Severe Storms

WW 0688 Status Updates
STATUS REPORT ON WW 688 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. ..LYONS..09/21/23 ATTN...WFO...GID... STATUS REPORT FOR WT 688 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS KSC089-123-141-183-220040- KS . KANSAS COUNTIES INCLUDED ARE JEWELL MITCHELL OSBORNE SMITH NEC001-019-035-061-079-099-129-181-220040- NE . NEBRASKA COUNTIES INCLUDED ARE ADAMS BUFFALO CLAY FRANKLIN HALL KEARNEY NUCKOLLS WEBSTER THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE REFER TO WATCH COUNTY NOTIFICATION STATEMENTS FOR OFFICIAL INFORMATION ON COUNTIES...INDEPENDENT CITIES AND MARINE ZONES CLEARED FROM SEVERE THUNDERSTORM AND TORNADO WATCHES. Read more

WW 688 TORNADO KS NE 212150Z - 220300Z
URGENT - IMMEDIATE BROADCAST REQUESTED Tornado Watch Number 688 NWS Storm Prediction Center Norman OK 450 PM CDT Thu Sep 21 2023 The NWS Storm Prediction Center has issued a * Tornado Watch for portions of North central Kansas South central Nebraska * Effective this Thursday afternoon and evening from 450 PM until 1000 PM CDT. * Primary threats include... A couple tornadoes possible 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...Supercells will persist into this evening along a stationary front across southern Nebraska, with the potential to produce a couple of tornadoes and isolated very large hail of 2 to 2.5 inches in diameter. Some clustering of storms is expected later this evening into early tonight, with some increase in the threat for damaging winds as storms spread east-southeastward along the Nebraska/Kansas border. The tornado watch area is approximately along and 35 statute miles east and west of a line from 25 miles north of Kearney NE to 90 miles south of Hastings NE. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU8). 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. && OTHER WATCH INFORMATION...CONTINUE...WW 687... AVIATION...Tornadoes and 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 26010. ...Thompson Read more

WW 0687 Status Updates
STATUS REPORT ON WW 687 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. ..LYONS..09/21/23 ATTN...WFO...GLD...GID...LBF... STATUS REPORT FOR WT 687 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS KSC039-063-065-109-137-147-153-163-179-193-220040- KS . KANSAS COUNTIES INCLUDED ARE DECATUR GOVE GRAHAM LOGAN NORTON PHILLIPS RAWLINS ROOKS SHERIDAN THOMAS NEC005-029-041-047-049-063-065-069-073-075-083-085-087-091-101- 111-113-117-135-137-145-171-220040- NE . NEBRASKA COUNTIES INCLUDED ARE ARTHUR CHASE CUSTER DAWSON DEUEL FRONTIER FURNAS GARDEN GOSPER GRANT HARLAN HAYES HITCHCOCK HOOKER KEITH LINCOLN LOGAN MCPHERSON PERKINS PHELPS RED WILLOW THOMAS Read more

WW 687 TORNADO KS NE 211950Z - 220300Z
URGENT - IMMEDIATE BROADCAST REQUESTED Tornado Watch Number 687 NWS Storm Prediction Center Norman OK 250 PM CDT Thu Sep 21 2023 The NWS Storm Prediction Center has issued a * Tornado Watch for portions of Northwest Kansas Southwest Nebraska * Effective this Thursday afternoon and evening from 250 PM until 1000 PM CDT. * Primary threats include... A few tornadoes possible Scattered large hail likely with isolated very large hail events to 3 inches in diameter possible Scattered damaging wind gusts to 70 mph possible SUMMARY...Thunderstorms are expected to rapidly develop this afternoon along a dryline and warm front lying across the area. Supercells capable of very large hail and a few tornadoes are expected. The tornado watch area is approximately along and 60 statute miles east and west of a line from 35 miles south southwest of Hill City KS to 60 miles north northwest of North Platte NE. 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 3 inches. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 28025. ...Hart Read more

MD 2172 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR EASTERN KANSAS INTO FAR NORTHEAST OKLAHOMA
Mesoscale Discussion 2172 NWS Storm Prediction Center Norman OK 0518 PM CDT Thu Sep 21 2023 Areas affected...Eastern Kansas into far northeast Oklahoma Concerning...Severe potential...Watch unlikely Valid 212218Z - 220015Z Probability of Watch Issuance...20 percent SUMMARY...A few strong to severe storms appear probable this evening with an attendant risk for damaging winds and large hail. However, this risk should remain sufficiently isolated to preclude watch issuance. DISCUSSION...Over the past hour, isolated thunderstorms have initiated across eastern KS with somewhat rapid cloud top cooling noted in IR imagery (approximately 20 C over a 20 minute window). Broken cloud cover through the afternoon has muted diurnal destabilization to some degree, but seasonally rich low-level moisture (mid 60s dewpoints) is supporting MLCAPE values upwards of 2000 J/kg. Additionally, southeasterly low-level flow under southwesterly winds aloft is supporting effective bulk shear values near 35 knots - sufficiently for organized cells. Although the regional environment is supportive of supercells with an attendant hail/wind risk, east/southeast KS is on the periphery of stronger mesoscale and synoptic ascent to the northwest across northern KS and NE. This casts uncertainty onto storm coverage, and slow storm motions should limit the potential for storm interactions/upscale growth. Consequently, this threat should remain fairly isolated, and a watch will likely not be needed. ..Moore/Thompson.. 09/21/2023 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...SGF...EAX...TSA...TOP...ICT... LAT...LON 37089605 37569650 38159697 38739706 38929702 39139669 39079624 38679546 38159501 37569460 37149449 36759460 36649505 36709542 37089605 Read more

MD 2171 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR EASTERN NEW MEXICO INTO THE OKLAHOMA AND TEXAS PANHANDLES
Mesoscale Discussion 2171 NWS Storm Prediction Center Norman OK 0443 PM CDT Thu Sep 21 2023 Areas affected...Eastern New Mexico into the Oklahoma and Texas Panhandles Concerning...Severe potential...Watch unlikely Valid 212143Z - 212345Z Probability of Watch Issuance...20 percent SUMMARY...Thunderstorms will increase in coverage over the next few hours, and a few strong to severe storms appear likely. Severe wind and large hail will be the primary threats, but confidence in the coverage/duration of this threat is limited and watch issuance is not anticipated. DISCUSSION...Convective initiation is well underway across central to eastern NM within the left-exit region of an approaching upper jet. This high-based activity is developing on the western fringe of the low-level moisture plume over the Plains with dewpoints in the upper 40s to low 50s and dewpoint depressions upwards of 40-50 F noted in latest surface obs. Although buoyancy profiles are somewhat meager (MLCAPE between 500-1000 J/kg), the deeply-mixed low-level thermodynamic profile is conducive for strong to severe downburst winds. Combined with weak low-level flow, this may favor undercutting outflows and storm clustering with time, which limits confidence in the duration of any particular strong/severe storm. However, strong speed shear in the 0-6 km layer will support initial cell organization with an attendant hail risk. The expectation over the next several hours is for additional storms to develop across eastern NM, slowly intensifying (with perhaps some clustering/upscale growth) as they migrate into the TX/OK Panhandles where low-level moisture improves. However, increasing inhibition closer to the TX/western OK border and the onset of nocturnal cooling later this evening may limit the eastward extent of the threat. ..Moore/Thompson.. 09/21/2023 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...DDC...LUB...AMA...MAF...PUB...ABQ...EPZ... LAT...LON 33500539 33750532 36570391 36760369 37300238 37370157 37160094 36540052 35430051 34140145 33480266 33120417 33040464 33020500 33100523 33300532 33500539 Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0359 PM CDT Thu Sep 21 2023 Valid 231200Z - 291200Z ...Day 3/Saturday... On the backside of a midlevel low tracking northeastward across the northern Plains, strong deep-layer northwesterly flow will overspread the northern/central High Plains. As a result, 25+ mph sustained west-northwesterly surface winds (with higher gusts) are expected across portions of southern WY, western NE, and far northeastern CO. While these winds could briefly overlap 20-30 percent RH over the area, marginal fuels should generally limit the fire-weather risk. ...Days 4-5/Sunday-Monday... Southwesterly midlevel flow will gradually strengthen across the Northwest on Days 4-5/Sunday-Monday, favoring breezy southwesterly surface winds across portions of northeastern CA, northwestern NV, and far southeastern OR -- where 15-20 percent RH is possible. With that said, fuels are generally unsupportive of large fires over these areas -- precluding Critical probabilities. ...Days 6-8/Tuesday-Thursday... The potential for dry/breezy conditions should focus over portions of the Southwest and Great Basin late in the extended forecast period, and potentially over the High Plains depending on moisture return. However, additional rainfall over already marginal fuels across these areas cast uncertainty on the fire-weather risk. ..Weinman.. 09/21/2023 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0249 PM CDT Thu Sep 21 2023 Valid 212000Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF WESTERN KS AND WESTERN/CENTRAL NE...AND OVER PARTS OF SOUTHERN OK AND NORTH TX... ...SUMMARY... Widely scattered strong to severe thunderstorms are possible this afternoon into tonight across parts of the southern and central Plains. ...20Z Update... ...NE/KS... Recent surface analysis places a low near the CO/NE/KS border intersection, with a dryline extending southward across western KS. As mentioned in recently issued MCD #2168, storm initiation appears probable in the next couple of hours across parts of southwestern Nebraska. The deepening surface low is supporting robust southeasterly flow and strong low-level shear. Moderate westerly flow exists atop this low-level southeasterly flow, supporting 30 to 40 kt of effective bulk shear. Strong buoyancy has also developed ahead of the dryline, with recent mesoanalysis estimating 1500 to 2500 J/kg MLCAPE across western KS and western/central NE. The overall environment supports supercells capable of all severe hazards including large to very-large (1-3 in.) hail, severe wind gusts (60-70 mph), and tornadoes. The tornado threat will generally be maximized near the warm front where surface winds remain more backed. ...Southern OK/North TX... Despite widespread clouds, temperatures have reached the upper 80s/low 90s across much of the region. Dewpoints are in the upper 60s/low 70s, and this combination of temperatures and dewpoints is supporting strong buoyancy. Recent mesoanalysis estimates MLCAPE is around 2000-2500 J/kg. Vertical shear is modest, but sufficient for some updraft organization. As such, a few strong to severe thunderstorms remain possible, with large hail and damaging gusts as the primary threats. ..Mosier.. 09/21/2023 .PREV DISCUSSION... /ISSUED 1112 AM CDT Thu Sep 21 2023/ ...Central and Southern Plains... Morning water vapor imagery shows a subtle shortwave trough crossing the Rockies of central CO. This feature will move eastward and provide weak large scale ascent across much of the central Plains this afternoon and evening. Morning model solutions are diverse in placement/timing of thunderstorm activity, but generally show a larger envelope of potential risk. Therefore have expanded the MRGL to include much more of the central and southern Plains. ...NE/KS... A rather pronounced surface dryline is expected to develop later today from western NE southward into western KS, with dewpoints in the 60s and MLCAPE values of over 2500 J/kg to the east of the boundary. Given the weak forcing and some cap, the areal coverage of convective initiation is uncertain. However, any storm that forms along this axis will have a conditional threat of very large hail and a tornado or two. These storms may persist for several hours after dark and track eastward into parts of north central KS and central NE. ...OK/TX... A weak sub-tropical shortwave trough is moving into west TX. Lift ahead of this feature is resulting in a large region of accas and a few showers and thunderstorms moving into southwest OK/northwest TX. Continued daytime heating is expected to lead to convective intensification by late afternoon across north TX and southern OK. The strongest cells in this area may produce hail and gusty winds for a few hours into this evening. ...Eastern NC... The outer bands of the strengthening tropical system off the southeast Atlantic coast are forecast to still be well offshore by Fri/12z. Therefore will defer any increasing tornado risk to the Day2 period. Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0207 PM CDT Thu Sep 21 2023 Valid 221200Z - 231200Z The latest fuels information suggests that fine fuels have dried sufficiently over portions of the mountains/I-25 corridor in southern Colorado to support some fire potential. Given the expectation for sustained southwesterly surface winds of 15-25 mph (with higher gusts) and around 10 percent RH, the Elevated highlights were expanded westward into this area. Over the southeast Colorado plains, the Elevated highlights were trimmed as the latest guidance suggests sustained surface winds will be too weak for an appreciable fire-weather risk. For additional details, see the previous discussion below. ..Weinman.. 09/21/2023 .PREV DISCUSSION... /ISSUED 0157 AM CDT Thu Sep 21 2023/ ...Synopsis... An upper low across eastern Oregon will start to fill during the day Friday and eventually become a negatively tilted open wave across the central/northern Rockies. As this upper-level pattern evolves, lee troughing is expected, which will bring some breezy conditions from the Southwest into the central Rockies and also the central High Plains and the central Plains. Farther west in Arizona and Utah, fuels are too moist to support fire spread. However, in the plains across southeast Colorado and northeast New Mexico and vicinity, some drier fuels are present. These fuels will likely dry further with single-digit relative humidity. Therefore, an Elevated area has been added for portions of the central High Plains for Friday. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook AMEND 1 NWS Storm Prediction Center Norman OK 0127 PM CDT Thu Sep 21 2023 Valid 231200Z - 241200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CENTRAL/SOUTHERN PLAINS INTO PARTS OF MO/IA/SOUTHERN MN... AMENDED TO ADD SEVERE PROBABILITIES OVER THE COASTAL MID-ATLANTIC ...SUMMARY... Severe thunderstorms are possible on Saturday across parts of the central and southern Plains into Iowa and Missouri. ...Coastal Mid-Atlantic... Recently issued track of Potential Tropical Cyclone 16 brings it onshore over coastal NC early Saturday morning, and then northward into the Chesapeake Bay by Saturday evening. Recent guidance suggests the warm sector to the north and east of the system's center should penetrate far enough inland to support modest buoyancy and deeper convective cores. Given the strong low to mid-level wind fields, any updrafts that are able to deepen and mature could produce tornadoes. Mesoscale details, in particular how much buoyancy develops inland, remain uncertain enough to introducing only a Marginal/Level 2 risk with this amendment. -- PREVIOUS DISCUSSION -- ...Great Plains into parts of MN/IA/MO... A seasonably strong mid/upper-level cyclone is forecast to move eastward across SD on Saturday. The primary surface low attendant to this mid/upper cyclone is forecast to move from the central Plains into the Dakotas as the system begins to occlude, while secondary surface low development is possible along the trailing front across the southern Plains. Moderate to locally strong buoyancy is expected to develop across a broad area of the Great Plains on Saturday, east of the cold front and outside of any areas where outflow persists from morning convection. One notable midlevel jet maximum is forecast to move from the central Plains into the Dakotas, while a southern-stream jet maximum will begin to impinge upon parts of the southern Plains. Organized convection will be possible Saturday into Saturday night across a broad region from the Great Plains into parts of MN/IA/MO, with a mixture of supercells and organized clusters possible along/east of a cold front. Initial development is most likely closer to the mid/upper-level low across the central/northern Plains, with storm development into parts of the southern Plains expected by early Saturday evening. All severe hazards will be possible, though primary storm mode and evolution of mesoscale details remain uncertain at this forecast range. ...Eastern NC into the Mid Atlantic... A surface low is forecast to move from near or just offshore of eastern NC into parts of the Mid Atlantic on Saturday. Depending on the westward extent of the track, richer low-level moisture may spread into coastal areas of the Mid Atlantic region, potentially accompanied by increasing low-level flow/shear and some threat for a brief tornado or two. Depending on the ultimate track and intensity of this system, severe probabilities may eventually be needed for some part of this region. ..Mosier/Dean.. 09/21/2023 Read more

No watches are valid as of Wed Sep 20 22:31:02 UTC 2023.

No Mesoscale Discussions are in effect as of Wed Sep 20 22:31:02 UTC 2023.

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0324 PM CDT Wed Sep 20 2023 Valid 221200Z - 281200Z ...Day 3/Friday... A strong westerly mid/upper-level jet streak, accompanying a deep midlevel low tracking eastward across the northern Rockies, will impinge on the central Rockies and adjacent High Plains on Day 3/Friday. A related surface low will deepen over the KS/CO border, yielding a tightening surface pressure gradient across the region. Downslope warming/drying (10-15 percent RH) over northeast NM, the western TX/OK Panhandles, and southeastern CO, combined with breezy/gusty westerly surface winds, will support elevated to locally critical fire-weather conditions. The primary limiting factor is marginal fuels across the area, precluding 70-percent Critical probabilities. Beyond Day 3/Friday, the potential for critical meteorological conditions over dry fuels appears low. ..Weinman.. 09/20/2023 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0246 PM CDT Wed Sep 20 2023 Valid 202000Z - 211200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER SOUTHEAST OKLAHOMA INTO NORTHEAST TEXAS...AND OVER PARTS OF THE NORTHERN GREAT BASIN... ...SUMMARY... Strong storms capable of hail and gusty winds are possible across parts of southeastern Oklahoma and northeast Texas through this evening. Gusty winds may also accompany a few storms over the northern Great Basin. ...OK/TX... A very conditional risk for a strong/severe storm through early evening continues across parts of southeast OK into northeast TX. The Marginal (level 1 of 5) risk area has been trimmed from portions of eastern OK into western AR and far northeast TX. Persistent clouds and showers/thunderstorms have limited heating much of the day. Southwestern portions of the Marginal risk area have largely cleared out this afternoon and allowed temperatures to warm into the upper 70s to mid 80s. However, quite a bit of inhibition remains. Furthermore, HRRR and RRFS guidance shows little convective development this afternoon/evening. Some cumulus development is noted closer to the I-35 corridor amid stronger instability and weaker inhibition. Nebulous large-scale ascent may be insufficient to overcome this inhibition. However, if a storm can develop near the western edge of the Marginal risk and track southeast along residual outflow, a risk for hail and strong gusts could occur for a few hours. ...NV/UT/ID/WY... No changes have been made with the 20z update. See previous discussion below for more details. ..Leitman.. 09/20/2023 .PREV DISCUSSION... /ISSUED 1109 AM CDT Wed Sep 20 2023/ ...OK/AR/TX/LA... A persistent nocturnal MCS is weakening over western AR, with clearing skies over eastern OK in its wake. Strong heating will help yield a moderately unstable air mass by late afternoon across southeastern OK, where there will be some chance of a thunderstorm or two. Effective shear values of 40-50 knots and steep mid-level lapse rates will support a risk of large hail and damaging winds in any persistent storm that develops. However, weakening large scale support and a residual cap suggest the risk of initiation is rather low in the primary instability region. ...NV/UT/ID/WY... A rather dynamic upper trough is digging quickly southeastward today across the Pacific Northwest region. This will allow large scale ascent to overspread much of the northern Great Basin by this afternoon. A corridor of mid-level moisture ahead of the trough extends from northern NV into northwest WY, and should be favorable for the development of scattered high-based showers and thunderstorms later today. Skies are currently clear in this region, allowing steep low-level lapse rates to develop. As winds aloft strengthen this afternoon, the potential will exist for gusty/damaging wind gusts in a few of the fast-moving storms. Read more

MD 2164 CONCERNING SEVERE THUNDERSTORM WATCH 686... FOR NORTHWEST TEXAS AND WESTERN OKLAHOMA.
Mesoscale Discussion 2164 NWS Storm Prediction Center Norman OK 0555 PM CDT Tue Sep 19 2023 Areas affected...Northwest Texas and western Oklahoma. Concerning...Severe Thunderstorm Watch 686... Valid 192255Z - 200030Z The severe weather threat for Severe Thunderstorm Watch 686 continues. SUMMARY...Increasing coverage and intensity of severe thunderstorms is expected through the evening. DISCUSSION...Showers which developed across the Texas Panhandle have intensified into supercells over the last hour as they moved into increasing instability (1500 J/kg MLCAPE). Effective shear of 40 to 45 knots per FDR VWP will continue to maintain the supercell threat through the evening. The long, relatively straight hodographs supports splitting supercells, the first of which has already occurred along the Texas/Oklahoma border east of Childress. Given moderate instability to the north of these ongoing storms, there may sufficient instability to support longer lived left-moving supercells capable of large to very large hail, particularly across southwest Oklahoma. ..Bentley.. 09/19/2023 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...FWD...OUN...SJT...LUB...AMA...MAF... LAT...LON 32900070 33680061 34800021 35779936 36029885 36059816 35919752 34969739 33669768 32809812 32579908 32900070 Read more

WW 0686 Status Updates
STATUS REPORT ON WW 686 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. ..KERR..09/19/23 ATTN...WFO...OUN...LUB...AMA...SJT...FWD... STATUS REPORT FOR WS 686 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS OKC009-011-015-017-031-033-039-043-051-055-057-065-067-073-075- 137-141-149-192340- OK . OKLAHOMA COUNTIES INCLUDED ARE BECKHAM BLAINE CADDO CANADIAN COMANCHE COTTON CUSTER DEWEY GRADY GREER HARMON JACKSON JEFFERSON KINGFISHER KIOWA STEPHENS TILLMAN WASHITA TXC009-023-075-077-087-101-125-151-155-191-197-207-237-253-263- 269-275-337-345-417-429-433-447-485-487-503-192340- TX . TEXAS COUNTIES INCLUDED ARE ARCHER BAYLOR CHILDRESS CLAY COLLINGSWORTH COTTLE DICKENS FISHER FOARD HALL HARDEMAN HASKELL JACK JONES KENT KING KNOX MONTAGUE Read more

WW 686 SEVERE TSTM OK TX 192145Z - 200400Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 686 NWS Storm Prediction Center Norman OK 445 PM CDT Tue Sep 19 2023 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Western Oklahoma Northwest Texas * Effective this Tuesday afternoon and evening from 445 PM until 1100 PM CDT. * 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...Isolated severe thunderstorms are expected to develop through early evening and move southeast. Very large hail, possibly up to baseball size, and damaging winds will be possible. The severe thunderstorm watch area is approximately along and 70 statute miles east and west of a line from 110 miles southwest of Wichita Falls TX to 60 miles north northeast of Clinton OK. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU6). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A Severe Thunderstorm Watch means conditions are favorable for severe thunderstorms in and close to the watch area. Persons in these areas should be on the lookout for threatening weather conditions and listen for later statements and possible warnings. Severe thunderstorms can and occasionally do produce tornadoes. && AVIATION...A few severe thunderstorms with hail surface and aloft to 2.5 inches. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 28030. ...Bunting Read more

MD 2163 CONCERNING SEVERE THUNDERSTORM WATCH 686... FOR NORTH-CENTRAL TEXAS.
Mesoscale Discussion 2163 NWS Storm Prediction Center Norman OK 0520 PM CDT Tue Sep 19 2023 Areas affected...north-central Texas. Concerning...Severe Thunderstorm Watch 686... Valid 192220Z - 192345Z The severe weather threat for Severe Thunderstorm Watch 686 continues. SUMMARY...A supercell across north-central Texas could pose a large hail threat this evening. DISCUSSION...A supercell formed on the western periphery of mid-day elevated convection which moved east across north-central Texas. Given only weak CINH near this storm and its radar depiction over the last hour, this storm has likely rooted and is surface based in a region with around 1000 J/kg MLCAPE. 40+ knots of mid-level northwesterly flow (per FWD VWP) has yielded near 50 knots of effective shear. This environment will support supercells capable of large hail (potentially 2+ inches). If this storm continues to turn right, which it has started to do over the last 15 to 30 minutes, portions of at least the northern DFW metro area may be impacted by large to very large hail this evening. If this storm continues to maintain its current intensity or strengthen, an expansion of watch 686 may be needed. ..Bentley/Bunting.. 09/19/2023 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...FWD... LAT...LON 33649755 33609688 33189611 32739589 32469641 32599703 32869743 33099767 33269770 33649755 Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0358 PM CDT Tue Sep 19 2023 Valid 211200Z - 271200Z On the backside of a midlevel cut-off low centered over portions of Oregon, a substantial mid/upper-level jet streak will overspread the West Coast on Day 3/Thursday. In the northern Sacramento Valley, boundary-layer mixing into the strong flow aloft, coupled with a tightening surface pressure gradient, will favor breezy/gusty surface winds and 10-15 percent RH on Day 3/Thursday. While this may yield elevated fire-weather conditions, confidence in the development of critical conditions is too low for probabilities at this time. Along the southeastern periphery of the midlevel low, strong deep-layer southwesterly flow will be in place across much of the Southwest into the central/southern Rockies on Days 3-5/Thursday-Saturday. A deeply mixed boundary layer across these areas will support 20+ mph sustained southwesterly surface winds and 15-20 percent RH. These meteorological conditions would typically warrant Critical probabilities, though ample rainfall and generally unreceptive fuels should limit the overall fire-weather threat. Beyond Day 5/Saturday, strong midlevel flow accompanying a mid/upper-level trough will overspread the northwestern CONUS, favoring strengthening surface winds across the region. While this may lead to an increase in fire-weather concerns, rainfall preceding this system and continued model disagreement limits confidence in the fire-weather threat. ..Weinman.. 09/19/2023 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0358 PM CDT Tue Sep 19 2023 Valid 211200Z - 271200Z On the backside of a midlevel cut-off low centered over portions of Oregon, a substantial mid/upper-level jet streak will overspread the West Coast on Day 3/Thursday. In the northern Sacramento Valley, boundary-layer mixing into the strong flow aloft, coupled with a tightening surface pressure gradient, will favor breezy/gusty surface winds and 10-15 percent RH on Day 3/Thursday. While this may yield elevated fire-weather conditions, confidence in the development of critical conditions is too low for probabilities at this time. Along the southeastern periphery of the midlevel low, strong deep-layer southwesterly flow will be in place across much of the Southwest into the central/southern Rockies on Days 3-5/Thursday-Saturday. A deeply mixed boundary layer across these areas will support 20+ mph sustained southwesterly surface winds and 15-20 percent RH. These meteorological conditions would typically warrant Critical probabilities, though ample rainfall and generally unreceptive fuels should limit the overall fire-weather threat. Beyond Day 5/Saturday, strong midlevel flow accompanying a mid/upper-level trough will overspread the northwestern CONUS, favoring strengthening surface winds across the region. While this may lead to an increase in fire-weather concerns, rainfall preceding this system and continued model disagreement limits confidence in the fire-weather threat. ..Weinman.. 09/19/2023 ...Please see www.spc.noaa.gov/fire for graphic product... Read more