Severe Storms

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1116 AM CDT Fri Jul 21 2023 Valid 211630Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE MID-SOUTH/TENNESSEE VALLEY/SOUTHEAST...NORTHEAST STATES...AND SOUTHERN HIGH PLAINS... ...SUMMARY... Severe thunderstorms capable of wind damage and some hail are expected across the Mid-South and Tennessee Valley to the Southeast States, while additional severe storms will be possible across the Northeast and High Plains. ...AR into the Southeast States... A large MCS that tracked across southern OK last night is now over northern/central AR. This system and its attendant MCV will move into western TN this afternoon, where sufficient heating and a very moist air mass will support the potential for re-intensification. If this scenario occurs, locally damaging wind gusts would be the main concern. To the southeast of the MCS, a weak surface boundary extends across southeast AR into portions of MS/AL/GA. A very unstable air mass will become established this afternoon along this axis, where scattered thunderstorm development is expected. MLCAPE values around 3000 J/kg will combine with winds in the 5-7km layer around 30 knots to pose some risk of damaging wind gusts in the stronger cells. The risk of wind damage will increase later this afternoon if sufficient thunderstorm coverage can result in more organized outflows. ...New England... An upper trough is moving across the northeast states today, with an associated cold front currently extending across parts of eastern NY/PA. Clouds have been clearing ahead of the front across western New England, where temperatures will rapidly warm into the 80s. Ample low-level moisture is present from southern VT/NH southward, where upper 60s/lower 70s dewpoints will yield afternoon MLCAPE values of 1500-2000 J/kg. Forecast soundings show sufficient deep layer shear for a few organized/rotating storms capable of strong/damaging wind gusts and perhaps hail for a few hours this afternoon. ...Northeast NM... Weak easterly low-level upslope flow is present today over northeast NM, helping to transport 60s dewpoints westward toward the higher terrain. Thunderstorms are expected to form in the mountains near Raton and drift southeastward through the afternoon. Steep low-level lapse rates and 30-40 knots of effective shear will promote the development of a few supercells capable of large hail and damaging wind gusts. ..Hart/Thornton.. 07/21/2023 Read more

WW 0533 Status Updates
STATUS REPORT ON WW 533 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 15 ESE FSM TO 35 ESE FYV TO 15 ENE UMN. WW 533 WILL BE ALLOWED TO EXPIRE AT 211500Z. FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 1663 ..DEAN..07/21/23 ATTN...WFO...TSA... STATUS REPORT FOR WS 533 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS ARC015-087-211500- AR . ARKANSAS COUNTIES INCLUDED ARE CARROLL MADISON 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

MD 1653 CONCERNING SEVERE THUNDERSTORM WATCH 526... FOR SOUTHEAST WYOMING INTO EASTERN COLORADO
Mesoscale Discussion 1653 NWS Storm Prediction Center Norman OK 0519 PM CDT Thu Jul 20 2023 Areas affected...Southeast Wyoming into Eastern Colorado Concerning...Severe Thunderstorm Watch 526... Valid 202219Z - 210015Z The severe weather threat for Severe Thunderstorm Watch 526 continues. SUMMARY...All severe hazards will remain possible this afternoon into the evening, particularly for southeast Colorado. The tornado threat will be maximized along/near a surface boundary from near Lamar to northeast of Pueblo. DISCUSSION...Numerous supercells continue in eastern Colorado into southeast Wyoming. The most intense of these storms are in southeast Colorado where surface heating has been greater. Strong northwesterly effective shear and MLCAPE of 1500-2000 J/kg (maximized in southeast Colorado with lesser amounts farther north) will continue to support supercells capable of severe wind gusts, large to very large hail, and perhaps a tornado or two. A surface boundary is evident within surface observations and local radar imagery in southeast Colorado. KPUX VAD profiles show slightly more enlarged low-level hodographs as a result. The tornado threat this afternoon will be maximized along/near this boundary. With time, storm interactions should lead to upscale growth into an MCS, a consensus scenario in high-resolution guidance. At that time, severe wind gusts (some exceeding 75 mph) would become the primary threat. For northeast Colorado into southeast Wyoming, the overall threat will be somewhat mitigated by lesser buoyancy and more stable air just to the east. ..Wendt.. 07/20/2023 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...GLD...PUB...BOU...CYS... LAT...LON 37450480 38940506 39970512 41380526 41540455 40730275 37900213 37250218 37070350 37210427 37450480 Read more

WW 0528 Status Updates
STATUS FOR WATCH 0528 HAS NOT BEEN ISSUED YET Read more

WW 528 SEVERE TSTM MD NY OH PA WV LE LO 202215Z - 210700Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 528 NWS Storm Prediction Center Norman OK 615 PM EDT Thu Jul 20 2023 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Maryland Panhandle Western to central New York Eastern Ohio Western, central and northeastern Pennsylvania Extreme northern West Virginia Lake Erie Lake Ontario * Effective this Thursday night and Friday morning from 615 PM until 300 AM EDT. * Primary threats include... Scattered damaging wind gusts to 70 mph likely Isolated large hail events to 1.5 inches in diameter possible SUMMARY...An extensive arc of thunderstorms with damaging to severe gusts is expected to sweep eastward and southeastward across the watch area into tonight. This complex may be preceded by at least isolated cells capable of localized large hail and wind damage. The severe thunderstorm watch area is approximately along and 120 statute miles east and west of a line from 15 miles southwest of Morgantown WV to 50 miles northwest of Syracuse NY. 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 524...WW 525...WW 526...WW 527... 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 29035. ...Edwards Read more

WW 0524 Status Updates
STATUS REPORT ON WW 524 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 35 SSW HUF TO 25 ESE LAF TO 25 WSW FWA TO 25 ENE FWA TO 40 WNW FDY TO 5 SW TOL TO 30 E TOL TO 45 NW CLE. ..BENTLEY..07/20/23 ATTN...WFO...ILX...IWX...IND...ILN...CLE... STATUS REPORT FOR WS 524 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS INC001-003-009-011-021-023-031-035-041-047-053-057-059-063-065- 067-069-075-081-095-097-107-109-119-133-135-139-145-159-161-169- 177-179-202340- IN . INDIANA COUNTIES INCLUDED ARE ADAMS ALLEN BLACKFORD BOONE CLAY CLINTON DECATUR DELAWARE FAYETTE FRANKLIN GRANT HAMILTON HANCOCK HENDRICKS HENRY HOWARD HUNTINGTON JAY JOHNSON MADISON MARION MONTGOMERY MORGAN OWEN PUTNAM RANDOLPH RUSH SHELBY TIPTON UNION WABASH WAYNE WELLS OHC003-005-007-011-021-023-033-035-037-039-041-043-049-055-057- 063-065-069-075-077-083-085-089-091-093-095-097-099-101-103-107- 109-113-117-123-125-133-135-137-139-143-147-149-151-153-155-159- 161-169-173-175-202340- Read more

WW 524 SEVERE TSTM IL IN MI OH PA LE 201845Z - 210300Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 524 NWS Storm Prediction Center Norman OK 245 PM EDT Thu Jul 20 2023 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of East Central Illinois Northern and Central Indiana Southern Lower Michigan Northern and Central Ohio Northwest Pennsylvania Lake Erie * Effective this Thursday afternoon and evening from 245 PM until 1100 PM EDT. * Primary threats include... Scattered large hail and isolated very large hail events to 2 inches in diameter likely Scattered damaging winds likely with isolated significant gusts to 75 mph possible A tornado or two possible SUMMARY...Thunderstorms are expected to intensify this afternoon and spread across much of the watch area through the evening. The strongest storms will pose a risk of damaging wind gusts, large hail, and perhaps a tornado or two. The severe thunderstorm watch area is approximately along and 60 statute miles north and south of a line from 15 miles south of Champaign IL to 15 miles east southeast of Erie PA. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU4). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A Severe Thunderstorm Watch means conditions are favorable for severe thunderstorms in and close to the watch area. Persons in these areas should be on the lookout for threatening weather conditions and listen for later statements and possible warnings. Severe thunderstorms can and occasionally do produce tornadoes. && OTHER WATCH INFORMATION...CONTINUE...WW 522...WW 523... 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 500. Mean storm motion vector 29035. ...Hart Read more

MD 1652 CONCERNING SEVERE POTENTIAL...WATCH LIKELY FOR NORTHERN INTO EASTERN GEORGIA...WESTERN INTO SOUTHERN SOUTH CAROLINA
Mesoscale Discussion 1652 NWS Storm Prediction Center Norman OK 0459 PM CDT Thu Jul 20 2023 Areas affected...northern into eastern Georgia...western into southern South Carolina Concerning...Severe potential...Watch likely Valid 202159Z - 210030Z Probability of Watch Issuance...80 percent SUMMARY...Severe storms may extend south and east of watch 525, with severe wind gusts expected. A new watch appears likely. DISCUSSION...A line of storms extending across northern GA and into far northeast AL is producing measured severe gusts over 50 kt at multiple observing sites. Westerly low-level winds will continue to feed unstable air into the region ahead of this line of storms as it moves southeastward this evening. Although effective shear is only on the order of 25-30 kt, similar deep-layer mean wind speeds will favor a forward-propagating system with strong to severe outflow. Given the uncapped air mass downstream with mid 70s F dewpoints and MLCAPE around 2500 J/kg, the threat may extend to the coast. As such, a continued severe risk is anticipated given ample instability and current organization of this system. ..Jewell.. 07/20/2023 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...CHS...CAE...GSP...FFC... LAT...LON 32638243 33418384 33688435 33888465 34078469 34298438 34478395 34558354 34218279 33648159 32787979 32578001 32178055 31788083 31798131 32638243 Read more

MD 1651 CONCERNING SEVERE THUNDERSTORM WATCH 527... FOR SOUTHWEST KANSAS...OKLAHOMA PANHANDLE...NORTHERN TEXAS PANHANDLE...NORTHWEST OKLAHOMA
Mesoscale Discussion 1651 NWS Storm Prediction Center Norman OK 0449 PM CDT Thu Jul 20 2023 Areas affected...Southwest Kansas...Oklahoma Panhandle...northern Texas Panhandle...northwest Oklahoma Concerning...Severe Thunderstorm Watch 527... Valid 202149Z - 202345Z The severe weather threat for Severe Thunderstorm Watch 527 continues. SUMMARY...All severe hazards will be possible late this afternoon and evening. Very large hail threat will focus in southwest Kansas near Dodge City. Tornado threat will focus along a surface boundary in the combined Panhandles. The primary hazard will eventually be severe (potentially significant) wind gusts as an MCS organizes and moves out of southeast Colorado. DISCUSSION...An ongoing, intense supercell continues across parts of southwest Kansas just north of Garden City. Hail of 1.75-2.5 inches has already been reported with this storm and current dual-pol radar presentation from KDDC would suggest very large hail remains a potential threat. Furthermore, a tornado has been reported with this storm as well. This storms and any other that develop nearby are the greatest short-term severe threat. Later this evening, convection that is ongoing in eastern Colorado is expected to grow upscale. Temperatures near 90F and dewpoints in the upper 60s to low 70s F will support moderate to strong buoyancy late this afternoon and evening. Combined with strong northwesterly effective shear, this environment will support potential for an intense line of storms capable of scattered severe wind gusts (some of which may exceed 75 mph). Given the linear storm mode expected, the tornado threat will be somewhat modulated. The greatest threat for a tornado or two would be along and just north of the surface boundary into the Texas/Oklahoma Panhandles. ..Wendt.. 07/20/2023 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...OUN...DDC...GLD...AMA... LAT...LON 36619841 35969900 35699948 35720080 36050165 36400186 37440197 38170198 38610183 38760140 38740051 37939893 37149850 36619841 Read more

WW 0525 Status Updates
STATUS REPORT ON WW 525 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 35 SSW HSV TO 20 NW HSV TO 30 NNW HSV TO 25 WSW CHA TO 30 ESE CHA TO 60 ESE CHA TO 45 NW AND TO 15 SSW AVL. ..BENTLEY..07/20/23 ATTN...WFO...BMX...HUN...FFC...GSP...MRX... STATUS REPORT FOR WS 525 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS ALC019-049-071-083-089-095-103-202240- AL . ALABAMA COUNTIES INCLUDED ARE CHEROKEE DEKALB JACKSON LIMESTONE MADISON MARSHALL MORGAN GAC011-013-015-047-055-057-059-083-085-105-111-115-117-119-123- 129-137-139-147-157-187-195-213-219-221-227-241-257-281-291-295- 311-313-317-202240- GA . GEORGIA COUNTIES INCLUDED ARE BANKS BARROW BARTOW CATOOSA CHATTOOGA CHEROKEE CLARKE DADE DAWSON ELBERT FANNIN FLOYD FORSYTH FRANKLIN GILMER GORDON HABERSHAM HALL HART JACKSON LUMPKIN Read more

WW 0526 Status Updates
STATUS REPORT ON WW 526 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. ..BENTLEY..07/20/23 ATTN...WFO...BOU...PUB...GLD...CYS... STATUS REPORT FOR WS 526 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS COC001-005-009-011-013-014-017-025-031-035-039-041-055-059-061- 063-069-071-073-075-087-089-099-101-119-121-123-125-202240- CO . COLORADO COUNTIES INCLUDED ARE ADAMS ARAPAHOE BACA BENT BOULDER BROOMFIELD CHEYENNE CROWLEY DENVER DOUGLAS ELBERT EL PASO HUERFANO JEFFERSON KIOWA KIT CARSON LARIMER LAS ANIMAS LINCOLN LOGAN MORGAN OTERO PROWERS PUEBLO TELLER WASHINGTON WELD YUMA NEC105-202240- NE . NEBRASKA COUNTIES INCLUDED ARE KIMBALL Read more

WW 525 SEVERE TSTM AL GA NC SC TN 201910Z - 210200Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 525 NWS Storm Prediction Center Norman OK 310 PM EDT Thu Jul 20 2023 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Northern Alabama Northern Georgia Western North Carolina Upstate South Carolina Southeast Tennessee * Effective this Thursday afternoon and evening from 310 PM until 1000 PM EDT. * Primary threats include... Scattered large hail and isolated very large hail events to 2 inches in diameter possible Scattered damaging wind gusts to 70 mph possible SUMMARY...Scattered thunderstorms over middle Tennessee will track southeastward across the watch area through the afternoon, posing a risk of damaging wind gusts. The severe thunderstorm watch area is approximately along and 45 statute miles north and south of a line from 35 miles north northwest of Muscle Shoals AL to 40 miles south of Spartanburg 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 522...WW 523...WW 524... AVIATION...A few severe thunderstorms with hail surface and aloft to 2 inches. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 29030. ...Hart Read more

WW 526 SEVERE TSTM CO NE WY 201930Z - 210300Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 526 NWS Storm Prediction Center Norman OK 130 PM MDT Thu Jul 20 2023 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Eastern Colorado Southwest Nebraska Southeast Wyoming * Effective this Thursday afternoon and evening from 130 PM until 900 PM MDT. * Primary threats include... Widespread large hail and isolated very large hail events to 3 inches in diameter likely Scattered damaging winds and isolated significant gusts to 75 mph likely A tornado or two possible SUMMARY...Thunderstorms will develop off the foothills this afternoon and spread into the plains. Supercells capable of very large hail and damaging winds are the main threat. There is a corridor across east-central Colorado that may also see a few tornadoes. The severe thunderstorm watch area is approximately along and 75 statute miles east and west of a line from 35 miles northeast of Cheyenne WY to 50 miles west southwest of Springfield CO. 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 522...WW 523...WW 524...WW 525... AVIATION...A few severe thunderstorms with hail surface and aloft to 3 inches. Extreme turbulence and surface wind gusts to 65 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 27030. ...Hart Read more

WW 0527 Status Updates
STATUS FOR WATCH 0527 HAS NOT BEEN ISSUED YET Read more

WW 527 SEVERE TSTM KS OK TX 202140Z - 210500Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 527 NWS Storm Prediction Center Norman OK 440 PM CDT Thu Jul 20 2023 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Western Kansas Northwestern Oklahoma including OK Panhandle Northern Panhandle of Texas * Effective this Thursday afternoon from 440 PM until Midnight CDT. * Primary threats include... Widespread damaging winds and isolated significant gusts to 75 mph likely Scattered large hail likely with isolated very large hail events to 4 inches in diameter possible A tornado or two possible SUMMARY...Thunderstorm coverage is increasing around an ongoing supercell over western Kansas that poses a threat of large to giant hail, and perhaps a tornado or two in the short term. This activity may move into northwestern Oklahoma. Separately, a complex of strong-severe thunderstorms is expected to organize out of eastern CO and move southeastward over much of the watch area this evening, offering severe winds and occasional large hail over a broad swath of the south-central High Plains. The severe thunderstorm watch area is approximately along and 105 statute miles north and south of a line from 60 miles north of Elkhart KS to 70 miles east southeast of Dodge City KS. 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 522...WW 524...WW 525...WW 526... AVIATION...A few severe thunderstorms with hail surface and aloft to 4 inches. Extreme turbulence and surface wind gusts to 65 knots. A few cumulonimbi with maximum tops to 550. Mean storm motion vector 30030. ...Edwards Read more

MD 1650 CONCERNING SEVERE THUNDERSTORM WATCH 523...524... FOR CENTRAL/NORTHERN IN/OH INTO FAR SOUTHEAST MI
Mesoscale Discussion 1650 NWS Storm Prediction Center Norman OK 0401 PM CDT Thu Jul 20 2023 Areas affected...Central/northern IN/OH into far southeast MI Concerning...Severe Thunderstorm Watch 523...524... Valid 202101Z - 202230Z The severe weather threat for Severe Thunderstorm Watch 523, 524 continues. SUMMARY...Some threat for damaging wind and hail will continue into early evening. DISCUSSION...While a well-organized bowing cluster has moved into Ontario, somewhat more discrete storms are ongoing along a cold front into northeast IN and extreme southeast MI. With moderate buoyancy and increasing deep-layer shear (as noted in the 20Z ILN and PIT soundings) in advance of a midlevel shortwave trough moving across MI, strong to potentially severe storms will persist into early evening and perhaps increase in coverage into parts of northern OH. Relatively steep midlevel lapse rates will continue to support a large hail threat with any of the more discrete cells, with some potential for an increasing damaging wind threat as one or more upscale growing clusters eventually evolve with time. Farther southwest, prefrontal storms across central IN had shown a weakening trend after their initial development, but some strengthening has been noted again over the last 30 minutes. While large-scale ascent is somewhat weaker compared to areas farther north/east, a few stronger storms may pose a hail and damaging wind threat as they approach southeast IN and southwest OH into early evening. ..Dean.. 07/20/2023 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...CLE...ILN...DTX...IWX...GRR...IND...LOT... LAT...LON 40438356 39368728 40108737 40528706 41328606 41868510 42178377 42298186 42188113 41718081 41108119 40658224 40438356 Read more

WW 0522 Status Updates
STATUS REPORT ON WW 522 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 15 SE AZO TO 10 SSE JXN TO 5 E ARB TO 20 E MTC. ..BENTLEY..07/20/23 ATTN...WFO...GRR...APX...DTX... STATUS REPORT FOR WS 522 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS MIC091-115-161-163-202240- MI . MICHIGAN COUNTIES INCLUDED ARE LENAWEE MONROE WASHTENAW WAYNE LCZ423-LEZ444-202240- CW . ADJACENT COASTAL WATERS INCLUDED ARE DETROIT RIVER MICHIGAN WATERS OF LAKE ERIE FROM DETROIT RIVER TO NORTH CAPE MI 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

MD 1649 CONCERNING SEVERE POTENTIAL...SEVERE THUNDERSTORM WATCH LIKELY FOR PARTS OF WESTERN NY...WESTERN PA...AND FAR EASTERN OH
Mesoscale Discussion 1649 NWS Storm Prediction Center Norman OK 0356 PM CDT Thu Jul 20 2023 Areas affected...Parts of western NY...western PA...and far eastern OH Concerning...Severe potential...Severe Thunderstorm Watch likely Valid 202056Z - 202230Z Probability of Watch Issuance...95 percent SUMMARY...The risk of severe winds will increase in the next few hours as an organized MCS overspreads the area from the west. A watch issuance is likely for parts of the area in the next hour or so. DISCUSSION...Recent radar data from KDTX depicts a well-organized bowing MCS tracking eastward at around 40 kt in Ontario -- where a recent 63-kt gust was measured. Ahead of the MCS, antecedent diurnal heating of a relatively moist air mass (generally lower/middle 60s dewpoints) has contributed to weak/moderate surface-based instability -- with the greater instability confined to western PA and eastern OH (see 20Z observed PIT and 19Z BUF soundings). 40-50 kt midlevel winds should support continued convective organization as it crosses Lake Erie and approaches western NY, eastern OH, and western PA -- with a risk of severe winds during the next few hours. While there is some uncertainty on how intense the northern portion of the line will be given less instability farther north, the well-established cold pool and favorable deep-layer shear will still pose a risk of severe outflow winds. A watch will likely be issued in the next hour or so. ..Weinman/Hart.. 07/20/2023 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...BGM...BUF...CTP...PBZ...CLE... LAT...LON 41018093 41438034 41777990 42277963 42717940 43077923 43357902 43467833 43397673 43197649 42297671 41617709 41107755 40547849 40197938 40007998 39918060 39968119 40208158 40518157 40738134 41018093 Read more

WW 0523 Status Updates
STATUS REPORT ON WW 523 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 50 NW CHA TO 30 SSW CSV TO 25 SE CSV. ..BENTLEY..07/20/23 ATTN...WFO...LMK...OHX... STATUS REPORT FOR WS 523 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS TNC003-031-055-061-099-117-119-202140- TN . TENNESSEE COUNTIES INCLUDED ARE BEDFORD COFFEE GILES GRUNDY LAWRENCE MARSHALL MAURY 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

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0300 PM CDT Thu Jul 20 2023 Valid 202000Z - 211200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE SOUTHERN/CENTRAL HIGH PLAINS...AND THE GREAT LAKES/MIDWEST... ...SUMMARY... Scattered severe thunderstorms are expected near the Colorado Front Range into the central/southern High Plains, with other severe storms across the Midwest/Great Lakes, as well as the Tennessee Valley and Southeast States. ...20Z Update... Severe probabilities have been trimmed behind convection ongoing across the Great Lakes, Midwest, and TN Valley. A substantial threat for damaging winds and large hail remains apparent with these thunderstorms as they spread eastward across IL, OH, and western PA/NY this afternoon and early evening. A tornado or two also remains possible, mainly across portions of southeastern Lower MI and northern OH near Lake Erie. See Mesoscale Discussion 1646 for more details on the near-term severe threat across parts of Lower MI. A separate cluster of convection should continue to pose a threat for mainly damaging winds this afternoon and evening as it moves east-southeastward across parts of the Southeast. See Mesoscale Discussion 1645 for more meteorological details regarding this threat. No changes have been made to the Enhanced Risk across the southern/central High Plains. ..Gleason.. 07/20/2023 .PREV DISCUSSION... /ISSUED 1058 AM CDT Thu Jul 20 2023/ ...Central High Plains... Water vapor imagery shows a shortwave trough moving across UT this morning. Large scale ascent ahead of this trough, along with strengthening westerly flow aloft will aid in the development of scattered thunderstorms along the foothills of CO by early afternoon. These storms will spread eastward through the afternoon and evening into western KS and parts of the TX/OK Panhandles. Forecast soundings appear quite favorable for supercells capable of very large hail and perhaps a tornado or two. As the activity moves eastward, upscale organization is likely with one or more bowing complexes capable of damaging wind gusts. These storms may persist well after midnight into southern KS/northern OK. ...Upper OH Valley... A strong and progressive upper trough over WI/Upper MI will track southeastward today, with its associated cold front sweeping across Lower MI and into the Upper OH Valley. Thunderstorms have already developed along part of the front over northwest Lower MI. Full sunshine ahead of the front will yield afternoon MLCAPE values of 2500 J/kg, along with steep low and mid-level lapse rates. Supercells and bowing structures are expected, capable of large hail and damaging wind gusts. An isolated tornado or two is also possible. This activity will build southward into northern IN and spread eastward over much of OH and western NY/PA this evening with a continued risk of damaging winds and hail. Refer to MCD #1641 for further short-term details. ...TN Valley... A remnant area of convection is affecting southern MO, with one intense cell along the leading edge near Paducah. More storms are expected to eventually develop along the leading edge as the activity tracks east-southeastward along an outflow boundary/differential heating zone extending into northern TN. Sufficient winds aloft and a very moist/unstable air mass will promote a risk of damaging winds and perhaps hail in the strongest cells this afternoon. Read more