Subj : DAY2SVR: Nws Storm Prediction Center Norman Ok To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Thu Jun 22 2023 17:33:14 ACUS02 KWNS 221733 SWODY2 SPC AC 221731 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1231 PM CDT Thu Jun 22 2023 Valid 231200Z - 241200Z ....THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FOR EASTERN WYOMING INTO THE NEBRASKA PANHANDLE AND FAR SOUTHWEST SOUTH DAKOTA... ....SUMMARY... Scattered severe thunderstorms are forecast across eastern Wyoming into the Nebraska Panhandle and southwest South Dakota late Friday afternoon through the evening. ....Synopsis... A potent mid-level shortwave trough over the Desert Southwest will weaken slightly as it quickly moves northeast into the central Rockies by early evening and near the Black Hills by daybreak Saturday. A persistent mid-level anticyclone will reside across northern Mexico with increasing west-southwest flow overspreading northern portion of the southern High Plains during the day. A broad, very moist boundary layer will extend northward from the southern Great Plains into the north-central High Plains during the day. Isolated to scattered severe thunderstorms are forecast in several clusters from parts of the north-central High Plains and Black Hills vicinity, southward into the southern High Plains. ....WY/MT into SD and NE... Increasing large-scale forcing for ascent will quickly spread northeast across the central Rockies during the day overhead an adequately moist/destabilizing boundary layer. Strong heating will promote isolated to scattered thunderstorms developing by early-mid afternoon initially over western WY and spreading eastward coincident with the leading edge of stronger ascent. Models indicate moderate buoyancy over eastern WY with veering/strengthening flow with height---supporting supercells. Large to very large hail and an isolated risk for a tornado will be the primary hazards with this activity over eastern WY during the late afternoon/early evening. Additional storm development is forecast to occur as storms move into slightly richer moisture near the WY/NE border. It seems plausible upscale growth into a cluster/MCS will occur across NE into southwestern SD during the evening as a southerly LLJ strengthens. This activity will likely weaken late overnight as it moves into eastern portions of SD/NE. ....Central/Southern High Plains... Large-scale forcing for ascent will likely be more subtle across the central and southern High Plains than farther north, but moderate to strong southwesterly flow across the region will still promote afternoon thunderstorm development. Thunderstorm development is anticipated across the high terrain over the region, as well as along the lee trough. Strong to extreme buoyancy and vertical shear will support supercells capable of very large hail and an isolated risk for a tornado---dependent on mesoscale factors. Some organization/upscale growth into one or more convective lines appears possible, with guidance indicating the most likely location for this organization is across the TX Panhandle. That being said, confidence in storm evolution and duration has limited predictability given the lack of stronger large-scale forcing for ascent. ...Smith.. 06/22/2023 $$ = = = 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) .