Severe Storms

WW 569 SEVERE TSTM CT DC DE MD NJ NY PA VA CW 291850Z - 300100Z
0- URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 569 NWS Storm Prediction Center Norman OK 250 PM EDT Sat Jul 29 2023 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Southern Connecticut District Of Columbia Delaware Maryland New Jersey Southeast New York Southeast Pennsylvania Northern Virginia Coastal Waters * Effective this Saturday afternoon and evening from 250 PM until 900 PM EDT. * Primary threats include... Scattered damaging wind gusts to 70 mph possible Isolated large hail events to 1 inch in diameter possible SUMMARY...Widely scattered to scattered thunderstorms are expected to form this afternoon and spread eastward to the Mid-Atlantic coast. The storm environment supports a mix of multicell clusters and some supercells capable of producing damaging winds and isolated large hail through late evening. The severe thunderstorm watch area is approximately along and 90 statute miles east and west of a line from 45 miles west northwest of Bridgeport CT to 30 miles west of Patuxent River MD. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU9). 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 567...WW 568... AVIATION...A few severe thunderstorms with hail surface and aloft to 1 inch. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 27035. ...Thompson Read more

WW 0570 Status Updates
STATUS REPORT ON WW 570 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 15 S LOZ TO 35 SE LOZ TO 45 W TRI TO 30 N HSS TO 15 SSW TRI TO 10 E TRI TO 20 S BLF TO 15 NNW PSK TO 15 NNW SSU. FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 1778 ..BENTLEY..07/29/23 ATTN...WFO...JKL...GSP...RNK...MRX...RLX... STATUS REPORT FOR WS 570 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS NCC003-005-009-011-021-023-027-033-075-087-111-115-121-157-169- 171-173-189-193-197-199-292340- NC . NORTH CAROLINA COUNTIES INCLUDED ARE ALEXANDER ALLEGHANY ASHE AVERY BUNCOMBE BURKE CALDWELL CASWELL GRAHAM HAYWOOD MCDOWELL MADISON MITCHELL ROCKINGHAM STOKES SURRY SWAIN WATAUGA WILKES YADKIN YANCEY TNC001-009-013-019-025-029-057-059-063-067-073-089-091-093-105- 123-155-163-171-173-179-292340- TN . TENNESSEE COUNTIES INCLUDED ARE ANDERSON BLOUNT CAMPBELL Read more

WW 0571 Status Updates
STATUS REPORT ON WW 571 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. ..BENTLEY..07/29/23 ATTN...WFO...AKQ... STATUS REPORT FOR WS 571 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS MDC019-039-045-047-292340- MD . MARYLAND COUNTIES INCLUDED ARE DORCHESTER SOMERSET WICOMICO WORCESTER VAC001-007-025-033-036-041-049-053-057-065-073-075-081-085-087- 093-095-097-101-103-109-111-115-117-119-127-131-133-135-145-147- 149-159-175-181-183-193-199-550-570-595-620-650-670-700-710-730- 735-740-760-800-810-830-292340- VA . VIRGINIA COUNTIES INCLUDED ARE ACCOMACK AMELIA BRUNSWICK CAROLINE CHARLES CITY CHESTERFIELD CUMBERLAND DINWIDDIE ESSEX FLUVANNA GLOUCESTER GOOCHLAND GREENSVILLE HANOVER HENRICO ISLE OF WIGHT JAMES CITY KING AND QUEEN KING WILLIAM LANCASTER LOUISA LUNENBURG MATHEWS MECKLENBURG MIDDLESEX NEW KENT NORTHAMPTON Read more

WW 570 SEVERE TSTM KY NC TN VA WV 291945Z - 300200Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 570 NWS Storm Prediction Center Norman OK 345 PM EDT Sat Jul 29 2023 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Southeast Kentucky Northwest North Carolina Northeast Tennessee Western Virginia Extreme southern West Virginia * Effective this Saturday afternoon and evening from 345 PM until 1000 PM EDT. * Primary threats include... Scattered damaging wind gusts to 70 mph possible Isolated large hail events to 1 inch in diameter possible SUMMARY...Multicell clusters of storms are expected to increase in coverage and persist through late evening while spreading east-southeastward. Downbursts with wind damage and isolated large hail will be the main severe threats. The severe thunderstorm watch area is approximately along and 50 statute miles north and south of a line from 20 miles north northwest of Knoxville TN to 40 miles east northeast of Lynchburg VA. 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. && OTHER WATCH INFORMATION...CONTINUE...WW 567...WW 568...WW 569... AVIATION...A few severe thunderstorms with hail surface and aloft to 1 inch. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 550. Mean storm motion vector 30025. ...Thompson Read more

WW 571 SEVERE TSTM MD VA CW 292020Z - 300200Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 571 NWS Storm Prediction Center Norman OK 420 PM EDT Sat Jul 29 2023 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Southern Maryland Central and southeast Virginia Coastal Waters * Effective this Saturday afternoon and evening from 420 PM until 1000 PM EDT. * Primary threats include... Scattered damaging wind gusts to 70 mph possible Isolated large hail events to 1 inch in diameter possible SUMMARY...Scattered thunderstorms are expected to form and spread east-southeastward across southeast Virginia and southern Maryland through late evening, with an attendant threat for damaging gusts and isolated large hail. The severe thunderstorm watch area is approximately along and 55 statute miles north and south of a line from 45 miles south of Charlottesville VA to 35 miles south southeast of Wallops VA. 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 567...WW 568...WW 569...WW 570... AVIATION...A few severe thunderstorms with hail surface and aloft to 1 inch. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 550. Mean storm motion vector 30025. ...Thompson Read more

WW 0572 Status Updates
STATUS REPORT ON WW 572 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. ..JEWELL..07/29/23 ATTN...WFO...ILX...PAH...IND... STATUS REPORT FOR WS 572 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS ILC021-023-025-033-035-047-049-055-059-065-069-077-079-081-101- 145-159-165-173-185-191-193-199-292340- IL . ILLINOIS COUNTIES INCLUDED ARE CHRISTIAN CLARK CLAY CRAWFORD CUMBERLAND EDWARDS EFFINGHAM FRANKLIN GALLATIN HAMILTON HARDIN JACKSON JASPER JEFFERSON LAWRENCE PERRY RICHLAND SALINE SHELBY WABASH WAYNE WHITE WILLIAMSON INC027-051-083-125-129-147-153-163-173-292340- IN . INDIANA COUNTIES INCLUDED ARE DAVIESS GIBSON KNOX PIKE POSEY SPENCER SULLIVAN VANDERBURGH WARRICK Read more

WW 572 SEVERE TSTM IL IN KY MO 292045Z - 300200Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 572 NWS Storm Prediction Center Norman OK 345 PM CDT Sat Jul 29 2023 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Southern Illinois Southwest Indiana Western Kentucky Extreme southeast Missouri * Effective this Saturday afternoon and evening from 345 PM until 900 PM CDT. * Primary threats include... Scattered damaging wind gusts to 70 mph possible Isolated large hail events to 1 inch in diameter possible SUMMARY...A long-lived convective cluster with a history of damaging winds is expected to persist for a few more hours while moving across parts of southern Illinois, southwest Indiana and western Kentucky. The severe thunderstorm watch area is approximately along and 60 statute miles north and south of a line from 10 miles west southwest of Scott Afb IL to 25 miles northeast of Evansville IN. 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 567...WW 568...WW 569...WW 570...WW 571... AVIATION...A few severe thunderstorms with hail surface and aloft to 1 inch. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 550. Mean storm motion vector 28035. ...Thompson Read more

MD 1778 CONCERNING SEVERE THUNDERSTORM WATCH 570... FOR WESTERN NORTH CAROLINA AND FAR SOUTHWEST VIRGINIA
Mesoscale Discussion 1778 NWS Storm Prediction Center Norman OK 0456 PM CDT Sat Jul 29 2023 Areas affected...Western North Carolina and far southwest Virginia Concerning...Severe Thunderstorm Watch 570... Valid 292156Z - 292330Z The severe weather threat for Severe Thunderstorm Watch 570 continues. SUMMARY...A line of strong to severe storms with damaging wind gusts are expected to continue southeast through the evening. DISCUSSION...Moderate instability exists ahead of a line of storms now crossing the Appalachians across eastern Tennessee and far western North Carolina/Virginia. While shear is quite weak ahead of the line (15 to 20 knots) there is some stronger 4-5km flow (35-40 knots per JKL VWP) upstream. This stronger flow is likely aiding in organization of the storms and should continue to balance the cold pool sufficiently for a continued damaging wind threat through the evening. If this line of storms can maintain intensity and organization as it moves southeast this evening, a downstream watch may need to be considered across portions of western and central North Carolina. ..Bentley.. 07/29/2023 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...RAH...RNK...CAE...GSP...MRX... LAT...LON 34978084 34768135 34538246 34728310 34998351 35378344 36128315 36708212 37048107 37098041 36787954 36487895 36077901 35667952 35298017 34978084 Read more

WW 0567 Status Updates
STATUS REPORT ON WW 567 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 15 S TBN TO 10 NW FAM TO 25 NE FAM TO 25 SSW BLV TO 10 NW BLV TO 5 WSW ALN TO 25 NW ALN TO 35 SSE UIN TO 30 SE UIN TO 35 W SPI. ..JEWELL..07/29/23 ATTN...WFO...LSX...EAX...SGF... STATUS REPORT FOR WS 567 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS ILC005-027-051-061-083-117-119-121-135-157-163-189-292340- IL . ILLINOIS COUNTIES INCLUDED ARE BOND CLINTON FAYETTE GREENE JERSEY MACOUPIN MADISON MARION MONTGOMERY RANDOLPH ST. CLAIR WASHINGTON MOC065-093-123-179-186-187-292340- MO . MISSOURI COUNTIES INCLUDED ARE DENT IRON MADISON REYNOLDS STE. GENEVIEVE ST. FRANCOIS 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 567 SEVERE TSTM IL MO 291625Z - 300000Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 567 NWS Storm Prediction Center Norman OK 1125 AM CDT Sat Jul 29 2023 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Extreme west central and southwest Illinois Northern and eastern Missouri * Effective this Saturday morning and evening from 1125 AM until 700 PM CDT. * Primary threats include... Scattered damaging wind gusts to 70 mph possible Isolated large hail events to 1 inch in diameter possible SUMMARY...A long-lived cluster of storms, with a history of damaging winds, will likely persist through the afternoon while moving across northern Missouri and toward the Saint Louis vicinity. The severe thunderstorm watch area is approximately along and 60 statute miles either side of a line from 25 miles southwest of Chillicothe MO to 10 miles south of Scott Afb IL. 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 566... AVIATION...A few severe thunderstorms with hail surface and aloft to 1 inch. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 550. Mean storm motion vector 30040. ...Thompson Read more

MD 1777 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR PORTIONS OF MIDDLE AND EASTERN TENNESSEE
Mesoscale Discussion 1777 NWS Storm Prediction Center Norman OK 0430 PM CDT Sat Jul 29 2023 Areas affected...Portions of Middle and eastern Tennessee Concerning...Severe potential...Watch unlikely Valid 292130Z - 292300Z Probability of Watch Issuance...20 percent SUMMARY...An isolated damaging wind threat will exist with storms drifting south through Middle Tennessee. DISCUSSION...Storms have developed along the surface front near the Tennessee/Kentucky border west of watch 570. These storms have formed in a region with strong instability (2500 to 3000 J/kg MLCAPE) and weak effective shear (~15 knots per OHX VWP). The weak shear will likely limit overall organization with a more outflow dominant line expected. However, given the hot, moist, and unstable downstream environment, some stronger, water-loaded downdrafts are possible with some threat for damaging wind gusts. A severe thunderstorm watch is unlikely, unless the line of storms begins to show better organization and a greater threat for damaging wind gusts. ..Bentley/Grams.. 07/29/2023 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...GSP...MRX...JKL...LMK...OHX...HUN... LAT...LON 36458701 36528682 36428613 36398582 36488552 36668500 36718463 36338370 35438363 35238483 35258631 35428687 35708758 36058739 36458701 Read more

MD 1776 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR SOUTHEAST WYOMING INTO THE COLORADO FRONT RANGE
Mesoscale Discussion 1776 NWS Storm Prediction Center Norman OK 0348 PM CDT Sat Jul 29 2023 Areas affected...Southeast Wyoming into the Colorado Front Range Concerning...Severe potential...Watch possible Valid 292048Z - 292245Z Probability of Watch Issuance...40 percent SUMMARY...Strong/severe wind gusts will be the primary hazard with storm clusters moving off of the terrain. Large hail could occur with the strongest initial updrafts. A watch is possible later this afternoon. DISCUSSION...Modestly moist upslope flow into the terrain has allowed convection from the Front Range into the Laramie mountains to deepen over the last few hours. The moist layer is rather shallow (per DDC/AMA soundings this morning) and dewpoints have consequently mixed out into the upper 50s/low 60s F. Some capping remains on the Plains to the east as a result. However, moisture is also slightly higher than some guidance has suggested. With time and continued heating (likely upper 80s to perhaps lower 90s F), a few deeper updrafts will develop. Given the modest deep-layer shear (stronger north, weaker south) and large temperature/dewpoint spreads at the surface, outflow will be prevalent. Congealing cold pools will be the likely mechanism to drive storms out onto the Plains. The strongest storms would be capable of large hail initially, although strong/severe wind gusts are the primary hazard expected late this afternoon. A severe thunderstorm watch is possible this afternoon, but timing is uncertain as to when storms will move off of the terrain. ..Wendt/Thompson.. 07/29/2023 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...GLD...PUB...BOU...CYS... LAT...LON 38550462 40280522 41370543 41920506 41960422 41160357 40030309 39100286 38380321 38220381 38550462 Read more

MD 1775 CONCERNING SEVERE THUNDERSTORM WATCH 568...569... FOR SOUTHEASTERN NEW YORK/SOUTHERN NEW ENGLAND SOUTHWARD TO THE CHESAPEAKE BAY
Mesoscale Discussion 1775 NWS Storm Prediction Center Norman OK 0345 PM CDT Sat Jul 29 2023 Areas affected...Southeastern New York/southern New England southward to the Chesapeake Bay Concerning...Severe Thunderstorm Watch 568...569... Valid 292045Z - 292245Z The severe weather threat for Severe Thunderstorm Watch 568, 569 continues. SUMMARY...Strong/locally severe storms will continue across parts of the Northeast and Mid-Atlantic regions over the next few hours. DISCUSSION...Latest radar loop shows widespread thunderstorm activity from northeastern Pennsylvania and southeastern New York into parts of southern New England, with more isolated storms extending southward to Maryland and northern Virginia. The storms are occurring within an airmass generally characterized by 1000 to 1500 J/kg mixed-layer CAPE, though instability is greater with southward extent across the Chesapeake Bay area. Within the broader area of convection, isolated stronger storms are ongoing -- the strongest of which are within a broken band from Maryland across the Capitol region. Locally damaging wind gusts remain the primary risk with these storms, and those across the remainder of WW 568 and 569 over the next few hours. ..Goss.. 07/29/2023 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...GYX...BOX...OKX...ALY...PHI...BGM...AKQ...CTP... LWX... LAT...LON 43147132 42177061 41457154 40677385 39797500 38447600 38167755 38627818 40837644 41917662 42827455 43147132 Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0259 PM CDT Sat Jul 29 2023 Valid 292000Z - 301200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHEAST/MID-ATLANTIC...MID MISSISSIPPI VALLEY...AND NORTHERN/CENTRAL PLAINS... ...SUMMARY... Widely scattered to scattered severe thunderstorms with damaging winds are possible over southern New England into the Mid-Atlantic and Missouri through this evening. Large hail and strong to severe outflow gusts are also possible this evening into tonight across the central/northern High Plains. ...20Z Update... Severe probabilities have been adjusted across MO into southern IL/IN and western KY based on a persistent MCS moving east-southeastward over MO. Several damaging wind and multiple measured severe gusts have been noted with this cluster, and this should remain the primary severe threat through the rest of the afternoon. The northern extent of the wind threat should be constrained by a weak front/instability gradient extending across southern IL. See Mesoscale Discussion 1774 for more details. Otherwise, minor adjustments have been made to the Marginal/Slight Risk areas across New England and the Mid-Atlantic into the Carolinas based on recent observational and short-term model trends. No changes have been made to the Slight Risk across the northern and central High Plains. Greater confidence exists for convection to develop over the higher terrain of northern/central CO and spread eastward into the adjacent High Plains over the next couple of hours. Both large hail and severe wind gusts will be possible with any supercells that can be sustained. ..Gleason.. 07/29/2023 .PREV DISCUSSION... /ISSUED 1114 AM CDT Sat Jul 29 2023/ ...Mid-Atlantic to southern New England through this evening... Overnight convection has largely dissipated over PA, with some convection persisting across NY from Lake Ontario eastward along a surface front that is moving slowly southward. A convectively-augmented midlevel trough and belt of 40-50 kt midlevel flow will continue eastward today over PA/NY, as an associated/weak surface cyclone likewise develops eastward. 12z regional soundings revealed poor midlevel lapse rates in the warm sector, but surface heating in cloud breaks will contribute to destabilization through the afternoon as temperatures warm into the 80s across southern New England and the 90s into VA/Mid-Atlantic. Scattered thunderstorms are expected to form by early-mid afternoon along the surface wind shift/front and along differential heating zones and spread eastward through this evening. MLCAPE of 1000-1500 J/kg, steepening low-level lapse rates and the increasing midlevel flow from west-to-east suggest that damaging winds will be the main threat with a mix of multicell clusters and some supercells this afternoon into this evening. Additional clusters/bands of storms are expected this afternoon from eastern KY/TN into western VA along a diffuse outflow/front. This area will lie along the southern fringe of the westerlies aloft, but thermodynamic profiles will favor occasional downbursts with wind damage. ...MO to western KY through this evening... An MCS and associated MCV are ongoing over northwest MO, with a history of measured severe outflow gusts the past few hours. Given the organized nature of the MCS/cold pool and surface heating/destabilization ongoing along an outflow-reinforced front from northern MO to southern IL/western KY, the MCS may persist into the afternoon. Damaging winds will continue to be the main concern with these storms. ...Central/northern High Plains through tonight... Subtle perturbations will continue to move around the northern periphery of the midlevel high centered over the Four Corners, with post-frontal/upslope low-level flow established from northeast CO to MT. The lower Plains should generally remained capped, with storm initiation focused by terrain circulations later this afternoon/evening from the CO Front Range into southeast WY. Isolated severe outflow gusts and large hail will be the main threats given moderate buoyancy, steep midlevel lapse rates and effective bulk shear in the 30-40 kt range. A cluster or two of storms could persist into tonight with isolated severe potential into NE. Farther north, the details of storm development/coverage are uncertain through tonight. Diurnal, surface-based convection is in question given the somewhat cool boundary layer and clouds into western ND. The potential for elevated storms, including a couple of supercells, is a bit higher tonight, with an attendant threat for isolated large hail. Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0259 PM CDT Sat Jul 29 2023 Valid 301200Z - 311200Z The previous forecast (see below) generally remains on track, and only minor adjustments were made based on the latest high-resolution guidance consensus. In particular, the Elevated highlights in southeastern OR were expanded slightly northeastward into the Blue Mountains -- where confidence in the overlap of around 15 mph sustained southwesterly surface winds and 10-15 percent RH has increased. While near-critical conditions are possible in the lee of the northern Sierra and southern Cascades in southern OR/northwest NV, current thinking is that sustained surface winds will generally remain below 20 mph. In addition to the fire-weather concerns addressed below, a few other areas of localized concern are possible: 1) In southern CA, gusty north-northwesterly surface winds and warm/dry conditions are expected tonight across parts of southern Santa Barbara County. While locally elevated conditions are possible here, the localized nature of the threat precludes Elevated highlights. 2) A couple dry thunderstorms capable of isolated lightning-induced ignitions are possible in western MT along the western edge of a deeper monsoonal moisture plume. However, storm coverage appears too isolated for highlights. 3) Continued warm/dry/gusty conditions and increasingly receptive fuels across west and central TX could promote locally elevated fire-weather conditions. With that said, sustained surface winds generally below 15 mph should limit the overall fire-weather threat. ..Weinman.. 07/29/2023 .PREV DISCUSSION... /ISSUED 0159 AM CDT Sat Jul 29 2023/ ...Synopsis... Moderate mid-level flow will remain across most of the Northwest on Sunday. This will result in elevated fire weather conditions where deep mixing and/or terrain effects support some of the stronger mid-level flow transporting to the surface. This will include downslope flow/deep mixing across northeast California, northwest Nevada, southeast Oregon and far southwest Idaho, deep mixing in the Columbia Basin, and deep mixing parallel to the Snake River Plain across eastern Idaho. These stronger winds will occur among single-digit relative humidity in the lee of the Sierra and Snake River Plain and humidity around 20 percent in the Columbia River Basin. This justifies 3 Elevated areas, where the combination of wind and relative humidity will lead to some increased threat for large fires. ...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 1230 PM CDT Sat Jul 29 2023 Valid 301200Z - 311200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHERN/CENTRAL HIGH PLAINS...MID MISSOURI VALLEY INTO THE TENNESSEE VALLEY AND SOUTHEAST...AND ARIZONA... ...SUMMARY... Isolated strong to severe thunderstorms appear possible Sunday from parts of the mid Missouri Valley into the Tennessee Valley and Southeast, as well portions of the northern/central High Plains, and Arizona. ...Synopsis... An expansive upper ridge/anticyclone will remain centered over much of the Southwest and southern Plains on Sunday. Multiple low-amplitude, mid-level perturbations are forecast to advance around the crest of this upper ridge across the northern Rockies and adjacent High Plains through the period. Large-scale upper troughing will be maintained over a majority of the eastern states and Canada. A belt of enhanced mid-level northwesterly winds should persist between the upper ridge/trough over portions of the Upper Midwest, OH/TN Valleys, and eastern CONUS. At the surface, weak lee troughing should exist across parts of the northern/central High Plains. Farther east, an ill-defined and convectively reinforced front should extend from parts of the Mid-Atlantic westward into the TN Valley and Mid-South. ...Northern/Central High Plains... At least isolated thunderstorms should develop by mid Sunday afternoon across the higher terrain of the northern/central Rockies. This activity is forecast to develop generally eastward into the adjacent northern/central High Plains with time. As this convection encounters greater low-level moisture and instability along/east of the weak lee trough, it should gradually strengthen. Various NAM/RAP forecast soundings across eastern MT/WY into the Dakotas and western NE depict favorable deep-layer shear that would support supercells. An isolated threat for large hail and severe wind gusts would accompany this activity as it moves eastward through Sunday evening/night, as steep mid-level lapse rates aid robust updrafts and hail production. At this point, confidence in a more concentrated corridor of severe potential remains low, as large-scale ascent associated with weak mid-level impulses rounding the upper ridge appears somewhat nebulous. ...Mid Missouri Valley into the Tennessee Valley and Southeast... Convective evolution remains uncertain across these regions on Sunday. Thunderstorms may once again be ongoing at the start of the period across parts of the Mid MO Valley and vicinity, in association with earlier/overnight convection across the central Plains. An isolated wind threat could persist with this activity Sunday morning into afternoon as it spreads southeastward across MO into the Mid-South and TN Valley with a destabilizing airmass along/south of a weak front. A convectively generated MCV related to convection ongoing in the Day 1 period across MO will probably be located somewhere across the TN Valley and southern Appalachians by Sunday morning. Renewed convective development across GA into SC should occur by Sunday afternoon along/east of this MCV and related weak mid-level perturbation. Although deep-layer shear is forecast to remain weak, a mix of pulse and loosely organized multicells appear possible. Steepening low-level lapse rates and destabilization of a moist boundary layer should promote some threat for damaging winds with the strongest cores. Other convection also appears likely to develop across the Deep South/central Gulf Coast vicinity, with some of this activity related to various sea breezes. Based on consensus of latest guidance showing at least scattered thunderstorms developing across much of this area, have expanded the Marginal Risk for damaging winds to include more of the Southeast. ...Arizona... Thunderstorms that develop over the higher terrain of the Rim and southeastern AZ should be able to move into the lower deserts late Sunday afternoon through Sunday evening, as easterly mid-level flow around 15-25 kt on the southern periphery of the upper ridge/anticyclone should aid westward propagation. Very steep low/mid-level lapse rates associated with a hot and well-mixed boundary layer may prove favorable for convective downdrafts occasionally producing severe wind gusts. ..Gleason.. 07/29/2023 Read more

WW 0560 Status Updates
STATUS FOR WATCH 0560 HAS NOT BEEN ISSUED YET Read more

WW 560 SEVERE TSTM IA NE WI 282200Z - 290500Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 560 NWS Storm Prediction Center Norman OK 500 PM CDT Fri Jul 28 2023 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Southwest to northeast Iowa Eastern Nebraska Southwest Wisconsin * Effective this Friday afternoon from 500 PM until Midnight CDT. * 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...Initial storms developing along a front from the Mid-Missouri Valley to north-central Iowa will likely grow upscale into multiple southeast-moving clusters this evening. The severe thunderstorm watch area is approximately along and 55 statute miles north and south of a line from 20 miles northwest of Lincoln NE to 45 miles north northeast of Dubuque IA. 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. && OTHER WATCH INFORMATION...CONTINUE...WW 557...WW 558...WW 559... 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 600. Mean storm motion vector 30030. ...Grams Read more

WW 0557 Status Updates
STATUS REPORT ON WW 557 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 15 ESE BKW TO 35 SW DUJ TO 30 NNE FKL TO 25 N YNG TO 40 W ERI. FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 1752 ..SUPINIE..07/28/23 ATTN...WFO...CLE...PBZ...RLX... STATUS REPORT FOR WS 557 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS PAC039-049-282240- PA . PENNSYLVANIA COUNTIES INCLUDED ARE CRAWFORD ERIE WVC075-083-093-282240- WV . WEST VIRGINIA COUNTIES INCLUDED ARE POCAHONTAS RANDOLPH TUCKER LEZ149-282240- CW . ADJACENT COASTAL WATERS INCLUDED ARE CONNEAUT OH TO RIPLEY NY Read more

WW 557 SEVERE TSTM OH PA WV LE 281820Z - 290000Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 557 NWS Storm Prediction Center Norman OK 220 PM EDT Fri Jul 28 2023 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Eastern Ohio Western Pennsylvania Western and northern West Virginia Lake Erie * Effective this Friday afternoon and evening from 220 PM until 800 PM EDT. * Primary threats include... Scattered damaging wind gusts to 70 mph possible SUMMARY...A band of thunderstorms will spread eastward across eastern Ohio, West Virginia and western Pennsylvania through the afternoon, with an attendant threat for occasional wind damage. The severe thunderstorm watch area is approximately along and 45 statute miles east and west of a line from 35 miles north northwest of Franklin PA to 40 miles south of Charleston WV. 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. && AVIATION...A few severe thunderstorms with hail surface and aloft to 0.5 inches. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 550. Mean storm motion vector 27025. ...Thompson Read more