BBS: TELESC.NET.BR Assunto: DAY3SVR: Nws Storm Prediction Center Norman Ok De: COD Weather Processor Data: Thu, 21 May 2026 19:28:48 +0000 ----------------------------------------------------------- ACUS03 KWNS 211928 SWODY3 SPC AC 211927 Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0227 PM CDT Thu May 21 2026 Valid 231200Z - 241200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF CENTRAL AND SOUTH TEXAS TO THE MIDDLE TEXAS COAST AND IN THE VICINITY OF THE RATON MESA INTO THE TEXAS AND OKLAHOMA PANHANDLES... ...SUMMARY... Scattered strong to potentially severe storms appear possible across portions of central and south Texas toward the middle Texas coast. Isolated strong to severe storms are also possible from the Raton Mesa vicinity into the Oklahoma and Texas Panhandles. ...Synopsis... Broader-scale troughing will be maintained over the north-central U.S. Saturday into Saturday night, with an embedded short-wave trough moving through the central Plains. To the immediate east, a short-wave trough initially over the OH Valley will lift northeast through the Great Lakes. Meanwhile, a lower-latitude disturbance is forecast to slowly track through TX. At the surface, an area of low pressure will gradually undergo occlusion over OH into southwest Ontario with a trailing front extending southwest through the lower OH Valley into the southern Plains. ...Central and Southern Texas to the Middle Texas Coast... There is general agreement in 12z model guidance that thunderstorms will develop fairly early in the day across the Edwards Plateau, east of a weak surface low and approaching short-wave trough. The downstream air mass across central and southern TX is expected to be moist with dewpoints in the 60s to low 70s, and within the eastern fringe of a steep mid-level lapse rate plume, yielding moderate to strong afternoon instability. As such, the early-day thunderstorms are expected to increase in coverage and intensity through the afternoon while advancing east/southeast into central and deep south TX, and eventually toward the TX coast. Some enhancement of deep-layer shear is forecast across south TX, which will aid in hail production and cold pool organization, and resultant damaging wind potential. ...Raton Mesa into the Oklahoma and Texas Panhandles... Southeasterly, upslope flow will contribute to isolated thunderstorm development by mid to late afternoon along favored terrain. The combination of a moderately unstable, steep-lapse-rate environment and around 30 kt of deep-layer shear will support some potential for supercell storm modes with an attendant risk for large hail. Storms will tend to drift southeast into the OK and TX panhandles before weakening. ...Southeast... A moist and moderately unstable air mass is expected to develop Saturday afternoon, with terrain and sea-breeze boundaries serving as the main foci for diurnally enhanced thunderstorm development. The models focus the most concentrated thunderstorm activity from the Savannah River Valley into north FL. There is some model signal for a weak mid-level disturbance and slightly stronger deep-layer shear to potentially enhance that thunderstorm regime. Low wind probabilities may eventually need to be added if confidence increases in the existence of those features. ...Upper Ohio Valley... A conditional risk of severe storms exists across the upper OH Valley Saturday afternoon, east of the surface low and associated surface front, where vertical shear will be enhanced. The main uncertainty is the degree of instability within the narrow warm sector, which varies considerably from model to model. Low severe-weather probabilities may eventually be included, should subsequent model trends indicate a more consistent signal for stronger air mass destabilization. ..Mead.. 05/21/2026 $$ = = = 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 3.28-Linux * Origin: Capitol City Online (1:2320/107) ----------------------------------------------------------- [Voltar]