Subj : DAY1SVR: Day 1 Convective Outlook To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Thu Nov 16 2023 12:30:21 ACUS01 KWNS 161230 SWODY1 SPC AC 161228 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0628 AM CST Thu Nov 16 2023 Valid 161300Z - 171200Z ....NO SEVERE THUNDERSTORM AREAS FORECAST... ....SUMMARY... A few strong storms may threaten the southern and eastern Florida Peninsula, but the bulk of the activity is expected to remain offshore. ....Synopsis... The mid/upper-level pattern over the western CONUS will continue to be characterized by converging split flow in the Rockies region -- downstream from a cut-off synoptic cyclone over the Pacific. That cyclone will begin to move slowly eastward through the period, but will remain well offshore until day 2. An ejecting, deamplifying, basal shortwave trough will cross the central CA coastal areas around 00Z. Forecast soundings suggest deep-enough buoyancy for isolated coastal and inland thunder potential with convection occupying a related swath of large-scale DCVA/lift and strongly difluent mid/upper flow. Isolated elevated thunderstorms also may develop in a low-level warm/moist-advection swath farther southeast from the lower Colorado River Valley across parts of AZ, but with more marginal instability and somewhat weaker lift. A northern-stream trough initially was located from northwestern Hudson Bay southwestward over MT. This feature should amplify and move eastward to northwestern ON, Lake Superior, the upper Mississippi Valley, and the lower Missouri Valley by 12Z tomorrow. Downstream height falls will spread over much of the eastern CONUS. The southeastern periphery of those height falls will encourage a continued slow eastward shift of a weaker, southern-stream, mid/upper-level trough now apparent in moisture-channel imagery over the eastern Gulf. That trough should extend from just off the JAX/DAB area southwestward across the peninsula near FMY by 12Z. As that occurs, a low-level cyclone -- its center now apparent in satellite imagery near 26N89W -- will be left behind to continue drifting southwestward and weakening gradually. A quasistationary frontal zone extends from there roughly eastward across parts of the Keys and Straits to another low -- apparent as part of a prominent MCV on radar and satellite imagery near Bimini. Extensive convection has accompanied the eastern circulation -- which may pivot northward near the Gulf Stream today, but remaining largely offshore. Behind/southwest of it, several stable layers aloft -- sampled by 12Z KEY/MFL soundings, should inhibit convective potential over south FL. Scattered showers and isolated thunderstorms may occur in MCV-enhanced/deep low-level easterlies farther north across central/eastern FL. Adequate speed shear, but little directional change in the easterly layer, will render modest, somewhat hook-shaped low-level hodographs, beneath weak midlevel southerlies/southwesterlies. A few cells may exhibit weak rotation inland, or produce strong gusts with downdrafts superimposed on the ambient/gradient flow, but the greatest convective coverage and intensity should be out to sea. ...Edwards/Gleason.. 11/16/2023 $$ = = = 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) .