Severe Storms

WW 0449 Status Updates
STATUS FOR WATCH 0449 HAS NOT BEEN ISSUED YET Read more

WW 449 SEVERE TSTM CO NM 052055Z - 060500Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 449 NWS Storm Prediction Center Norman OK 255 PM MDT Wed Jul 5 2023 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Southeast Colorado Northeast New Mexico * Effective this Wednesday afternoon and evening from 255 PM until 1100 PM MDT. * Primary threats include... Scattered large hail and isolated very large hail events to 3 inches in diameter possible Isolated damaging wind gusts to 70 mph possible A tornado or two possible SUMMARY...A couple supercells will initially be slow-moving adjacent to the Sangre de Cristos. With time this evening, additional supercells should develop across southeast Colorado. The severe thunderstorm watch area is approximately along and 60 statute miles east and west of a line from 45 miles east southeast of Las Vegas NM to 45 miles north northwest of La Junta CO. 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. && AVIATION...A few severe thunderstorms with hail surface and aloft to 3 inches. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 550. Mean storm motion vector 30025. ...Grams Read more

MD 1433 CONCERNING SEVERE POTENTIAL...WATCH LIKELY FOR MUCH OF SOUTHEAST COLORADO INTO NORTHEAST NEW MEXICO AND THE FAR WESTERN OK/TX PANHANDLES
Mesoscale Discussion 1433 NWS Storm Prediction Center Norman OK 0335 PM CDT Wed Jul 05 2023 Areas affected...much of southeast Colorado into northeast New Mexico and the far western OK/TX Panhandles Concerning...Severe potential...Watch likely Valid 052035Z - 052230Z Probability of Watch Issuance...80 percent SUMMARY...At least isolated supercells capable of very large hail, damaging gusts and a brief tornado threat are expected to form in the next few hours. DISCUSSION...A very moist yet cool air mass currently exists across much of the central Plains, with easterly surface winds over the High Plains of CO/NM. Visible satellite imagery shows breaks in the cloud fields, with temperatures gradually rising. Of note are the upper 70s F temperatures now into the Raton/Trinidad area, which when combined with mid 50s dewpoints results in very strong instability. Farther north toward Colorado Springs, stratus has locked in cool temperatures for much of the day, but recent observations indicate mixing is underway with winds out of the south around 15 mph. The moist upslope flow combined with heating will lead to at least isolated supercells forming off the high terrain, with initial hail threat. Continued heating as well as persistent moist easterly flow will support the hail/wind/tor threat extending eastward perhaps toward the Panhandles tonight. ..Jewell/Grams.. 07/05/2023 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...AMA...PUB...BOU...ABQ... LAT...LON 36310503 36680489 37090479 37410488 37660495 37940491 38260500 38950483 38960468 38880426 38510337 38230253 37900226 37510218 37160219 36700231 36280263 35900298 35820325 35800359 36130465 36310503 Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0242 PM CDT Wed Jul 05 2023 Valid 052000Z - 061200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CENTRAL HIGH PLAINS INTO THE SOUTHERN PLAINS... ...SUMMARY... Scattered large hail and damaging winds are possible across a portion of eastern Colorado and northeast New Mexico to northwest Oklahoma through tonight. Scattered damaging winds are also possible over northern Illinois and southeast Wisconsin through early evening. ...20Z Update... No major changes have been made to the Day 1 Convective Outlook. Relatively cool, cloudy conditions persist from the southern Plains to the Colorado Front Range due to the passage of an earlier MCS. Nonetheless, steep mid-level lapse rates should overspread the gradually warming boundary layer through the day to support supercell development off of the higher terrain. Severe hail and the chance of a tornado are the initial concerns, before upscale growth into an MCS supports a severe wind threat across southwest KS, northwest OK, and the TX Panhandle later this evening. Otherwise, pulse cellular storms and multicells will continue to pose a damaging gust threat across the MS Valley into the Southeast through the remainder of the afternoon. ..Squitieri.. 07/05/2023 .PREV DISCUSSION... /ISSUED 1132 AM CDT Wed Jul 05 2023/ ...Southern Rockies to south KS and OK... Composite outflow/effective surface cold front attendant to a decaying MCS extends from southern OK to the TX Panhandle. Rather pronounced differential heating will occur and yield an intense surface temperature gradient from around 100 along the Red River to upper 60s holding in parts of eastern CO/northwest KS. Late afternoon thunderstorm development should largely be focused along the higher terrain of CO to northeast NM with a fair amount of MLCIN likely holding over the adjacent High Plains north of the Raton Mesa. A few supercells should form with a primary threat of large hail but may struggle to move off the terrain north of the Panhandles early. Additional storms may also form near the outflow/front intersection in the eastern TX Panhandle vicinity along the fringe of the mid-level flow. This evening, a strengthening low-level jet atop the robust baroclinic zone will yield increasing storm coverage as inhibition becomes minimized for slightly elevated parcels. This should favor a mix of supercells and clusters over eastern CO and southwest KS that may grow upscale into a southeast-moving MCS overnight into parts of the TX Panhandle and northwest OK. Large hail will be a threat mainly early, with strong to severe wind gust potential lingering into the overnight. ...AR to WI/MI... A well-defined MCV is evident across northeast MO with a separate MCV approaching the Ozark Plateau attendant to a decaying MCS in OK. The northern one should remain coincident near a slow-moving cold front that arcs from the Mid-MS Valley to eastern WI. While there is flow enhancement evident on the backside of the Ozarks MCV, effective bulk shear downstream of both MCVs should remain weak up to around 20 kts (south of south WI). In addition, mid-level lapse rates will be weak, but nearly full insolation will support a plume of MLCAPE from 2000-3000 J/kg. Morning CAM guidance is consistent in indicating scattered to widespread storms later this afternoon. But the weakly sheared environment suggest clusters will only be loosely organized, suggesting severe gust potential will be relatively sporadic and ill-defined across much of the region. One exception may be across northern IL to southeast WI where slightly stronger deep-layer shear is expected. ...GA and the Carolinas... An MCV over the southern Appalachians drifting east and differential boundary-layer heating owing to its attendant cloud canopy should help focus scattered thunderstorm development to its south in GA and east-southeast across parts of the Carolinas. Relatively greater heating will occur across the coastal plain and parts of the Piedmont, yielding a pronounced MLCAPE gradient from west to east amid weak mid-level lapse rates. Flow enhancement appears minor, resulting in effective bulk shear only up to around 20 kts. This may be adequate for loosely organized, slow-moving multicell clusters that may produce isolated damaging winds. Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0154 PM CDT Wed Jul 05 2023 Valid 061200Z - 071200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF NORTHERN ARIZONA... The forecast for critical fire weather conditions remains on track for northern Arizona on Thursday (see previous discussion below). The only change to the outlook was to expand the elevated area into portions of western Colorado, where fuels are becoming more receptive for the spread of wildfires, and meteorological conditions (surface RH <15% and sustained winds >15 mph) will likely elevate fire-weather concerns during the afternoon. Regarding dry-thunderstorm potential, the forecast for isolated dry thunderstorms across the southern Cascades in Oregon into northeastern Oregon on Thursday also remains on track (see previous discussion below). ..Jirak.. 07/05/2023 .PREV DISCUSSION... /ISSUED 0200 AM CDT Wed Jul 05 2023/ ...Synopsis... ...Wind/RH... Midlevel west-southwesterly flow will strengthen across the Southwest into the central/southern Rockies on Day 2/Thursday. Over northern AZ, efficient diurnal heating/mixing amid a dry antecedent air mass will yield 10-15 percent minimum RH during the afternoon. Forecast soundings over this area depict around 30 kt of flow in the middle/upper-portions of the diurnally deepening boundary layer -- supporting sustained west-southwesterly surface winds near 25 mph (with higher gusts). Given increasingly dry fuels over this area, critical fire-weather conditions are expected. While critical meteorological conditions may also expand northward into southern UT, fuels are not as supportive of large fires. ...Isolated Dry Thunderstorms... Midlevel ascent preceding a low-amplitude shortwave trough will glance southern OR during the afternoon. This, combined with terrain circulations along the Cascades, could support isolated high-based thunderstorm development given weak instability. Inverted-V thermodynamic profiles and around 0.6 inch PW suggest dry thunderstorms capable of lightning-induced ignitions will be possible. ...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 1227 PM CDT Wed Jul 05 2023 Valid 061200Z - 071200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS EASTERN COLORADO INTO WESTERN KANSAS AND FAR NORTHWEST OKLAHOMA... ...SUMMARY... Severe storms capable of producing large hail, damaging gusts, and a couple of tornadoes, are forecast from the northern High Plains southeastward to Kansas and Oklahoma. ...Synopsis... Thunderstorms will be ongoing tomorrow (Thursday) morning across parts of the central Plains and are expected to drift into the Lower MS Valley by afternoon, supporting an isolated severe threat. An embedded mid-level impulse will traverse the central Rockies and eject into the central Plains during the afternoon, providing enough deep-layer ascent over a moist, unstable airmass to support severe thunderstorm development (with all hazards possible) across the central High Plains. Organized storm clusters may persist with some severe threat into the central and southern Plains into the evening hours. ...Central High Plains into the central and southern Plains... Guidance consensus depicts considerable cloud cover across the High Plains (especially around the WY/NE border) during the morning/early afternoon hours, suggesting that surface temperatures should only reach the 70s to perhaps 80 F by afternoon peak heating. Despite the modest surface temperatures, upper 50s F surface dewpoints should extend westward to the immediate lee of the central Rockies, with 60+ F dewpoints likely along the NE/CO/KS border and points east. 8+ C/km mid-level lapse rates will overspread this relatively moist low-level airmass, supporting 2000+ J/kg SBCAPE by mid afternoon along the High Plains. Considerable veering and strengthening winds with height will support elongated hodographs with modest low-level curvature, suggesting supercells as the likely initial storm mode. Large hail is the greatest threat with the supercells. The longest-lived supercells may produce instances of 2+ inch hail and/or a tornado. This is especially the case in eastern CO, where a Category 3/Enhanced risk has been introduced. During the evening hours, upscale growth into one or more MCSs is likely, with severe gusts becoming the dominant severe hazard. Latest guidance consensus suggests that a longer-lived MCS may develop across KS and progress to the OK border during the night, where a couple of 65+ kt gusts also cannot be ruled out. ...Southern High Plains... Surface lee troughing across parts of southeast NM, along with strong surface heating of a deep, dry/well-mixed boundary layer, may aid in the initiation of isolated high-based thunderstorms along/ahead of a diffuse dryline by mid to late afternoon. Given some stronger speed shear in the mid-levels (and associated hodograph elongation), a couple of multicellular storm structures may materialize, supporting a couple of severe downbursts given 9+ C/km low-level lapse rates. ...Arklatex into the Lower MS Valley... MCS remnants will slowly drift southeast into the Arklatex region at the start of the period (12Z Thursday morning), posing a limited damaging gust threat. By afternoon though, strong surface heating will promote surface temperatures approaching 90 F in spots, amid 70+ F dewpoints, contributing to 2000-3000 J/kg of tall, thin SBCAPE (given mediocre mid-level lapse rates). Deep-layer shear is also expected to be quite poor, which should limit storm organization. However, convergence along outflow boundaries left behind by preceding convection may serve as the impetus for the initiation of thunderstorm clusters. Water loaded downdrafts associated with these clusters may support brief instances of damaging to potentially severe downburst winds, warranting the introduction of a Category 1/Marginal Risk. ..Squitieri.. 07/05/2023 Read more

No Mesoscale Discussions are in effect as of Tue Jul 4 21:46:17 UTC 2023.

WW 0444 Status Updates
STATUS REPORT ON WW 444 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. ..WENDT..07/04/23 ATTN...WFO...BOU...PUB...GLD...CYS... STATUS REPORT FOR WS 444 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS COC001-005-011-013-014-017-019-025-031-035-039-041-047-059-061- 063-069-073-075-087-089-095-099-101-115-121-123-125-042240- CO . COLORADO COUNTIES INCLUDED ARE ADAMS ARAPAHOE BENT BOULDER BROOMFIELD CHEYENNE CLEAR CREEK CROWLEY DENVER DOUGLAS ELBERT EL PASO GILPIN JEFFERSON KIOWA KIT CARSON LARIMER LINCOLN LOGAN MORGAN OTERO PHILLIPS PROWERS PUEBLO SEDGWICK WASHINGTON WELD YUMA NEC007-033-105-157-042240- NE . NEBRASKA COUNTIES INCLUDED ARE BANNER CHEYENNE KIMBALL SCOTTS BLUFF Read more

WW 444 SEVERE TSTM CO NE WY 042005Z - 050500Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 444 NWS Storm Prediction Center Norman OK 205 PM MDT Tue Jul 4 2023 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Eastern Colorado Southwest Nebraska Panhandle Southeast Wyoming * Effective this Tuesday afternoon and evening from 205 PM until 1100 PM MDT. * Primary threats include... Scattered damaging winds and isolated significant gusts to 80 mph likely Scattered large hail and isolated very large hail events to 2.5 inches in diameter possible A tornado or two possible SUMMARY...Initial supercells should evolve into a cluster across the eastern Colorado plains, with renewed development expected along the Front Range later this evening. Large hail will be the main threat early and late, with the greatest severe wind threat during the early evening. The severe thunderstorm watch area is approximately along and 80 statute miles east and west of a line from 30 miles west northwest of Scottsbluff NE to 5 miles east southeast of La Junta CO. 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 2.5 inches. Extreme turbulence and surface wind gusts to 70 knots. A few cumulonimbi with maximum tops to 550. Mean storm motion vector 29030. ...Grams Read more

WW 0445 Status Updates
STATUS REPORT ON WW 445 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. ..WENDT..07/04/23 ATTN...WFO...OAX...FSD...GID... STATUS REPORT FOR WS 445 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS IAC085-093-129-133-155-165-193-042240- IA . IOWA COUNTIES INCLUDED ARE HARRISON IDA MILLS MONONA POTTAWATTAMIE SHELBY WOODBURY KSC089-123-141-147-163-183-042240- KS . KANSAS COUNTIES INCLUDED ARE JEWELL MITCHELL OSBORNE PHILLIPS ROOKS SMITH NEC001-003-011-019-021-023-025-027-035-037-039-043-051-053-055- 059-061-065-073-077-079-081-083-093-099-109-119-121-125-129-137- 139-141-143-151-153-155-159-163-167-169-173-177-179-181-185- 042240- NE . NEBRASKA COUNTIES INCLUDED ARE Read more

WW 0446 Status Updates
STATUS REPORT ON WW 446 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. ..WENDT..07/04/23 ATTN...WFO...GLD...DDC... STATUS REPORT FOR WS 446 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS KSC023-039-051-055-063-065-067-071-075-093-101-109-135-137-153- 165-171-179-181-187-193-195-199-203-042240- KS . KANSAS COUNTIES INCLUDED ARE CHEYENNE DECATUR ELLIS FINNEY GOVE GRAHAM GRANT GREELEY HAMILTON KEARNY LANE LOGAN NESS NORTON RAWLINS RUSH SCOTT SHERIDAN SHERMAN STANTON THOMAS TREGO WALLACE WICHITA NEC057-087-145-042240- NE . NEBRASKA COUNTIES INCLUDED ARE DUNDY HITCHCOCK RED WILLOW THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE REFER TO WATCH COUNTY NOTIFICATION STATEMENTS FOR OFFICIAL Read more

WW 445 SEVERE TSTM IA KS NE 042030Z - 050300Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 445 NWS Storm Prediction Center Norman OK 330 PM CDT Tue Jul 4 2023 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Western Iowa North-central Kansas South-central to eastern Nebraska * Effective this Tuesday afternoon and evening from 330 PM until 1000 PM CDT. * Primary threats include... Scattered damaging winds and isolated significant gusts to 75 mph possible Scattered large hail and isolated very large hail events to 2.5 inches in diameter possible A tornado or two possible SUMMARY...Initial cells will pose a threat for large hail but should quickly cluster and likely spread east-southeast this evening. The severe thunderstorm watch area is approximately along and 70 statute miles east and west of a line from 55 miles west southwest of Concordia KS to 15 miles west northwest of Sioux City IA. 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 444... AVIATION...A few severe thunderstorms with hail surface and aloft to 2.5 inches. Extreme turbulence and surface wind gusts to 65 knots. A few cumulonimbi with maximum tops to 550. Mean storm motion vector 28025. ...Grams Read more

WW 446 SEVERE TSTM KS NE 042040Z - 050500Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 446 NWS Storm Prediction Center Norman OK 340 PM CDT Tue Jul 4 2023 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Western Kansas Far southwest Nebraska * Effective this Tuesday afternoon from 340 PM until Midnight CDT. * Primary threats include... Scattered damaging winds and isolated significant gusts to 80 mph possible Isolated very large hail events to 2.5 inches in diameter possible A tornado or two possible SUMMARY...Multicell clusters will develop along a quasi-stationary front, as well as spread east from eastern Colorado later this evening. The severe thunderstorm watch area is approximately along and 85 statute miles north and south of a line from 50 miles south southwest of Goodland KS to 25 miles east northeast of Hill City KS. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU6). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A Severe Thunderstorm Watch means conditions are favorable for severe thunderstorms in and close to the watch area. Persons in these areas should be on the lookout for threatening weather conditions and listen for later statements and possible warnings. Severe thunderstorms can and occasionally do produce tornadoes. && OTHER WATCH INFORMATION...CONTINUE...WW 444...WW 445... AVIATION...A few severe thunderstorms with hail surface and aloft to 2.5 inches. Extreme turbulence and surface wind gusts to 70 knots. A few cumulonimbi with maximum tops to 550. Mean storm motion vector 27030. ...Grams Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0251 PM CDT Tue Jul 04 2023 Valid 042000Z - 051200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS EAST-CENTRAL CO...NORTHERN KS...AND SOUTHERN NE... ...SUMMARY... Scattered severe thunderstorms are possible from the southern Rockies to the Upper Midwest through mainly this evening. The most probable corridor for significant severe wind and hail is across a portion of eastern Colorado, northern Kansas, and southern Nebraska. ...Discussion... The only notable change this outlook update is to reduce severe probabilities across parts of the Upper Midwest due primarily to observational trends (i.e., visible satellite, surface observations, model-derived instability fields) showing weaker instability and a lessening risk for severe thunderstorms. ..Smith.. 07/04/2023 .PREV DISCUSSION... /ISSUED 1130 AM CDT Tue Jul 04 2023/ ...Southern Rockies and the central Great Plains... Scattered thunderstorms will develop over the higher terrain near the UT/WY/CO border area east to the Front Range of CO/WY later this afternoon amid 40s to mid 50s surface dew points this morning. Steep mid-level lapse rates and fast mid-level westerlies centered over WY will support potential for a couple long-tracked supercells capable of large hail and severe wind gusts. This should evolve into a scattering of supercells over the central High Plains by early evening within a post-frontal, upslope flow regime. These will likely consolidate into an MCS as they spread away from the stronger mid-level flow and towards the deeply mixed boundary layer south of the front. The corridor immediately along the frontal zone will have the relatively greatest threat for significant severe wind gusts and a tornado or two. This MCS may merge with downstream convection that will likely develop separately in NE along the cold front. Overall, the hail threat should be mainly focused along the initial corridor of severe development and within the post-frontal regime, while the wind threat becomes the dominant hazard downstream until convection gradually subsides overnight. ...Upper Midwest... Remnants of a morning MCS have persisted across a portion of the Mid-MO Valley into the Twin Cities area. Attendant overturning and remnant cloud coverage is delaying diurnal destabilization, which 12Z guidance appears to be poorly handling overall. There appears to be a confined pocket of clearing behind the MCS outflow near a minor surface wave along the cold front. It is quite unclear whether there will be adequate recovery time across southeast SD northeastward across MN in the wake of this morning's activity. Conditionally, it will be a favorable setup for potential late afternoon to early evening redevelopment. Along the fringe of the stronger mid flow centered on the northern Great Plains overlapping the immediate frontal zone, 25-35 kt effective bulk shear would support organized multicell clusters and transient supercell structures. Primary change this outlook is to revamp the underlying hail probabilities which were forecast to be of equal weight and spatial extent as the wind probabilities. The large hail threat should be mainly focused along the initial corridor of severe development, with the wind threat largely being the dominant hazard downstream given the convective mode and weakness in the hodograph above the mid-levels. ...Mid and South Atlantic Coastal Plains to the Red River Valley... Primary change this outlook is to remove much of the hail probabilities which were forecast to be of equal weight as the wind probabilities for what will undoubtedly be a predominant sporadic damaging wind threat. A broad swath of moderate buoyancy with pockets of large buoyancy (MLCAPE around 3000 J/kg) are expected across parts of the Atlantic coastal plain across the Southeast through the Deep South to the Red River Valley. Weak to modest deep-layer shear and ill-defined synoptic/mesoscale features to help focus a more probable severe threat area, suggests a broad cat 1/MRGL risk remains warranted. Relatively greater potential for loosely organized multicell clusters and/or deeper updrafts is apparent over the eastern Carolinas and the Ark-La-Miss vicinity. Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0137 PM CDT Tue Jul 04 2023 Valid 051200Z - 061200Z The previous forecast (see below) remains on track, with no changes or additions made. ..Squitieri.. 07/04/2023 .PREV DISCUSSION... /ISSUED 0157 AM CDT Tue Jul 04 2023/ ...Synopsis... A belt of moderate west-southwesterly midlevel flow trailing a departing midlevel trough over the central Rockies will persist over the Southwest. Similar to Day 1/Tuesday, efficient diurnal heating amid a dry antecedent air mass will favor deep boundary-layer mixing into the enhanced flow aloft -- yielding 10 percent minimum RH and 15-20 mph winds across northern AZ. Given receptive fuels across this area, elevated to spotty critical fire-weather conditions are expected. Another day of diurnally driven, high-based thunderstorms are expected across parts of western CO, as a subtle shortwave impulse crosses the central Rockies. A deep/dry boundary layer and quick westerly storm motions should once again favor isolated dry thunderstorms capable of new fire starts. Farther north, a plume of adequate midlevel moisture should extend into the Northwest by late afternoon/evening. Diurnal heating beneath this plume of midlevel moisture may yield weak instability, supporting isolated high-based thunderstorm development over parts of south-central OR. With increasingly dry fuels over the region, isolated lightning-induced ignitions are possible. ...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 1228 PM CDT Tue Jul 04 2023 Valid 051200Z - 061200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE CENTRAL HIGH PLAINS EAST THROUGH THE OZARKS AND INTO THE MIDDLE MISSISSIPPI VALLEY... ...SUMMARY... Widely scattered storms are forecast from the central High Plains eastward into the middle Mississippi Valley on Wednesday. ...Central High Plains to the southwest Great Lakes... A cold front will continue to advance southeastward/southward across central portions of the country, as the southern extent of mid-level troughing crossing central Canada moves eastward across the northern and central Plains, toward the Mississippi Valley/Upper Great Lakes. Widely scattered showers/thunderstorms are forecast to be ongoing Wednesday morning from the eastern half of KS into the Ozarks with this activity weakening/dissipating by mid-late morning. Ahead of this associated convective debris over the mid MS Valley, heating amidst a very moist airmass characterized by upper 60s to lower 70s dewpoints, will result in a moderate to very unstable airmass across the mid MS Valley (MLCAPE ranging from 1000 J/kg in southern WI to 3000 J/kg in IL/MO). Frontal convergence and weakening convective inhibition will result in scattered thunderstorms growing upscale into one or more bands of storms while thunderstorm coverage increases into the early evening. Modest deep-layer westerly mid to high-level flow will limit overall storm intensity. The stronger storms across the central Great Lakes southwestward into the Ozarks will mainly pose a risk for damaging gusts. This threat will likely subside during the evening and as the activity pushes farther east/southeast into a flattened sub-tropical ridge. Farther west into the High Plains, weaker instability is expected due to more limited boundary-layer moisture. However, stronger mid-level flow near and to the cool side of the trailing, west-to-east segment of the front, atop low-level easterly/southeasterly flow, will result in deep-layer shear sufficient to support supercells. During the afternoon, isolated High-Plains storms should develop -- with attendant risks for large hail and severe gusts. Storms appear likely expand in coverage and shift out of the High Plains across parts of Kansas and Oklahoma during the evening into the overnight, as a modest, nocturnal increase in southeasterly low-level flow is expected. Some accompanying risk for severe gusts/large hail may persist across the Kansas/Oklahoma vicinity -- initially with frontal convection, but later with storms moving east-southeastward off the higher terrain to the west. ...The Southeast... Afternoon heating/destabilization along a weak/remnant baroclinic zone lying across the Southeast will again promote scattered thunderstorm development. Though limited shear expected across the area suggests largely disorganized storms, moderate mid-level westerly flow could support a couple of semi-organized, eastward-moving clusters with localized gusts mainly in the 45-60 mph range and resulting in pockets of wind damage. ..Smith.. 07/04/2023 Read more

WW 0441 Status Updates
STATUS REPORT ON WW 441 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 60 WNW RIW TO 35 NE COD TO 50 E BIL. ..FLOURNOY..07/03/23 ATTN...WFO...BYZ...UNR...RIW... STATUS REPORT FOR WS 441 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS MTC011-075-032240- MT . MONTANA COUNTIES INCLUDED ARE CARTER POWDER RIVER SDC007-019-033-047-055-063-071-081-093-095-102-103-105-121-123- 137-032240- SD . SOUTH DAKOTA COUNTIES INCLUDED ARE BENNETT BUTTE CUSTER FALL RIVER HAAKON HARDING JACKSON LAWRENCE MEADE MELLETTE OGLALA LAKOTA PENNINGTON PERKINS TODD TRIPP ZIEBACH WYC003-005-011-017-019-033-043-045-032240- WY Read more

WW 441 SEVERE TSTM MT SD WY 032100Z - 040600Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 441 NWS Storm Prediction Center Norman OK 300 PM MDT Mon Jul 3 2023 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Far southeast Montana Western South Dakota Northern Wyoming * Effective this Monday afternoon from 300 PM until Midnight MDT. * Primary threats include... Scattered damaging winds and isolated significant gusts to 90 mph likely Scattered large hail and isolated very large hail events to 3 inches in diameter possible A tornado or two possible SUMMARY...Multiple scenarios are expected this evening. A couple supercells should initially develop over the Black Hills and along a front over southwest South Dakota. Very large hail will be the main threat with these storms. A fast-moving cluster over northern Wyoming should develop into an MCS with embedded supercells and bowing structures spreading across western South Dakota later this evening. The severe thunderstorm watch area is approximately along and 70 statute miles north and south of a line from 50 miles west southwest of Sheridan WY to 15 miles east northeast of Philip SD. 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 438...WW 439...WW 440... AVIATION...A few severe thunderstorms with hail surface and aloft to 3 inches. Extreme turbulence and surface wind gusts to 80 knots. A few cumulonimbi with maximum tops to 550. Mean storm motion vector 27045. ...Grams Read more

WW 0440 Status Updates
STATUS REPORT ON WW 440 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 30 WSW SHD TO 5 WNW MRB TO 35 SSE IPT. ..FLOURNOY..07/03/23 ATTN...WFO...LWX...PHI...CTP... STATUS REPORT FOR WS 440 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS DEC001-003-005-032240- DE . DELAWARE COUNTIES INCLUDED ARE KENT NEW CASTLE SUSSEX DCC001-032240- DC . DISTRICT OF COLUMBIA COUNTIES INCLUDED ARE DISTRICT OF COLUMBIA MDC003-005-009-011-013-015-017-021-025-027-029-031-033-035-037- 041-043-510-032240- MD . MARYLAND COUNTIES INCLUDED ARE ANNE ARUNDEL BALTIMORE CALVERT CAROLINE CARROLL CECIL CHARLES FREDERICK HARFORD Read more

WW 440 SEVERE TSTM DC DE MD NJ PA VA WV CW 031855Z - 040200Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 440 NWS Storm Prediction Center Norman OK 255 PM EDT Mon Jul 3 2023 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of District Of Columbia Delaware Maryland New Jersey Southeast Pennsylvania Northern and central Virginia Eastern West Virginia Panhandle Coastal Waters * Effective this Monday afternoon and evening from 255 PM until 1000 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 SUMMARY...Isolated to scattered discrete storms should consolidate into a couple multicell clusters that spread east-northeast into this evening. The severe thunderstorm watch area is approximately along and 85 statute miles east and west of a line from 10 miles east northeast of Allentown PA to 55 miles southwest of Washington DC. 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 438...WW 439... 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 24035. ...Grams Read more