Subj : DAY3SVR: Nws Storm Prediction Center Norman Ok To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sun Aug 20 2023 06:48:02 ACUS03 KWNS 200647 SWODY3 SPC AC 200647 Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0147 AM CDT Sun Aug 20 2023 Valid 221200Z - 231200Z ....THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS TUESDAY ACROSS PARTS OF DEEP SOUTH TEXAS... ....SUMMARY... A tropical disturbance emerging from the Gulf of Mexico Tuesday may be accompanied by showers and thunderstorms with gusty winds and at least some potential for a tornado or two across parts of Deep South Texas. ....Synopsis... There may be some suppression of mid-level heights across the northern Rockies during this period, as several perturbations progress through broadly confluent southwesterly flow, downstream of mid-level troughing and an embedded low slowly progressing inland across the Pacific Northwest. However, a prominent warm-core ridge, centered at mid-levels across the lower Missouri Valley vicinity, appears likely to be maintained across much of the interior of the U.S., while large-scale mid-level troughing digs offshore of the northern into middle Atlantic coast. In the easterlies, to the south of this ridge, one tropical perturbation appears likely to continue migrating inland of the lower Texas coast through the Rio Grande Valley near and south of the Big Bend. A broader upstream wave may slowly shift west-northwestward across the Caribbean/Bahamas/south Florida vicinity. Once again, seasonably high boundary-layer moisture content may contribute to large potential instability, particularly with daytime heating Tuesday, across the Ozark Plateau and middle Mississippi Valley vicinity into portions of the Upper Midwest. However, it still appears that sustained deep convective development within this environment will be suppressed by large-scale subsidence and inhibition associated with warm and dry mid-levels. ....Deep South Texas... Models indicate that the inland migrating tropical perturbation will be accompanied by a belt of 30-40 kt easterly flow in lower/mid-levels. In the wake of the trough axis, forecast soundings depict enlarging clockwise-curved low-level hodographs, coincident with a weakly destabilizing tropical boundary layer. This regime could become conducive to the development of a few low-topped supercell structures, with embedded low-level mesocyclones posing a risk for producing tornadoes. ...Kerr.. 08/20/2023 $$ = = = 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) .