Subj : DAY1SVR: Day 1 Convective Outlook To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sun Sep 03 2023 20:02:13 ACUS01 KWNS 032002 SWODY1 SPC AC 032000 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0300 PM CDT Sun Sep 03 2023 Valid 032000Z - 041200Z ....THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE GREAT BASIN/INTERMOUNTAIN WEST... ....SUMMARY... Thunderstorms capable of severe wind gusts and hail remain possible across much of the Great Basin and Intermountain West this afternoon and evening, especially across parts of Nevada and Utah into southeast Idaho. ....20Z Update... The Slight Risk has been expanded slightly into a larger part of southeast ID and far western WY. Also, a small 15% hail area has been added where somewhat greater potential for supercells is expected later this afternoon. Otherwise, no changes have been made. Thunderstorms will continue to gradually increase in coverage and intensity this afternoon from NV into northwest UT and southern ID, as a seasonably strong mid/upper-level shortwave trough moves across the northern Great Basin. Moderate deep-layer shear and sufficient instability will continue to support the potential for organized storm clusters and a few supercells, with a threat of strong/severe gusts and some hail. See the previous discussion below for more information. Also refer to MCD 2076, WW 664, and WW 665 for more information regarding the short-term threat. ...Dean.. 09/03/2023 ..PREV DISCUSSION... /ISSUED 1130 AM CDT Sun Sep 03 2023/ ....Great Basin/Intermountain West... An upper trough centered over northern California early today will continue to spread east-northeastward over the Great Basin. Preceding the upper trough, 12z observed soundings from locations such as Elko NV, Boise ID, and Salt Lake City UT sampled a very moist air mass with Precipitable Water values generally ranging from 0.80-1.25 inches. Some stronger thunderstorms are already evident early today across western Nevada, and a further increase in coverage and intensity is likely regionally into the afternoon as the boundary layer heats, with plentiful cloud breaks noted across eastern Nevada into Utah this morning. Hail and strong/severe-caliber winds will be possible across a broad region, but the most organized and sustained storms, including some supercells, should occur across the eastern half of Nevada into western/north Utah and possibly southeast Idaho where effective shear should be around 35-45 kt. ....North Texas... Thunderstorms should increase this afternoon, at least in a widely scattered sense, on the immediate eastern periphery of an upper low centered across north Texas. Vertical shear will be weak, and overall buoyancy will be limited as compared to typical summertime standards. However, a pocket of cool mid-level temperatures (around -10C at 500 mb) could support some stronger (low-topped but high-based) storms as the boundary layer heats. A few storms could produce severe-caliber wind gusts. $$ = = = 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) .