Subj : DAY1SVR: Day 1 Convective Outlook To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Mon Mar 18 2024 12:42:06 ACUS01 KWNS 181242 SWODY1 SPC AC 181240 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0740 AM CDT Mon Mar 18 2024 Valid 181300Z - 191200Z ....THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON ACROSS CENTRAL FL AND MUCH OF THE FL ATLANTIC COAST... ....SUMMARY... Isolated large hail and wind damage is possible this afternoon across central Florida and along much of the Florida Atlantic coast. ....FL this afternoon... A northern stream shortwave trough will dig from the mid MS Valley this morning to the southern Appalachians this evening and off the Atlantic coast by early Tuesday. An associated stalled surface front across north FL this morning will begin to accelerate southeastward across the peninsula this evening through early Tuesday. The more pronounced midlevel height falls and forcing for ascent will pass north of FL, leaving shallow ascent along the front and/or differential heating boundaries (from convection moving inland from the northeast Gulf of Mexico this morning) to focus thunderstorm development. Forecast soundings suggest that moderate buoyancy (MLCAPE near 1500 J/kg), steep low-level lapse rates and 50 kt midlevel flow with relatively straight hodographs could support a supercell capable of producing isolated large hail (1-1.75 inches in diameter) and damaging gusts near 60 mph. The severe threat will peak by early-mid afternoon and then diminish into this evening. ....AZ/southern CA through this evening... As part of a Rex block, a closed low over AZ will drift westward today as an embedded speed max pivots from northern AZ toward southern CA. Low-level moisture will remain modest, but cool midlevel temperatures and daytime heating will contribute to at least weak buoyancy (SBCAPE of 250-750 J/kg). A few clusters of storms will form in the main band of ascent over the rim this afternoon, while other storms are expected to spread southwestward off the higher terrain toward the southern CA coast. The threat for severe storms will remain quite low, but the strongest storms could produce gusty outflow winds and small hail. ...Thompson/Dean.. 03/18/2024 $$ = = = 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) .