaths of severe/damaging winds generally 60-70 mph will likely occur as a mix of bowing line segments/clusters and a few supercells sweep eastward through the afternoon/evening. No changes have been made to the Enhanced Risk across parts of southern New England into the Mid-Atlantic, where the greatest concentration of damaging winds is still anticipated. Isolated hail and perhaps a tornado may also occur with any sustained supercell, although poor mid-level lapse rates and modest/veered low-level flow should hinder both of these threats, respectively. Deep-layer shear will be weaker with southward extent across the Mid-Atlantic into the Carolinas. Convective mode should also tend to be mainly multicellular across these regions. Even so, steepened low-level lapse rates and ample instability should support a threat for scattered damaging winds as thunderstorms develop and spread eastward to the Atlantic Coast this afternoon/evening. ...Northern/Central High Plains... A mid-level shortwave trough evident over the Northwest this morning will progress eastward across the northern Rockies and adjacent High Plains through tonight. A surface lee cyclone is forecast to deepen and consolidate over northern WY/southeast MT by this evening, as large-scale ascent preceding the upper trough overspreads the northern High Plains. Even though low-level moisture is expected to remain rather limited across this area, steep lapse rates and daytime heating will contribute to at least weak instability developing by late afternoon. Moderate to strong deep-layer shear will support updraft organization. Cellular convection that initially develops over the higher terrain of southwest MT and vicinity should quickly grow upscale into a small bowing cluster as it moves east-northeastward across central/eastern MT this evening. Large hail may occur initially, but a transition to mainly a severe/damaging wind threat appears likely as this mode transition occurs. Isolated significant severe wind gusts (75-80 mph) appear possible given the very steep/favorable low/mid-level lapse rates expected. This wind threat may continue into parts of western ND and vicinity tonight before convection eventually weakens. Farther south, isolated to scattered thunderstorms should develop along/east of the higher terrain from WY into CO. Various NAM/RAP forecast soundings across this area show favorable shear for organized convection, including the potential for a mix of multicells and perhaps a couple of supercells. The southern fringe of the stronger mid-level flow and the northwest edge of the monsoonal moisture may overlap enough in western CO to support an isolated threat for severe wind gusts. ...Arizona... Low/mid-level moisture should gradually increase through the period on the western periphery of a mid/upper-level high centered over the southern Plains. Diurnal heating in the wake of overnight convection should occur across the higher terrain of eastern/southeast AZ through this afternoon, which will aid in the development of weak to moderate instability. Expectations are for thunderstorms to initially form over the higher terrain, and then slowly westward late this afternoon and evening in response to around 15-20 kt of east-southeasterly mid-level flow. A very well mixed boundary layer, with steep lapse rates through much of the troposphere, should support a threat for isolated strong to severe wind gusts with this high-based convection. ..Gleason/Thornton.. 06/30/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Sun Jun 30 2024 Valid 301630Z - 011200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF SOUTHERN NEW ENGLAND AND THE EASTERN MID-ATLANTIC... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHERN HIGH PLAINS... ...SUMMARY... Scattered to numerous damaging wind gusts are likely across parts of the Northeast and Mid-Atlantic States this afternoon and evening. Large hail and severe/damaging winds should also occur from southern Montana into western North Dakota. ...Northeast/Mid-Atlantic into the Carolinas... A mid-level trough over the Great Lakes and eastern Canada will continue moving eastward through the period. An associated cold front will likewise advance east-southeastward across New England and much of the Mid-Atlantic through this evening. Based on area 12Z soundings and recent surface observations, a very moist airmass is in place ahead of the front, with surface dewpoints generally in the low to mid 70s. Filtered daytime heating with broken cloud cover will support weak to moderate instability through late this afternoon, with most guidance continuing to suggest a narrow corridor of 1000-2000 J/kg MLCAPE will be in place along/near the I-95 corridor from southern New England to the eastern Mid-Atlantic. Mid-level flow will increase through the day in tandem with the upper trough, which will foster strong deep-layer shear and organized convection. Expectations are for thunderstorms to continue increasing in coverage and intensity this afternoon, both along/ahead of the cold front and a pre-frontal surface trough. Multiple rounds of intense convection appear possible. Given a rather favorable thermodynamic and kinematic parameter space, swaths of severe/damaging winds generally 60-70 mph will likely occur as a mix of bowing line segments/clusters and a few supercells sweep eastward through the afternoon/evening. No changes have been made to the Enhanced Risk across parts of southern New England into the Mid-Atlantic, where the greatest concentration of damaging winds is still anticipated. Isolated hail and perhaps a tornado may also occur with any sustained supercell, although poor mid-level lapse rates and modest/veered low-level flow should hinder both of these threats, respectively. Deep-layer shear will be weaker with southward extent across the Mid-Atlantic into the Carolinas. Convective mode should also tend to be mainly multicellular across these regions. Even so, steepened low-level lapse rates and ample instability should support a threat for scattered damaging winds as thunderstorms develop and spread eastward to the Atlantic Coast this afternoon/evening. ...Northern/Central High Plains... A mid-level shortwave trough evident over the Northwest this morning will progress eastward across the northern Rockies and adjacent High Plains through tonight. A surface lee cyclone is forecast to deepen and consolidate over northern WY/southeast MT by this evening, as large-scale ascent preceding the upper trough overspreads the northern High Plains. Even though low-level moisture is expected to remain rather limited across this area, steep lapse rates and daytime heating will contribute to at least weak instability developing by late afternoon. Moderate to strong deep-layer shear will support updraft organization. Cellular convection that initially develops over the higher terrain of southwest MT and vicinity should quickly grow upscale into a small bowing cluster as it moves east-northeastward across central/eastern MT this evening. Large hail may occur initially, but a transition to mainly a severe/damaging wind threat appears likely as this mode transition occurs. Isolated significant severe wind gusts (75-80 mph) appear possible given the very steep/favorable low/mid-level lapse rates expected. This wind threat may continue into parts of western ND and vicinity tonight before convection eventually weakens. Farther south, isolated to scattered thunderstorms should develop along/east of the higher terrain from WY into CO. Various NAM/RAP forecast soundings across this area show favorable shear for organized convection, including the potential for a mix of multicells and perhaps a couple of supercells. The southern fringe of the stronger mid-level flow and the northwest edge of the monsoonal moisture may overlap enough in western CO to support an isolated threat for severe wind gusts. ...Arizona... Low/mid-level moisture should gradually increase through the period on the western periphery of a mid/upper-level high centered over the southern Plains. Diurnal heating in the wake of overnight convection should occur across the higher terrain of eastern/southeast AZ through this afternoon, which will aid in the development of weak to moderate instability. Expectations are for thunderstorms to initially form over the higher terrain, and then slowly westward late this afternoon and evening in response to around 15-20 kt of east-southeasterly mid-level flow. A very well mixed boundary layer, with steep lapse rates through much of the troposphere, should support a threat for isolated strong to severe wind gusts with this high-based convection. ..Gleason/Thornton.. 06/30/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Sun Jun 30 2024 Valid 301630Z - 011200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF SOUTHERN NEW ENGLAND AND THE EASTERN MID-ATLANTIC... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHERN HIGH PLAINS... ...SUMMARY... Scattered to numerous damaging wind gusts are likely across parts of the Northeast and Mid-Atlantic States this afternoon and evening. Large hail and severe/damaging winds should also occur from southern Montana into western North Dakota. ...Northeast/Mid-Atlantic into the Carolinas... A mid-level trough over the Great Lakes and eastern Canada will continue moving eastward through the period. An associated cold front will likewise advance east-southeastward across New England and much of the Mid-Atlantic through this evening. Based on area 12Z soundings and recent surface observations, a very moist airmass is in place ahead of the front, with surface dewpoints generally in the low to mid 70s. Filtered daytime heating with broken cloud cover will support weak to moderate instability through late this afternoon, with most guidance continuing to suggest a narrow corridor of 1000-2000 J/kg MLCAPE will be in place along/near the I-95 corridor from southern New England to the eastern Mid-Atlantic. Mid-level flow will increase through the day in tandem with the upper trough, which will foster strong deep-layer shear and organized convection. Expectations are for thunderstorms to continue increasing in coverage and intensity this afternoon, both along/ahead of the cold front and a pre-frontal surface trough. Multiple rounds of intense convection appear possible. Given a rather favorable thermodynamic and kinematic parameter space, swaths of severe/damaging winds generally 60-70 mph will likely occur as a mix of bowing line segments/clusters and a few supercells sweep eastward through the afternoon/evening. No changes have been made to the Enhanced Risk across parts of southern New England into the Mid-Atlantic, where the greatest concentration of damaging winds is still anticipated. Isolated hail and perhaps a tornado may also occur with any sustained supercell, although poor mid-level lapse rates and modest/veered low-level flow should hinder both of these threats, respectively. Deep-layer shear will be weaker with southward extent across the Mid-Atlantic into the Carolinas. Convective mode should also tend to be mainly multicellular across these regions. Even so, steepened low-level lapse rates and ample instability should support a threat for scattered damaging winds as thunderstorms develop and spread eastward to the Atlantic Coast this afternoon/evening. ...Northern/Central High Plains... A mid-level shortwave trough evident over the Northwest this morning will progress eastward across the northern Rockies and adjacent High Plains through tonight. A surface lee cyclone is forecast to deepen and consolidate over northern WY/southeast MT by this evening, as large-scale ascent preceding the upper trough overspreads the northern High Plains. Even though low-level moisture is expected to remain rather limited across this area, steep lapse rates and daytime heating will contribute to at least weak instability developing by late afternoon. Moderate to strong deep-layer shear will support updraft organization. Cellular convection that initially develops over the higher terrain of southwest MT and vicinity should quickly grow upscale into a small bowing cluster as it moves east-northeastward across central/eastern MT this evening. Large hail may occur initially, but a transition to mainly a severe/damaging wind threat appears likely as this mode transition occurs. Isolated significant severe wind gusts (75-80 mph) appear possible given the very steep/favorable low/mid-level lapse rates expected. This wind threat may continue into parts of western ND and vicinity tonight before convection eventually weakens. Farther south, isolated to scattered thunderstorms should develop along/east of the higher terrain from WY into CO. Various NAM/RAP forecast soundings across this area show favorable shear for organized convection, including the potential for a mix of multicells and perhaps a couple of supercells. The southern fringe of the stronger mid-level flow and the northwest edge of the monsoonal moisture may overlap enough in western CO to support an isolated threat for severe wind gusts. ...Arizona... Low/mid-level moisture should gradually increase through the period on the western periphery of a mid/upper-level high centered over the southern Plains. Diurnal heating in the wake of overnight convection should occur across the higher terrain of eastern/southeast AZ through this afternoon, which will aid in the development of weak to moderate instability. Expectations are for thunderstorms to initially form over the higher terrain, and then slowly westward late this afternoon and evening in response to around 15-20 kt of east-southeasterly mid-level flow. A very well mixed boundary layer, with steep lapse rates through much of the troposphere, should support a threat for isolated strong to severe wind gusts with this high-based convection. ..Gleason/Thornton.. 06/30/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Sun Jun 30 2024 Valid 301630Z - 011200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF SOUTHERN NEW ENGLAND AND THE EASTERN MID-ATLANTIC... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHERN HIGH PLAINS... ...SUMMARY... Scattered to numerous damaging wind gusts are likely across parts of the Northeast and Mid-Atlantic States this afternoon and evening. Large hail and severe/damaging winds should also occur from southern Montana into western North Dakota. ...Northeast/Mid-Atlantic into the Carolinas... A mid-level trough over the Great Lakes and eastern Canada will continue moving eastward through the period. An associated cold front will likewise advance east-southeastward across New England and much of the Mid-Atlantic through this evening. Based on area 12Z soundings and recent surface observations, a very moist airmass is in place ahead of the front, with surface dewpoints generally in the low to mid 70s. Filtered daytime heating with broken cloud cover will support weak to moderate instability through late this afternoon, with most guidance continuing to suggest a narrow corridor of 1000-2000 J/kg MLCAPE will be in place along/near the I-95 corridor from southern New England to the eastern Mid-Atlantic. Mid-level flow will increase through the day in tandem with the upper trough, which will foster strong deep-layer shear and organized convection. Expectations are for thunderstorms to continue increasing in coverage and intensity this afternoon, both along/ahead of the cold front and a pre-frontal surface trough. Multiple rounds of intense convection appear possible. Given a rather favorable thermodynamic and kinematic parameter space, swaths of severe/damaging winds generally 60-70 mph will likely occur as a mix of bowing line segments/clusters and a few supercells sweep eastward through the afternoon/evening. No changes have been made to the Enhanced Risk across parts of southern New England into the Mid-Atlantic, where the greatest concentration of damaging winds is still anticipated. Isolated hail and perhaps a tornado may also occur with any sustained supercell, although poor mid-level lapse rates and modest/veered low-level flow should hinder both of these threats, respectively. Deep-layer shear will be weaker with southward extent across the Mid-Atlantic into the Carolinas. Convective mode should also tend to be mainly multicellular across these regions. Even so, steepened low-level lapse rates and ample instability should support a threat for scattered damaging winds as thunderstorms develop and spread eastward to the Atlantic Coast this afternoon/evening. ...Northern/Central High Plains... A mid-level shortwave trough evident over the Northwest this morning will progress eastward across the northern Rockies and adjacent High Plains through tonight. A surface lee cyclone is forecast to deepen and consolidate over northern WY/southeast MT by this evening, as large-scale ascent preceding the upper trough overspreads the northern High Plains. Even though low-level moisture is expected to remain rather limited across this area, steep lapse rates and daytime heating will contribute to at least weak instability developing by late afternoon. Moderate to strong deep-layer shear will support updraft organization. Cellular convection that initially develops over the higher terrain of southwest MT and vicinity should quickly grow upscale into a small bowing cluster as it moves east-northeastward across central/eastern MT this evening. Large hail may occur initially, but a transition to mainly a severe/damaging wind threat appears likely as this mode transition occurs. Isolated significant severe wind gusts (75-80 mph) appear possible given the very steep/favorable low/mid-level lapse rates expected. This wind threat may continue into parts of western ND and vicinity tonight before convection eventually weakens. Farther south, isolated to scattered thunderstorms should develop along/east of the higher terrain from WY into CO. Various NAM/RAP forecast soundings across this area show favorable shear for organized convection, including the potential for a mix of multicells and perhaps a couple of supercells. The southern fringe of the stronger mid-level flow and the northwest edge of the monsoonal moisture may overlap enough in western CO to support an isolated threat for severe wind gusts. ...Arizona... Low/mid-level moisture should gradually increase through the period on the western periphery of a mid/upper-level high centered over the southern Plains. Diurnal heating in the wake of overnight convection should occur across the higher terrain of eastern/southeast AZ through this afternoon, which will aid in the development of weak to moderate instability. Expectations are for thunderstorms to initially form over the higher terrain, and then slowly westward late this afternoon and evening in response to around 15-20 kt of east-southeasterly mid-level flow. A very well mixed boundary layer, with steep lapse rates through much of the troposphere, should support a threat for isolated strong to severe wind gusts with this high-based convection. ..Gleason/Thornton.. 06/30/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Sun Jun 30 2024 Valid 301630Z - 011200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF SOUTHERN NEW ENGLAND AND THE EASTERN MID-ATLANTIC... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHERN HIGH PLAINS... ...SUMMARY... Scattered to numerous damaging wind gusts are likely across parts of the Northeast and Mid-Atlantic States this afternoon and evening. Large hail and severe/damaging winds should also occur from southern Montana into western North Dakota. ...Northeast/Mid-Atlantic into the Carolinas... A mid-level trough over the Great Lakes and eastern Canada will continue moving eastward through the period. An associated cold front will likewise advance east-southeastward across New England and much of the Mid-Atlantic through this evening. Based on area 12Z soundings and recent surface observations, a very moist airmass is in place ahead of the front, with surface dewpoints generally in the low to mid 70s. Filtered daytime heating with broken cloud cover will support weak to moderate instability through late this afternoon, with most guidance continuing to suggest a narrow corridor of 1000-2000 J/kg MLCAPE will be in place along/near the I-95 corridor from southern New England to the eastern Mid-Atlantic. Mid-level flow will increase through the day in tandem with the upper trough, which will foster strong deep-layer shear and organized convection. Expectations are for thunderstorms to continue increasing in coverage and intensity this afternoon, both along/ahead of the cold front and a pre-frontal surface trough. Multiple rounds of intense convection appear possible. Given a rather favorable thermodynamic and kinematic parameter space, swaths of severe/damaging winds generally 60-70 mph will likely occur as a mix of bowing line segments/clusters and a few supercells sweep eastward through the afternoon/evening. No changes have been made to the Enhanced Risk across parts of southern New England into the Mid-Atlantic, where the greatest concentration of damaging winds is still anticipated. Isolated hail and perhaps a tornado may also occur with any sustained supercell, although poor mid-level lapse rates and modest/veered low-level flow should hinder both of these threats, respectively. Deep-layer shear will be weaker with southward extent across the Mid-Atlantic into the Carolinas. Convective mode should also tend to be mainly multicellular across these regions. Even so, steepened low-level lapse rates and ample instability should support a threat for scattered damaging winds as thunderstorms develop and spread eastward to the Atlantic Coast this afternoon/evening. ...Northern/Central High Plains... A mid-level shortwave trough evident over the Northwest this morning will progress eastward across the northern Rockies and adjacent High Plains through tonight. A surface lee cyclone is forecast to deepen and consolidate over northern WY/southeast MT by this evening, as large-scale ascent preceding the upper trough overspreads the northern High Plains. Even though low-level moisture is expected to remain rather limited across this area, steep lapse rates and daytime heating will contribute to at least weak instability developing by late afternoon. Moderate to strong deep-layer shear will support updraft organization. Cellular convection that initially develops over the higher terrain of southwest MT and vicinity should quickly grow upscale into a small bowing cluster as it moves east-northeastward across central/eastern MT this evening. Large hail may occur initially, but a transition to mainly a severe/damaging wind threat appears likely as this mode transition occurs. Isolated significant severe wind gusts (75-80 mph) appear possible given the very steep/favorable low/mid-level lapse rates expected. This wind threat may continue into parts of western ND and vicinity tonight before convection eventually weakens. Farther south, isolated to scattered thunderstorms should develop along/east of the higher terrain from WY into CO. Various NAM/RAP forecast soundings across this area show favorable shear for organized convection, including the potential for a mix of multicells and perhaps a couple of supercells. The southern fringe of the stronger mid-level flow and the northwest edge of the monsoonal moisture may overlap enough in western CO to support an isolated threat for severe wind gusts. ...Arizona... Low/mid-level moisture should gradually increase through the period on the western periphery of a mid/upper-level high centered over the southern Plains. Diurnal heating in the wake of overnight convection should occur across the higher terrain of eastern/southeast AZ through this afternoon, which will aid in the development of weak to moderate instability. Expectations are for thunderstorms to initially form over the higher terrain, and then slowly westward late this afternoon and evening in response to around 15-20 kt of east-southeasterly mid-level flow. A very well mixed boundary layer, with steep lapse rates through much of the troposphere, should support a threat for isolated strong to severe wind gusts with this high-based convection. ..Gleason/Thornton.. 06/30/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Sun Jun 30 2024 Valid 301630Z - 011200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF SOUTHERN NEW ENGLAND AND THE EASTERN MID-ATLANTIC... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHERN HIGH PLAINS... ...SUMMARY... Scattered to numerous damaging wind gusts are likely across parts of the Northeast and Mid-Atlantic States this afternoon and evening. Large hail and severe/damaging winds should also occur from southern Montana into western North Dakota. ...Northeast/Mid-Atlantic into the Carolinas... A mid-level trough over the Great Lakes and eastern Canada will continue moving eastward through the period. An associated cold front will likewise advance east-southeastward across New England and much of the Mid-Atlantic through this evening. Based on area 12Z soundings and recent surface observations, a very moist airmass is in place ahead of the front, with surface dewpoints generally in the low to mid 70s. Filtered daytime heating with broken cloud cover will support weak to moderate instability through late this afternoon, with most guidance continuing to suggest a narrow corridor of 1000-2000 J/kg MLCAPE will be in place along/near the I-95 corridor from southern New England to the eastern Mid-Atlantic. Mid-level flow will increase through the day in tandem with the upper trough, which will foster strong deep-layer shear and organized convection. Expectations are for thunderstorms to continue increasing in coverage and intensity this afternoon, both along/ahead of the cold front and a pre-frontal surface trough. Multiple rounds of intense convection appear possible. Given a rather favorable thermodynamic and kinematic parameter space, swaths of severe/damaging winds generally 60-70 mph will likely occur as a mix of bowing line segments/clusters and a few supercells sweep eastward through the afternoon/evening. No changes have been made to the Enhanced Risk across parts of southern New England into the Mid-Atlantic, where the greatest concentration of damaging winds is still anticipated. Isolated hail and perhaps a tornado may also occur with any sustained supercell, although poor mid-level lapse rates and modest/veered low-level flow should hinder both of these threats, respectively. Deep-layer shear will be weaker with southward extent across the Mid-Atlantic into the Carolinas. Convective mode should also tend to be mainly multicellular across these regions. Even so, steepened low-level lapse rates and ample instability should support a threat for scattered damaging winds as thunderstorms develop and spread eastward to the Atlantic Coast this afternoon/evening. ...Northern/Central High Plains... A mid-level shortwave trough evident over the Northwest this morning will progress eastward across the northern Rockies and adjacent High Plains through tonight. A surface lee cyclone is forecast to deepen and consolidate over northern WY/southeast MT by this evening, as large-scale ascent preceding the upper trough overspreads the northern High Plains. Even though low-level moisture is expected to remain rather limited across this area, steep lapse rates and daytime heating will contribute to at least weak instability developing by late afternoon. Moderate to strong deep-layer shear will support updraft organization. Cellular convection that initially develops over the higher terrain of southwest MT and vicinity should quickly grow upscale into a small bowing cluster as it moves east-northeastward across central/eastern MT this evening. Large hail may occur initially, but a transition to mainly a severe/damaging wind threat appears likely as this mode transition occurs. Isolated significant severe wind gusts (75-80 mph) appear possible given the very steep/favorable low/mid-level lapse rates expected. This wind threat may continue into parts of western ND and vicinity tonight before convection eventually weakens. Farther south, isolated to scattered thunderstorms should develop along/east of the higher terrain from WY into CO. Various NAM/RAP forecast soundings across this area show favorable shear for organized convection, including the potential for a mix of multicells and perhaps a couple of supercells. The southern fringe of the stronger mid-level flow and the northwest edge of the monsoonal moisture may overlap enough in western CO to support an isolated threat for severe wind gusts. ...Arizona... Low/mid-level moisture should gradually increase through the period on the western periphery of a mid/upper-level high centered over the southern Plains. Diurnal heating in the wake of overnight convection should occur across the higher terrain of eastern/southeast AZ through this afternoon, which will aid in the development of weak to moderate instability. Expectations are for thunderstorms to initially form over the higher terrain, and then slowly westward late this afternoon and evening in response to around 15-20 kt of east-southeasterly mid-level flow. A very well mixed boundary layer, with steep lapse rates through much of the troposphere, should support a threat for isolated strong to severe wind gusts with this high-based convection. ..Gleason/Thornton.. 06/30/2024 Read more