Subj : DAY1SVR: Day 1 Convective Outlook To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Thu Sep 14 2023 20:01:59 ACUS01 KWNS 142001 SWODY1 SPC AC 142000 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0300 PM CDT Thu Sep 14 2023 Valid 142000Z - 151200Z ....THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM EASTERN NM TO PARTS OF THE TX GULF COAST... ....SUMMARY... Isolated severe thunderstorm are possible along an axis from eastern New Mexico to the Texas Gulf Coast, mainly from late afternoon through this evening. ....20Z Update... The Marginal Risk has been expanded slightly northeastward along the upper TX Gulf Coast, in advance of a strong storm cluster near and northeast of Houston. These storms have developed within an environment characterized by rich low-level moisture and moderate buoyancy, but also weak midlevel lapse rates and warm temperatures aloft. Within this regime, effective shear of 25-30 kt will support modestly organized storms with a threat of locally damaging gusts until storms reach the coast. Deepening cumulus and recent storm development is ongoing across parts of the TX Hill Country, in the vicinity of a weak surface low/trough. It remains possible that a supercell or two will evolve out of this developing convection and move southeastward later this afternoon into this evening. Weak midlevel lapse rates may tend to limit storm severity, but any sustained supercell could pose a threat of localized severe gusts and hail approaching severe limits. Additional strong to isolated severe storm development will be possible across parts of eastern NM later this afternoon into this evening. See the previous discussion below for more details. ...Dean.. 09/14/2023 ..PREV DISCUSSION... /ISSUED 1124 AM CDT Thu Sep 14 2023/ ....NM/TX... Current visible satellite imagery and surface analysis shows a boundary extending from southeast NM into central TX. A very moist and moderately unstable air mass is present along and south of this boundary, along with mostly clear skies and steepening low level lapse rates. Large scale forcing is weak across this region, but most 12z CAM solutions show isolated thunderstorms developing near the boundary by late afternoon and evening. Forecast soundings suggest sufficient mid/upper level westerly flow for organized multicell or occasional supercell structures capable of hail and gusty winds. $$ = = = 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) .