Severe Storms

WW 551 SEVERE TSTM MI OH LE LH 261805Z - 262300Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 551 NWS Storm Prediction Center Norman OK 205 PM EDT Wed Jul 26 2023 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Southeast Lower Michigan Northern Ohio Lake Erie Lake Huron * Effective this Wednesday afternoon and evening from 205 PM until 700 PM EDT. * Primary threats include... Scattered damaging winds likely with isolated significant gusts to 75 mph possible Isolated large hail events to 1.5 inches in diameter possible A tornado or two possible SUMMARY...Several fast-moving clusters of thunderstorms will track across the watch area this afternoon. The strongest cells will pose a risk of damaging wind gusts and some hail. The severe thunderstorm watch area is approximately along and 70 statute miles east and west of a line from 20 miles north of Bad Axe MI to 40 miles west southwest of Cleveland OH. 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 550... AVIATION...A few severe thunderstorms with hail surface and aloft to 1.5 inches. Extreme turbulence and surface wind gusts to 65 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 27040. ...Hart Read more

MD 1729 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR NORTHEASTERN COLORADO...FAR SOUTHEASTERN WYOMING...FAR SOUTHWESTERN NEBRASKA...NORTHWESTERN KANSAS
Mesoscale Discussion 1729 NWS Storm Prediction Center Norman OK 0337 PM CDT Wed Jul 26 2023 Areas affected...northeastern Colorado...far southeastern Wyoming...far southwestern Nebraska...northwestern Kansas Concerning...Severe potential...Watch possible Valid 262037Z - 262230Z Probability of Watch Issuance...60 percent SUMMARY...Severe potential increasing into the afternoon/evening. DISCUSSION...Thunderstorm activity has been ongoing across the Front Range and areas just west and south of the Denver Metro. Dew points within this region are generally in the mid 40s to 50s. High-based convection is expected to gradually shift into the plains through the evening, where a more moist and unstable air mass is available. This may lead to a more organized severe threat later for northeastern Colorado/far southeastern Wyoming persisting into southwestern Nebraska and northwestern Kansas later this evening. The main threats would be damaging winds, given "inverted V" thermodynamic profiles. Hodographs are generally straight with deep layer shear around 40 kts which may support a few isolated instances of large hail early on. Trends will be monitored for potential watch issuance over the next few hours. ..Thornton/Hart.. 07/26/2023 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...LBF...GLD...PUB...BOU...CYS... LAT...LON 39530518 40060541 40500555 40700557 40990554 41170528 41290472 41330402 41340345 41310280 41250216 41110177 40910133 40600097 40120067 39790057 39460060 39420062 38960088 38700117 38670145 38620178 38600312 38540348 38520383 38530407 38630430 38800463 38960485 39530518 Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0302 PM CDT Wed Jul 26 2023 Valid 262000Z - 271200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS PORTIONS OF THE SOUTHERN GREAT LAKES REGION... ...SUMMARY... Severe thunderstorm gusts remain possible this afternoon and evening for parts of the southern Great Lakes, along with occasional large hail. Severe gusts also are possible over parts of the central High Plains this afternoon. ...20Z Update... The primary changes to the ongoing forecast were to reduce wind probabilities in the wake of convection, trim severe probabilities behind the shortwave trough in the Upper Midwest along with minor changes to the general thunderstorm area. The remainder of forecast remains on track with additional thunderstorm development possible in the southern Great Lakes region as the low-level jet intensifies later today/tonight. ..Wendt.. 07/26/2023 .PREV DISCUSSION... /ISSUED 1109 AM CDT Wed Jul 26 2023/ ...Lower MI and Vicinity... Multiple strong/severe MCSs are ongoing this morning over western Lower MI, Lake MI, and southern WI. Two lead bowing clusters of convection over western Lower MI will likely continue to track quickly eastward today into a progressively more unstable air mass. Dewpoints in the mid/upper 60s and relatively strong heating will yield afternoon MLCAPE values over 2000 J/kg. Mid-level lapse rates are not particularly steep, but rather strong winds aloft and mesoscale organization of these clusters will help to pose a risk of damaging winds across much of central/eastern Lower MI through the afternoon. The potential also exists for a few supercells to form ahead of the main bowing structures, posing a risk of hail and a few tornadoes as well. Behind the lead convection, another bowing MCS is moving across southwest WI. These storms are closer to the mid-level vorticity center and even stronger winds aloft. It is unclear how much destabilization can occur in the wake of the lead storms, but it seems plausible that this cluster will also pose a severe risk through much of the afternoon and evening, traversing a similar track as the southern lead bowing structure. ...UT to CO/KS/NE... A corridor of sufficient mid-level moisture is expected to result in scattered high-based showers and thunderstorms from parts of UT into northern CO and southern WY today. As the storms over the CO mountains spread eastward into the plains, they will encounter an increasingly moist and unstable air mass. A few of these storms may become severe by late afternoon/evening with damaging winds being the main concern. ...Southern AZ... Several 12z HREF members show a cluster of thunderstorms developing over the higher terrain of southern AZ and spreading northwestward during the evening. If this scenario unfolds, strong wind gusts could affect the region. Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0210 PM CDT Wed Jul 26 2023 Valid 271200Z - 281200Z The previous forecast remains valid with only minor adjustments for the latest guidance. A few hours of dry and breezy conditions are possible from the southern Cascades to the northern Great Basin. A few thunderstorms are also possible early in the morning and again in the afternoon. However, lightning coverage will be low. Please see the prior discussion for more information. ..Lyons.. 07/26/2023 .PREV DISCUSSION... /ISSUED 0107 AM CDT Wed Jul 26 2023/ ...Synopsis... Strong mid-level flow will traverse the periphery of a stationary upper ridge (centered over the Southern Rockies) and will overspread the northern Great Basin tomorrow/Thursday. By afternoon peak heating, downslope flow along the higher terrain will support 15-20 mph sustained westerly surface winds from the California/Nevada border into the Snake River Plain. Coinciding these breezy surface conditions will be 10-15 percent RH, warranting the introduction of Elevated highlights. Monsoonal moisture associated with the upper ridge will support another day of scattered thunderstorms over the Rockies. Any strikes that can occur in patchy dry fuel beds will support a localized wildfire-spread threat. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

WW 0550 Status Updates
STATUS REPORT ON WW 550 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. ..WEINMAN..07/26/23 ATTN...WFO...IWX...GRR... STATUS REPORT FOR WS 550 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS INC039-087-091-141-151-261940- IN . INDIANA COUNTIES INCLUDED ARE ELKHART LAGRANGE LA PORTE ST. JOSEPH STEUBEN MIC005-015-021-023-025-027-035-037-045-057-059-065-067-073-075- 077-081-085-105-107-117-121-123-127-133-139-149-159-261940- MI . MICHIGAN COUNTIES INCLUDED ARE ALLEGAN BARRY BERRIEN BRANCH CALHOUN CASS CLARE CLINTON EATON GRATIOT HILLSDALE INGHAM IONIA ISABELLA JACKSON KALAMAZOO KENT LAKE MASON MECOSTA MONTCALM MUSKEGON NEWAYGO OCEANA OSCEOLA OTTAWA ST. JOSEPH VAN BUREN Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1237 PM CDT Wed Jul 26 2023 Valid 271200Z - 281200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS PORTIONS OF NEW ENGLAND INTO THE MID-ATLANTIC... ...SUMMARY... Widely scattered severe thunderstorms are forecast across southern New England southward into portions of the Mid-Atlantic states on Thursday. Damaging gusts and a couple tornadoes will be the primary hazards. ...Synopsis... A shortwave trough currently in the upper Midwest will continue eastward into Thursday. This feature is forecast to reach New England by early afternoon. Strong mid-level flow will persist across the northern periphery of the upper-level ridge in the northern Plains into the upper Mississippi Valley. A surface low will move through the Northeast along with an associated warm front and a weak front/surface trough trailing into the Blue Ridge/Piedmont regions. Another surface boundary in the northern Plains into northern Minnesota/Wisconsin/Upper Peninsula Michigan will sag southward. ...Northeast/Mid-Atlantic... Some ongoing activity is expected during the morning within the Northeast, likely near the Canadian border. Some lingering cloud cover can be expected perhaps into the early afternoon. Cloud cover will generally decrease with southward extent into the Mid-Atlantic. Heating through broken cloud cover in New England should be sufficient to promote at least 1000-1500 J/kg MLCAPE given the moist airmass expected. Deep-layer shear with the shortwave trough will not be overly strong (30-40 kts), but should allow for some storm organization with a mix of discrete cells and multicells. Low-level wind fields will be moderately strong and promote a risk for damaging winds with the strongest updrafts. Near the warm front, low-level shear will also favor some potential for low-level rotation and a threat for a couple tornadoes. Should greater surface heating occur, greater risk for damaging winds could be realized. Farther south into the Mid-Atlantic, weaker shear will be present. Stronger surface heating will still promote buoyancy perhaps in excess of 2000 J/kg MLCAPE. Damaging wind gusts and isolated large hail would be the main threats with activity moving off of the Blue Ridge. ...Central High Plains into Upper Midwest... Deep-layer shear will be maximized near the surface boundary and weaken with southward extent across the broad region. Scattered storms appear most likely within the higher terrain of Wyoming into eastern Colorado. These storms would primarily pose a threat of strong/severe wind gusts. Strong heating within the Plains could allow for isolated strong/severe storms to develop. Forcing will be weak and capping will keep storm development uncertain. Guidance does show a weak surface low developing in Minnesota into northwest Wisconsin. Surface convergence may be great enough to allow a cluster of storms to develop. Shear in this region would be favorable for supercells initially. Large hail and strong/severe wind gusts would be possible. Weak low-level shear and deep-layer shear parallel to the boundary, however, suggests upscale growth would occur relatively quickly and limit the duration of the large hail threat. ..Wendt.. 07/26/2023 Read more

MD 1707 CONCERNING SEVERE THUNDERSTORM WATCH 546... FOR SOUTHERN NEW ENGLAND
Mesoscale Discussion 1707 NWS Storm Prediction Center Norman OK 0516 PM CDT Tue Jul 25 2023 Areas affected...Southern New England Concerning...Severe Thunderstorm Watch 546... Valid 252216Z - 260015Z The severe weather threat for Severe Thunderstorm Watch 546 continues. SUMMARY...A few strong storms will spread across southern New England this evening. Gusty winds remain the primary threat. DISCUSSION...Large-scale forcing ahead of progressive short-wave trough is advancing across the northern Middle Atlantic into southern New England early this evening. A small pocket of modest instability has yet to be overturned over eastern CT/RI into southeast MA. Over the next few hours, strong convection is expected to propagate east-southeast across southern New England with an attendant threat for gusty winds. Even so, convection should gradually weaken as it progresses toward coastal MA due to weaker buoyancy. ..Darrow.. 07/25/2023 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...BOX...OKX... LAT...LON 41987258 42007127 41267136 41157283 41987258 Read more

MD 1706 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR PORTIONS OF EASTERN NORTH DAKOTA INTO FAR WESTERN MINNESOTA
Mesoscale Discussion 1706 NWS Storm Prediction Center Norman OK 0457 PM CDT Tue Jul 25 2023 Areas affected...portions of eastern North Dakota into far western Minnesota Concerning...Severe potential...Watch possible Valid 252157Z - 252330Z Probability of Watch Issuance...60 percent SUMMARY...The severe threat is increasing across portions of North Dakota into northwestern Minnesota. Severe hail and wind are the main threats. Convective coverage trends are being monitored for the need of a Severe Thunderstorm Watch. DISCUSSION...MRMS mosaic radar imagery depicts an increase in convective intensity across ND as a subtle mid-level trough overspreads the region, with at least one supercell taking shape in Cavalier County, ND. Though appreciable convective inhibition remains in place, strong surface heating of a moist low-level airmass (characterized by near 70 F surface dewpoints) supports 3000-5000 J/kg MLCAPE (per 21Z mesoanalysis). At the moment, it is unclear if the upper support across the northern Plains will compensate for the substantial CINH to support a relatively widespread severe threat. On the other hand, given the instability, any storm that can mature and become sustained should support a severe wind and hail threat. As such, convective trends will continue to be monitored for the need of a Severe Thunderstorm Watch. ..Squitieri/Thompson.. 07/25/2023 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...FGF...BIS... LAT...LON 45989853 48399840 48999806 49119739 48909647 48519616 47829605 47139604 46549596 46269604 46129634 45949714 45989853 Read more

WW 0546 Status Updates
140- STATUS REPORT ON WW 546 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 20 W BWI TO 10 ENE TTN TO 30 NNE EWR TO 25 N POU. ..KERR..07/25/23 ATTN...WFO...OKX...BOX...ALY...LWX...PHI...CTP... STATUS REPORT FOR WS 546 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS CTC001-003-005-007-009-011-013-015-252140- CT . CONNECTICUT COUNTIES INCLUDED ARE FAIRFIELD HARTFORD LITCHFIELD MIDDLESEX NEW HAVEN NEW LONDON TOLLAND WINDHAM DEC001-003-005-252140- DE . DELAWARE COUNTIES INCLUDED ARE KENT NEW CASTLE SUSSEX DCC001-252140- DC . DISTRICT OF COLUMBIA COUNTIES INCLUDED ARE DISTRICT OF COLUMBIA Read more

WW 546 SEVERE TSTM CT DC DE MD NJ NY PA VA CW 251610Z - 260000Z
0- URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 546 NWS Storm Prediction Center Norman OK 1210 PM EDT Tue Jul 25 2023 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Connecticut District Of Columbia Delaware Eastern Maryland New Jersey Southeast New York Eastern Pennsylvania Northern Virginia Coastal Waters * Effective this Tuesday afternoon and evening from 1210 PM until 800 PM EDT. * Primary threats include... Scattered damaging wind gusts to 70 mph possible Isolated large hail events to 1.5 inches in diameter possible SUMMARY...Thunderstorms will increase from northern Virginia into eastern Pennsylvania this afternoon, then track eastward across the watch area through the day. Damaging winds are possible in the strongest storms. The severe thunderstorm watch area is approximately along and 70 statute miles east and west of a line from 10 miles west northwest of Windsor Locks CT to 45 miles east southeast of Washington DC. 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. && 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 27030. ...Hart Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0246 PM CDT Tue Jul 25 2023 Valid 252000Z - 261200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE NORTHEAST...AND OVER PARTS OF THE NORTHERN PLAINS... ...SUMMARY... Scattered severe wind/hail-producing thunderstorms are possible across parts of the Northern Plains and the Northeast into this evening. Isolated severe gusts are also possible over portions of the Interior West. ...20z Update... No changes have been made to the outlook with the 20z Update. Scattered severe thunderstorms will continue to shift east/northeast across WW 546 the next few hours before moving offshore the Mid-Atlantic/Northeast coast. Additional severe thunderstorms are expected to develop over the northern Plains in the next few hours. These storms will shift east/southeast through the evening into early tonight, producing hail and damaging gusts. ..Leitman.. 07/25/2023 .PREV DISCUSSION... /ISSUED 1129 AM CDT Tue Jul 25 2023/ ...Mid Atlantic into southern New England... A remnant MCV is currently over eastern PA. This feature is embedded within a larger-scale shortwave trough and associated 40 knot mid-level jet moving into the northeast states. Forcing ahead of these features is leading to scattered thunderstorm development. Strong heating across the region, coupled with dewpoints in the 70s will lead to moderate CAPE values over 2000 J/kg. Sufficient winds aloft and steep low-level lapse rates will promote locally damaging wind gusts in the stronger cells through early evening. Storms will eventually build southward into eastern VA/MD as well. ...Northern Plains... Water vapor imagery shows a fast-moving shortwave trough over MT/WY. This feature will emerge into the Plains this afternoon, with large scale ascent overspreading the Dakotas. As this ascent reaches the western edge of deeper/richer moisture over central ND/SD, thunderstorms are expected to rapidly develop. Initial storms will likely be supercells with a risk of large hail and damaging winds. Storms should congeal upscale through the evening as they track east-southeastward into southwest MN/western IA with a continued risk of damaging winds. Other more isolated severe storms may develop southward into parts of NE and northeast CO, with a localized risk of damaging winds and hail. Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0247 PM CDT Tue Jul 25 2023 Valid 261200Z - 271200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF NORTHWEST NV...PORTIONS OF FAR SOUTHERN OR...AND NORTHEAST CA... ...Eastern OR/WA and the ID Panhandle... A shortwave mid-level trough is forecast to move over portions of the Northern Great Basin into the Northwest late D2/Wed into early D3/Thur morning. Subtle forcing for ascent, and mid-level moisture will aid in isolated, mostly nocturnal, thunderstorm chances. Hi-res guidance shows some potential for lightning to interact with drier fuel beds across far eastern WA/OR into portions of the ID Panhandle. Should this occur, a few lightning ignitions are possible as fuels have dried over the preceding days. However, overall confidence in storm coverage is too low for IsoDryT highlights. Otherwise critical fire-weather conditions are possible over the northern great Basin. The prior forecast remains valid with no changes. See previous discussion. ..Lyons.. 07/25/2023 .PREV DISCUSSION... /ISSUED 0142 AM CDT Tue Jul 25 2023/ ...Synopsis... A series of mid-level troughs will crest the southern Rockies stationary ridge and traverse the Pacific Northwest and northern Rockies tomorrow/Wednesday. Strong forcing accompanying the passing troughs will support widespread 15+ mph sustained westerly surface winds amid 15-20 percent RH by afternoon peak heating in and to the south of the Harney Basin and also northern Montana, necessitating Elevated highlights. Surface winds may be stronger along the California/Nevada/Oregon border, prompting the addition of Critical highlights this outlook. Similar to previous days, monsoonal moisture associated with the stationary upper ridge may promote a few high-based thunderstorms with erratic wind gusts by afternoon, with fire starts possible wherever lightning can strike in dry fuel beds. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

MD 1701 CONCERNING SEVERE THUNDERSTORM WATCH 545... FOR PORTIONS OF KY...IN...AND OH
Mesoscale Discussion 1701 NWS Storm Prediction Center Norman OK 0512 PM CDT Mon Jul 24 2023 Areas affected...Portions of KY...IN...and OH Concerning...Severe Thunderstorm Watch 545... Valid 242212Z - 242345Z The severe weather threat for Severe Thunderstorm Watch 545 continues. SUMMARY...Ongoing thunderstorms should continue to pose a threat for severe hail and damaging winds for a couple more hours this evening. DISCUSSION...Convection that strengthened earlier this afternoon across the OH Valley along and ahead of a weak front has produced occasional severe hail and damaging winds over the past couple of hours. The thermodynamic environment across this region remains favorable for robust thunderstorms in the short term, with latest mesoanalysis estimates showing around 2000-3500 J/kg MLCAPE present. Recent VWPs from area radars suggest low to mid-level flow remains fairly modest below about 6 km AGL, with some strengthening of northwesterly winds around 7-9 km AGL. A mix of multicells and marginal supercells should continue to pose a threat for mainly severe hail and damaging winds, respectively. This convection is forecast to slowly spread east-southeastward across parts of KY, southern/eastern IN, and southern/western OH over the next couple of hours. A less unstable airmass with eastward extent across the OH Valley and eventual nocturnal cooling should limit the overall severe threat farther east later this evening. ..Gleason.. 07/24/2023 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...PBZ...RLX...CLE...JKL...ILN...LMK...IND...PAH... LAT...LON 38678706 40068577 40528325 40278228 39778216 38768269 38098396 37728517 36668570 36668740 37698688 38678706 Read more

MD 1700 CONCERNING SEVERE THUNDERSTORM WATCH 544... FOR PARTS OF NORTHEAST PENNSYLVANIA INTO NEW YORK
Mesoscale Discussion 1700 NWS Storm Prediction Center Norman OK 0453 PM CDT Mon Jul 24 2023 Areas affected...parts of northeast Pennsylvania into New York Concerning...Severe Thunderstorm Watch 544... Valid 242153Z - 250000Z The severe weather threat for Severe Thunderstorm Watch 544 continues. SUMMARY...The severe threat continues across Severe Thunderstorm Watch 544. Strong wind gusts remain the primary concern this evening. DISCUSSION...Multiple rounds of thunderstorms have moved across the portions of the Hudson Valley this afternoon with a history of damaging gusts. The airmass across much of eastern NY into New England has become overturned by earlier storms, though ongoing storms across central NY are approaching from the west. Given limited airmass modification ahead of these storms (i.e. surface temperatures warming into the mid 70s F), a couple of additional strong wind gusts may still occur before storms wane in intensity this evening. An instance or two of large hail also cannot be ruled out. Storms should gradually decrease in intensity this evening as nocturnal cooling and further airmass overturning occurs with ongoing storms. ..Squitieri.. 07/24/2023 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...BTV...ALY...BGM...BUF...CTP... LAT...LON 41707685 44037537 44877431 44687379 44327331 43807306 43217324 42647373 42027431 41687478 41467516 41267618 41707685 Read more

MD 1699 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR PORTIONS OF NORTHEAST NEVADA INTO NORTHWESTERN UTAH...SOUTHEAST IDAHO...WESTERN WYOMING
Mesoscale Discussion 1699 NWS Storm Prediction Center Norman OK 0433 PM CDT Mon Jul 24 2023 Areas affected...portions of northeast Nevada into northwestern Utah...southeast Idaho...western Wyoming Concerning...Severe potential...Watch unlikely Valid 242133Z - 242300Z Probability of Watch Issuance...20 percent SUMMARY...A couple of severe gusts may accompany the stronger storms this evening. A WW issuance is not expected. DISCUSSION...Scattered thunderstorms are developing along the northwestern periphery of a monsoonal moisture plume as an embedded 500 mb impulse grazes the Great Basin. These storms are developing atop a heated, mixed boundary layer, characterized by surface temperatures exceeding 90 F in several locales. The strong surface heating has resulted in boundary-layer lapse rates reaching 10 C/km in some locales. As such, efficient evaporative cooling with the more intense storm cores may support a couple of severe gusts. Nonetheless, the severe threat should remain isolated and a WW issuance is not expected. ..Squitieri.. 07/24/2023 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...RIW...TFX...SLC...PIH...BOI...LKN... LAT...LON 39861606 42611407 44001218 44451148 44521117 43620941 43080924 42010920 40881014 40031094 39621187 39571332 39651460 39861606 Read more

WW 0545 Status Updates
STATUS REPORT ON WW 545 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. ..GLEASON..07/24/23 ATTN...WFO...IND...LMK...ILN... STATUS REPORT FOR WS 545 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS INC005-011-013-019-025-027-029-031-035-037-041-043-047-055-057- 059-061-063-065-071-077-079-081-083-093-095-097-101-105-109-115- 117-119-123-135-137-139-143-145-155-159-161-175-177-242240- IN . INDIANA COUNTIES INCLUDED ARE BARTHOLOMEW BOONE BROWN CLARK CRAWFORD DAVIESS DEARBORN DECATUR DELAWARE DUBOIS FAYETTE FLOYD FRANKLIN GREENE HAMILTON HANCOCK HARRISON HENDRICKS HENRY JACKSON JEFFERSON JENNINGS JOHNSON KNOX LAWRENCE MADISON MARION MARTIN MONROE MORGAN OHIO ORANGE OWEN PERRY RANDOLPH RIPLEY RUSH SCOTT SHELBY SWITZERLAND TIPTON UNION WASHINGTON WAYNE KYC003-005-009-015-017-023-027-029-031-037-041-061-073-077-081- 085-091-093-097-099-103-111-117-123-135-141-161-163-179-181-183- Read more

WW 545 SEVERE TSTM IN KY OH 241940Z - 250200Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 545 NWS Storm Prediction Center Norman OK 340 PM EDT Mon Jul 24 2023 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Southern Indiana Northern Kentucky Southwest Ohio * Effective this Monday afternoon and evening from 340 PM until 1000 PM EDT. * Primary threats include... Scattered damaging wind gusts to 70 mph possible Scattered large hail events to 1.5 inches in diameter possible SUMMARY...Thunderstorms will increase in coverage this afternoon in a moist and very unstable air mass. The strongest cells will pose a risk of damaging wind gusts and hail through the afternoon and early evening. The severe thunderstorm watch area is approximately along and 75 statute miles north and south of a line from 45 miles south southwest of Bloomington IN to 30 miles east of Columbus OH. 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 544... 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 28030. ...Hart Read more

WW 0544 Status Updates
STATUS REPORT ON WW 544 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. ..KERR..07/24/23 ATTN...WFO...ALY...BGM...BUF...BTV... STATUS REPORT FOR WS 544 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS CTC005-242140- CT . CONNECTICUT COUNTIES INCLUDED ARE LITCHFIELD MAC003-242140- MA . MASSACHUSETTS COUNTIES INCLUDED ARE BERKSHIRE NYC001-007-011-015-017-019-021-023-025-027-031-033-035-039-041- 043-045-049-053-057-065-067-075-077-083-089-091-093-095-097-099- 101-105-107-109-111-113-115-123-242140- NY . NEW YORK COUNTIES INCLUDED ARE ALBANY BROOME CAYUGA CHEMUNG CHENANGO CLINTON COLUMBIA CORTLAND DELAWARE Read more

WW 544 SEVERE TSTM CT MA NY PA VT 241705Z - 250000Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 544 NWS Storm Prediction Center Norman OK 105 PM EDT Mon Jul 24 2023 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Western Connecticut Western Massachusetts Central and Eastern New York Northeast Pennsylvania Vermont * Effective this Monday afternoon and evening from 105 PM until 800 PM EDT. * Primary threats include... Scattered damaging wind gusts to 70 mph possible Isolated large hail events to 1.5 inches in diameter possible SUMMARY...Thunderstorms will continue to increase in coverage and intensity through the afternoon as daytime heating destabilizes the atmosphere. The strongest storms this afternoon will pose a risk of locally damaging wind gusts. The severe thunderstorm watch area is approximately along and 90 statute miles east and west of a line from 35 miles west of Monticello NY to 35 miles north northwest of Burlington VT. 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. && 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 24025. ...Hart Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0250 PM CDT Mon Jul 24 2023 Valid 242000Z - 251200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE NORTHEAST AND THE OHIO VALLEY... ...SUMMARY... Severe thunderstorms associated with strong wind gusts will be possible into these evening across parts of the Northeast states and the Ohio Valley. ...20z Update... A small southward expansion to the Marginal risk (level 1 of 5) over TN has been made to account for a developing cluster over southeast MO and potential for that cluster to continue south/southeast through early evening. Reference MCD 1697 for short term details on this severe risk. The Slight risk (level 2 of 5) as also been expanded westward across parts of southern IN, central/western KY and northwest TN to account for ongoing observational trends. Reference MCD 1695 and WW 545 for more information. Otherwise, the Marginal risk has been trimmed across much of MO into parts of IL where morning convection has resulted in stronger inhibition and lowered severe potential. Reference MCDs 1696 and WW 544 for more information regarding short term severe potential across the Northeast. ..Leitman.. 07/24/2023 .PREV DISCUSSION... /ISSUED 1122 AM CDT Mon Jul 24 2023/ ...Northeast... Morning water vapor loop shows a series of shortwave troughs over western/central NY and Lake Ontario. Lift ahead of these systems will promote the development of scattered thunderstorms across parts of NY/PA, spreading eastward into VT. Forecast soundings show relatively steep low-level lapse rates and sufficient westerly flow above 3km to help organize the stronger cells and pose a risk of damaging wind gusts. Please refer to MCD #1694 for further details. ...OH Valley... A moist low-level air mass is present today from southern OH westward into IN/IL/KY with dewpoints in the upper 60s and 70s. A shortwave trough over WI will approach the area later this afternoon, with isolated to scattered thunderstorm development likely. Ample CAPE and sufficient northwest flow aloft will result in a few strong/severe storms capable of damaging wind gusts. A consensus of 12z guidance shows a higher concentration of storms over parts of southwest OH and adjacent parts of KY/IN. Therefore a small SLGT has been added for that region. ...NV/UT/ID/MT/WY... A large upper ridge is in place today over much of the Great Basin, with a band of stronger flow extending from NV into UT/ID and WY/MT. A shortwave trough embedded in this flow over NV will track northeastward and aid in the development scattered high-based showers and thunderstorms later today. This activity may pose a risk of gusty/damaging winds through the evening. Read more