Subj : DAY1SVR: Day 1 Convective Outlook To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sat Dec 02 2023 12:44:47 ACUS01 KWNS 021244 SWODY1 SPC AC 021243 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0643 AM CST Sat Dec 02 2023 Valid 021300Z - 031200Z ....THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS NEAR THE COAST OF THE FLORIDA PANHANDLE AND A SMALL PART OF SOUTHWESTERN ALABAMA... ....SUMMARY... Isolated severe storms are possible over parts of the north-central/ northeastern Gulf Coast region. ....Synopsis... A mid/upper-level, synoptic-scale trough, with associated cyclonic flow traversed by several shortwave perturbations/vorticity lobes -- is expected to move eastward from its present position over the Rocky Mountain States. Leading/basal shortwave troughs -- now apparent in moisture-channel imagery over western CO and NM -- are forecast to merge today, reaching portions of KS, OK and north TX by 00Z. The combined perturbation then should eject northeastward across parts of the Mid-Mississippi Valley and Mid-South regions by 12Z tomorrow. As that occurs, 500-mb heights in the extensive field of southwesterlies over the Gulf Coast States will fall slightly, with a somewhat tightening gradient. At the surface, 11Z analysis showed a cold front extending from near TOL southwestward over southern IN, western parts of KY/TN, southwestern MS, between LCH-ARA, then over the northwestern Gulf to southeast of BRO. The front is expected to drift southeastward through the period, reaching eastern TN, northeastern/west-central AL, and south-central parts of MS/LA by 00Z. Substantial convective potential should remain prefrontal. ....North-central/northeastern Gulf Coast region... Isolate severe thunderstorms, with brief strong-severe gusts and/or potential for a couple tornadoes, are possible over the outlook area through this evening. Potential appears relatively maximized nearest the coast, where a few severe cells may move inland from the Gulf. Although the direct fields of large-scale ascent/DCVA related to the southern Rockies/Plains troughing will miss the region well to the northwest, the peripheral response discussed above should increase deep shear slightly over the region throughout the day. In the absence of a substantial, closer perturbation to elicit near-surface mass response, the persistent warm-advection/moisture-transport regime will continue, but with weakening and veering flow in the lower boundary layer after this morning. This should reduce hodograph size overall today, with the possible exception of localized boundary effects. The greatest low-level shear will be inland this morning, where stable to moist-adiabatic near-surface lapse rates are present, while instability should be most favorable over the Gulf, with some modified marine air spreading inland this evening and overnight when low-level wind profiles are more unidirectional than at present. The extensive area of overland clouds/precip is expected to persist for at lest a few more hours, and imparts considerable uncertainty/ conditionality on sufficiency of destabilization to support severe potential with inland extent. Unconditional severe probabilities accordingly decrease inland, and appear greatest over portions of southwestern AL and the FL Panhandle where 500-1000 J/kg MLCAPE and 40-450-kt effective-shear magnitudes should be present. ...Edwards/Kerr.. 12/02/2023 $$ = = = 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) .