Subj : MESO: Mesoscale Discussion 1126 To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sat Jun 17 2023 19:31:08 ACUS11 KWNS 171931 SWOMCD SPC MCD 171930=20 TXZ000-172130- Mesoscale Discussion 1126 NWS Storm Prediction Center Norman OK 0230 PM CDT Sat Jun 17 2023 Areas affected...Portions of northwest/west-central into central TX Concerning...Severe potential...Severe Thunderstorm Watch likely=20 Valid 171930Z - 172130Z Probability of Watch Issuance...95 percent SUMMARY...Thunderstorms producing very large hail (2-3+ inches in diameter) and significant severe wind gusts (60-80 mph) are expected to develop and move eastward this afternoon/evening. Severe Thunderstorm Watch issuance will likely be needed soon. DISCUSSION...19Z surface analysis shows a dryline extending southward across west TX. Strong daytime heating has already encouraged surface temperatures to reach into the 90s and low 100s both ahead and behind the dryline. As an upper trough over the central/southern Rockies continues to eject over the High Plains this afternoon, a 50+ kt westerly mid-level jet will overspread more of the southern High Plains. Additional diurnal heating and ascent attendant to the mid-level jet should erode lingering convective inhibition along the length of the dryline, extending from northwest into west-central TX. At least isolated convective initiation appears increasingly likely by 20-21Z (3-4 PM CDT) along the dryline, although determining precise locations for a more favored corridor of development remains uncertain. There does appear to be a residual boundary, probably from prior convection, extending from near KSNK to KSWW to the vicinity of KABI that may help focus convective initiation. Recent visible satellite imagery also shows towering cu north of San Angelo TX. Once thunderstorms form, they are expected to quickly become severe. Very rich low-level moisture and steep mid-level lapse rates are contributing to around 2500-3500+ J/kg of MLCAPE. 40-50+ kt of deep-layer shear will easily support supercells with initial development, with a threat for very large hail (2-3+ inches in diameter). Although details remain unclear, some upscale growth into a severe MCS may occur this evening across western north TX and vicinity. Significant damaging winds of 60-80 mph appear possible if this mode transition occurs. ...Gleason/Hart.. 06/17/2023 ....Please see https://urldefense.com/v3/__http://www.spc.noaa.gov__;!!DZ3fj= g!5ay8HO9J-kCZqfEtqYS-fw5l_gABTNQyZTdpVdzBLfjNNvGbTtt7_Hm5Ml93c4AJKagywmCeE= sKJiLaLqAmERfoTGdk$ for graphic product... ATTN...WFO...FWD...OUN...EWX...SJT...LUB...MAF... LAT...LON 32100070 33900090 34510072 34479999 33769824 32809793 31469808 30989843 30559897 30509980 31110074 32100070=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) .