Severe Storms

WW 641 SEVERE TSTM AL MS TN 131835Z - 140100Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 641 NWS Storm Prediction Center Norman OK 135 PM CDT Sun Aug 13 2023 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Northern Alabama Northeast Mississippi Middle Tennessee * Effective this Sunday afternoon and evening from 135 PM until 800 PM CDT. * Primary threats include... Scattered damaging wind gusts to 60 mph possible SUMMARY...Storms are expected to continue to intensify across the region with a linear cluster evolving, with damaging winds as the primary severe hazard. The severe thunderstorm watch area is approximately along and 80 statute miles north and south of a line from 60 miles northwest of Muscle Shoals AL to 60 miles southeast of Nashville TN. 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 640... AVIATION...A few severe thunderstorms with hail surface and aloft to 1 inch. Extreme turbulence and surface wind gusts to 50 knots. A few cumulonimbi with maximum tops to 550. Mean storm motion vector 28025. ...Guyer Read more

WW 0640 Status Updates
STATUS REPORT ON WW 640 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. ..WEINMAN..08/13/23 ATTN...WFO...GYX...CAR... STATUS REPORT FOR WS 640 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS MEC001-003-005-007-009-011-013-015-017-019-021-023-025-027-031- 132240- ME . MAINE COUNTIES INCLUDED ARE ANDROSCOGGIN AROOSTOOK CUMBERLAND FRANKLIN HANCOCK KENNEBEC KNOX LINCOLN OXFORD PENOBSCOT PISCATAQUIS SAGADAHOC SOMERSET WALDO YORK NHC001-003-015-017-132240- NH . NEW HAMPSHIRE COUNTIES INCLUDED ARE BELKNAP CARROLL ROCKINGHAM STRAFFORD 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 640 SEVERE TSTM ME NH 131750Z - 140100Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 640 NWS Storm Prediction Center Norman OK 150 PM EDT Sun Aug 13 2023 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Maine Eastern New Hampshire * Effective this Sunday afternoon and evening from 150 PM until 900 PM EDT. * Primary threats include... Scattered damaging wind gusts to 65 mph possible Scattered large hail events to 1.5 inches in diameter possible SUMMARY...Scattered thunderstorms are forecast to intensify this afternoon with the stronger storms being capable of large hail and damaging gusts. This activity will gradually move from west to east across the watch area through the afternoon into the early evening. The severe thunderstorm watch area is approximately along and 70 statute miles east and west of a line from 30 miles northwest of Caribou ME to 10 miles southeast of Portsmouth NH. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU0). 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 55 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 26025. ...Smith Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0352 PM CDT Sun Aug 13 2023 Valid 151200Z - 211200Z The extended period forecast remains challenging with upper low/Rex block pattern in the eastern Pacific. Model guidance continues to vary with the progression/evolution of this feature in the near term. This variance increases with time. At the surface, a cold front will move through the Southern Plains early in the week. Other cold fronts will make progress into the Plains mid/late week. ...Northwest... Thunderstorm chances will increases into southern Oregon starting on Tuesday. Another push of mid-level moisture will begin on Thursday and renew thunderstorm potential. Activity will move northward each day into the weekend and early next week. There is some uncertainty as to when thunderstorm activity will begin to decrease. The GFS is more bullish on moving a shortwave trough across the Canadian border and pushing moisture out of the region at least temporarily. PWAT values will be a bit on the marginal side for dry thunderstorms in addition to storm motions being relatively slow between the upper low and the stronger mid-level winds to the north. As storms move northward, though, some drier storms would be possible along the leading edge of the moisture. Given all the complicating factors, confidence in placing dry thunderstorm highlights is low. Potential for locally dry and windy conditions is evident within the Cascade gaps/Columbia Gorge as temperatures increase into the Columbia Basin. The signal for more broadly critical fire weather is currently on Thursday when mid-level winds will be stronger and a surface low will deepen to the northeast. This could continue on Friday afternoon as well, but model differences in the upper/low-level patterns decrease confidence. ...Northern California... Thunderstorm activity is possible each afternoon from Tuesday into potentially the weekend. Storm motions will initially be slow and PWAT values will be somewhat high. Lighting outside of storm cores would remain a concern. The upper low is forecast to remain off the central California coast into the weekend and even intensify. As this occurs, drier air may get pulled northward. Thunderstorm potential will gradually decrease south to north with time. A few drier storms may occur later in the week, but with storm potential every afternoon in the same areas, fuels may be affected by that time. ...Montana... With an upper-level trough moving through the northern Plains on Tuesday/Wednesday, some dry and windy conditions are possible for parts of Montana. Some downslope enhancement is possible in the lee of the Rockies on Tuesday. Spatial extent of the fire weather threat appears very limited given the modest surface gradient and upper-level winds. Greater potential for critical fire weather is evident on Thursday as mid-level winds will be somewhat stronger across the terrain and a deeper surface low is expected to the north. Some potential could also exist into Friday, but the evolution of the upper-level/surface pattern is a bit too uncertain for highlights. ...Texas... Cooler, but relatively dry, northerly winds will be present behind the cold front perhaps into Tuesday/Wednesday of next week. There is low-end potential for a pocket of dry and windy conditions to develop in parts of East Texas on the western flank of an upper trough on Tuesday. Heat will return by late week. With a surface trough remaining in the region into the weekend, some concerns for elevated fire weather may develop in portions of western/central Texas. Furthermore, isolated thunderstorms are possible during the afternoons with the intense heat and may pose some concern for lightning ignitions given the dry fuels. ..Wendt.. 08/13/2023 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0245 PM CDT Sun Aug 13 2023 Valid 132000Z - 141200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS THE OZARKS... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE SOUTH-CENTRAL PLAINS TO THE TENNESSEE VALLEY...AND PORTIONS OF NEW ENGLAND... ...SUMMARY... Severe thunderstorm wind gusts, large hail and a tornado threat are expected late this afternoon into tonight, especially across the south-central Plains and Ozarks. Other severe thunderstorms will persist into early evening across New England. ...20z Update... The overall forecast philosophy is unchanged from the 1630z outlook (see previous discussion below). The only minor change in severe probabilities is across parts of southeast MN into extreme southwest WI and eastern IA where the Marginal (level 1 of 5) risk has been expanded. This expansion is related to severe potential late tonight into early Monday morning associated with convection beneath the cold core of the upper shortwave trough and in the vicinity of the surface low. Damaging wind potential will continue this afternoon across the TN Valley as an ongoing MCS spreads east/southeast. Ref Severe Thunderstorm Watch 641 and forthcoming MCDs for short term severe trends. Additional isolated severe storms will continue the next several hours across parts of Maine and vicinity where Severe Thunderstorm Watch 640 is in effect until early 01z. Severe potential is expected to increase from late afternoon into this evening across the south-central Plains toward southern MO. See MCD 1982 for short term severe potential across parts of KS. Early day convection has modified and stabilized the low-levels across MO (per mesoanalysis and 18z SGF RAOB) and will likely delay convection until this evening as the airmass recovers and a low-level jet increases. Convection will then spread east/southeast from KS/OK along residual outflow/differential heating corridor posing an all-hazards risk. ..Leitman.. 08/13/2023 .PREV DISCUSSION... /ISSUED 1154 AM CDT Sun Aug 13 2023/ ...South-Central Plains/Ozarks/Mid-South... The Lower Missouri Valley/Ozarks continue to be considerably influenced by persistent convection/MCVs at midday, with only modestly broken cloud cover across much of the warm sector ahead of the primary front. But a gradual trend of thinning/less prevalent cloud cover is noted from the west across the south-central Plains, which should allow for moderate to locally strong destabilization into/around peak heating. Deep convection is expected to develop in multiple zones by late afternoon/sunset, including across the middle Missouri Valley/eastern South Dakota vicinity near the surface low, and otherwise near the south/southeastward-moving front across southeast Nebraska and portions of Kansas, as well as across the Oklahoma/Texas Panhandles and western/northern Oklahoma. Some of this convection, as it evolves across eastern Kansas toward the Ozarks, will interface with residual differential heating and a weak residual boundary or two. Seasonally strong winds aloft will influence supercell-favorable hodographs, with large hail initially the primary hazard. Several clusters of storms should evolve by early evening, potentially including northern Oklahoma/southeast Kansas into the Ozarks, where a somewhat higher-probability for wind damage, along with some tornado potential, is expected to exist this evening, and possibly linger into the overnight. ...Tennessee Valley/southern Appalachians... On the northern fringe of the upper ridge and stronger capping aloft, a remnant cluster/MCV across far southeast Missouri/northeast Arkansas at midday will likely influence additional downstream convective development and intensification this afternoon within a moderate to strongly unstable environment. Westerlies remain a bit stronger than typical mid-August scenarios, and this should influence the persistence and organization of the storms, with some semi-organized multicellular clusters possible. Wind damage will be the primary hazard regionally. For additional details, see Mesoscale Discussion 1981. ...New England... A Slight Risk has been introduced for expectations of a somewhat greater severe-weather potential today. Isolated/widely scattered thunderstorms are expected to further develop through early afternoon along and ahead of the surface cold front. A moderately unstable environment and with deep-layer shear around 30-35 kt will support some organized multicells capable of severe hail and locally damaging wind gusts. For additional details, see Mesoscale Discussion 1980. Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0214 PM CDT Sun Aug 13 2023 Valid 141200Z - 151200Z The forecast generally remains on track. Breezy conditions are expected behind the cold front in Texas. However, RH will generally remain above critical thresholds. Some locally elevated conditions are certainly possible. Dry thunderstorm activity remains possible overnight in northern California. Coverage still appears to be very low at this time. ..Wendt.. 08/13/2023 .PREV DISCUSSION... /ISSUED 0152 AM CDT Sun Aug 13 2023/ ...Synopsis... High pressure over the Northwest is forecast to intensify as it moves inland over portions of WA and OR. Gusty north winds and hot surface conditions are expected to support local fire-weather concerns. A weak mid-level low and monsoon moisture will also lift north across CA, supporting the potential for dry thunderstorms late D2/Monday into early D3/Tuesday. ...Northwest... As the upper ridge continues to intensify and move inland, northerly flow is forecast to increase across portions of southwest WA and central OR. Bolstered by a thermally induced surface trough, surface gusts of 15-25 mph gusts are expected within the higher terrain. Poor overnight humidity recoveries from the dry northerly flow and hot afternoon temperatures will support surface RH values below 35%. A few hours of elevated fire-weather conditions appear likely given critically dry fuels. ...Northern CA... Monsoon moisture associated with the weak upper low is forecast to move into portions of northern CA late D2/Monday into early D3/Tuesday. Model soundings show PWAT values of 0.7 to 0.8 inches atop dry low levels. Weak buoyancy aloft may support isolated thunderstorms into the overnight hours, with the potential for lightning ignitions given the dry low-level air mass. However, significant uncertainty remains on storm coverage and the exact placement with relatively modest forcing for ascent. IsoDryT highlight will be withheld for now, but may be needed should greater confidence in dry storm coverage develop in subsequent forecasts. ...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 Sun Aug 13 2023 Valid 141200Z - 151200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM EASTERN KENTUCKY AND TENNESSEE INTO THE MID-ATLANTIC STATES... ...SUMMARY... Severe thunderstorms are possible Monday afternoon and evening across portions of Kentucky and Tennessee, extending north and east to the Mid-Atlantic States. ...Synopsis... A mid/upper shortwave trough oriented from the Upper Midwest to the southern Plains will develop eastward, extending from the eastern Great Lakes to the Mid-South by Tuesday morning. This will bring an belt of enhanced deep-layer southwesterly flow stretching across the Ohio Valley vicinity to the Mid-Atlantic and southern New England. At the surface, low pressure in the vicinity of eastern IA at the beginning of the period will track east to Lake Erie by 12z Tuesday. A cold front attendant to the low will shift east/southeast, extending from eastern IL to northern TX by late afternoon. This front will continue east/southeast through the overnight hours, becoming aligned along the central/southern Appalachians to south TX. A pre-frontal trough is forecast ahead of the main cold front and will become the main focus for strong/severe thunderstorm development (along with any outflow/MCVs associated with prior day's or ongoing morning convection) from KY/TN eastward. Another band of strong/severe thunderstorms attendant to the synoptic cold front and surface low are possible across parts of northern IL/far southern WI eastward across southern Lower MI/IN and northern/western OH from Monday morning into the early evening. ...OH/TN Valley vicinity to the Mid-Atlantic... Convection will likely be ongoing Monday morning across the Lower OH Valley in association with a lead shortwave impulse ahead of the main mid/upper trough. This cluster/MCS will spread east/northeast across WV/VA and southern PA through the afternoon and over the Delaware Valley during the evening. Outflow from morning convection may sag southward into Middle/eastern TN and become a focus for additional diurnal convection from the Cumberland Plateau eastward into the Carolinas. A warm front will be draped across northern MD into southern NJ. To the south of the warm front, southwesterly low-level flow will maintain upper 60s to low 70s F dewpoints, contributing to 1500-2500 J/kg MLCAPE (locally higher possible across eastern KY into TN). Moderate to strong vertical shear and steep low-level lapse rates will support a damaging wind risk from eastern KY into WV and the Mid-Atlantic. Where low-level flow is expected to remain more southeasterly in the vicinity warm front in the Delmarva vicinity, a locally higher tornado risk is possible. Further south across TN into the Carolinas, large-scale ascent will be somewhat weaker. However, moderate to strong instability, steep low-level lapse rates and modest vertical shear will support a risk for damaging winds. The greatest concentration of severe gusts is expected across parts of Middle into eastern TN. ...Lake Michigan vicinity into western OH... Beneath the core of the main upper trough and surface low, a tongue of boundary-layer moisture (dewpoints in the 60s) will arc westward from eastern OH to far eastern IA and southern WI/MI. This will result in a narrow corridor of MLCAPE up to 1000 J/kg. Within this cold core setup, enhanced low-level shear along a warm front will lead to enlarged low-level hodographs, becoming elongated above 2 km. This could support a couple of brief tornadoes and/or strong gusts from stronger cells from late morning into the afternoon. If any organized strong/deeper updrafts can be maintained, isolated hail to near 1 inch also will be possible. ..Leitman.. 08/13/2023 Read more

MD 1972 CONCERNING SEVERE THUNDERSTORM WATCH 636... FOR SOUTHWESTERN KANSAS...THE OKLAHOMA AND NORTHERN TEXAS PANHANDLE VICINITY
Mesoscale Discussion 1972 NWS Storm Prediction Center Norman OK 0519 PM CDT Sat Aug 12 2023 Areas affected...southwestern Kansas...the Oklahoma and northern Texas Panhandle vicinity Concerning...Severe Thunderstorm Watch 636... Valid 122219Z - 122315Z The severe weather threat for Severe Thunderstorm Watch 636 continues. SUMMARY...An evolving cluster of thunderstorms may continue to slowly organize and become accompanied by increasing potential to produce strong to severe wind gusts across and northeast of the Liberal KS vicinity through 7-9 PM CDT. DISCUSSION...Strongest convection has gradually consolidated near the western Oklahoma Panhandle vicinity, perhaps aided by forcing for ascent within a zone of enhanced lower/mid-tropospheric warm advection, downstream of a weak upper impulse turning northeastward across the southern Rockies. Modest easterly to northeasterly near surface inflow of moist air characterized by mixed-layer CAPE on the order of 2000+ J/kg may maintain vigorous convective development during the next few hours, and it appears possible that an MCV may gradually form as activity propagates northeastward. As it does, strengthening rear inflow to its south through southeast may gradually be accompanied by increasing potential for strong to severe surface gusts by early evening. ..Kerr.. 08/12/2023 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...OUN...DDC...AMA...PUB... LAT...LON 36920195 37490234 37850038 36959951 36310003 36140169 36920195 Read more

MD 1971 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR SOUTH-CENTRAL GA...INTO PORTIONS OF SOUTHEAST AL
Mesoscale Discussion 1971 NWS Storm Prediction Center Norman OK 0513 PM CDT Sat Aug 12 2023 Areas affected...south-central GA...into portions of southeast AL Concerning...Severe potential...Watch unlikely Valid 122213Z - 130015Z Probability of Watch Issuance...20 percent SUMMARY...Scattered storms may pose an isolated risk for damaging gusts through this evening. DISCUSSION...Over the last hour, scattered thunderstorms across parts of central GA and eastern AL have shown occasional intensification and the potential for isolated damaging gusts. Ongoing within a strongly unstable (3000-4000 J/kg), but weakly sheared environment, storms are excepted to remain predominately multi-cellular. With less than 20 kt of deep-layer shear evident on the FFC VAD, storm organization potential does not appear high. Upscale growth doesn't appear overly likely either, given the weak background and surface flow. Thus, the severe wind risk should be tied to occasional downdraft pulses within the strongest of the ongoing multi-cell clusters. Driven by the buoyancy, isolated damaging gusts will remain possible through this evening as storm slowly propagate south by southeast. The severe risk should gradually diminish after sunset with the onset of nocturnal stabilization. ..Lyons/Thompson.. 08/12/2023 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...CAE...FFC...TAE...BMX... LAT...LON 33808304 33888274 33808261 33328225 32928228 32608233 32278252 31968279 31748305 31518348 30978444 30828505 30878515 30938543 31158561 31828570 32318558 32958480 33188436 33388404 33638350 33808304 Read more

WW 0638 Status Updates
STATUS FOR WATCH 0638 HAS NOT BEEN ISSUED YET Read more

WW 638 SEVERE TSTM CT NJ NY PA CW 122210Z - 130400Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 638 NWS Storm Prediction Center Norman OK 610 PM EDT Sat Aug 12 2023 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Western Connecticut Northern New Jersey Southeast New York East central Pennsylvania Coastal Waters * Effective this Saturday night from 610 PM until Midnight EDT. * Primary threats include... Scattered damaging wind gusts to 70 mph possible Scattered large hail events to 1.5 inches in diameter possible A tornado or two possible SUMMARY...Scattered thunderstorms will persist through the evening, some of which will be supercells capable of producing occasional large hail and wind damage. Additional storms will spread into the area late this evening and early tonight, with a continued severe threat. An isolated tornado or two could also occur with favorable storm interactions. The severe thunderstorm watch area is approximately along and 50 statute miles east and west of a line from 55 miles north of Poughkeepsie NY to 35 miles west southwest of Newark NJ. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU8). 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 633...WW 634...WW 635...WW 636...WW 637... 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 28025. ...Thompson Read more

WW 0637 Status Updates
STATUS REPORT ON WW 637 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 1968 ..WEINMAN..08/12/23 ATTN...WFO...UNR... STATUS REPORT FOR WS 637 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS SDC007-033-055-071-093-102-103-122240- SD . SOUTH DAKOTA COUNTIES INCLUDED ARE BENNETT CUSTER HAAKON JACKSON MEADE OGLALA LAKOTA PENNINGTON 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 637 SEVERE TSTM SD 122040Z - 130300Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 637 NWS Storm Prediction Center Norman OK 240 PM MDT Sat Aug 12 2023 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Western South Dakota * Effective this Saturday afternoon and evening from 240 PM until 900 PM MDT. * Primary threats include... Scattered damaging wind gusts to 70 mph possible Scattered large hail events to 1.5 inches in diameter possible SUMMARY...Initially isolated thunderstorms near the Black Hills will gradually increase in coverage this evening as the storms develop eastward east of the Black Hills. Large hail will be possible with supercells through this evening. The risk for severe gusts will probably increase once storm coverage increases. The severe thunderstorm watch area is approximately along and 55 statute miles east and west of a line from 45 miles north northeast of Rapid City SD to 80 miles south southwest of Philip SD. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU7). 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 633...WW 634...WW 635...WW 636... 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 29025. ...Smith Read more

MD 1970 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR PARTS OF EASTERN PA...NORTHERN NJ AND FAR SOUTHERN NY STATE
Mesoscale Discussion 1970 NWS Storm Prediction Center Norman OK 0438 PM CDT Sat Aug 12 2023 Areas affected...parts of eastern PA...northern NJ and far southern NY State Concerning...Severe potential...Watch possible Valid 122138Z - 122345Z Probability of Watch Issuance...40 percent SUMMARY...Isolated severe storms with the potential for damaging gusts, hail and perhaps a tornado are possible this afternoon through the early evening. Uncertainty on the severe risk is high, but a weather watch is being considered. DISCUSSION...As of 2130 UTC, regional radar analysis showed isolated thunderstorms ongoing across parts of far eastern PA, NJ and southern NY State. Thus far, these storms have remained isolated in coverage ahead of a large cluster of more robust storms over western PA and northeast OH. Despite limited synoptic forcing for ascent from the lagging upper trough, the environment ahead of these isolated storms appears favorable to support some risk for severe weather this evening. Surface temps in the low to mid 80s are supporting ~1500 J/kg of MLCAPE with area VADs showing 40-50 kt of effective shear. With a CAPE/shear parameter space favorable for supercells, damaging gusts, hail and perhaps a brief tornado appear possible if storms are able to maintain intensity. The primary uncertainty with regards to the severe threat is the expected storm coverage. Broad-scale ascent is weak and thus far storms have been only marginally organized, likely from lingering inhibition evident on the 20z ALY sounding. However, recent HRRR runs suggests additional storm development/organization is possible through the early evening with a focus across far southern NY state into portions of northern NJ and far eastern PA. While confidence in storm evolution and the severe threat is low, conditions will be monitored for a possible watch. ..Lyons/Thompson.. 08/12/2023 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...OKX...ALY...PHI...BGM...CTP...LWX... LAT...LON 40177641 40687634 41157528 41377481 41857451 42157433 42287362 42077335 41707327 41227345 40827370 40397411 39927446 39657481 39507502 39467533 39527569 39627604 39677617 40177641 Read more

WW 0636 Status Updates
STATUS REPORT ON WW 636 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. ..WEINMAN..08/12/23 ATTN...WFO...PUB...DDC...ABQ...AMA... STATUS REPORT FOR WS 636 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS COC009-011-099-122240- CO . COLORADO COUNTIES INCLUDED ARE BACA BENT PROWERS KSC025-055-057-067-069-075-081-083-093-119-129-175-187-189- 122240- KS . KANSAS COUNTIES INCLUDED ARE CLARK FINNEY FORD GRANT GRAY HAMILTON HASKELL HODGEMAN KEARNY MEADE MORTON SEWARD STANTON STEVENS NMC059-122240- NM . NEW MEXICO COUNTIES INCLUDED ARE Read more

WW 636 SEVERE TSTM CO KS NM OK TX 122005Z - 130300Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 636 NWS Storm Prediction Center Norman OK 305 PM CDT Sat Aug 12 2023 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Southeast Colorado Southwest Kansas Far northeast New Mexico Oklahoma Panhandle Texas Panhandle * Effective this Saturday afternoon and evening from 305 PM until 1000 PM CDT. * Primary threats include... Scattered damaging wind gusts to 70 mph likely Scattered large hail events to 1.5 inches in diameter possible SUMMARY...Scattered to numerous thunderstorms are forecast to develop and consolidate into a thunderstorm cluster moving generally west to east across the watch area. Severe gusts will be the primary threat with the stronger thunderstorm outflow. Large hail may accompany the stronger thunderstorm cores. The severe thunderstorm watch area is approximately along and 90 statute miles north and south of a line from 40 miles northwest of Clayton NM to 50 miles east southeast of Liberal KS. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU6). 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 633...WW 634...WW 635... 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 25020. ...Smith Read more

WW 0635 Status Updates
STATUS REPORT ON WW 635 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 30 NE RMG TO 35 SW AVL TO 15 NNE TRI. ..WEINMAN..08/12/23 ATTN...WFO...FFC...GSP...RNK...MRX... STATUS REPORT FOR WS 635 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS GAC011-015-057-085-105-117-119-137-139-147-187-227-241-257-281- 291-311-122240- GA . GEORGIA COUNTIES INCLUDED ARE BANKS BARTOW CHEROKEE DAWSON ELBERT FORSYTH FRANKLIN HABERSHAM HALL HART LUMPKIN PICKENS RABUN STEPHENS TOWNS UNION WHITE NCC003-009-011-021-023-027-035-045-071-089-109-111-115-121-149- 161-175-189-199-122240- NC . NORTH CAROLINA COUNTIES INCLUDED ARE ALEXANDER ASHE AVERY BUNCOMBE BURKE CALDWELL CATAWBA CLEVELAND GASTON HENDERSON LINCOLN MCDOWELL MADISON MITCHELL POLK Read more

WW 635 SEVERE TSTM GA NC SC TN 121840Z - 130000Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 635 NWS Storm Prediction Center Norman OK 240 PM EDT Sat Aug 12 2023 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Northern Georgia Western North Carolina Upstate of South Carolina Eastern Tennessee * Effective this Saturday afternoon and evening from 240 PM until 800 PM EDT. * Primary threats include... Scattered damaging wind gusts to 65 mph possible Isolated large hail events to 1 inch in diameter possible SUMMARY...A well-developed thunderstorm cluster moving east across the middle and eastern portions of Tennessee will continue into the southern Appalachians this afternoon. Damaging gusts will be the primary hazard with the stronger cores through the early evening. The severe thunderstorm watch area is approximately along and 65 statute miles east and west of a line from 5 miles north northwest of Bristol TN to 60 miles west southwest of Anderson SC. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU5). 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 633...WW 634... AVIATION...A few severe thunderstorms with hail surface and aloft to 1 inch. Extreme turbulence and surface wind gusts to 55 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 27035. ...Smith Read more

WW 0634 Status Updates
STATUS REPORT ON WW 634 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 5 ENE FDY TO 55 NNE CLE. FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 1969 ..WEINMAN..08/12/23 ATTN...WFO...BUF...BGM...CLE...PBZ...ILN...CTP... STATUS REPORT FOR WT 634 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS NYC003-007-009-011-013-015-017-023-025-051-053-065-067-069-075- 077-097-099-101-105-107-109-117-123-122240- NY . NEW YORK COUNTIES INCLUDED ARE ALLEGANY BROOME CATTARAUGUS CAYUGA CHAUTAUQUA CHEMUNG CHENANGO CORTLAND DELAWARE LIVINGSTON MADISON ONEIDA ONONDAGA ONTARIO OSWEGO OTSEGO SCHUYLER SENECA STEUBEN SULLIVAN TIOGA TOMPKINS WAYNE YATES OHC005-007-013-019-029-031-033-035-041-043-055-059-063-065-067- 075-077-081-083-085-089-091-093-099-101-103-111-117-119-121-133- 139-143-147-151-153-155-157-159-169-175-122240- OH . OHIO COUNTIES INCLUDED ARE Read more

WW 634 TORNADO NY OH PA WV LE 121650Z - 130100Z
URGENT - IMMEDIATE BROADCAST REQUESTED Tornado Watch Number 634 NWS Storm Prediction Center Norman OK 1250 PM EDT Sat Aug 12 2023 The NWS Storm Prediction Center has issued a * Tornado Watch for portions of Southern and central New York Northern and eastern Ohio Western and northern Pennsylvania West Virginia Panhandle Lake Erie * Effective this Saturday afternoon and evening from 1250 PM until 900 PM EDT. * Primary threats include... A couple tornadoes possible Scattered damaging wind gusts to 70 mph likely Scattered large hail and isolated very large hail events to 2.5 inches in diameter possible SUMMARY...Scattered to numerous strong to severe thunderstorms are forecast to develop this afternoon and persist into this evening as this activity moves generally west to east across the watch area. The stronger storms are expected to become supercellular and pose a large to very large hail threat, but also some tornado risk. The tornado watch area is approximately along and 70 statute miles north and south of a line from 50 miles south southeast of Utica NY to 45 miles northwest of Columbus OH. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU4). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A Tornado Watch means conditions are favorable for tornadoes and 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. && OTHER WATCH INFORMATION...CONTINUE...WW 633... AVIATION...Tornadoes and a few severe thunderstorms with hail surface and aloft to 2.5 inches. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 27030. ...Smith Read more