Severe Storms

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1242 AM CDT Sat Aug 17 2024 Valid 171200Z - 181200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE OHIO VALLEY/KY...UTAH REGION...AND PARTS OF WESTERN OREGON/SOUTHWEST WASHINGTON... ...SUMMARY... Scattered severe thunderstorms are possible in parts of Kentucky and the Ohio Valley on Saturday afternoon. Isolated severe thunderstorms are also expected across the Utah region and over parts of western Oregon into southwest Washington. Wind and hail are the primary threats. ...Ohio Valley/KY... Great Lakes/Midwest trough will progress east today and extend from Lower MI-KY by 18/00z. High-level diffluent flow will be noted across the OH Valley into the Mid South which will prove favorable for scattered robust convection, especially by early afternoon as the boundary layer destabilizes with daytime heating. Strength of this feature will encourage a notable synoptic front to advance into OH/western KY by late afternoon, coincident with favorable upper diffluence. Latest model guidance suggests a considerable amount of convection will likely evolve along/ahead the wind shift, concentrated within a zone of stronger instability -- KY/southern OH. While some supercell potential does exist across this region, the majority of storms will likely be multicellular with clusters common. Wind/hail are expected with this activity. ...Utah Region... Well-defined mid-level short-wave trough is lifting north across the lower CO River Valley late this evening. With the upper ridge holding across the southern Rockies, this feature will progress across UT early in the period before shifting into eastern ID/southwest WY by late afternoon. Latest HREF model guidance actually reflects this short wave well with all members exhibiting substantial convection near the mid-level vort over southeast NV at sunrise. This activity will spread/develop northeast across UT during the day within a strongly sheared environment. Though, lapse rates will be seasonally weak given the convective coverage and cloud cover. Even so, robust organized updrafts are expected and wind should be the primary threat with these storms. ...Western OR/Southwest WA... Strong 500mb speed max will round the base of the offshore trough and translate across northern CA into eastern OR by early evening. Left exit region of this feature will aid UVV near the higher terrain and cooling/moistening mid-levels will contribute to modest buoyancy along the cyclonic side of the speed max. Forecast soundings exhibit strongly sheared profiles and isolated supercells are expected to develop, then spread north-northeast as a short-wave trough ejects into southern WA. Hail/wind are possible with these storms. ..Darrow/Squitieri.. 08/17/2024 Read more

MD 1927 CONCERNING SEVERE THUNDERSTORM WATCH 628... FOR PORTIONS OF EASTERN OKLAHOMA INTO FAR NORTHWESTERN ARKANSAS
Mesoscale Discussion 1927 NWS Storm Prediction Center Norman OK 0921 PM CDT Fri Aug 16 2024 Areas affected...portions of eastern Oklahoma into far northwestern Arkansas Concerning...Severe Thunderstorm Watch 628... Valid 170221Z - 170345Z The severe weather threat for Severe Thunderstorm Watch 628 continues. SUMMARY...The severe threat continues across Severe Thunderstorm Watch 628, with a severe wind/hail threat persisting. Upscale growth into a more organized cluster of storms is possible, and local spatial/temporal extensions of the watch may be needed should this upscale growth occur. DISCUSSION...Multicells and supercells persist across northeast OK with a history of severe wind and hail. These storms are displaced slightly on the cool side of a convective outflow boundary that continues to surge southward in tandem with a leading convective complex in northwestern AR. MLCINH will increase through the evening given nocturnal cooling. However, the rate of MLCINH increase will be gradual given abundant low-level moisture, which is also contributing to 4000 J/kg MUCAPE. Given adequate deep-layer shear also in place, at least a short-term severe threat should persist. However, should storms catch up to and anchor along the leading outflow boundary while also merging cold pools, a more organized MCS could materialize with a persistent severe gust threat, and an occasional instance of large hail also possible. Should an MCS develop, temporal and/or spatial southward extensions of Severe Thunderstorm Watch 628 may be needed. ..Squitieri.. 08/17/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...SGF...TSA...OUN... LAT...LON 35369608 35889652 36499658 36869641 36989592 36959520 36779434 36449384 36149386 35739411 35259441 34839469 34579504 34549519 34959592 35369608 Read more

MD 1926 CONCERNING SEVERE POTENTIAL...WATCH LIKELY FOR PORTIONS OF NORTHWESTERN ARKANSAS
Mesoscale Discussion 1926 NWS Storm Prediction Center Norman OK 0845 PM CDT Fri Aug 16 2024 Areas affected...portions of northwestern Arkansas Concerning...Severe potential...Watch likely Valid 170145Z - 170245Z Probability of Watch Issuance...95 percent SUMMARY...The severe threat is increasing across portions of northwestern AR. Severe gusts are the main threat, though a few instances of large hail are also possible. A WW will be needed soon to address the impending severe threat. DISCUSSION...A robust multicellular cluster (perhaps with embedded transient supercells) continues to rapidly propagate to the southeast. Multiple instances of 70-80 mph gusts and wind damage have been reported with this cluster, and MRMS MESH suggests that at least some marginally severe hail may be falling in the stronger storm cores. Preceding these storms is a thermodynamic airmass characterized by 2000-3000 J/kg MLCAPE amid only slowly increasing MLCINH. Effective bulk shear values are likely exceeding 30 kts per 00Z mesoanalysis, which is sufficient for continued storm organization and intensity given the aforementioned buoyancy. Though MLCINH should ultimately tame severe potential later tonight, at least some concentrated severe wind/hail threat may still materialize over the next couple of hours. A WW issuance will be needed soon to address the near-term severe threat. ..Squitieri/Edwards.. 08/17/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...LZK...TSA... LAT...LON 35459441 36189344 36449288 36229238 35719219 35369230 35039262 34929309 34939366 34999419 35459441 Read more

MD 1925 CONCERNING SEVERE THUNDERSTORM WATCH 628... FOR PORTIONS OF WESTERN OKLAHOMA INTO FAR NORTHWESTERN ARKANSAS
Mesoscale Discussion 1925 NWS Storm Prediction Center Norman OK 0738 PM CDT Fri Aug 16 2024 Areas affected...Portions of western Oklahoma into far northwestern Arkansas Concerning...Severe Thunderstorm Watch 628... Valid 170038Z - 170215Z The severe weather threat for Severe Thunderstorm Watch 628 continues. SUMMARY...The severe threat continues across Severe Thunderstorm Watch 628. Severe wind and hail remain the primary threats over the next few hours. DISCUSSION...A robust uptick in convective coverage and intensity has been noted in north-central Oklahoma to southeast Kansas over the past couple of hours, where severe wind and hail have been observed. Despite weak forcing, thunderstorms have managed to initiate off of multiple converging low-level baroclinic/outflow boundaries. Furthermore, the OUN 00Z observed sounding shows near 3000 J/kg MLCAPE atop a mixed boundary layer, characterized by 30F T/Td spreads. 20-30 F spreads are also evident across eastern OK ahead of the ongoing storms, with 00Z mesoanalysis depicting over 4500 J/kg MLCAPE (given mid 70s F surface dewpoints). Meanwhile, the 00Z OUN sounding, as well as VNX, TLX, and INX VAD profilers show hodographs with modest low-level curvature and mid-level elongation, supporting supercell structures when accounting for the strong to locally extreme buoyancy in place. As such, supercells may persist into northeast OK over the next few hours with a continued severe-wind threat, though large hail is also possible. ..Squitieri.. 08/17/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...SGF...TSA...ICT...OUN... LAT...LON 35209990 36199857 36849753 37039542 36979429 36659377 36289372 36029411 35869555 35629666 35099774 34889843 34939930 35209990 Read more

WW 0628 Status Updates
STATUS REPORT ON WW 628 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 35 SE END TO 20 NE END TO 35 SSE ICT. ..SQUITIERI..08/17/24 ATTN...WFO...TSA...SGF...OUN... STATUS REPORT FOR WS 628 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS ARC007-015-087-143-170340- AR . ARKANSAS COUNTIES INCLUDED ARE BENTON CARROLL MADISON WASHINGTON MOC009-119-145-170340- MO . MISSOURI COUNTIES INCLUDED ARE BARRY MCDONALD NEWTON OKC001-021-035-037-041-071-097-103-105-113-115-117-119-131-143- 145-147-170340- OK . OKLAHOMA COUNTIES INCLUDED ARE ADAIR CHEROKEE CRAIG CREEK DELAWARE KAY Read more

WW 0628 Status Updates
STATUS REPORT ON WW 628 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 35 SE END TO 20 NE END TO 35 SSE ICT. ..SQUITIERI..08/17/24 ATTN...WFO...TSA...SGF...OUN... STATUS REPORT FOR WS 628 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS ARC007-015-087-143-170340- AR . ARKANSAS COUNTIES INCLUDED ARE BENTON CARROLL MADISON WASHINGTON MOC009-119-145-170340- MO . MISSOURI COUNTIES INCLUDED ARE BARRY MCDONALD NEWTON OKC001-021-035-037-041-071-097-103-105-113-115-117-119-131-143- 145-147-170340- OK . OKLAHOMA COUNTIES INCLUDED ARE ADAIR CHEROKEE CRAIG CREEK DELAWARE KAY Read more

WW 0628 Status Updates
STATUS REPORT ON WW 628 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 35 SE END TO 20 NE END TO 35 SSE ICT. ..SQUITIERI..08/17/24 ATTN...WFO...TSA...SGF...OUN... STATUS REPORT FOR WS 628 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS ARC007-015-087-143-170340- AR . ARKANSAS COUNTIES INCLUDED ARE BENTON CARROLL MADISON WASHINGTON MOC009-119-145-170340- MO . MISSOURI COUNTIES INCLUDED ARE BARRY MCDONALD NEWTON OKC001-021-035-037-041-071-097-103-105-113-115-117-119-131-143- 145-147-170340- OK . OKLAHOMA COUNTIES INCLUDED ARE ADAIR CHEROKEE CRAIG CREEK DELAWARE KAY Read more

WW 0628 Status Updates
STATUS REPORT ON WW 628 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 35 SE END TO 20 NE END TO 35 SSE ICT. ..SQUITIERI..08/17/24 ATTN...WFO...TSA...SGF...OUN... STATUS REPORT FOR WS 628 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS ARC007-015-087-143-170340- AR . ARKANSAS COUNTIES INCLUDED ARE BENTON CARROLL MADISON WASHINGTON MOC009-119-145-170340- MO . MISSOURI COUNTIES INCLUDED ARE BARRY MCDONALD NEWTON OKC001-021-035-037-041-071-097-103-105-113-115-117-119-131-143- 145-147-170340- OK . OKLAHOMA COUNTIES INCLUDED ARE ADAIR CHEROKEE CRAIG CREEK DELAWARE KAY Read more

WW 0628 Status Updates
STATUS REPORT ON WW 628 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 35 SE END TO 20 NE END TO 35 SSE ICT. ..SQUITIERI..08/17/24 ATTN...WFO...TSA...SGF...OUN... STATUS REPORT FOR WS 628 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS ARC007-015-087-143-170340- AR . ARKANSAS COUNTIES INCLUDED ARE BENTON CARROLL MADISON WASHINGTON MOC009-119-145-170340- MO . MISSOURI COUNTIES INCLUDED ARE BARRY MCDONALD NEWTON OKC001-021-035-037-041-071-097-103-105-113-115-117-119-131-143- 145-147-170340- OK . OKLAHOMA COUNTIES INCLUDED ARE ADAIR CHEROKEE CRAIG CREEK DELAWARE KAY Read more

WW 628 SEVERE TSTM AR MO OK 162035Z - 170400Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 628 NWS Storm Prediction Center Norman OK 335 PM CDT Fri Aug 16 2024 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Northwest Arkansas Extreme southwest Missouri Northern Oklahoma * Effective this Friday afternoon and evening from 335 PM until 1100 PM CDT. * Primary threats include... Scattered damaging winds likely with isolated significant gusts to 75 mph possible Scattered large hail likely with isolated very large hail events to 2.5 inches in diameter possible SUMMARY...Multiple areas of thunderstorm development are possible along and south of the Kansas/Oklahoma border through late evening, in a storm environment favoring organized clusters and supercells. The more intense storms will be capable of producing very large hail up to 2.5 inches in diameter, as well as severe outflow winds up to 75 mph. The severe thunderstorm watch area is approximately along and 35 statute miles north and south of a line from 40 miles west southwest of Alva OK to 30 miles south southeast of Monett MO. 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 627... 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 600. Mean storm motion vector 30025. ...Thompson Read more

WW 0629 Status Updates
STATUS FOR WATCH 0629 HAS NOT BEEN ISSUED YET Read more

WW 0629 Status Updates
STATUS FOR WATCH 0629 HAS NOT BEEN ISSUED YET Read more

WW 0629 Status Updates
STATUS FOR WATCH 0629 HAS NOT BEEN ISSUED YET Read more

WW 0629 Status Updates
STATUS FOR WATCH 0629 HAS NOT BEEN ISSUED YET Read more

WW 0629 Status Updates
STATUS FOR WATCH 0629 HAS NOT BEEN ISSUED YET Read more

WW 629 SEVERE TSTM AR 170200Z - 170700Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 629 NWS Storm Prediction Center Norman OK 900 PM CDT Fri Aug 16 2024 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of West-central to north-central Arkansas * Effective this Friday night and Saturday morning from 900 PM until 200 AM CDT. * Primary threats include... Scattered damaging winds and isolated significant gusts to 75 mph possible Isolated very large hail events to 2 inches in diameter possible SUMMARY...A complex of severe thunderstorms -- with a history of severe as recently as a 56-kt gust at NW AR Regional (XNA) at 141Z -- is expected to pose a continuing severe-wind and hail threat southeastward into more of AR this evening. Some expansion or shift in motion toward southward also is possible. The severe thunderstorm watch area is approximately along and 40 statute miles north and south of a line from 10 miles south of Fort Smith AR to 55 miles northeast of Russellville AR. 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 628... AVIATION...A few severe thunderstorms with hail surface and aloft to 2 inches. Extreme turbulence and surface wind gusts to 65 knots. A few cumulonimbi with maximum tops to 600. Mean storm motion vector 32035. ...Edwards Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0751 PM CDT Fri Aug 16 2024 Valid 170100Z - 171200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE SOUTHERN PLAINS/SOUTHEAST KANSAS INTO NORTHERN ARKANSAS... ...SUMMARY... Scattered severe thunderstorms remain possible this evening across portions of the southern Plains/southeast Kansas into northwest Arkansas. Damaging gusts and hail are the primary threats. ...01z Update... Low-amplitude short-wave trough is currently evident in satellite imagery, extending from southeast KS-northeast TX Panhandle. This feature is digging southeast within mean northwesterly flow along the back side of the Great Lakes/OH Valley trough. Synoptic front that advanced into this region arcs across MO-southern KS-northern TX Panhandle. This boundary is serving as a focus for scattered robust convection, mostly concentrated across southeast KS/extreme northeast OK along the northern fringe of a most buoyant airmass. Surface temperatures remain in the 90s to near 100F south of the boundary across much of OK into the TX south Plains. 00z sounding from OUN exhibits MLCAPE on the order of 3000 J/kg with 30kt 0-6km bulk shear. Latest VWP data depicts 1km flow around 15kt across northeast OK, but models suggest LLJ will increase over the next several hours into northeast OK where values may exceed 30kt. This will favor a southeast-moving complex of storms into northern AR later this evening. Damaging gusts and hail remain the primary threats. ..Darrow.. 08/17/2024 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0751 PM CDT Fri Aug 16 2024 Valid 170100Z - 171200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE SOUTHERN PLAINS/SOUTHEAST KANSAS INTO NORTHERN ARKANSAS... ...SUMMARY... Scattered severe thunderstorms remain possible this evening across portions of the southern Plains/southeast Kansas into northwest Arkansas. Damaging gusts and hail are the primary threats. ...01z Update... Low-amplitude short-wave trough is currently evident in satellite imagery, extending from southeast KS-northeast TX Panhandle. This feature is digging southeast within mean northwesterly flow along the back side of the Great Lakes/OH Valley trough. Synoptic front that advanced into this region arcs across MO-southern KS-northern TX Panhandle. This boundary is serving as a focus for scattered robust convection, mostly concentrated across southeast KS/extreme northeast OK along the northern fringe of a most buoyant airmass. Surface temperatures remain in the 90s to near 100F south of the boundary across much of OK into the TX south Plains. 00z sounding from OUN exhibits MLCAPE on the order of 3000 J/kg with 30kt 0-6km bulk shear. Latest VWP data depicts 1km flow around 15kt across northeast OK, but models suggest LLJ will increase over the next several hours into northeast OK where values may exceed 30kt. This will favor a southeast-moving complex of storms into northern AR later this evening. Damaging gusts and hail remain the primary threats. ..Darrow.. 08/17/2024 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0751 PM CDT Fri Aug 16 2024 Valid 170100Z - 171200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE SOUTHERN PLAINS/SOUTHEAST KANSAS INTO NORTHERN ARKANSAS... ...SUMMARY... Scattered severe thunderstorms remain possible this evening across portions of the southern Plains/southeast Kansas into northwest Arkansas. Damaging gusts and hail are the primary threats. ...01z Update... Low-amplitude short-wave trough is currently evident in satellite imagery, extending from southeast KS-northeast TX Panhandle. This feature is digging southeast within mean northwesterly flow along the back side of the Great Lakes/OH Valley trough. Synoptic front that advanced into this region arcs across MO-southern KS-northern TX Panhandle. This boundary is serving as a focus for scattered robust convection, mostly concentrated across southeast KS/extreme northeast OK along the northern fringe of a most buoyant airmass. Surface temperatures remain in the 90s to near 100F south of the boundary across much of OK into the TX south Plains. 00z sounding from OUN exhibits MLCAPE on the order of 3000 J/kg with 30kt 0-6km bulk shear. Latest VWP data depicts 1km flow around 15kt across northeast OK, but models suggest LLJ will increase over the next several hours into northeast OK where values may exceed 30kt. This will favor a southeast-moving complex of storms into northern AR later this evening. Damaging gusts and hail remain the primary threats. ..Darrow.. 08/17/2024 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0751 PM CDT Fri Aug 16 2024 Valid 170100Z - 171200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE SOUTHERN PLAINS/SOUTHEAST KANSAS INTO NORTHERN ARKANSAS... ...SUMMARY... Scattered severe thunderstorms remain possible this evening across portions of the southern Plains/southeast Kansas into northwest Arkansas. Damaging gusts and hail are the primary threats. ...01z Update... Low-amplitude short-wave trough is currently evident in satellite imagery, extending from southeast KS-northeast TX Panhandle. This feature is digging southeast within mean northwesterly flow along the back side of the Great Lakes/OH Valley trough. Synoptic front that advanced into this region arcs across MO-southern KS-northern TX Panhandle. This boundary is serving as a focus for scattered robust convection, mostly concentrated across southeast KS/extreme northeast OK along the northern fringe of a most buoyant airmass. Surface temperatures remain in the 90s to near 100F south of the boundary across much of OK into the TX south Plains. 00z sounding from OUN exhibits MLCAPE on the order of 3000 J/kg with 30kt 0-6km bulk shear. Latest VWP data depicts 1km flow around 15kt across northeast OK, but models suggest LLJ will increase over the next several hours into northeast OK where values may exceed 30kt. This will favor a southeast-moving complex of storms into northern AR later this evening. Damaging gusts and hail remain the primary threats. ..Darrow.. 08/17/2024 Read more