Severe Storms

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

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0150 PM CDT Thu Jul 20 2023 Valid 211200Z - 221200Z An Elevated area has been added for the Columbia Gorge and vicinity in anticipation of dry, breezy conditions Friday afternoon and evening. As a mid-level wave begins to impinge on the West Coast ridge, downslope flow will yield deep boundary-layer mixing to the east of the Cascades. Local channeling through the Columbia Gorge should yield stronger sustained winds there, supporting a local elevated threat for fire spread. Elsewhere, transient elevated fire-weather conditions may develop across the Southwest. Locally stronger winds are possible across the Four Corners region and vicinity; no highlights are added in this outlook due to uncertainties regarding downstream moisture return. Lightning strikes are also possible Friday afternoon/evening across portions of central and northern AZ, but the threat appears isolated at this time. Please see the previous discussion for more information. ..Flournoy.. 07/20/2023 .PREV DISCUSSION... /ISSUED 0116 AM CDT Thu Jul 20 2023/ ...Synopsis... The persistent upper-level ridge will remain within the West on Friday. A strong upper-level trough will try to push into the Northwest through the period. Mid-level winds will increase as a result. High pressure at the surface will be situated along and east of the Rockies. A surface trough is again expected in the Columbia Basin. Given weak surface winds, low large fire potential is evident across areas of the Southwest, Great Basin, and Northwest that have dry fuels. However, there will be some increase in the winds east of the Cascades as the surface trough deepens and mid-level winds increase. It is possible some locally elevated conditions will exist for a brief period. The most likely locations for these conditions will be within the terrain of the Columbia Gorge and Cascade gaps. Given the limited duration and extent of these conditions, no highlights will be added at this time. ...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 Thu Jul 20 2023 Valid 211200Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE LOWER MISSISSIPPI VALLEY INTO THE SOUTHEAST... ...SUMMARY... Strong to severe severe thunderstorms appear possible over parts of the Southeast, Mid-Atlantic into New England, southern/central High Plains, and Southwest on Friday. The greatest potential for scattered damaging winds should exist from parts of the lower Mississippi Valley into the Southeast. ...Synopsis... Upper ridging will persist Friday over much of the Southwest into the northern Rockies. Downstream, an upper trough should move slowly northeastward across the Mid-Atlantic and New England through the period. Between these two features, a broad zone of modestly enhanced mid-level west-northwesterly flow will remain over much of the Plains and eastern states. At the surface, a weak low over northern NY/southern Ontario should develop slowly northeastward through the day in tandem with the upper trough. Attendant cold front extending southward from the surface low across the East Coast states should bend westward across the Southeast into the lower MS Valley. Rich low-level moisture, and appreciable severe potential, should remain confined along/south of this front Friday. ...Lower Mississippi Valley into the Southeast... Thunderstorms posing some threat for strong/gusty winds should be ongoing Friday morning across parts of eastern OK into western AR. This activity will likely be tied to a convectively enhanced mid-level shortwave trough forecast to advance quickly east-southeastward across the lower MS Valley and Southeast through the day. It remains unclear whether this small bowing cluster will persist or slowly weaken through Friday morning as it approaches the Mid-South/lower MS Valley. If it can be maintained and eventually restrengthen as it progresses east-southeastward, then a corridor of greater damaging wind potential is evident from near Memphis TN to the Atlantic Coast, along/south of the weak front and outflow from prior convection. Moderate instability should develop through Friday afternoon across this area with robust diurnal heating of a moist low-level airmass. Modestly enhanced mid-level flow and around 25-40 kt of deep-layer shear will promote convective organization, with the internal dynamics of the MCS or remnant MCV also providing some enhancement to the low/mid-level winds. There also appears to be some potential for additional robust thunderstorm development along the outflow of the morning activity. Regardless of which scenario plays out, enough model guidance suggests potential for scattered strong to severe thunderstorms capable of producing mainly damaging winds to justify adding a Slight Risk. Some threat for hail may also exist with the more robust updrafts. ...Mid-Atlantic into New England... Showers and isolated thunderstorms will probably be ongoing at the start of the period across parts of the Mid-Atlantic into NY, related to convection from today that is forecast develop over the Great Lakes/OH Valley. In the wake of this morning activity, most guidance shows at least modest destabilization occurring ahead of a weak front that should advance slowly eastward through the day. Additional thunderstorms should develop by Friday afternoon along and ahead of this front in a weakly to moderately unstable environment. Even though mid-level winds do not appear overly strong, enough flow and related effective bulk shear should be present for modest updraft organization. Isolated damaging winds and hail may occur with the strongest convection. Based on latest guidance, the Marginal Risk has been expanded northward to include more of the Mid-Atlantic and parts of New England. ...Southern/Central High Plains... Model guidance indicates strong heating and orographic ascent will favor isolated to scattered thunderstorms developing Friday from eastern WY southward to the Raton Mesa vicinity in northeastern NM. Isolated convection may also develop across western NE along/south of a weak surface boundary. It appears a relative minimum in overall thunderstorm coverage may exist south of the Palmer Divide in CO to near the CO/NM border. Still, steep low/mid-level lapse rates and strengthening mid/high-level northwesterly flow with height across the southern/central High Plains should act to organize a few of the stronger updrafts. Isolated large hail and severe gusts should be the primary risks. This activity will likely weaken during the evening as it moves further south-southeastward into the High Plains. ... Southeastern Arizona... Isolated to perhaps widely scattered thunderstorms should develop over the higher terrain of southeastern AZ and vicinity by late Friday afternoon. Large surface temperature-dewpoint spreads are forecast, and this activity will likely remain high-based. Even though deep-layer shear should remain modest, some of this convection could produce isolated severe/damaging winds given the dry sub-cloud layer potential for evaporatively cooled downdraft accelerations. ..Gleason.. 07/20/2023 Read more

MD 1635 CONCERNING SEVERE THUNDERSTORM WATCH 518...520... FOR NORTHERN INTO CENTRAL MINNESOTA AND NORTHWEST WISCONSIN
Mesoscale Discussion 1635 NWS Storm Prediction Center Norman OK 0517 PM CDT Wed Jul 19 2023 Areas affected...Northern into central Minnesota and northwest Wisconsin Concerning...Severe Thunderstorm Watch 518...520... Valid 192217Z - 192345Z The severe weather threat for Severe Thunderstorm Watch 518, 520 continues. SUMMARY...Large hail will remain a threat for the remainder of the afternoon. Very large hail would be possible with the most organized supercells. Storm coverage is expected to increase in northwestern Wisconsin and parts of central Minnesota. DISCUSSION...Storm coverage and intensity has been greatest over northern Minnesota into the Duluth vicinity. Large-scale ascent with the trough has helped to sustain convection that has produced several large hail reports as well as a 2.5 inch report in Itasca county. Currently, the strongest storms are moving into northwest Wisconsin. MRMS MESH data suggest large hail is probable with these storms. Activity has been more isolated in parts of central Minnesota. This may be due in part to dry low levels and entrainment as well as veered surface winds and weak convergence. However, with mid-level ascent increasing in this area, intensification of this activity is possible as it tracks southeastward to near the Twin Cities. The eastward extent of the threat will probably remain limited to due to influences from cloud cover lasting into the afternoon. Stable billow clouds are still evident on visible satellite. ..Wendt.. 07/19/2023 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...DLH...ARX...MPX...FGF... LAT...LON 45079082 44479286 44349372 44379433 44549485 44779534 44879542 45179564 45459547 45609534 45949471 46349393 47039385 47399404 47879476 48419475 48629405 48569353 48199272 46719097 46219039 45339064 45159079 45079082 Read more

WW 0520 Status Updates
STATUS FOR WATCH 0520 HAS NOT BEEN ISSUED YET Read more

WW 520 SEVERE TSTM MN WI 192215Z - 200500Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 520 NWS Storm Prediction Center Norman OK 515 PM CDT Wed Jul 19 2023 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of South-central Minnesota Western Wisconsin * Effective this Wednesday afternoon from 515 PM until Midnight CDT. * 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 A tornado or two possible SUMMARY...Increasing thunderstorm coverage over central/southwestern MN, and a favorable environment to the east across the remainder of the watch area (including Twin Cities metro) suggests a severe wind/hail threat will increase for another few hours and persist into late evening. The severe thunderstorm watch area is approximately along and 100 statute miles east and west of a line from 45 miles south southwest of Minneapolis MN to 40 miles north northeast of Minneapolis MN. 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 517...WW 518...WW 519... 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 29020. ...Edwards Read more

WW 0519 Status Updates
STATUS REPORT ON WW 519 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. ..JEWELL..07/19/23 ATTN...WFO...PUB...GLD...BOU...DDC...ABQ...AMA... STATUS REPORT FOR WS 519 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS COC009-011-017-025-041-061-063-071-073-089-099-101-125-192240- CO . COLORADO COUNTIES INCLUDED ARE BACA BENT CHEYENNE CROWLEY EL PASO KIOWA KIT CARSON LAS ANIMAS LINCOLN OTERO PROWERS PUEBLO YUMA KSC023-039-063-065-071-075-093-101-109-129-137-153-171-179-181- 187-193-199-203-192240- KS . KANSAS COUNTIES INCLUDED ARE CHEYENNE DECATUR GOVE GRAHAM GREELEY HAMILTON KEARNY LANE LOGAN MORTON NORTON RAWLINS SCOTT SHERIDAN SHERMAN STANTON THOMAS WALLACE WICHITA Read more

WW 519 SEVERE TSTM CO KS NE NM OK TX 192050Z - 200400Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 519 NWS Storm Prediction Center Norman OK 250 PM MDT Wed Jul 19 2023 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Eastern Colorado Western Kansas Southwest Nebraska Northeast New Mexico Western Oklahoma Panhandle Northwest Texas Panhandle * Effective this Wednesday afternoon and evening from 250 PM until 1000 PM MDT. * Primary threats include... Scattered large hail and isolated very large hail events to 2.5 inches in diameter possible Scattered damaging wind gusts to 70 mph possible SUMMARY...Thunderstorms will develop off the mountains of central Colorado, and along a boundary extending northeastward into Kansas. All of these storms will spread southeastward this evening with a risk of damaging wind gusts and large hail. The severe thunderstorm watch area is approximately along and 105 statute miles north and south of a line from 40 miles southwest of La Junta CO to 70 miles south southeast of Mccook NE. 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 517...WW 518... AVIATION...A few severe thunderstorms with hail surface and aloft to 2.5 inches. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 27025. ...Hart Read more

WW 0517 Status Updates
STATUS REPORT ON WW 517 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 15 S HSE TO 30 ENE EWN TO 30 NE EWN TO 45 NE EWN TO 25 S ECG TO 20 SE ECG TO 30 ENE ECG TO 45 ESE ORF. ..JEWELL..07/19/23 ATTN...WFO...MHX...AKQ... STATUS REPORT FOR WT 517 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS NCC013-055-095-177-192240- NC . NORTH CAROLINA COUNTIES INCLUDED ARE BEAUFORT DARE HYDE TYRRELL AMZ131-135-231-ANZ658-192240- CW . ADJACENT COASTAL WATERS INCLUDED ARE ALLIGATOR RIVER PAMLICO SOUND CROATAN AND ROANOKE SOUNDS COASTAL WATERS FROM NC VA BORDER TO CURRITUCK BEACH LIGHT NC OUT 20 NM Read more

WW 517 TORNADO NC VA CW 191705Z - 192300Z
URGENT - IMMEDIATE BROADCAST REQUESTED Tornado Watch Number 517 NWS Storm Prediction Center Norman OK 105 PM EDT Wed Jul 19 2023 The NWS Storm Prediction Center has issued a * Tornado Watch for portions of Northeast North Carolina Southeast Virginia Coastal Waters * Effective this Wednesday afternoon and evening from 105 PM until 700 PM EDT. * Primary threats include... A couple tornadoes possible Scattered damaging wind gusts to 70 mph possible Isolated large hail events to 1 inch in diameter possible SUMMARY...A cluster of thunderstorms over northeast North Carolina will track eastward this afternoon posing a risk of a few tornadoes and damaging wind gusts. The tornado watch area is approximately along and 40 statute miles north and south of a line from 65 miles west of Elizabeth City NC to 45 miles east southeast of Norfolk VA. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU7). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A Tornado Watch means conditions are favorable for tornadoes and severe thunderstorms in and close to the watch area. Persons in these areas should be on the lookout for threatening weather conditions and listen for later statements and possible warnings. && AVIATION...Tornadoes and 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 25030. ...Hart Read more

WW 0518 Status Updates
STATUS REPORT ON WW 518 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. ..WENDT..07/19/23 ATTN...WFO...DLH...FGF...MPX... STATUS REPORT FOR WS 518 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS MNC001-007-017-021-025-035-059-061-065-071-077-095-115-137- 192240- MN . MINNESOTA COUNTIES INCLUDED ARE AITKIN BELTRAMI CARLTON CASS CHISAGO CROW WING ISANTI ITASCA KANABEC KOOCHICHING LAKE OF THE WOODS MILLE LACS PINE ST. LOUIS WIC005-007-013-031-095-107-113-129-192240- WI . WISCONSIN COUNTIES INCLUDED ARE BARRON BAYFIELD BURNETT DOUGLAS POLK RUSK SAWYER WASHBURN LSZ144-145-192240- CW Read more

WW 518 SEVERE TSTM MN WI LS 192015Z - 200300Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 518 NWS Storm Prediction Center Norman OK 315 PM CDT Wed Jul 19 2023 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Northeast Minnesota Northwest Wisconsin Lake Superior * Effective this Wednesday afternoon and evening from 315 PM until 1000 PM CDT. * 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 A tornado or two possible SUMMARY...Thunderstorms are increasing in coverage and intensity over northern Minnesota. These storms will track eastward through the afternoon and early evening, posing a risk of large hail and damaging winds. The severe thunderstorm watch area is approximately along and 55 statute miles east and west of a line from 40 miles west northwest of International Falls MN to 95 miles south of Duluth MN. 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 517... 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 27030. ...Hart Read more

MD 1634 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR NORTH-CENTRAL NEBRASKA INTO SOUTHEASTERN SOUTH DAKOTA
Mesoscale Discussion 1634 NWS Storm Prediction Center Norman OK 0356 PM CDT Wed Jul 19 2023 Areas affected...North-central Nebraska into southeastern South Dakota Concerning...Severe potential...Watch possible Valid 192056Z - 192300Z Probability of Watch Issuance...60 percent SUMMARY...The area is being monitored for increasing severe-thunderstorm potential this afternoon. Very large hail and damaging winds are the main concerns. A watch is possible for parts of the area. DISCUSSION...In the wake of widespread morning convection across central Nebraska and southeastern South Dakota, cloud breaks are supporting filtered diurnal heating of a moist air mass (middle/upper 60s dewpoints) along/south of a southward-moving cold front. Clear skies north of the front and the early-day convection/ongoing cloud coverage to the south have weakened the frontal circulation, though a surface wind shift is still evident. During the next couple of hours, isolated to widely scattered thunderstorms may develop in the vicinity of the wind shift and perhaps subtle differential heating boundaries in central NE. Steep midlevel lapse rates atop the destabilizing boundary-layer and a long/straight hodograph (40-50 kt of effective shear) will support supercells capable of producing large to very large hail and locally severe gusts. Thunderstorm coverage is uncertain given lingering inhibition associated with the antecedent outflow, though convective trends are being monitored for a watch for parts of the area. ..Weinman/Hart.. 07/19/2023 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...FSD...OAX...ABR...GID...LBF...UNR... LAT...LON 42310154 42020159 41620142 41380109 41140070 41090018 41339961 42129854 42449812 42789751 43039675 43259661 43699652 43869681 43899735 43829799 43639900 43379977 42850084 42510130 42310154 Read more

MD 1632 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR PARTS OF EASTERN NEVADA AND WESTERN UT
Mesoscale Discussion 1632 NWS Storm Prediction Center Norman OK 0321 PM CDT Wed Jul 19 2023 Areas affected...Parts of eastern Nevada and western UT Concerning...Severe potential...Watch unlikely Valid 192021Z - 192245Z Probability of Watch Issuance...20 percent SUMMARY...Thunderstorm coverage will gradually increase through the afternoon. Strong to severe gusts may accompany the stronger storms. A watch is not currently expected. DISCUSSION...A vorticity maximum embedded in a belt of moderate west-southwesterly midlevel flow (evident in water vapor imagery) will continue east-northeastward across eastern Nevada and western UT this afternoon into early evening. As DCVA preceding this feature overspreads a diurnally destabilizing air mass, thunderstorm coverage will gradually increase during the next few hours as boundary-layer inhibition continues to erode. While modest deep-layer shear (20-30 kt of effective shear) may limit convective organization to an extent, at least loosely organized updrafts embedded in larger clusters of eastward-moving storms will be possible. This, combined with the diurnally deepening boundary layer and steepening low-level lapse rates (characterized by inverted-V thermodynamic profiles) will support strong to severe outflow winds -- especially with any loosely organized clusters. ..Weinman/Hart.. 07/19/2023 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...SLC...PIH...VEF...LKN... LAT...LON 41841428 41991358 41991292 41891222 41501168 41011154 40591148 39261186 38641232 38241280 38191335 38191395 38251503 38481545 38661570 39001577 39571572 40011559 40991505 41481472 41841428 Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0258 PM CDT Wed Jul 19 2023 Valid 192000Z - 201200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CENTRAL PLAINS INTO THE UPPER MIDWEST...AND EASTERN NORTH CAROLINA INTO SOUTHEASTERN VIRGINIA... ...SUMMARY... Scattered severe thunderstorms capable of producing damaging winds and hail are expected this afternoon into tonight across parts of the Upper Midwest, central Plains, and Mid Atlantic regions. More isolated strong to severe thunderstorms may also occur from the Ozarks into the lower Ohio and Tennessee Valleys, and parts of the Great Basin. ...20Z Update... The Slight Risk has been expanded across parts of eastern NC based on recent convective trends. See Mesoscale Discussion 1628 for more details on the near-term severe threat for this area. Have trimmed the Marginal Risk across parts of the TN and lower OH Valley. There still appears to be some potential for strong to locally severe thunderstorms late tonight into early Thursday morning over portions of this region as convection spreads eastward in a modest low-level warm advection regime ahead of an approaching upper trough. Small adjustments have also been made to the Marginal/Slight Risk areas across the mid MO Valley into eastern SD/western MN based on observational and short-term model trends. ..Gleason.. 07/19/2023 .PREV DISCUSSION... /ISSUED 1121 AM CDT Wed Jul 19 2023/ ...MN/WI... An upper low is tracking southeastward out of southern Manitoba into ND. At the surface, a quasi-stationary boundary extends from northwest MN southward to near MSP. Westerly low-level winds and strong heating west of the boundary, combined with backed flow to the east and more persistent low-level moisture, will lead to an axis of thunderstorm development this afternoon. Forecast soundings show low-level and deep-layer shear profiles favorable for rotating storms capable of hail and gusty winds. A tornado or two is also possible. These storms will drift eastward into the MN Arrowhead region and northern WI during the evening. ...Central Plains... A broad upper ridge is positioned from the Four Corners region eastward across the southeast states today, with the southern fringe of stronger westerlies extending across CO/KS. Rich low-level moisture is present across much of the central Plains, with dewpoints in the upper 60s and 70s from eastern CO into central NE. Thunderstorms are expected to develop along the western edge of the greater moisture by mid-afternoon along an axis from north-central NE into northwest KS and eastern CO. These storms will spread southeastward through the evening, posing a risk of very large hail and damaging winds. Activity is expected to build as far south as parts of the TX/OK Panhandles during the evening. ...KS/MO... Multiple 12z CAM solutions suggest that a cluster of storms over northern KS will grow upscale and become very organized late tonight, resulting in a corridor of severe wind potential from eastern KS across central into southeast MO. At this point, the confidence in this scenario remains low but will be monitored. ...VA/NC... A remnant MCV is evident in satellite/radar imagery over north-central NC. The associated cluster of thunderstorms will track northeastward toward the coast this afternoon, posing a risk of damaging wind gusts. Please refer to MCD #1627 for further details. ...UT... A cluster of showers and thunderstorms over western NV is associated with a weak mid-level shortwave trough. Weak but sufficient forcing ahead of this system will lead to scattered thunderstorm development later today over eastern NV and western UT. Forecast soundings show inverted-v profiles, but with pockets of CAPE around 500-1000 J/kg and with 25-30 knots of westerly mid-level flow. This will be sufficient to pose a risk of locally severe wind gusts in the stronger cells. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0258 PM CDT Wed Jul 19 2023 Valid 192000Z - 201200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CENTRAL PLAINS INTO THE UPPER MIDWEST...AND EASTERN NORTH CAROLINA INTO SOUTHEASTERN VIRGINIA... ...SUMMARY... Scattered severe thunderstorms capable of producing damaging winds and hail are expected this afternoon into tonight across parts of the Upper Midwest, central Plains, and Mid Atlantic regions. More isolated strong to severe thunderstorms may also occur from the Ozarks into the lower Ohio and Tennessee Valleys, and parts of the Great Basin. ...20Z Update... The Slight Risk has been expanded across parts of eastern NC based on recent convective trends. See Mesoscale Discussion 1628 for more details on the near-term severe threat for this area. Have trimmed the Marginal Risk across parts of the TN and lower OH Valley. There still appears to be some potential for strong to locally severe thunderstorms late tonight into early Thursday morning over portions of this region as convection spreads eastward in a modest low-level warm advection regime ahead of an approaching upper trough. Small adjustments have also been made to the Marginal/Slight Risk areas across the mid MO Valley into eastern SD/western MN based on observational and short-term model trends. ..Gleason.. 07/19/2023 .PREV DISCUSSION... /ISSUED 1121 AM CDT Wed Jul 19 2023/ ...MN/WI... An upper low is tracking southeastward out of southern Manitoba into ND. At the surface, a quasi-stationary boundary extends from northwest MN southward to near MSP. Westerly low-level winds and strong heating west of the boundary, combined with backed flow to the east and more persistent low-level moisture, will lead to an axis of thunderstorm development this afternoon. Forecast soundings show low-level and deep-layer shear profiles favorable for rotating storms capable of hail and gusty winds. A tornado or two is also possible. These storms will drift eastward into the MN Arrowhead region and northern WI during the evening. ...Central Plains... A broad upper ridge is positioned from the Four Corners region eastward across the southeast states today, with the southern fringe of stronger westerlies extending across CO/KS. Rich low-level moisture is present across much of the central Plains, with dewpoints in the upper 60s and 70s from eastern CO into central NE. Thunderstorms are expected to develop along the western edge of the greater moisture by mid-afternoon along an axis from north-central NE into northwest KS and eastern CO. These storms will spread southeastward through the evening, posing a risk of very large hail and damaging winds. Activity is expected to build as far south as parts of the TX/OK Panhandles during the evening. ...KS/MO... Multiple 12z CAM solutions suggest that a cluster of storms over northern KS will grow upscale and become very organized late tonight, resulting in a corridor of severe wind potential from eastern KS across central into southeast MO. At this point, the confidence in this scenario remains low but will be monitored. ...VA/NC... A remnant MCV is evident in satellite/radar imagery over north-central NC. The associated cluster of thunderstorms will track northeastward toward the coast this afternoon, posing a risk of damaging wind gusts. Please refer to MCD #1627 for further details. ...UT... A cluster of showers and thunderstorms over western NV is associated with a weak mid-level shortwave trough. Weak but sufficient forcing ahead of this system will lead to scattered thunderstorm development later today over eastern NV and western UT. Forecast soundings show inverted-v profiles, but with pockets of CAPE around 500-1000 J/kg and with 25-30 knots of westerly mid-level flow. This will be sufficient to pose a risk of locally severe wind gusts in the stronger cells. Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0225 PM CDT Wed Jul 19 2023 Valid 201200Z - 211200Z ...NO CRITICAL AREAS... No changes, the previous forecast discussion remains valid. ..Lyons.. 07/19/2023 .PREV DISCUSSION... /ISSUED 0200 AM CDT Wed Jul 19 2023/ ...Synopsis... Upper-level ridging will remain the dominant feature across the West on Thursday. This ridge may shift slightly eastward through the period. As this occurs, stronger mid-level winds will move inland in the Northwest late Thursday into Friday. At the surface, the pressure pattern will remain nebulous across the West. However, a surface thermal pressure trough will likely develop into the Columbia Basin. Fire weather concerns will again be minimal across the U.S. on account of weak surface. Hot and dry conditions will continue in the Southwest, Great Basin, and Northwest. Some locally elevated conditions could occur in terrain-favored areas. Flow through the Cascade gaps and Columbia Gorge will likely increase as the trough approaches. The increase in surface winds will not occur during the diurnal RH minimum though. While mid-level moisture is expected to be pushed east, a few thunderstorms are possible from eastern Nevada into western Colorado. Fuels are still not expected to be critically dry and storm coverage will be lower than previous days. Confidence in lightning ignitions remains too low for highlights. ...Please see www.spc.noaa.gov/fire for graphic product... Read more