Subj : DAY1SVR: Day 1 Convective Outlook To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Mon Mar 03 2025 06:01:55 ACUS01 KWNS 030601 SWODY1 SPC AC 030600 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1200 AM CST Mon Mar 03 2025 Valid 031200Z - 041200Z ....THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF CENTRAL OKLAHOMA INTO NORTHERN TEXAS... ....SUMMARY... Thunderstorms should increase this evening and merge into a squall line tonight across portions of the southern Plains. Severe gusts, hail, and a few tornadoes are possible with the stronger storms. ....Synopsis... A pronounced mid-level trough will traverse the southern Rockies today and eject into the Southern Plains tonight, encouraging rapid development and deepening of a surface low over the central Plains through the period. During the day and especially evening hours, a strong southerly low-level jet will develop across the southern and central Plains as an 80-100 kt 500 mb jet streak pivots around the mid-level trough and overspreads the low-level jet axis. At the same time, modified boundary-layer moisture will advect northward, promoting marginal instability across the warm sector ahead of the surface low. The net result will be increasing deep-layer ascent, supporting thunderstorm development amid strong unidirectional shear profiles. A squall line should develop later tonight and promote severe potential, with all severe hazards possible. ....Central and southern Plains this evening into tonight... A southerly 850 mb jet increases to well over 50 kts after sunset, overspread by at least 80 kts of southerly 500 mb flow, contributing to over 50 kts of effective bulk shear. A surface cold front will surge eastward after 00Z across western OK/TX, supporting thunderstorm development. While supercell structures may develop initially, rapid upscale growth is expected given linear forcing (e.g. unidirectional vertical wind profiles above the boundary layer). The best chance for large hail will be with the more discrete storm structures, thereafter, severe gusts become the primary concern with squall line development. Overnight, low 60s F surface dewpoints will overspread much of TX into central OK beneath 7+ C/km mid-level lapse rates as temperatures above the boundary layer cool with the approach of the upper trough, yielding over 1000 J/kg MLCAPE. However, boundary-layer lapse rates appear to be poor in some deterministic guidance, raising some concerns as to how much appreciable surface-based buoyancy can materialize tonight. Forecast soundings show elongated hodographs, with a noticeable degree of curvature in the 0-3 km layer, potentially yielding up to 500 m2/s2 of effective SRH. Such shear profiles amid marginal instability would favor a QLCS tornado threat if said instability can become surface-based. At the moment, confidence is not overly high in appreciable boundary layer destabilization. However, higher severe probabilities may be needed in later outlooks if greater boundary-layer buoyancy becomes apparent. ...Squitieri/Goss.. 03/03/2025 $$ = = = 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 3.20-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .