Subj : DAY1SVR: Day 1 Convective Outlook To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Tue Sep 03 2024 19:46:06 ACUS01 KWNS 031946 SWODY1 SPC AC 031944 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0244 PM CDT Tue Sep 03 2024 Valid 032000Z - 041200Z ....THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHERN ROCKIES/GREAT BASIN AND ADJACENT HIGH PLAINS... ....SUMMARY... Scattered thunderstorms developing across the northern Rockies and adjacent portions of the Great Basin this afternoon will pose an isolated severe risk, before spreading eastward toward the northern High Plains this evening. ....20Z Update... The previous forecast remains on track, and no changes were made with this update. Widely scattered thunderstorms are evolving across the northern Rockies and adjacent Great Basin this afternoon. These storms are generally focused in a band of midlevel ascent preceding a compact midlevel low tracking eastward across central ID. This activity will continue spreading east-northeastward through the afternoon, with initial semi-discrete clusters/transient supercells posing a risk of sporadic, marginally severe hail and locally severe gusts. See MCDs 2044/2045 for details on the near-term severe risk. Later this afternoon, a more-focused corridor of severe-wind potential is possible from portions of northwest WY into southwest/south-central MT, especially with any upscale-grown clusters amid steep deep-layer lapse rates. A 15-percent wind-driven Slight Risk was considered here, though confidence in the development of an organized/consolidated cold pool remains too low for an upgrade. ...Weinman.. 09/03/2024 ..PREV DISCUSSION... /ISSUED 1130 AM CDT Tue Sep 03 2024/ ....Northern Great Basin/Rockies into the Adjacent High Plains... Visible-satellite imagery this morning shows a smoke-encased mid to upper-level low/vorticity maximum over central ID. This upper feature will move to near southwest MT/eastern ID late tonight. The satellite data late this morning shows agitated cumulus developing immediately ahead of the vorticity max near the ID/MT border, and as large-scale ascent spreads east, additional thunderstorms (widely scattered to scattered coverage) should develop over the higher terrain through early afternoon in tandem with daytime heating. Forecast soundings across southwest MT into northwest WY show 500-1000 J/kg MLCAPE with some elongation of the hodograph. A few of the stronger storms will probably acquire transient supercell characteristics and have an associated hail/wind threat. Some clustering may eventually evolve by early evening as storms move into south-central MT and adjacent parts of northern WY. Somewhat more limited low-level moisture should be present this afternoon farther south into WY and northern UT. Even so, diurnal heating will aid in a deeply mixed boundary layer by this afternoon, and steep mid-level lapse rates are also expected to remain over this region. The net result will be high-based thunderstorms capable of producing isolated severe gusts initially developing across northern UT into far eastern ID, and subsequently moving east-northeastward over WY through the evening. $$ = = = 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 3.20-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .