Subj : DAY1SVR: Day 1 Convective Outlook To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sat Mar 11 2023 05:17:28 ACUS01 KWNS 110517 SWODY1 SPC AC 110515 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1115 PM CST Fri Mar 10 2023 Valid 111200Z - 121200Z ....THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM EASTERN OKLAHOMA INTO NORTHERN MISSISSIPPI... ....SUMMARY... Scattered severe thunderstorms producing primarily large damaging hail will be possible Saturday evening and overnight mainly from eastern Oklahoma, Arkansas and northern Mississippi. ....Eastern OK to Northern MS... Low-amplitude short-wave trough, currently over NV, is forecast to eject across the Great Basin into the central Plains during the afternoon before advancing into the lower OH Valley by the end of the period. This feature will suppress the height field a bit over OK/AR which will dislodge a lee surface cyclone from southeast CO early in the period. This low will be forced into central OK by early afternoon and low-level flow should veer in response to deepening westerlies. Even so, boundary-layer moisture is expected to markedly increase across the warm sector into eastern OK prior to dryline/frontal passage. Latest guidance suggests lower 60s surface dew points will surge to near I-40 over eastern OK just prior to the wind shift. As the low is shunted southeast to near the Red River, strong surface heating ahead of the front will result in a plume of steep low-level lapse rates spreading across northwest TX into south-central OK. Forecast soundings suggest inhibition will be negligible by 22z as surface temperatures warm into the lower-mid 80s immediately behind the dryline. Convection may struggle for a few hours given the expected veered low-level flow; however, deep convection should root into the increasingly moist boundary layer across eastern OK, possibly by 00z. Strong surface-6km shear favors supercells, and forecast soundings exhibit substantial SBCAPE (in excess of 2000 J/kg) and steep lapse rates. Latest thinking is isolated supercells should develop ahead of the cold front/dryline over OK then mature as they track east-southeast toward southern AR. Very large hail is possible with some of this activity. With time these storms should become elevated. Farther south into north-central TX, forecast soundings exhibit uncapped surface parcels a good distance south along the dryline. This is well south of the influence of the short wave/height falls. While profiles suggest convection is possible, it's not entirely clear whether updrafts will be sustained along southern portions of the dryline within a weakly forced environment. Have expanded probabilities a bit south to account for this risk, but the more concentrated convection should initiate over eastern OK then spread across AR toward northern MS during the overnight hours. ...Darrow/Moore.. 03/11/2023 $$ = = = 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) .