Subj : DAY2SVR: Nws Storm Prediction Center Norman Ok To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sun Aug 27 2023 17:19:45 ACUS02 KWNS 271719 SWODY2 SPC AC 271718 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1218 PM CDT Sun Aug 27 2023 Valid 281200Z - 291200Z ....THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM THE LOWER MS VALLEY ACROSS MUCH OF THE SOUTHEAST INTO THE CAROLINAS... ....SUMMARY... Isolated damaging winds may occur with thunderstorms that develop across parts of the Southeast on Monday. ....Synopsis... Upper ridging is forecast to begin the period covering much of the western CONUS, with the exception of the Pacific Northwest which will be under the influence of an approaching upper trough. As this upper trough progresses eastward, the upper ridging is expected to move eastward into the High Plains amid some dampening of its northwest periphery. Upper troughing is expected to persist from the Canadian Prairies eastward across much of eastern Canada, with its southern periphery stretching from the Upper Midwest across the Great Lakes and Northeast. Some deepening of this upper troughing is anticipated late in the period as a shortwave trough drops through northwest Ontario and the Upper Midwest. ....Lower MS Valley/Southeast/Carolinas... A warm and moist airmass is expected to remain in place across the region on Monday, particularly to the south of a weak frontal boundary that will extend from eastern NC southwestward into southern LA. Heating of this moist air mass will result in moderate to strong buoyancy and steep low-level lapse rates. Scattered to numerous thunderstorms should develop by Monday afternoon along the length of the front from LA to NC as convective temperatures are breached. Vertical shear will be weak, with generally multicellular storm mode anticipated. Even so, strong, water-loaded downdrafts are possible, producing isolated gusty winds around 45-60 mph and occasional tree damage. ....Central/Southern High Plains... Persistent low/mid-level moisture should contribute to another day of afternoon thunderstorm development across the Rockies. Prevailing westerly/northwesterly flow aloft will push these storms into the lower elevations of the High Plains. A generally outflow-dominant, multicellular mode is anticipated, with at least some risk for a strong gust or two given the high storm bases and steep low-level lapse rates. However,the overall severe threat currently appears too limited to add wind probabilities ....Upper Midwest... A surface low and attendant cold front are expected to move through the northern/central Plains and Upper Midwest/Upper Great Lakes ahead of the northwest Ontario shortwave. Modest buoyancy may develop ahead of this front, supported by surface dewpoints in the upper 50s/low 60s and relatively cool mid-level temperatures. Even with these cooler mid-level temperatures, lapse rates will remain fairly poor, limiting the overall buoyancy and potentially contribute to shallow, limited-duration updrafts. Mid-level flow should increase across the region ahead of the approaching wave, contributing to moderate vertical shear, and there is some potential for a strong storm or two. However, overall severe coverage should remain very isolated. ...Mosier.. 08/27/2023 $$ = = = 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) .