Subj : DAY1SVR: Day 1 Convective Outlook To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Wed Mar 20 2024 19:44:07 ACUS01 KWNS 201944 SWODY1 SPC AC 201942 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0242 PM CDT Wed Mar 20 2024 Valid 202000Z - 211200Z ....THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS NORTHWEST TEXAS INTO WESTERN OKLAHOMA...AND ACROSS THE TEXAS COAST... ....SUMMARY... Isolated, marginally severe storms will be possible through this evening across parts of western Oklahoma and northwest Texas. Hail will be possible early Thursday morning across the Texas Coastal Plain vicinity. ....20z Update... The only changes with the 20z update were to adjust 10 percent thunderstorm probabilities based on ongoing convection and trends in short term guidance. The Marginal (level 1 of 5) risks across TX and OK remain unchanged from the previous outlook. Isolated large hail will be the main risk, though strong gusts also are possible with storms across the northwest TX into western OK. See previous discussion below for more details. ...Leitman.. 03/20/2024 ..PREV DISCUSSION... /ISSUED 1133 AM CDT Wed Mar 20 2024/ ....Parts of western and central Oklahoma and adjacent portions of Texas... Rather steep mid-level lapse rates across the Oklahoma/Texas area are contributing to isolated/high-based convection across central Oklahoma late this morning. Daytime heating of a very modestly moist boundary layer will push mixed-layer CAPE values up to 500 J/kg mixed-layer CAPE locally across portions of the Texas Panhandle/northwestern Texas and into western and central Oklahoma this afternoon. This will be sufficient -- given modest ascent in the vicinity of weak surface low pressure over northern Oklahoma and associated surface troughing extending southwestward -- to permit additional/new storm development this afternoon. With a rather deep mixed-layer evolving through peak heating, a few strong wind gusts could occur near more intense convection. Marginal hail also cannot be ruled out, given ample shear and the steep mid-level lapse rates. Overall risk will remain limited and isolated. ....Middle Texas Coast vicinity... Low-level warm advection/quasi-geostrophic ascent will increase across eastern Texas tonight, as short-wave troughing shifts into the southern Plains from northern Mexico. Atop a low-level stable layer, steep mid-level lapse rates may support development of isolated thunderstorms very late in the period, in response to the increasing ascent. With ample cloud-layer shear for sustained updrafts, some risk for hail may evolve toward the end of the period, with a couple of the strongest storms -- largely in the inch to inch-and-a-half range. ....Elsewhere... Very weak convection is ongoing across the Northeast, as strong upper troughing shifts across the region. Convection will remain very low-topped and likely with little to no lightning given lack of appreciable CAPE. However, very strong deep-layer flow across the region will likely promote gusty winds, and associated tree damage this afternoon/evening. $$ = = = 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 3.20-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .