Severe Storms

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0253 PM CDT Fri Aug 09 2024 Valid 092000Z - 101200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM FAR EASTERN PA INTO NJ...EASTERN NY...AND WESTERN NEW ENGLAND... ...SUMMARY... A couple of tornadoes will be possible today from parts of the Mid-Atlantic states northward across portions of New England. A few strong wind gusts will also be possible across this region, along with parts of the southern High Plains, and southern Wyoming. ...20Z Update... Overall forecast reasoning remains valid. Post-TC Debby continues to progress northeastward across New York, with a band of deeper convection extending from just east of its center southward into far eastern PA/far western NJ. Area VADs show strong wind fields throughout the eastern portion of this cyclone, but limited buoyancy has tempered storm depth and persistence thus far. Given the robust wind fields, the potential for damaging gusts and/or brief tornadoes will persist throughout the afternoon and into the evening, particularly in areas ahead of the main convective line where more cellular storms are likely. Farther west, afternoon/evening thunderstorms are still possible across the higher terrain of WY, CO, and NM, with these storms then moving into the central/southern High Plains thereafter. Moderate (around 30 kt) mid-level westerlies may support some organization/upscale growth of storms into the evening, along with accompanying potential for a couple of strong gusts. ..Mosier.. 08/09/2024 .PREV DISCUSSION... /ISSUED 1140 AM CDT Fri Aug 09 2024/ ...Portions of the Mid-Atlantic and New England... As the center of P.T.C. Debby -- now over south-central New York -- continues moving north-northeastward across New York today, and then into Quebec/across the St. Lawrence Valley this evening and tonight, very strong low-level shear will continue to spread northward across eastern New York and much of New England. While northward destabilization will be hindered by a lack of appreciable daytime heating due to widespread cloud cover, a very moist boundary layer (dewpoints in the upper 60s to low 70s) spreading northward toward the Canadian border will support at least neutrally buoyant profiles across most of New England this evening and tonight. As such, low (2%) tornado probability is being expanded northward/northeastward in this update, to include the remainder of northern Vermont and northern New Hampshire, and much of Maine, to cover the potential for a brief tornadic spin-up after dark. Otherwise, greatest potential for a couple of tornadoes will exist this afternoon and into this evening from eastern Pennsylvania/eastern New York into parts of New Jersey, and across the Hudson and Champlain Valleys into western Vermont, western Massachusetts, and western Connecticut. ...Southern High Plains... Afternoon storm development is expected across the Raton Mesa vicinity of northeastern New Mexico, aided by afternoon heating/destabilization, and the eastward advance of a mid-level vort max across southern Colorado. Moderate (around 30 kt) mid-level westerlies may support some organization/upscale growth of storms into the evening, along with accompanying potential for a couple of strong gusts as convection crosses the Oklahoma and northern Texas Panhandle area. ...Southern Wyoming... Daytime heating/modest destabilization across the Intermountain West will support development of isolated to scattered afternoon and evening thunderstorms. With a belt of moderate (30 to 40 kt) northwesterly flow across the Wyoming vicinity, some storm organization will be possible. Some CAMs suggest eventual upscale growth into a loosely organized cluster by this evening, moving east-southeastward toward southeastern portions of the state. Resulting potential for a few stronger wind gusts with this activity warrants inclusion of 5% wind probability/MRGL risk area. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0253 PM CDT Fri Aug 09 2024 Valid 092000Z - 101200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM FAR EASTERN PA INTO NJ...EASTERN NY...AND WESTERN NEW ENGLAND... ...SUMMARY... A couple of tornadoes will be possible today from parts of the Mid-Atlantic states northward across portions of New England. A few strong wind gusts will also be possible across this region, along with parts of the southern High Plains, and southern Wyoming. ...20Z Update... Overall forecast reasoning remains valid. Post-TC Debby continues to progress northeastward across New York, with a band of deeper convection extending from just east of its center southward into far eastern PA/far western NJ. Area VADs show strong wind fields throughout the eastern portion of this cyclone, but limited buoyancy has tempered storm depth and persistence thus far. Given the robust wind fields, the potential for damaging gusts and/or brief tornadoes will persist throughout the afternoon and into the evening, particularly in areas ahead of the main convective line where more cellular storms are likely. Farther west, afternoon/evening thunderstorms are still possible across the higher terrain of WY, CO, and NM, with these storms then moving into the central/southern High Plains thereafter. Moderate (around 30 kt) mid-level westerlies may support some organization/upscale growth of storms into the evening, along with accompanying potential for a couple of strong gusts. ..Mosier.. 08/09/2024 .PREV DISCUSSION... /ISSUED 1140 AM CDT Fri Aug 09 2024/ ...Portions of the Mid-Atlantic and New England... As the center of P.T.C. Debby -- now over south-central New York -- continues moving north-northeastward across New York today, and then into Quebec/across the St. Lawrence Valley this evening and tonight, very strong low-level shear will continue to spread northward across eastern New York and much of New England. While northward destabilization will be hindered by a lack of appreciable daytime heating due to widespread cloud cover, a very moist boundary layer (dewpoints in the upper 60s to low 70s) spreading northward toward the Canadian border will support at least neutrally buoyant profiles across most of New England this evening and tonight. As such, low (2%) tornado probability is being expanded northward/northeastward in this update, to include the remainder of northern Vermont and northern New Hampshire, and much of Maine, to cover the potential for a brief tornadic spin-up after dark. Otherwise, greatest potential for a couple of tornadoes will exist this afternoon and into this evening from eastern Pennsylvania/eastern New York into parts of New Jersey, and across the Hudson and Champlain Valleys into western Vermont, western Massachusetts, and western Connecticut. ...Southern High Plains... Afternoon storm development is expected across the Raton Mesa vicinity of northeastern New Mexico, aided by afternoon heating/destabilization, and the eastward advance of a mid-level vort max across southern Colorado. Moderate (around 30 kt) mid-level westerlies may support some organization/upscale growth of storms into the evening, along with accompanying potential for a couple of strong gusts as convection crosses the Oklahoma and northern Texas Panhandle area. ...Southern Wyoming... Daytime heating/modest destabilization across the Intermountain West will support development of isolated to scattered afternoon and evening thunderstorms. With a belt of moderate (30 to 40 kt) northwesterly flow across the Wyoming vicinity, some storm organization will be possible. Some CAMs suggest eventual upscale growth into a loosely organized cluster by this evening, moving east-southeastward toward southeastern portions of the state. Resulting potential for a few stronger wind gusts with this activity warrants inclusion of 5% wind probability/MRGL risk area. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0253 PM CDT Fri Aug 09 2024 Valid 092000Z - 101200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM FAR EASTERN PA INTO NJ...EASTERN NY...AND WESTERN NEW ENGLAND... ...SUMMARY... A couple of tornadoes will be possible today from parts of the Mid-Atlantic states northward across portions of New England. A few strong wind gusts will also be possible across this region, along with parts of the southern High Plains, and southern Wyoming. ...20Z Update... Overall forecast reasoning remains valid. Post-TC Debby continues to progress northeastward across New York, with a band of deeper convection extending from just east of its center southward into far eastern PA/far western NJ. Area VADs show strong wind fields throughout the eastern portion of this cyclone, but limited buoyancy has tempered storm depth and persistence thus far. Given the robust wind fields, the potential for damaging gusts and/or brief tornadoes will persist throughout the afternoon and into the evening, particularly in areas ahead of the main convective line where more cellular storms are likely. Farther west, afternoon/evening thunderstorms are still possible across the higher terrain of WY, CO, and NM, with these storms then moving into the central/southern High Plains thereafter. Moderate (around 30 kt) mid-level westerlies may support some organization/upscale growth of storms into the evening, along with accompanying potential for a couple of strong gusts. ..Mosier.. 08/09/2024 .PREV DISCUSSION... /ISSUED 1140 AM CDT Fri Aug 09 2024/ ...Portions of the Mid-Atlantic and New England... As the center of P.T.C. Debby -- now over south-central New York -- continues moving north-northeastward across New York today, and then into Quebec/across the St. Lawrence Valley this evening and tonight, very strong low-level shear will continue to spread northward across eastern New York and much of New England. While northward destabilization will be hindered by a lack of appreciable daytime heating due to widespread cloud cover, a very moist boundary layer (dewpoints in the upper 60s to low 70s) spreading northward toward the Canadian border will support at least neutrally buoyant profiles across most of New England this evening and tonight. As such, low (2%) tornado probability is being expanded northward/northeastward in this update, to include the remainder of northern Vermont and northern New Hampshire, and much of Maine, to cover the potential for a brief tornadic spin-up after dark. Otherwise, greatest potential for a couple of tornadoes will exist this afternoon and into this evening from eastern Pennsylvania/eastern New York into parts of New Jersey, and across the Hudson and Champlain Valleys into western Vermont, western Massachusetts, and western Connecticut. ...Southern High Plains... Afternoon storm development is expected across the Raton Mesa vicinity of northeastern New Mexico, aided by afternoon heating/destabilization, and the eastward advance of a mid-level vort max across southern Colorado. Moderate (around 30 kt) mid-level westerlies may support some organization/upscale growth of storms into the evening, along with accompanying potential for a couple of strong gusts as convection crosses the Oklahoma and northern Texas Panhandle area. ...Southern Wyoming... Daytime heating/modest destabilization across the Intermountain West will support development of isolated to scattered afternoon and evening thunderstorms. With a belt of moderate (30 to 40 kt) northwesterly flow across the Wyoming vicinity, some storm organization will be possible. Some CAMs suggest eventual upscale growth into a loosely organized cluster by this evening, moving east-southeastward toward southeastern portions of the state. Resulting potential for a few stronger wind gusts with this activity warrants inclusion of 5% wind probability/MRGL risk area. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0253 PM CDT Fri Aug 09 2024 Valid 092000Z - 101200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM FAR EASTERN PA INTO NJ...EASTERN NY...AND WESTERN NEW ENGLAND... ...SUMMARY... A couple of tornadoes will be possible today from parts of the Mid-Atlantic states northward across portions of New England. A few strong wind gusts will also be possible across this region, along with parts of the southern High Plains, and southern Wyoming. ...20Z Update... Overall forecast reasoning remains valid. Post-TC Debby continues to progress northeastward across New York, with a band of deeper convection extending from just east of its center southward into far eastern PA/far western NJ. Area VADs show strong wind fields throughout the eastern portion of this cyclone, but limited buoyancy has tempered storm depth and persistence thus far. Given the robust wind fields, the potential for damaging gusts and/or brief tornadoes will persist throughout the afternoon and into the evening, particularly in areas ahead of the main convective line where more cellular storms are likely. Farther west, afternoon/evening thunderstorms are still possible across the higher terrain of WY, CO, and NM, with these storms then moving into the central/southern High Plains thereafter. Moderate (around 30 kt) mid-level westerlies may support some organization/upscale growth of storms into the evening, along with accompanying potential for a couple of strong gusts. ..Mosier.. 08/09/2024 .PREV DISCUSSION... /ISSUED 1140 AM CDT Fri Aug 09 2024/ ...Portions of the Mid-Atlantic and New England... As the center of P.T.C. Debby -- now over south-central New York -- continues moving north-northeastward across New York today, and then into Quebec/across the St. Lawrence Valley this evening and tonight, very strong low-level shear will continue to spread northward across eastern New York and much of New England. While northward destabilization will be hindered by a lack of appreciable daytime heating due to widespread cloud cover, a very moist boundary layer (dewpoints in the upper 60s to low 70s) spreading northward toward the Canadian border will support at least neutrally buoyant profiles across most of New England this evening and tonight. As such, low (2%) tornado probability is being expanded northward/northeastward in this update, to include the remainder of northern Vermont and northern New Hampshire, and much of Maine, to cover the potential for a brief tornadic spin-up after dark. Otherwise, greatest potential for a couple of tornadoes will exist this afternoon and into this evening from eastern Pennsylvania/eastern New York into parts of New Jersey, and across the Hudson and Champlain Valleys into western Vermont, western Massachusetts, and western Connecticut. ...Southern High Plains... Afternoon storm development is expected across the Raton Mesa vicinity of northeastern New Mexico, aided by afternoon heating/destabilization, and the eastward advance of a mid-level vort max across southern Colorado. Moderate (around 30 kt) mid-level westerlies may support some organization/upscale growth of storms into the evening, along with accompanying potential for a couple of strong gusts as convection crosses the Oklahoma and northern Texas Panhandle area. ...Southern Wyoming... Daytime heating/modest destabilization across the Intermountain West will support development of isolated to scattered afternoon and evening thunderstorms. With a belt of moderate (30 to 40 kt) northwesterly flow across the Wyoming vicinity, some storm organization will be possible. Some CAMs suggest eventual upscale growth into a loosely organized cluster by this evening, moving east-southeastward toward southeastern portions of the state. Resulting potential for a few stronger wind gusts with this activity warrants inclusion of 5% wind probability/MRGL risk area. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0253 PM CDT Fri Aug 09 2024 Valid 092000Z - 101200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM FAR EASTERN PA INTO NJ...EASTERN NY...AND WESTERN NEW ENGLAND... ...SUMMARY... A couple of tornadoes will be possible today from parts of the Mid-Atlantic states northward across portions of New England. A few strong wind gusts will also be possible across this region, along with parts of the southern High Plains, and southern Wyoming. ...20Z Update... Overall forecast reasoning remains valid. Post-TC Debby continues to progress northeastward across New York, with a band of deeper convection extending from just east of its center southward into far eastern PA/far western NJ. Area VADs show strong wind fields throughout the eastern portion of this cyclone, but limited buoyancy has tempered storm depth and persistence thus far. Given the robust wind fields, the potential for damaging gusts and/or brief tornadoes will persist throughout the afternoon and into the evening, particularly in areas ahead of the main convective line where more cellular storms are likely. Farther west, afternoon/evening thunderstorms are still possible across the higher terrain of WY, CO, and NM, with these storms then moving into the central/southern High Plains thereafter. Moderate (around 30 kt) mid-level westerlies may support some organization/upscale growth of storms into the evening, along with accompanying potential for a couple of strong gusts. ..Mosier.. 08/09/2024 .PREV DISCUSSION... /ISSUED 1140 AM CDT Fri Aug 09 2024/ ...Portions of the Mid-Atlantic and New England... As the center of P.T.C. Debby -- now over south-central New York -- continues moving north-northeastward across New York today, and then into Quebec/across the St. Lawrence Valley this evening and tonight, very strong low-level shear will continue to spread northward across eastern New York and much of New England. While northward destabilization will be hindered by a lack of appreciable daytime heating due to widespread cloud cover, a very moist boundary layer (dewpoints in the upper 60s to low 70s) spreading northward toward the Canadian border will support at least neutrally buoyant profiles across most of New England this evening and tonight. As such, low (2%) tornado probability is being expanded northward/northeastward in this update, to include the remainder of northern Vermont and northern New Hampshire, and much of Maine, to cover the potential for a brief tornadic spin-up after dark. Otherwise, greatest potential for a couple of tornadoes will exist this afternoon and into this evening from eastern Pennsylvania/eastern New York into parts of New Jersey, and across the Hudson and Champlain Valleys into western Vermont, western Massachusetts, and western Connecticut. ...Southern High Plains... Afternoon storm development is expected across the Raton Mesa vicinity of northeastern New Mexico, aided by afternoon heating/destabilization, and the eastward advance of a mid-level vort max across southern Colorado. Moderate (around 30 kt) mid-level westerlies may support some organization/upscale growth of storms into the evening, along with accompanying potential for a couple of strong gusts as convection crosses the Oklahoma and northern Texas Panhandle area. ...Southern Wyoming... Daytime heating/modest destabilization across the Intermountain West will support development of isolated to scattered afternoon and evening thunderstorms. With a belt of moderate (30 to 40 kt) northwesterly flow across the Wyoming vicinity, some storm organization will be possible. Some CAMs suggest eventual upscale growth into a loosely organized cluster by this evening, moving east-southeastward toward southeastern portions of the state. Resulting potential for a few stronger wind gusts with this activity warrants inclusion of 5% wind probability/MRGL risk area. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0253 PM CDT Fri Aug 09 2024 Valid 092000Z - 101200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM FAR EASTERN PA INTO NJ...EASTERN NY...AND WESTERN NEW ENGLAND... ...SUMMARY... A couple of tornadoes will be possible today from parts of the Mid-Atlantic states northward across portions of New England. A few strong wind gusts will also be possible across this region, along with parts of the southern High Plains, and southern Wyoming. ...20Z Update... Overall forecast reasoning remains valid. Post-TC Debby continues to progress northeastward across New York, with a band of deeper convection extending from just east of its center southward into far eastern PA/far western NJ. Area VADs show strong wind fields throughout the eastern portion of this cyclone, but limited buoyancy has tempered storm depth and persistence thus far. Given the robust wind fields, the potential for damaging gusts and/or brief tornadoes will persist throughout the afternoon and into the evening, particularly in areas ahead of the main convective line where more cellular storms are likely. Farther west, afternoon/evening thunderstorms are still possible across the higher terrain of WY, CO, and NM, with these storms then moving into the central/southern High Plains thereafter. Moderate (around 30 kt) mid-level westerlies may support some organization/upscale growth of storms into the evening, along with accompanying potential for a couple of strong gusts. ..Mosier.. 08/09/2024 .PREV DISCUSSION... /ISSUED 1140 AM CDT Fri Aug 09 2024/ ...Portions of the Mid-Atlantic and New England... As the center of P.T.C. Debby -- now over south-central New York -- continues moving north-northeastward across New York today, and then into Quebec/across the St. Lawrence Valley this evening and tonight, very strong low-level shear will continue to spread northward across eastern New York and much of New England. While northward destabilization will be hindered by a lack of appreciable daytime heating due to widespread cloud cover, a very moist boundary layer (dewpoints in the upper 60s to low 70s) spreading northward toward the Canadian border will support at least neutrally buoyant profiles across most of New England this evening and tonight. As such, low (2%) tornado probability is being expanded northward/northeastward in this update, to include the remainder of northern Vermont and northern New Hampshire, and much of Maine, to cover the potential for a brief tornadic spin-up after dark. Otherwise, greatest potential for a couple of tornadoes will exist this afternoon and into this evening from eastern Pennsylvania/eastern New York into parts of New Jersey, and across the Hudson and Champlain Valleys into western Vermont, western Massachusetts, and western Connecticut. ...Southern High Plains... Afternoon storm development is expected across the Raton Mesa vicinity of northeastern New Mexico, aided by afternoon heating/destabilization, and the eastward advance of a mid-level vort max across southern Colorado. Moderate (around 30 kt) mid-level westerlies may support some organization/upscale growth of storms into the evening, along with accompanying potential for a couple of strong gusts as convection crosses the Oklahoma and northern Texas Panhandle area. ...Southern Wyoming... Daytime heating/modest destabilization across the Intermountain West will support development of isolated to scattered afternoon and evening thunderstorms. With a belt of moderate (30 to 40 kt) northwesterly flow across the Wyoming vicinity, some storm organization will be possible. Some CAMs suggest eventual upscale growth into a loosely organized cluster by this evening, moving east-southeastward toward southeastern portions of the state. Resulting potential for a few stronger wind gusts with this activity warrants inclusion of 5% wind probability/MRGL risk area. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0253 PM CDT Fri Aug 09 2024 Valid 092000Z - 101200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM FAR EASTERN PA INTO NJ...EASTERN NY...AND WESTERN NEW ENGLAND... ...SUMMARY... A couple of tornadoes will be possible today from parts of the Mid-Atlantic states northward across portions of New England. A few strong wind gusts will also be possible across this region, along with parts of the southern High Plains, and southern Wyoming. ...20Z Update... Overall forecast reasoning remains valid. Post-TC Debby continues to progress northeastward across New York, with a band of deeper convection extending from just east of its center southward into far eastern PA/far western NJ. Area VADs show strong wind fields throughout the eastern portion of this cyclone, but limited buoyancy has tempered storm depth and persistence thus far. Given the robust wind fields, the potential for damaging gusts and/or brief tornadoes will persist throughout the afternoon and into the evening, particularly in areas ahead of the main convective line where more cellular storms are likely. Farther west, afternoon/evening thunderstorms are still possible across the higher terrain of WY, CO, and NM, with these storms then moving into the central/southern High Plains thereafter. Moderate (around 30 kt) mid-level westerlies may support some organization/upscale growth of storms into the evening, along with accompanying potential for a couple of strong gusts. ..Mosier.. 08/09/2024 .PREV DISCUSSION... /ISSUED 1140 AM CDT Fri Aug 09 2024/ ...Portions of the Mid-Atlantic and New England... As the center of P.T.C. Debby -- now over south-central New York -- continues moving north-northeastward across New York today, and then into Quebec/across the St. Lawrence Valley this evening and tonight, very strong low-level shear will continue to spread northward across eastern New York and much of New England. While northward destabilization will be hindered by a lack of appreciable daytime heating due to widespread cloud cover, a very moist boundary layer (dewpoints in the upper 60s to low 70s) spreading northward toward the Canadian border will support at least neutrally buoyant profiles across most of New England this evening and tonight. As such, low (2%) tornado probability is being expanded northward/northeastward in this update, to include the remainder of northern Vermont and northern New Hampshire, and much of Maine, to cover the potential for a brief tornadic spin-up after dark. Otherwise, greatest potential for a couple of tornadoes will exist this afternoon and into this evening from eastern Pennsylvania/eastern New York into parts of New Jersey, and across the Hudson and Champlain Valleys into western Vermont, western Massachusetts, and western Connecticut. ...Southern High Plains... Afternoon storm development is expected across the Raton Mesa vicinity of northeastern New Mexico, aided by afternoon heating/destabilization, and the eastward advance of a mid-level vort max across southern Colorado. Moderate (around 30 kt) mid-level westerlies may support some organization/upscale growth of storms into the evening, along with accompanying potential for a couple of strong gusts as convection crosses the Oklahoma and northern Texas Panhandle area. ...Southern Wyoming... Daytime heating/modest destabilization across the Intermountain West will support development of isolated to scattered afternoon and evening thunderstorms. With a belt of moderate (30 to 40 kt) northwesterly flow across the Wyoming vicinity, some storm organization will be possible. Some CAMs suggest eventual upscale growth into a loosely organized cluster by this evening, moving east-southeastward toward southeastern portions of the state. Resulting potential for a few stronger wind gusts with this activity warrants inclusion of 5% wind probability/MRGL risk area. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0253 PM CDT Fri Aug 09 2024 Valid 092000Z - 101200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM FAR EASTERN PA INTO NJ...EASTERN NY...AND WESTERN NEW ENGLAND... ...SUMMARY... A couple of tornadoes will be possible today from parts of the Mid-Atlantic states northward across portions of New England. A few strong wind gusts will also be possible across this region, along with parts of the southern High Plains, and southern Wyoming. ...20Z Update... Overall forecast reasoning remains valid. Post-TC Debby continues to progress northeastward across New York, with a band of deeper convection extending from just east of its center southward into far eastern PA/far western NJ. Area VADs show strong wind fields throughout the eastern portion of this cyclone, but limited buoyancy has tempered storm depth and persistence thus far. Given the robust wind fields, the potential for damaging gusts and/or brief tornadoes will persist throughout the afternoon and into the evening, particularly in areas ahead of the main convective line where more cellular storms are likely. Farther west, afternoon/evening thunderstorms are still possible across the higher terrain of WY, CO, and NM, with these storms then moving into the central/southern High Plains thereafter. Moderate (around 30 kt) mid-level westerlies may support some organization/upscale growth of storms into the evening, along with accompanying potential for a couple of strong gusts. ..Mosier.. 08/09/2024 .PREV DISCUSSION... /ISSUED 1140 AM CDT Fri Aug 09 2024/ ...Portions of the Mid-Atlantic and New England... As the center of P.T.C. Debby -- now over south-central New York -- continues moving north-northeastward across New York today, and then into Quebec/across the St. Lawrence Valley this evening and tonight, very strong low-level shear will continue to spread northward across eastern New York and much of New England. While northward destabilization will be hindered by a lack of appreciable daytime heating due to widespread cloud cover, a very moist boundary layer (dewpoints in the upper 60s to low 70s) spreading northward toward the Canadian border will support at least neutrally buoyant profiles across most of New England this evening and tonight. As such, low (2%) tornado probability is being expanded northward/northeastward in this update, to include the remainder of northern Vermont and northern New Hampshire, and much of Maine, to cover the potential for a brief tornadic spin-up after dark. Otherwise, greatest potential for a couple of tornadoes will exist this afternoon and into this evening from eastern Pennsylvania/eastern New York into parts of New Jersey, and across the Hudson and Champlain Valleys into western Vermont, western Massachusetts, and western Connecticut. ...Southern High Plains... Afternoon storm development is expected across the Raton Mesa vicinity of northeastern New Mexico, aided by afternoon heating/destabilization, and the eastward advance of a mid-level vort max across southern Colorado. Moderate (around 30 kt) mid-level westerlies may support some organization/upscale growth of storms into the evening, along with accompanying potential for a couple of strong gusts as convection crosses the Oklahoma and northern Texas Panhandle area. ...Southern Wyoming... Daytime heating/modest destabilization across the Intermountain West will support development of isolated to scattered afternoon and evening thunderstorms. With a belt of moderate (30 to 40 kt) northwesterly flow across the Wyoming vicinity, some storm organization will be possible. Some CAMs suggest eventual upscale growth into a loosely organized cluster by this evening, moving east-southeastward toward southeastern portions of the state. Resulting potential for a few stronger wind gusts with this activity warrants inclusion of 5% wind probability/MRGL risk area. Read more

WW 0617 Status Updates
STATUS REPORT ON WW 617 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 35 SSW ABE TO 30 SSW MSV TO 15 S SLK. FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 1874 ..WEINMAN..08/09/24 ATTN...WFO...BOX...ALY...OKX...PHI...BGM...BTV... STATUS REPORT FOR WT 617 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS CTC003-005-092040- CT . CONNECTICUT COUNTIES INCLUDED ARE HARTFORD LITCHFIELD MAC003-011-013-015-092040- MA . MASSACHUSETTS COUNTIES INCLUDED ARE BERKSHIRE FRANKLIN HAMPDEN HAMPSHIRE NJC003-013-019-021-023-027-031-035-037-039-041-092040- NJ . NEW JERSEY COUNTIES INCLUDED ARE BERGEN ESSEX HUNTERDON Read more

MD 1874 CONCERNING TORNADO WATCH 617... FOR PORTIONS OF SOUTHEASTERN NY...WESTERN MA...AND SOUTHERN VT
Mesoscale Discussion 1874 NWS Storm Prediction Center Norman OK 0127 PM CDT Fri Aug 09 2024 Areas affected...Portions of southeastern NY...western MA...and southern VT Concerning...Tornado Watch 617... Valid 091827Z - 092000Z The severe weather threat for Tornado Watch 617 continues. SUMMARY...Within Tornado Watch 617, a potentially favorable corridor for a couple tornadoes is evident from southeastern NY into western MA and southern VT this afternoon. DISCUSSION...Latest visible satellite imagery indicates filtered diurnal heating (temperatures climbing into the upper 70s/lower 80s) within small cloud breaks in the vicinity of an east/west-oriented warm front moving slowly northward across southeastern NY to near MA and VT. Given the high-PW/tropical airmass in place, this heating may yield sufficient (albeit weak) MLCAPE for a couple low-topped, surface-based showers/storms this afternoon. Any convection that can root in the boundary layer may evolve into low-topped supercells, aided by strong deep-layer flow/shear associated with Post-Tropical Cyclone Debby. Additionally, the aforementioned corridor will be located beneath the core of a northward-advancing low-level jet during peak heating -- on the eastern periphery of the most substantial surface-pressure falls. Here, large, clockwise-curved/sickle-shaped hodographs (around 400 m2/s2 0-500m SRH per KENX VWP), will conditionally support a couple tornadoes with the more robust surface-based convection. ..Weinman.. 08/09/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...GYX...BOX...ALY...BGM... LAT...LON 42657438 42987395 43107341 43057259 42917233 42607233 41887396 41987435 42327450 42657438 Read more

WW 0617 Status Updates
STATUS REPORT ON WW 617 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 1874 ..WEINMAN..08/09/24 ATTN...WFO...BOX...ALY...OKX...PHI...BGM...BTV... STATUS REPORT FOR WT 617 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS CTC003-005-091940- CT . CONNECTICUT COUNTIES INCLUDED ARE HARTFORD LITCHFIELD MAC003-011-013-015-091940- MA . MASSACHUSETTS COUNTIES INCLUDED ARE BERKSHIRE FRANKLIN HAMPDEN HAMPSHIRE NJC003-013-019-021-023-027-031-035-037-039-041-091940- NJ . NEW JERSEY COUNTIES INCLUDED ARE BERGEN ESSEX HUNTERDON MERCER MIDDLESEX MORRIS Read more

WW 0617 Status Updates
STATUS REPORT ON WW 617 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 1874 ..WEINMAN..08/09/24 ATTN...WFO...BOX...ALY...OKX...PHI...BGM...BTV... STATUS REPORT FOR WT 617 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS CTC003-005-091940- CT . CONNECTICUT COUNTIES INCLUDED ARE HARTFORD LITCHFIELD MAC003-011-013-015-091940- MA . MASSACHUSETTS COUNTIES INCLUDED ARE BERKSHIRE FRANKLIN HAMPDEN HAMPSHIRE NJC003-013-019-021-023-027-031-035-037-039-041-091940- NJ . NEW JERSEY COUNTIES INCLUDED ARE BERGEN ESSEX HUNTERDON MERCER MIDDLESEX MORRIS Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1251 PM CDT Fri Aug 09 2024 Valid 101200Z - 111200Z The primary change for this forecast update is an expansion of the isolated dry thunderstorm risk area into eastern WA. Latest ensemble guidance shows a reasonably strong signal for convection developing within the higher terrain of the Cascades before moving east into a drier air mass. While forecast soundings show PWAT values generally near or above 0.75 inches, ensemble QPF output shows low (less than 20%) probability for wetting rainfall. This signal, along with anticipated storm motions near 20 knots and antecedent dry fuel conditions, has increased confidence enough for a northwestward expansion of the dry thunderstorm risk area. A few dry thunderstorms are also possible further south across northern UT, but confidence in the coverage of dry vs wet thunderstorms is more limited based on PWAT and QPF forecasts. A swath of elevated (to perhaps locally critical) wind-driven fire weather conditions remains likely across northern NV. See the previous discussion for additional details. ..Moore.. 08/09/2024 .PREV DISCUSSION... /ISSUED 1240 AM CDT Fri Aug 09 2024/ ...Synopsis... The upper-level tough will continue into the northern Rockies, though it will lose more amplitude on Saturday. A surface trough will deepen in the northern Great Basin beneath a belt of stronger mid-level winds. Elevated fire weather conditions appear probable in portions of northern Nevada into southern Idaho. Surface winds near the trough and the lee of the Sierra will increase to 15-20 mph with RH falling into the teens to perhaps single digits during the afternoon. Additional isolated thunderstorms are possible in central Idaho. Given the stronger flow aloft and dry boundary layer, these storms may produce little rainfall. Some impact on fuels from potential precipitation occurring on Friday could occur. Highlights will be maintained where confidence in storm development is highest and fuels are sufficiently receptive. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1251 PM CDT Fri Aug 09 2024 Valid 101200Z - 111200Z The primary change for this forecast update is an expansion of the isolated dry thunderstorm risk area into eastern WA. Latest ensemble guidance shows a reasonably strong signal for convection developing within the higher terrain of the Cascades before moving east into a drier air mass. While forecast soundings show PWAT values generally near or above 0.75 inches, ensemble QPF output shows low (less than 20%) probability for wetting rainfall. This signal, along with anticipated storm motions near 20 knots and antecedent dry fuel conditions, has increased confidence enough for a northwestward expansion of the dry thunderstorm risk area. A few dry thunderstorms are also possible further south across northern UT, but confidence in the coverage of dry vs wet thunderstorms is more limited based on PWAT and QPF forecasts. A swath of elevated (to perhaps locally critical) wind-driven fire weather conditions remains likely across northern NV. See the previous discussion for additional details. ..Moore.. 08/09/2024 .PREV DISCUSSION... /ISSUED 1240 AM CDT Fri Aug 09 2024/ ...Synopsis... The upper-level tough will continue into the northern Rockies, though it will lose more amplitude on Saturday. A surface trough will deepen in the northern Great Basin beneath a belt of stronger mid-level winds. Elevated fire weather conditions appear probable in portions of northern Nevada into southern Idaho. Surface winds near the trough and the lee of the Sierra will increase to 15-20 mph with RH falling into the teens to perhaps single digits during the afternoon. Additional isolated thunderstorms are possible in central Idaho. Given the stronger flow aloft and dry boundary layer, these storms may produce little rainfall. Some impact on fuels from potential precipitation occurring on Friday could occur. Highlights will be maintained where confidence in storm development is highest and fuels are sufficiently receptive. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1251 PM CDT Fri Aug 09 2024 Valid 101200Z - 111200Z The primary change for this forecast update is an expansion of the isolated dry thunderstorm risk area into eastern WA. Latest ensemble guidance shows a reasonably strong signal for convection developing within the higher terrain of the Cascades before moving east into a drier air mass. While forecast soundings show PWAT values generally near or above 0.75 inches, ensemble QPF output shows low (less than 20%) probability for wetting rainfall. This signal, along with anticipated storm motions near 20 knots and antecedent dry fuel conditions, has increased confidence enough for a northwestward expansion of the dry thunderstorm risk area. A few dry thunderstorms are also possible further south across northern UT, but confidence in the coverage of dry vs wet thunderstorms is more limited based on PWAT and QPF forecasts. A swath of elevated (to perhaps locally critical) wind-driven fire weather conditions remains likely across northern NV. See the previous discussion for additional details. ..Moore.. 08/09/2024 .PREV DISCUSSION... /ISSUED 1240 AM CDT Fri Aug 09 2024/ ...Synopsis... The upper-level tough will continue into the northern Rockies, though it will lose more amplitude on Saturday. A surface trough will deepen in the northern Great Basin beneath a belt of stronger mid-level winds. Elevated fire weather conditions appear probable in portions of northern Nevada into southern Idaho. Surface winds near the trough and the lee of the Sierra will increase to 15-20 mph with RH falling into the teens to perhaps single digits during the afternoon. Additional isolated thunderstorms are possible in central Idaho. Given the stronger flow aloft and dry boundary layer, these storms may produce little rainfall. Some impact on fuels from potential precipitation occurring on Friday could occur. Highlights will be maintained where confidence in storm development is highest and fuels are sufficiently receptive. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1251 PM CDT Fri Aug 09 2024 Valid 101200Z - 111200Z The primary change for this forecast update is an expansion of the isolated dry thunderstorm risk area into eastern WA. Latest ensemble guidance shows a reasonably strong signal for convection developing within the higher terrain of the Cascades before moving east into a drier air mass. While forecast soundings show PWAT values generally near or above 0.75 inches, ensemble QPF output shows low (less than 20%) probability for wetting rainfall. This signal, along with anticipated storm motions near 20 knots and antecedent dry fuel conditions, has increased confidence enough for a northwestward expansion of the dry thunderstorm risk area. A few dry thunderstorms are also possible further south across northern UT, but confidence in the coverage of dry vs wet thunderstorms is more limited based on PWAT and QPF forecasts. A swath of elevated (to perhaps locally critical) wind-driven fire weather conditions remains likely across northern NV. See the previous discussion for additional details. ..Moore.. 08/09/2024 .PREV DISCUSSION... /ISSUED 1240 AM CDT Fri Aug 09 2024/ ...Synopsis... The upper-level tough will continue into the northern Rockies, though it will lose more amplitude on Saturday. A surface trough will deepen in the northern Great Basin beneath a belt of stronger mid-level winds. Elevated fire weather conditions appear probable in portions of northern Nevada into southern Idaho. Surface winds near the trough and the lee of the Sierra will increase to 15-20 mph with RH falling into the teens to perhaps single digits during the afternoon. Additional isolated thunderstorms are possible in central Idaho. Given the stronger flow aloft and dry boundary layer, these storms may produce little rainfall. Some impact on fuels from potential precipitation occurring on Friday could occur. Highlights will be maintained where confidence in storm development is highest and fuels are sufficiently receptive. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1251 PM CDT Fri Aug 09 2024 Valid 101200Z - 111200Z The primary change for this forecast update is an expansion of the isolated dry thunderstorm risk area into eastern WA. Latest ensemble guidance shows a reasonably strong signal for convection developing within the higher terrain of the Cascades before moving east into a drier air mass. While forecast soundings show PWAT values generally near or above 0.75 inches, ensemble QPF output shows low (less than 20%) probability for wetting rainfall. This signal, along with anticipated storm motions near 20 knots and antecedent dry fuel conditions, has increased confidence enough for a northwestward expansion of the dry thunderstorm risk area. A few dry thunderstorms are also possible further south across northern UT, but confidence in the coverage of dry vs wet thunderstorms is more limited based on PWAT and QPF forecasts. A swath of elevated (to perhaps locally critical) wind-driven fire weather conditions remains likely across northern NV. See the previous discussion for additional details. ..Moore.. 08/09/2024 .PREV DISCUSSION... /ISSUED 1240 AM CDT Fri Aug 09 2024/ ...Synopsis... The upper-level tough will continue into the northern Rockies, though it will lose more amplitude on Saturday. A surface trough will deepen in the northern Great Basin beneath a belt of stronger mid-level winds. Elevated fire weather conditions appear probable in portions of northern Nevada into southern Idaho. Surface winds near the trough and the lee of the Sierra will increase to 15-20 mph with RH falling into the teens to perhaps single digits during the afternoon. Additional isolated thunderstorms are possible in central Idaho. Given the stronger flow aloft and dry boundary layer, these storms may produce little rainfall. Some impact on fuels from potential precipitation occurring on Friday could occur. Highlights will be maintained where confidence in storm development is highest and fuels are sufficiently receptive. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1251 PM CDT Fri Aug 09 2024 Valid 101200Z - 111200Z The primary change for this forecast update is an expansion of the isolated dry thunderstorm risk area into eastern WA. Latest ensemble guidance shows a reasonably strong signal for convection developing within the higher terrain of the Cascades before moving east into a drier air mass. While forecast soundings show PWAT values generally near or above 0.75 inches, ensemble QPF output shows low (less than 20%) probability for wetting rainfall. This signal, along with anticipated storm motions near 20 knots and antecedent dry fuel conditions, has increased confidence enough for a northwestward expansion of the dry thunderstorm risk area. A few dry thunderstorms are also possible further south across northern UT, but confidence in the coverage of dry vs wet thunderstorms is more limited based on PWAT and QPF forecasts. A swath of elevated (to perhaps locally critical) wind-driven fire weather conditions remains likely across northern NV. See the previous discussion for additional details. ..Moore.. 08/09/2024 .PREV DISCUSSION... /ISSUED 1240 AM CDT Fri Aug 09 2024/ ...Synopsis... The upper-level tough will continue into the northern Rockies, though it will lose more amplitude on Saturday. A surface trough will deepen in the northern Great Basin beneath a belt of stronger mid-level winds. Elevated fire weather conditions appear probable in portions of northern Nevada into southern Idaho. Surface winds near the trough and the lee of the Sierra will increase to 15-20 mph with RH falling into the teens to perhaps single digits during the afternoon. Additional isolated thunderstorms are possible in central Idaho. Given the stronger flow aloft and dry boundary layer, these storms may produce little rainfall. Some impact on fuels from potential precipitation occurring on Friday could occur. Highlights will be maintained where confidence in storm development is highest and fuels are sufficiently receptive. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1251 PM CDT Fri Aug 09 2024 Valid 101200Z - 111200Z The primary change for this forecast update is an expansion of the isolated dry thunderstorm risk area into eastern WA. Latest ensemble guidance shows a reasonably strong signal for convection developing within the higher terrain of the Cascades before moving east into a drier air mass. While forecast soundings show PWAT values generally near or above 0.75 inches, ensemble QPF output shows low (less than 20%) probability for wetting rainfall. This signal, along with anticipated storm motions near 20 knots and antecedent dry fuel conditions, has increased confidence enough for a northwestward expansion of the dry thunderstorm risk area. A few dry thunderstorms are also possible further south across northern UT, but confidence in the coverage of dry vs wet thunderstorms is more limited based on PWAT and QPF forecasts. A swath of elevated (to perhaps locally critical) wind-driven fire weather conditions remains likely across northern NV. See the previous discussion for additional details. ..Moore.. 08/09/2024 .PREV DISCUSSION... /ISSUED 1240 AM CDT Fri Aug 09 2024/ ...Synopsis... The upper-level tough will continue into the northern Rockies, though it will lose more amplitude on Saturday. A surface trough will deepen in the northern Great Basin beneath a belt of stronger mid-level winds. Elevated fire weather conditions appear probable in portions of northern Nevada into southern Idaho. Surface winds near the trough and the lee of the Sierra will increase to 15-20 mph with RH falling into the teens to perhaps single digits during the afternoon. Additional isolated thunderstorms are possible in central Idaho. Given the stronger flow aloft and dry boundary layer, these storms may produce little rainfall. Some impact on fuels from potential precipitation occurring on Friday could occur. Highlights will be maintained where confidence in storm development is highest and fuels are sufficiently receptive. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1251 PM CDT Fri Aug 09 2024 Valid 101200Z - 111200Z The primary change for this forecast update is an expansion of the isolated dry thunderstorm risk area into eastern WA. Latest ensemble guidance shows a reasonably strong signal for convection developing within the higher terrain of the Cascades before moving east into a drier air mass. While forecast soundings show PWAT values generally near or above 0.75 inches, ensemble QPF output shows low (less than 20%) probability for wetting rainfall. This signal, along with anticipated storm motions near 20 knots and antecedent dry fuel conditions, has increased confidence enough for a northwestward expansion of the dry thunderstorm risk area. A few dry thunderstorms are also possible further south across northern UT, but confidence in the coverage of dry vs wet thunderstorms is more limited based on PWAT and QPF forecasts. A swath of elevated (to perhaps locally critical) wind-driven fire weather conditions remains likely across northern NV. See the previous discussion for additional details. ..Moore.. 08/09/2024 .PREV DISCUSSION... /ISSUED 1240 AM CDT Fri Aug 09 2024/ ...Synopsis... The upper-level tough will continue into the northern Rockies, though it will lose more amplitude on Saturday. A surface trough will deepen in the northern Great Basin beneath a belt of stronger mid-level winds. Elevated fire weather conditions appear probable in portions of northern Nevada into southern Idaho. Surface winds near the trough and the lee of the Sierra will increase to 15-20 mph with RH falling into the teens to perhaps single digits during the afternoon. Additional isolated thunderstorms are possible in central Idaho. Given the stronger flow aloft and dry boundary layer, these storms may produce little rainfall. Some impact on fuels from potential precipitation occurring on Friday could occur. Highlights will be maintained where confidence in storm development is highest and fuels are sufficiently receptive. ...Please see www.spc.noaa.gov/fire for graphic product... Read more