Subj : DAY2SVR: Nws Storm Predic To : All From : Mike Powell Date : Sat Apr 15 2023 17:48:00 ACUS02 KWNS 151730 SWODY2 SPC AC 151728 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1228 PM CDT Sat Apr 15 2023 Valid 161200Z - 171200Z ....THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM THE GREAT LAKES TO THE CAROLINAS...AND ACROSS PORTIONS OF FLORIDA... ....SUMMARY... Marginally severe thunderstorms, associated with isolated damaging winds and hail will be possible in parts of the Southeast and Carolinas, northward into the Appalachians and southern Great Lakes ....Synopsis... An upper low progged to lie over the eastern Iowa/northeastern Missouri/western Illinois vicinity at the start of the period, will shift east-northeastward toward Lake Michigan, while deepening through the period. Broad cyclonic flow surrounding the low will spread across much of the eastern third of the country, as broad mid-level height falls encompass nearly all of the eastern U.S. west and south of New England. In conjunction with the upper low's advance, a cold front will shift eastward across the eastern half of the country, reaching/cresting the Appalachians by early evening and then clearing the middle and southern Atlantic coastal region overnight. Elsewhere, an upper low over the northeastern Pacific will advance southeastward toward western Canada and the Pacific Northwest, with ridging sandwiched between the two upper lows to shift slowly eastward across the Intermountain West through the period. ....Portions of the Great Lakes region southeastward to the Carolinas... In the wake of diminishing/dissipating Day 1 convection across the mid Ohio and Tennessee Valleys, early-day convective redevelopment is expected along the advancing cold front. Initial redevelopment should occur nearer the upper low -- i.e. across lower Michigan and parts of the Midwest -- where somewhat steeper lapse rates aloft will reside. Eventually, with the aid of daytime heating/destabilization, storms should expand southward along the front into the southern Appalachians. While CAPE should remain limited overall -- in part due to prior-day convection and lingering cloud cover, strong flow aloft surrounding the upper low suggests some potential for organized storms/storm clusters, along with attendant/local potential for a few strong to severe wind gusts. Greatest potential may evolve across the Ohio vicinity during the afternoon, but questions regarding degree/coverage of wind potential preclude upgrade to slight risk at this time. Convection should spread into the central Appalachians during the evening, where some risk for a couple of strong gusts may linger. Meanwhile, there is some potential that ongoing convection early in the period may be crossing the Carolinas, which also could be accompanied by the risk for a strong gust or two, before moving offshore. ....Parts of central and southern Florida... Continued passage of weak disturbances aloft embedded in the southern-stream westerlies will result in weak height falls across Florida. This is reflected at the surface as development of weak troughing across central Florida per 12Z NAM guidance. Despite weak lapse rates aloft, daytime heating/destabilization should support scattered to isolated, afternoon storm development, which is depicted in several CAM runs across central and parts of southern Florida. With the southern fringe of the stronger mid-level westerlies aloft extending southward across central Florida, a strong to severe wind gust or two will be possible through early evening when convection should be weakening and moving offshore. ...Goss.. 04/15/2023 $$ --- SBBSecho 3.14-Linux * Origin: Ilink: CCO - capitolcityonline.net (454:1/105) .