Severe Storms

WW 0401 Status Updates
STATUS REPORT ON WW 401 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. ..THORNTON..06/27/23 ATTN...WFO...UNR... STATUS REPORT FOR WS 401 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS SDC007-019-033-047-055-063-071-081-093-095-102-103-105-121-137- 272240- SD . SOUTH DAKOTA COUNTIES INCLUDED ARE BENNETT BUTTE CUSTER FALL RIVER HAAKON HARDING JACKSON LAWRENCE MEADE MELLETTE OGLALA LAKOTA PENNINGTON PERKINS TODD ZIEBACH WYC011-045-272240- WY . WYOMING COUNTIES INCLUDED ARE CROOK WESTON THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE REFER TO WATCH COUNTY NOTIFICATION STATEMENTS FOR OFFICIAL INFORMATION ON COUNTIES...INDEPENDENT CITIES AND MARINE ZONES CLEARED FROM SEVERE THUNDERSTORM AND TORNADO WATCHES. Read more

WW 401 SEVERE TSTM SD WY 271920Z - 280200Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 401 NWS Storm Prediction Center Norman OK 120 PM MDT Tue Jun 27 2023 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Western South Dakota Northeast Wyoming * Effective this Tuesday afternoon and evening from 120 PM until 800 PM MDT. * Primary threats include... Scattered damaging winds and isolated significant gusts to 75 mph possible Scattered large hail and isolated very large hail events to 3 inches in diameter possible SUMMARY...A few supercells should develop and spread east across the Black Hills vicinity through early evening. Primary threat will be large hail. The severe thunderstorm watch area is approximately along and 60 statute miles north and south of a line from 80 miles west northwest of Rapid City SD to 50 miles east southeast of Philip SD. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU1). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A Severe Thunderstorm Watch means conditions are favorable for severe thunderstorms in and close to the watch area. Persons in these areas should be on the lookout for threatening weather conditions and listen for later statements and possible warnings. Severe thunderstorms can and occasionally do produce tornadoes. && OTHER WATCH INFORMATION...CONTINUE...WW 400... AVIATION...A few severe thunderstorms with hail surface and aloft to 3 inches. Extreme turbulence and surface wind gusts to 65 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 26030. ...Grams Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0254 PM CDT Tue Jun 27 2023 Valid 272000Z - 281200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS OVER PARTS OF SOUTHERN KANSAS AND FAR NORTHWEST OKLAHOMA ALONG THE BORDER... ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS OVER MUCH OF SOUTHERN KANSAS AND NORTHERN OKLAHOMA...AND OVER WESTERN NEBRASKA... ...SUMMARY... Supercells evolving into a narrow bowing complex appear likely across parts of southern Kansas and northern Oklahoma from late afternoon through tonight. Very large hail and perhaps a tornado will be the main threat initially, followed by potential for a swath of destructive wind gusts in excess of 80 mph. ...KS/OK area... Air mass recovery is being closely monitored in the wake of the earlier storms which have moved into central AR. Cool air currently resides over northeast OK and southeast KS, but winds have continued to veer and warming is underway. Areas of midlevel clouds do exist but substantial heating is occurring over much of the area. As such, the air mass should continue to destabilize, especially from western OK and the Panhandles into southwest KS within the 70s F dewpoint axis. Midday soundings from AMA show very steep lapse rates through a deep layer, approaching 9 C/km from the surface to 500 mb. Stronger mid and high-level flow exists just north of this area (40-60 kt at DDC), which will support supercells capable of very large hail with the activity now forming over northeast NM and southeast CO. These storms should merge over time, producing a substantial cold pool with a narrow corridor of destructive winds forecast near the KS/OK border. For more information see MCD 1307. ..Jewell.. 06/27/2023 .PREV DISCUSSION... /ISSUED 1130 AM CDT Tue Jun 27 2023/ ...Raton Mesa to the Ozarks and Lower MS Valley... A stout mid-level anticyclone will remain anchored across central TX with a couple of ridge-riding MCSs possible around it. A plume of large to extreme buoyancy will become centered from southwest KS to the Ark-La-Miss at peak heating amid 70s surface dew points and very steep mid-level lapse rates of 8-9 C/km atop the moist axis. A small elevated cluster in eastern OK may track southeast along the pronounced buoyancy gradient, with a possibility for surface-based development downstream of it along the effective front towards the Ark-La-Miss. The weak large-scale forcing for ascent lowers confidence in the overall scenario, but there is potential for multicell clusters to spread southeast into the Lower MS Valley later this afternoon. Primary threat will be scattered damaging winds. Outflow from the morning complex in OK has reinforced the baroclinic zone across central to southern OK, but the leading edge of 70s surface dew points in southwest OK will advect north into northwest OK by late afternoon. Initial thunderstorm development is expected by mid afternoon in the Raton Mesa vicinity, and storms will subsequently spread into southwest KS and the northern Panhandles by early evening. The initial storms will likely consist of a few supercells capable of producing very large hail of 2-3 inches in diameter. An increase in low-level shear this evening and increasing moisture with eastward extent could result in a window of opportunity for a tornado or two with the more discrete supercells. Thereafter, upscale growth into a small but particularly intense MCS appears probable, due to storm interactions/mergers in the very steep lapse rate environment and strengthening low-level jet. Localized swaths of destructive severe wind gusts from 80-110 mph will be possible into tonight across southern KS/northern OK. The overall threat will likely remain spatially confined owing to the pronounced EML/capping to its south and residual influence of this morning's convection, especially with eastern extent towards the Ozarks overnight. ...Northwest KS to ND... In the wake of elevated morning storms associated with warm advection near 700 mb, low-level moisture advection and surface heating will contribute to stronger destabilization from northwest KS into southwest SD where MLCAPE of 1500-3000 J/kg should be common. Farther north, more modest boundary-layer moisture will result in MLCAPE of 1000-2000 J/kg. Lee cyclogenesis across eastern CO will help sharpen the dryline by late afternoon close to the longitude of the CO/KS border, which should focus widely scattered thunderstorm development in northwest KS and western KS. Additional storms should develop over the Black Hills, with more isolated activity also possible into ND. With a mid-level jetlet crossing the southern Rockies into the central High Plains, relatively long/straight hodographs will favor a few intense supercells capable of producing very large to giant hail and isolated severe wind gusts centered on western NE. Some clustering may occur during the evening as a southerly low-level jet intensifies but pronounced MLCIN and lack of instability with eastern extent suggest the severe threat should wane into central to eastern portions of NE/KS/SD. ...Mid-Atlantic into eastern NY... A mid-level trough with embedded perturbations and an associated surface cold front will move slowly eastward across NY/PA and toward the Mid-Atlantic coast. Lapse rates, buoyancy and vertical shear have all been reduced compared to yesterday, in the wake of prior widespread convection and as the primary jet moves offshore. Still, slightly cool mid-level temperatures and surface heating with residual moisture in cloud breaks could support isolated damaging winds in the strongest storms today. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0254 PM CDT Tue Jun 27 2023 Valid 272000Z - 281200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS OVER PARTS OF SOUTHERN KANSAS AND FAR NORTHWEST OKLAHOMA ALONG THE BORDER... ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS OVER MUCH OF SOUTHERN KANSAS AND NORTHERN OKLAHOMA...AND OVER WESTERN NEBRASKA... ...SUMMARY... Supercells evolving into a narrow bowing complex appear likely across parts of southern Kansas and northern Oklahoma from late afternoon through tonight. Very large hail and perhaps a tornado will be the main threat initially, followed by potential for a swath of destructive wind gusts in excess of 80 mph. ...KS/OK area... Air mass recovery is being closely monitored in the wake of the earlier storms which have moved into central AR. Cool air currently resides over northeast OK and southeast KS, but winds have continued to veer and warming is underway. Areas of midlevel clouds do exist but substantial heating is occurring over much of the area. As such, the air mass should continue to destabilize, especially from western OK and the Panhandles into southwest KS within the 70s F dewpoint axis. Midday soundings from AMA show very steep lapse rates through a deep layer, approaching 9 C/km from the surface to 500 mb. Stronger mid and high-level flow exists just north of this area (40-60 kt at DDC), which will support supercells capable of very large hail with the activity now forming over northeast NM and southeast CO. These storms should merge over time, producing a substantial cold pool with a narrow corridor of destructive winds forecast near the KS/OK border. For more information see MCD 1307. ..Jewell.. 06/27/2023 .PREV DISCUSSION... /ISSUED 1130 AM CDT Tue Jun 27 2023/ ...Raton Mesa to the Ozarks and Lower MS Valley... A stout mid-level anticyclone will remain anchored across central TX with a couple of ridge-riding MCSs possible around it. A plume of large to extreme buoyancy will become centered from southwest KS to the Ark-La-Miss at peak heating amid 70s surface dew points and very steep mid-level lapse rates of 8-9 C/km atop the moist axis. A small elevated cluster in eastern OK may track southeast along the pronounced buoyancy gradient, with a possibility for surface-based development downstream of it along the effective front towards the Ark-La-Miss. The weak large-scale forcing for ascent lowers confidence in the overall scenario, but there is potential for multicell clusters to spread southeast into the Lower MS Valley later this afternoon. Primary threat will be scattered damaging winds. Outflow from the morning complex in OK has reinforced the baroclinic zone across central to southern OK, but the leading edge of 70s surface dew points in southwest OK will advect north into northwest OK by late afternoon. Initial thunderstorm development is expected by mid afternoon in the Raton Mesa vicinity, and storms will subsequently spread into southwest KS and the northern Panhandles by early evening. The initial storms will likely consist of a few supercells capable of producing very large hail of 2-3 inches in diameter. An increase in low-level shear this evening and increasing moisture with eastward extent could result in a window of opportunity for a tornado or two with the more discrete supercells. Thereafter, upscale growth into a small but particularly intense MCS appears probable, due to storm interactions/mergers in the very steep lapse rate environment and strengthening low-level jet. Localized swaths of destructive severe wind gusts from 80-110 mph will be possible into tonight across southern KS/northern OK. The overall threat will likely remain spatially confined owing to the pronounced EML/capping to its south and residual influence of this morning's convection, especially with eastern extent towards the Ozarks overnight. ...Northwest KS to ND... In the wake of elevated morning storms associated with warm advection near 700 mb, low-level moisture advection and surface heating will contribute to stronger destabilization from northwest KS into southwest SD where MLCAPE of 1500-3000 J/kg should be common. Farther north, more modest boundary-layer moisture will result in MLCAPE of 1000-2000 J/kg. Lee cyclogenesis across eastern CO will help sharpen the dryline by late afternoon close to the longitude of the CO/KS border, which should focus widely scattered thunderstorm development in northwest KS and western KS. Additional storms should develop over the Black Hills, with more isolated activity also possible into ND. With a mid-level jetlet crossing the southern Rockies into the central High Plains, relatively long/straight hodographs will favor a few intense supercells capable of producing very large to giant hail and isolated severe wind gusts centered on western NE. Some clustering may occur during the evening as a southerly low-level jet intensifies but pronounced MLCIN and lack of instability with eastern extent suggest the severe threat should wane into central to eastern portions of NE/KS/SD. ...Mid-Atlantic into eastern NY... A mid-level trough with embedded perturbations and an associated surface cold front will move slowly eastward across NY/PA and toward the Mid-Atlantic coast. Lapse rates, buoyancy and vertical shear have all been reduced compared to yesterday, in the wake of prior widespread convection and as the primary jet moves offshore. Still, slightly cool mid-level temperatures and surface heating with residual moisture in cloud breaks could support isolated damaging winds in the strongest storms today. Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0118 PM CDT Tue Jun 27 2023 Valid 281200Z - 291200Z ...CRITICAL FIRE WEATHER AREA FOR NORTHEASTERN ARIZONA INTO NORTHWESTERN NEW MEXICO... The dry thunderstorm forecast was adjusted to account for the latest model guidance. With the trough weakening, it appears there will be an area of lighter surface winds in New Mexico. The elevated area was adjusted to reflect this trend. Still, some enhanced surface winds do appear possible in parts of the Permian Basin vicinity due to the surface trough in the central/southern Plains. An elevated area was added to this region where fuels have dried out in the presence of recently hot surface temperatures. ..Wendt.. 06/27/2023 .PREV DISCUSSION... /ISSUED 0210 AM CDT Tue Jun 27 2023/ ...Synopsis... While the mid-level trough is forecast to weaken as the main wave exits to the northeast, moderate mid-level flow will remain over the Southwest for Day2/Wed. Gusty winds and low humidity over dry fuels will support widespread elevated and critical fire-weather conditions. Isolated dry thunderstorms are also possible. ...Southwest into the Four Corners... Another day of dry and windy conditions is expected as the main upper trough begins to shift to the northeast. Poor overnight humidity recoveries will persist with single RH values 7-12% likely across portions of northeast AZ and western NM through the afternoon. With surface winds of 20-25 mph expected atop dry fuels, several hours of elevated and critical fire-weather conditions are expected. Fire concerns may linger into the evening with another day of poor humidity recoveries below 30% expected While lift will be weaker than the preceding days, lingering mid-level moisture with PWATs of 0.5-0.6 inches will support isolated high-based thunderstorm along the higher terrain of central NM. With dry sub-cloud layers in excess of 3km, little wetting rainfall is expected. Weak MUCAPE will however support the potential for isolated dry lightning strikes within very receptive fuels. ...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 0118 PM CDT Tue Jun 27 2023 Valid 281200Z - 291200Z ...CRITICAL FIRE WEATHER AREA FOR NORTHEASTERN ARIZONA INTO NORTHWESTERN NEW MEXICO... The dry thunderstorm forecast was adjusted to account for the latest model guidance. With the trough weakening, it appears there will be an area of lighter surface winds in New Mexico. The elevated area was adjusted to reflect this trend. Still, some enhanced surface winds do appear possible in parts of the Permian Basin vicinity due to the surface trough in the central/southern Plains. An elevated area was added to this region where fuels have dried out in the presence of recently hot surface temperatures. ..Wendt.. 06/27/2023 .PREV DISCUSSION... /ISSUED 0210 AM CDT Tue Jun 27 2023/ ...Synopsis... While the mid-level trough is forecast to weaken as the main wave exits to the northeast, moderate mid-level flow will remain over the Southwest for Day2/Wed. Gusty winds and low humidity over dry fuels will support widespread elevated and critical fire-weather conditions. Isolated dry thunderstorms are also possible. ...Southwest into the Four Corners... Another day of dry and windy conditions is expected as the main upper trough begins to shift to the northeast. Poor overnight humidity recoveries will persist with single RH values 7-12% likely across portions of northeast AZ and western NM through the afternoon. With surface winds of 20-25 mph expected atop dry fuels, several hours of elevated and critical fire-weather conditions are expected. Fire concerns may linger into the evening with another day of poor humidity recoveries below 30% expected While lift will be weaker than the preceding days, lingering mid-level moisture with PWATs of 0.5-0.6 inches will support isolated high-based thunderstorm along the higher terrain of central NM. With dry sub-cloud layers in excess of 3km, little wetting rainfall is expected. Weak MUCAPE will however support the potential for isolated dry lightning strikes within very receptive fuels. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1232 PM CDT Tue Jun 27 2023 Valid 281200Z - 291200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER THE UPPER MISSISSIPPI VALLEY... ...SUMMARY... Severe storms are most likely Wednesday afternoon and evening over parts of the upper Mississippi Valley. Sporadic severe storms are also possible over the lower Mississippi Valley, and over parts of northern to central Plains ...Synopsis... An upper high will remain situated over the southern Plains, with 50 kt midlevel winds from CO into the Midwest enhancing shear. A weak surface trough will extend from near Minneapolis southwestward into the central Plains with moderate instability along that axis. A subtle disturbance aloft will round the ridge and move from MN into MI, providing a focus for severe storms. Otherwise, diurnal activity is expected from eastern WY into NE from afternoon through evening, with continued destabilization possible overnight there. Remnant MCS activity may persist into portions of the lower MS Valley from the previous nights activity, while diurnal storms develop over the KS portion of the surface trough. ...Upper MS Valley... Moderate instability will develop during the day from IA into MN and western WI with low-level shear supporting a few supercells after 21Z. Large hail will also be likely given steep lapse rates aloft and ample shear. Storms are likely to spread southeastward during the evening, with greater uncertainty regarding MCS potential overnight. A low-level warm advection zone will develop from western WI into IL late in the day and overnight as 850 mb winds veer, and this could support at least an isolated severe risk through that corridor, depending on destabilization. Damaging winds would be the primary concern overnight. ...Northern/Central Plains... A few supercells are expected to form after 21Z from southeast WY into western NE, where low-level winds will veer to easterly, supporting moisture advection. This will occur beneath 40+ kt midlevel winds, with large hail likely. Additional severe storms with hail and wind may develop even after 00Z as the low-level jet increases over the CO/NE/KS area and capping remains minimal along I-80. ...Lower MS Valley... Northerly winds east of the upper ridge along with a moist unstable air mass will conditionally support southward-moving storms. Models solutions vary as to how much activity may be ongoing Wednesday morning, but any activity that exists or develops in this north-south warm advection zone may produce damaging gusts. ..Jewell.. 06/27/2023 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1232 PM CDT Tue Jun 27 2023 Valid 281200Z - 291200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER THE UPPER MISSISSIPPI VALLEY... ...SUMMARY... Severe storms are most likely Wednesday afternoon and evening over parts of the upper Mississippi Valley. Sporadic severe storms are also possible over the lower Mississippi Valley, and over parts of northern to central Plains ...Synopsis... An upper high will remain situated over the southern Plains, with 50 kt midlevel winds from CO into the Midwest enhancing shear. A weak surface trough will extend from near Minneapolis southwestward into the central Plains with moderate instability along that axis. A subtle disturbance aloft will round the ridge and move from MN into MI, providing a focus for severe storms. Otherwise, diurnal activity is expected from eastern WY into NE from afternoon through evening, with continued destabilization possible overnight there. Remnant MCS activity may persist into portions of the lower MS Valley from the previous nights activity, while diurnal storms develop over the KS portion of the surface trough. ...Upper MS Valley... Moderate instability will develop during the day from IA into MN and western WI with low-level shear supporting a few supercells after 21Z. Large hail will also be likely given steep lapse rates aloft and ample shear. Storms are likely to spread southeastward during the evening, with greater uncertainty regarding MCS potential overnight. A low-level warm advection zone will develop from western WI into IL late in the day and overnight as 850 mb winds veer, and this could support at least an isolated severe risk through that corridor, depending on destabilization. Damaging winds would be the primary concern overnight. ...Northern/Central Plains... A few supercells are expected to form after 21Z from southeast WY into western NE, where low-level winds will veer to easterly, supporting moisture advection. This will occur beneath 40+ kt midlevel winds, with large hail likely. Additional severe storms with hail and wind may develop even after 00Z as the low-level jet increases over the CO/NE/KS area and capping remains minimal along I-80. ...Lower MS Valley... Northerly winds east of the upper ridge along with a moist unstable air mass will conditionally support southward-moving storms. Models solutions vary as to how much activity may be ongoing Wednesday morning, but any activity that exists or develops in this north-south warm advection zone may produce damaging gusts. ..Jewell.. 06/27/2023 Read more

WW 0394 Status Updates
STATUS REPORT ON WW 394 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. ..WENDT..06/26/23 ATTN...WFO...RAH...GSP...CAE... STATUS REPORT FOR WS 394 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS NCC001-003-007-023-025-027-035-037-045-051-057-059-063-067-069- 071-077-081-085-093-097-101-105-109-111-119-123-125-135-145-149- 151-153-159-161-165-167-179-181-183-185-262240- NC . NORTH CAROLINA COUNTIES INCLUDED ARE ALAMANCE ALEXANDER ANSON BURKE CABARRUS CALDWELL CATAWBA CHATHAM CLEVELAND CUMBERLAND DAVIDSON DAVIE DURHAM FORSYTH FRANKLIN GASTON GRANVILLE GUILFORD HARNETT HOKE IREDELL JOHNSTON LEE LINCOLN MCDOWELL MECKLENBURG MONTGOMERY MOORE ORANGE PERSON POLK RANDOLPH RICHMOND ROWAN RUTHERFORD SCOTLAND STANLY UNION VANCE WAKE WARREN SCC021-023-025-057-083-087-091-262240- SC Read more

WW 394 SEVERE TSTM NC SC 262050Z - 270300Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 394 NWS Storm Prediction Center Norman OK 450 PM EDT Mon Jun 26 2023 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Western to central North Carolina Northern South Carolina * Effective this Monday afternoon and evening from 450 PM until 1100 PM EDT. * Primary threats include... Scattered damaging winds likely with isolated significant gusts to 75 mph possible Scattered large hail and isolated very large hail events to 2 inches in diameter possible SUMMARY...A few supercells should develop off the higher terrain of western North Carolina and northwest South Carolina, likely growing upscale into one or more clusters across the Piedmont later this evening. The severe thunderstorm watch area is approximately along and 50 statute miles north and south of a line from 20 miles north of Greenville SC to 25 miles east southeast of Raleigh NC. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU4). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A Severe Thunderstorm Watch means conditions are favorable for severe thunderstorms in and close to the watch area. Persons in these areas should be on the lookout for threatening weather conditions and listen for later statements and possible warnings. Severe thunderstorms can and occasionally do produce tornadoes. && OTHER WATCH INFORMATION...CONTINUE...WW 391...WW 392...WW 393... AVIATION...A few severe thunderstorms with hail surface and aloft to 2 inches. Extreme turbulence and surface wind gusts to 65 knots. A few cumulonimbi with maximum tops to 550. Mean storm motion vector 27035. ...Grams Read more

WW 0392 Status Updates
STATUS REPORT ON WW 392 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. ..WENDT..06/26/23 ATTN...WFO...LWX... STATUS REPORT FOR WS 392 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS DCC001-262240- DC . DISTRICT OF COLUMBIA COUNTIES INCLUDED ARE DISTRICT OF COLUMBIA MDC001-003-005-013-015-017-021-025-027-031-033-043-510-262240- MD . MARYLAND COUNTIES INCLUDED ARE ALLEGANY ANNE ARUNDEL BALTIMORE CARROLL CECIL CHARLES FREDERICK HARFORD HOWARD MONTGOMERY PRINCE GEORGES WASHINGTON MARYLAND INDEPENDENT CITIES INCLUDED ARE BALTIMORE CITY Read more

WW 392 SEVERE TSTM DC MD VA WV CW 261815Z - 270100Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 392 NWS Storm Prediction Center Norman OK 215 PM EDT Mon Jun 26 2023 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of District Of Columbia Maryland Northern Virginia Eastern West Virginia Panhandle Coastal Waters * Effective this Monday afternoon and evening from 215 PM until 900 PM EDT. * Primary threats include... Scattered damaging wind gusts to 65 mph likely Isolated large hail events to 1.5 inches in diameter possible SUMMARY...Thunderstorms developing along the eastern West Virginia Panhandle and northern Virginia border area should evolve into an east-northeast moving cluster towards the I-95 corridor later this afternoon into early evening. Damaging winds will be the main threat. The severe thunderstorm watch area is approximately along and 50 statute miles north and south of a line from 25 miles northwest of Staunton VA to 30 miles east northeast of Baltimore MD. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU2). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A Severe Thunderstorm Watch means conditions are favorable for severe thunderstorms in and close to the watch area. Persons in these areas should be on the lookout for threatening weather conditions and listen for later statements and possible warnings. Severe thunderstorms can and occasionally do produce tornadoes. && OTHER WATCH INFORMATION...CONTINUE...WW 391... AVIATION...A few severe thunderstorms with hail surface and aloft to 1.5 inches. Extreme turbulence and surface wind gusts to 55 knots. A few cumulonimbi with maximum tops to 450. Mean storm motion vector 25025. ...Grams Read more

WW 0393 Status Updates
STATUS REPORT ON WW 393 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. ..WENDT..06/26/23 ATTN...WFO...RNK...AKQ... STATUS REPORT FOR WS 393 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS NCC005-033-157-169-171-193-197-262240- NC . NORTH CAROLINA COUNTIES INCLUDED ARE ALLEGHANY CASWELL ROCKINGHAM STOKES SURRY WILKES YADKIN VAC007-009-011-019-023-025-029-031-033-035-036-037-041-045-049- 053-057-063-065-067-075-077-081-083-085-087-089-095-097-101-109- 111-117-121-127-135-141-143-145-147-149-155-161-163-175-181-183- 197-530-570-590-595-620-640-670-678-680-690-730-750-760-770-775- 830-262240- VA . VIRGINIA COUNTIES INCLUDED ARE AMELIA AMHERST APPOMATTOX BEDFORD BOTETOURT BRUNSWICK BUCKINGHAM CAMPBELL CAROLINE CARROLL CHARLES CITY CHARLOTTE CHESTERFIELD CRAIG CUMBERLAND DINWIDDIE ESSEX FLOYD FLUVANNA FRANKLIN GOOCHLAND Read more

WW 393 SEVERE TSTM NC VA 261915Z - 270200Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 393...CORRECTED NWS Storm Prediction Center Norman OK 320 PM EDT Mon Jun 26 2023 CORRECTED FOR MISSING INDEPENDENT CITY The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Northwest North Carolina Southern Virginia * Effective this Monday afternoon and evening from 320 PM until 1000 PM EDT. * Primary threats include... Scattered damaging wind gusts to 70 mph likely Isolated large hail events to 1.5 inches in diameter possible SUMMARY...Initially discrete cells over southwest Virginia into northwest North Carolina should consolidate into an eastward-moving cluster across southern Virginia through this evening. Damaging winds and isolated severe hail will be the main threats. The severe thunderstorm watch area is approximately along and 60 statute miles north and south of a line from 15 miles east southeast of Richmond VA to 35 miles southwest of Dublin VA. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU3). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A Severe Thunderstorm Watch means conditions are favorable for severe thunderstorms in and close to the watch area. Persons in these areas should be on the lookout for threatening weather conditions and listen for later statements and possible warnings. Severe thunderstorms can and occasionally do produce tornadoes. && OTHER WATCH INFORMATION...CONTINUE...WW 391...WW 392... AVIATION...A few severe thunderstorms with hail surface and aloft to 1.5 inches. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 26030. ...Grams Read more

WW 0391 Status Updates
STATUS REPORT ON WW 391 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 20 ESE ERI TO 30 NNE BFD TO 60 N ROC. ..WENDT..06/26/23 ATTN...WFO...PHI...BUF...BGM...CTP... STATUS REPORT FOR WS 391 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS NJC005-007-015-019-021-023-025-027-029-033-035-037-041-262240- NJ . NEW JERSEY COUNTIES INCLUDED ARE BURLINGTON CAMDEN GLOUCESTER HUNTERDON MERCER MIDDLESEX MONMOUTH MORRIS OCEAN SALEM SOMERSET SUSSEX WARREN NYC003-007-011-015-017-023-045-049-051-053-055-065-067-069-075- 097-099-101-107-109-117-123-262240- NY . NEW YORK COUNTIES INCLUDED ARE ALLEGANY BROOME CAYUGA CHEMUNG CHENANGO CORTLAND JEFFERSON LEWIS LIVINGSTON MADISON MONROE ONEIDA ONONDAGA ONTARIO OSWEGO SCHUYLER SENECA STEUBEN TIOGA TOMPKINS WAYNE Read more

WW 391 SEVERE TSTM DE NJ NY PA LE LO CW 261710Z - 270100Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 391 NWS Storm Prediction Center Norman OK 110 PM EDT Mon Jun 26 2023 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Northern Delaware New Jersey Western New York Central and eastern Pennsylvania Lake Erie Lake Ontario Coastal Waters * Effective this Monday afternoon and evening from 110 PM until 900 PM EDT. * Primary threats include... Scattered damaging wind gusts to 70 mph likely Isolated large hail events to 1.5 inches in diameter possible SUMMARY...Multiple areas of multicell clustering are expected with a few transient supercells across parts of New York and Pennsylvania into New Jersey. Strong to localized severe gusts producing damaging winds will be the main threat. The severe thunderstorm watch area is approximately along and 85 statute miles east and west of a line from 45 miles north northeast of Rochester NY to 45 miles southeast of Harrisburg PA. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU1). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A Severe Thunderstorm Watch means conditions are favorable for severe thunderstorms in and close to the watch area. Persons in these areas should be on the lookout for threatening weather conditions and listen for later statements and possible warnings. Severe thunderstorms can and occasionally do produce tornadoes. && AVIATION...A few severe thunderstorms with hail surface and aloft to 1.5 inches. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 21025. ...Grams Read more

MD 1288 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR PORTIONS OF FAR SOUTHEAST/COASTAL GA...COASTAL/CENTRAL SC...AND FAR SOUTHERN NC
Mesoscale Discussion 1288 NWS Storm Prediction Center Norman OK 0355 PM CDT Mon Jun 26 2023 Areas affected...Portions of far southeast/coastal GA...coastal/central SC...and far southern NC Concerning...Severe potential...Watch possible Valid 262055Z - 262230Z Probability of Watch Issuance...40 percent SUMMARY...Trends are being monitored for signs of increasing thunderstorm coverage/intensity, which may eventually prompt watch issuance. DISCUSSION...A thunderstorm has recently formed in far southeast/coastal GA in a weak low-level confluence regime, with other towering cu also developing in recent visible satellite imagery. Around 1500-2000 J/kg of MLCAPE is present downstream into coastal/central SC and far southern NC, with a very moist low-level airmass in place. Weak surface winds gradually increase through the boundary layer to around 30 kt around 2-3 km AGL based on recent VWPs from KCLX/KLTX. This region is on the southern fringe of enhanced mid-level westerly winds associated with an upper trough/low centered over the Great Lakes. Even so, around 25-35 kt of effective bulk shear should foster some organization with any convection that can form and be sustained. If robust convection can develop, a mix of multicells and marginal supercells, with an associated hail/damaging wind threat, appear possible. High-resolution guidance shows varying solutions regarding the number of thunderstorms which may develop across this area. Trends will be monitored for signs of increasing thunderstorm coverage/intensity, which may eventually prompt watch issuance. ..Gleason/Grams.. 06/26/2023 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...ILM...CHS...CAE... LAT...LON 32688195 33518119 34347924 33877852 33097916 32028086 32688195 Read more

MD 1286 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR PORTIONS OF NORTHERN WYOMING...FAR SOUTHEASTERN MONTANA...FAR WESTERN SOUTH DAKOTA
Mesoscale Discussion 1286 NWS Storm Prediction Center Norman OK 0324 PM CDT Mon Jun 26 2023 Areas affected...portions of northern Wyoming...far southeastern Montana...far western South Dakota Concerning...Severe potential...Watch possible Valid 262024Z - 262300Z Probability of Watch Issuance...60 percent SUMMARY...The severe threat is increasing across portions of the northern High Plains. A few supercells may develop, supporting a risk for large hail (including an instance or two of 2+ inch stones), as well as a couple of severe gusts. Convective trends are being monitored for the need of a Severe Thunderstorm Watch issuance later this afternoon. DISCUSSION...MRMS mosaic radar imagery and satellite data suggests that convection is gradually deepening along the higher terrain of the Rockies. Though convection has yet to move off of the higher terrain, stronger forcing should begin to overspread the northern High Plains in the next few hours in association with an approaching 500 mb vort max over northwestern UT. While low-level moisture is not overly rich, 8+ C/km lapse rates from the surface to 500 mb is supporting 2000+ J/kg SBCAPE/MUCAPE, which is adequate for supercell development given the presence of 40+ kt effective bulk shear values (driven by straight, long hodographs). The deep-layer speed shear may support sufficient enough hail growth for stones to exceed 1 inches in diameter, with a couple of 2+ inch diameter stones possible. A few severe gusts may also occur with the heavier supercell precipitation cores given the steep low-level lapse rates. It is unclear exactly when a significant uptick in convective intensity and relatively robust supercell development will occur. It is possible that such development may not occur for at least a few more hours. Nonetheless, Severe Thunderstorm Watch issuance will likely be needed at some point this afternoon or evening and convective trends are being monitored closely for more precise timing of the watch issuance. ..Squitieri/Grams.. 06/26/2023 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...UNR...CYS...BYZ...RIW... LAT...LON 43391037 44540896 45490731 45640592 45640456 45070351 44510309 44180317 43120370 42680452 42390547 42400736 42570816 43391037 Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0252 PM CDT Mon Jun 26 2023 Valid 262000Z - 271200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE MID ATLANTIC... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE CAROLINAS INTO PARTS OF NEW YORK... ...SUMMARY... Scattered damaging winds are most likely from the Carolinas to parts of the Mid-Atlantic and Northeast States through this evening. Minor adjustments to the marginal risk line were made across western PA as the stronger activity should remain east where watches are ongoing. The marginal risk area was also removed from southern LA as activity tonight will be focused farther north. Otherwise, a large area of instability remains from NY into the Carolinas, with scattered severe storms producing damaging wind gusts expected. For more information see MCDs 1283 1284 1285. ..Jewell.. 06/26/2023 .PREV DISCUSSION... /ISSUED 1129 AM CDT Mon Jun 26 2023/ ...Carolinas to southern VA... The more favorable thermodynamic and kinematic environment will be across this portion of the broader severe threat in the East. In the wake of a couple MCVs progressing through the central portions of Carolinas and VA, nearly full insolation across the western portions of these states, coincident with moderately steep mid-level lapse rates around 7 C/km, will support moderate buoyancy with MLCAPE of 1500-2500 J/kg towards early evening. The most consistent signal for scattered thunderstorm development is across the higher terrain of western NC later this afternoon. While low-level shear will be weak, a belt of 35-45 kt 500-mb westerlies will support a few cells with mid-level updraft rotation, mainly early before convection tends to consolidate into one or more organized clusters. This will likely support multiple swaths of damaging winds, centered mainly on the Piedmont, before convection tends to gradually weaken across the coastal plain tonight. ...Mid-Atlantic/Northeast States... Mid-level westerlies should be weaker north of southern VA, and become increasingly meridional from PA northward, yielding a more marginal deep-layer shear environment relative to farther south. In addition, isolated to scattered thunderstorms are already ongoing across parts of NJ/NY/PA and this will tend to subdue greater destabilization with north and east extent. The primary severe threat within this region will likely emanate from a later afternoon round of thunderstorms that form over the higher terrain from central PA to western VA. Morning CAM guidance is more consistent with convection being maintained east across eastern PA/central MD and parts of the DE and Potomac Valleys where multicell clustering should support scattered damaging winds. An MCV over north-central VA and relative instability minimum in its vicinity may be suppressive to maintaining multicell clustering into the Delmarva region later today. ...Lee of the north-central Rockies and Black Hills... A narrow zone of moderate low-level moisture return is expected to persist over the central High Plains beneath a low-amplitude mid-level ridge. Isolated to scattered thunderstorms appear most likely to develop along the northern periphery of this confined buoyancy plume where steep mid-level lapse rates support MLCAPE of 1000-2000 J/kg. A belt of moderate westerly mid-level flow between strong jets over the Southwest and Mid-MS Valley should be adequate to support a few supercells. Significant severe hail will be the main threat initially, especially with potential for a long-track supercell. An attempt at clustering towards the Black Hills/NE Panhandle vicinity might occur as the High Plains low-level jet strengthens this evening, but the confined spatial extent of the buoyancy plume and nocturnal increase in MLCIN yields low confidence in maintaining severe coverage beyond an isolated threat tonight. ...Ark-La-Tex vicinity... In the wake of a decaying MCS over southeast LA (see MCD 1281 for near-term discussion), regenerative convection may yield an isolated severe hail threat for a few more hours, but convection should become more suppressed later this afternoon amid difluent low-level flow. A separate round of elevated convection is anticipated overnight with weak 850-700 warm theta-e advection. Isolated large hail may occur initially owing to the large elevated buoyancy, but deep-layer shear magnitude/orientation will tend to favor a predominant cluster mode which should serve to marginalize the overall severe hail threat and support isolated damaging winds. ...Southern High Plains... Isolated storm development is possible across the southern High Plains, within a hot and well-mixed environment. Any deep convection would pose a threat for microbursts and perhaps marginally severe hail, though storm longevity appears limited at this time within this weakly forced regime. Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0154 PM CDT Mon Jun 26 2023 Valid 271200Z - 281200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF THE FOUR CORNERS... Based on latest guidance, only minor changes have been made to this forecast. The Elevated area was expanded slightly farther into western Colorado and north-central New Mexico, whereas the Critical area expanded slightly westward across northern Arizona and farther northeast into western Colorado. The meteorological reasoning remains the same as discussed below. ..Marsh.. 06/26/2023 .PREV DISCUSSION... /ISSUED 0155 AM CDT Mon Jun 26 2023/ ...Synopsis... A broad mid-level trough will remain in place over portions of the Southwest Day2/Tuesday. Strong winds aloft and dry surface conditions will again favor another day of critical fire concerns over portions of the Southwest and Four Corners region. ...Southwest... With the upper trough moving slowly over the Four Corners, strong flow aloft will remain in place over the exceedingly dry and warm air mass across the Southwest. Very poor overnight humidity recoveries of only 25-30% will support single digit RH values Day2/Tuesday afternoon. In combination with widespread surface winds of 25-30 mph and higher gusts, critical fire-weather conditions will be common across portions of eastern AZ, northwestern NM, into southwest CO and southeast UT. A few hours of localized extremely critical fire-weather conditions are also possible across northeast AZ owing to terrain-enhanced winds and occasional gusts of 35+ mph with single digit RH. Fire-weather concerns may linger into the overnight hours as poor humidity recoveries and gusty winds priest after sunset. ...Dry Thunderstorms... As the upper trough continues to deepen and overspread the region, broad forcing for ascent and orographic lift will support isolated to widely scattered thunderstorm Day2/Tuesday afternoon. Area model soundings show deep and dry profiles in the lowest 3 km with PWATs near 0.75 inches. The combination of dry sub-cloud layers and moderate storm motions of 25-30 kt will favor very low precipitation efficiency. Thus, wetting rainfall is unlikely to occur with any thunderstorms. Dry lightning strikes appear likely over receptive fuels across central NM, necessitating IsoDryT highlights. ...Please see www.spc.noaa.gov/fire for graphic product... Read more