Subj : DAY1SVR: Day 1 Convective Outlook To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sat Dec 17 2022 05:58:09 ACUS01 KWNS 170558 SWODY1 SPC AC 170556 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1156 PM CST Fri Dec 16 2022 Valid 171200Z - 181200Z ....NO SEVERE THUNDERSTORM AREAS FORECAST... ....SUMMARY... Severe thunderstorms are not forecast on Saturday. ....Synopsis... Broad large-scale troughing will encompass the eastern half of the CONUS -- peripheral to a deep/vertically stacked cyclone centered over the Upper Great Lakes and parts of Ontario. At the same time, an embedded mid/upper-level jet streak will extend from the Lower MS Valley through the Mid-Atlantic states before advancing off the Eastern Seaboard during the evening hours. In the low-levels, an east-west-oriented quasi-stationary surface boundary will initially extend from the FL Keys westward into the central Gulf of Mexico. Large-scale ascent within the right-entrance region of the aforementioned jet streak will support the development of an eastward-advancing frontal wave over the central Gulf of Mexico. The low-level mass response preceding this wave will allow the frontal boundary to lift northward into southern FL during the afternoon hours -- when an uptick in thunderstorm development is expected. ....Southern Florida... As the frontal boundary lifts northward from the Keys, upper 60s/lower 70s boundary-layer dewpoints will overspread southeastern FL, which combined with filtered diurnal heating will yield moderate instability (1000-1500 J/kg MLCAPE). Modest west-southwesterly midlevel flow atop weak southeasterly low-level flow will contribute to around 40 kt of effective shear characterized by a generally long/straight hodograph. While this environment will conditionally support a couple rotating/splitting storms (particularly over southeastern FL), deep west-southwesterly flow should generally keep most of this activity offshore. Therefore, no severe probabilities have been introduced with this outlook. Additional thunderstorm development is also expected ahead of the eastward-advancing frontal wave, and some of this activity could spread eastward into southwest FL during the evening hours. However, cool inland surface temperatures and drier boundary-layer conditions should generally limit thunderstorm intensity over land. ...Weinman/Guyer.. 12/17/2022 $$ = = = 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) .