Subj : DAY2SVR: Nws Storm Prediction Center Norman Ok To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Mon Jun 05 2023 06:01:36 ACUS02 KWNS 050601 SWODY2 SPC AC 050600 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 0100 AM CDT Mon Jun 05 2023 Valid 061200Z - 071200Z ....THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE SIERRAS/GREAT BASIN...SOUTHERN HIGH PLAINS...AND NORTHEASTERN GEORGIA/SOUTH CAROLINA... ....SUMMARY... Isolated strong to severe thunderstorms may occur Tuesday across parts of the Sierras/Great Basin, southern High Plains, and northeastern Georgia into South Carolina. ....Synopsis... A stagnant upper-air pattern will persist over the CONUS on Tuesday, with an upper ridge centered over the northern Plains and central Canada. A closed upper low will remain over CA, with a separate upper trough/low across the eastern CONUS and Canadian Maritime provinces. ....Sierras/Great Basin... High-based thunderstorms should develop by early Tuesday afternoon across parts of the northern Sierras into the Great Basin as modest large-scale ascent attendant to a upper low over CA overspreads this area. Low-level moisture will remain quite limited, but diurnal mixing of the boundary layer and corresponding steepening of low-level lapse rates should encourage efficient convective downdraft momentum transfer to the surface. 25-35 kt of deep-layer shear should act to organize thunderstorms. Isolated severe wind gusts may occur with the more robust cores as they spread generally west-northwestward through the early evening. Occasional hail may also occur with the initially more discrete thunderstorms before clustering occurs. ....Southern High Plains... Limited low-level moisture will remain over the southern High Plains on Tuesday. Even with this region beneath mid-level ridging, most guidance still suggests that at least isolated convection will develop Tuesday afternoon along the higher terrain of central/eastern NM and west TX. Around 20-30 kt of effective bulk shear is forecast, mainly owing to modestly strengthening flow at mid/upper levels. While this shear appears marginal for organized convection, occasional instances of hail may occur with initial robust cores, as steep mid-level lapse rates should be present. Some upscale growth into loosely organized clusters will be possible by early evening. With steepened low-level lapse rates from daytime heating, isolated strong to severe wind gusts may occur before thunderstorms eventually weaken with eastward extent. ....South Carolina/Georgia... Thunderstorms may form by Tuesday afternoon along or just ahead of a weak surface trough/front from northern GA into SC. This region will be on the southwestern fringe of stronger flow aloft associated with an upper low over the Northeast. Moderate instability is forecast to develop through the day along/south of the trough/front, but deep-layer shear should remain generally modest. Even so, any convection that can develop may be capable of producing isolated hail and damaging winds as it spreads east-southeastward to the Atlantic Coast through Tuesday evening. Poor low-level convergence and weak ascent aloft cast some uncertainty regarding overall thunderstorm coverage. ....Northeast... Weak instability may develop Tuesday in close proximity to the upper low over portions of the Northeast. Thunderstorms that form across parts of New England and move quickly east-southeastward could produce occasional strong/gusty winds. However, confidence in severe-caliber gusts remains too low to include any wind probabilities at this time. ....South Florida... Modestly enhanced mid-level west-southwesterly flow should be present over south FL on Tuesday in association with a sub-tropical jet. Even though large-scale ascent will remain nebulous, most guidance indicates that isolated to scattered thunderstorms should develop along various sea breezes Tuesday afternoon. Gusty winds and small hail may occur with the strongest updrafts. ...Gleason.. 06/05/2023 $$ = = = 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) .