Subj : MESO: Mesoscale Discussion 1039 To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Wed Jun 14 2023 17:13:30 ACUS11 KWNS 141713 SWOMCD SPC MCD 141712=20 LAZ000-ARZ000-TXZ000-OKZ000-141845- Mesoscale Discussion 1039 NWS Storm Prediction Center Norman OK 1212 PM CDT Wed Jun 14 2023 Areas affected...portions of far northeast Texas into southwestern Arkansas and northern Louisiana Concerning...Severe Thunderstorm Watch 290... Valid 141712Z - 141845Z The severe weather threat for Severe Thunderstorm Watch 290 continues. SUMMARY...Upscale growth of ongoing storms into an intense bow echo is possible over the next few hours. Large hail and severe gusts are the main concern. A few 65+ kt gusts are possible and trends are being monitored for the development of a derecho-producing MCS. DISCUSSION...Supercells that have been traversing the Red River have shown signs of some upscale growth into a possible MCS. These storms show 60 kft tops, with a wide area of 50 dBZ echoes exceeding 40 kft per latest MRMS mosaic radar data. Latest satellite data also show a broadening area of rapidly cooling cloud tops. The ongoing storms are progressing east-southeastward along/just north of a diffuse baroclinic zone, with low/upper 80s F temperatures on the cool/warm side of the boundary. Along both sides, dewpoints are exceeding 75 F. Mid-level lapse rates of 7.5+ C/km are overspreading this very moist low-level airmass over a long west-to-east corridor, supporting extreme instability (4500+ J/kg SBCAPE) far downstream of the upscale-growing convection. Coinciding this corridor of extreme buoyancy is very strong (65+ kts) effective bulk shear, with regional VADs and 16Z mesoanalysis showing hodographs that are modestly curved at the low levels and elongated above 3 km AGL.=20=20 Potential exists for large hail (some 2+ inches in diameter) if the ongoing convection remains more cellular. If further upscale growth occurs, an intense bow echo, capable of widespread severe winds and some hurricane-force gusts, may develop and may set the stage for initiating a derecho-type event. However, the occurrence of a derecho is highly conditional on further upscale growth. ...Squitieri.. 06/14/2023 ....Please see https://urldefense.com/v3/__http://www.spc.noaa.gov__;!!DZ3fj= g!9wgkCy_DnkE6ruMLo_qkjvXDNbXgpsW2VgGRdhmCkwSFiIVRVJHGIUvl9qtaA3Qklf8s0T2pV= G279X-XP_S9c2pMMeQ$ for graphic product... ATTN...WFO...JAN...LZK...SHV... LAT...LON 33669459 33579316 33139210 32639184 32319209 32199268 32299353 32479423 32709466 33059496 33669459=20 =3D =3D =3D To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM. --- SBBSecho 3.14-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .