Subj : DAY1SVR: Day 1 Convective Outlook To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sun Jun 04 2023 19:46:33 ACUS01 KWNS 041946 SWODY1 SPC AC 041944 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0244 PM CDT Sun Jun 04 2023 Valid 042000Z - 051200Z ....THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS SOUTH TEXAS...PARTS OF THE SOUTHERN APPALACHIANS TO TENNESSEE VALLEY...AND SOUTH-CENTRAL LOUISIANA... ....SUMMARY... Isolated severe thunderstorms are possible across south Texas, parts of the southern Appalachians to Tennessee Valley, and south-central Louisiana into this evening. ....20Z Update... ....South-Central LA... Temperatures have climbed into the upper 80s and low 90s across south-central LA, amid dewpoints in the upper 60s. Thunderstorms have developed in the BTR vicinity, and are moving westward/southwestward into the steep low-level lapse rates environment downstream. As a result, there appears to be a corridor of slightly greater risk for damaging gusts over this area. ....South TX... As mentioned in MCD #935 and the previous outlook, isolated severe storms are possible later this afternoon across south TX. Destabilization continues south and west of an MCV (and associated cloud cover), with thunderstorm initiation ongoing on remnant outflow from south of JCT to HDO to about 20 miles west of SAT. Another outflow boundary, this one oriented more north to south, extends from near HDO southward/south-southeastward through ALI. Cumulus is building along this boundary as well, with additional thunderstorms possible here as well. Moderate buoyancy and modest shear could support of a few more robust updrafts, which could produce hail and localized severe gusts. ....Southern Appalachians to TN Valley... Overall storm coverage is still expected to increase across the region over the next few hours, with several multicell clusters possible. Earlier cloud cover has tempered heating across northern GA and adjacent portions of southeastern TN, limiting heating and keeping low-level lapse rates modest. However, skies and clearing and the resultant heating could steepen low-level lapse rates enough to support a few damaging gusts. Steep low-level lapse rates are already in place across western and middle TN, where additional storm development in ongoing. Damaging gusts are possible with these storms as well. ...Mosier.. 06/04/2023 ..PREV DISCUSSION... /ISSUED 1117 AM CDT Sun Jun 04 2023/ ....South TX... In the wake of several clusters that resulted in extensive convective overturning yesterday afternoon through last night, appreciable buoyancy (MLCAPE in excess of 2000 J/kg) should largely be confined to south TX later this afternoon. With minimal large-scale ascent and light low-level winds through tonight, convective development appears ill-defined, but may be initially focused to the south of a remnant MCV in central TX. 20-30 kt mid-level northwesterlies should offer adequate deep shear to support a few transient supercells and multicell clustering. Amid more moderate mid-level lapse rates compared to yesterday, isolated severe hail and wind will be possible into this evening. ....Southern Appalachians to TN Valley... A belt of 15-25 kt mid-level north-northeasterlies will persist across the WV portion of the Appalachians owing to peripheral influence of a quasi-stationary mid/upper low near the New England coast. This should be adequate to support small to marginally severe hail in isolated storms that form in and south of this region, along with locally strong gusts later this afternoon. Farther west-southwest, weak deep-layer shear will mitigate organized severe storms, but sporadic microbursts will remain possible where moderate buoyancy can develop. $$ = = = 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) .