Subj : DAY1SVR: Day 1 Convective Outlook To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sat Sep 07 2024 19:39:59 ACUS01 KWNS 071939 SWODY1 SPC AC 071938 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0238 PM CDT Sat Sep 07 2024 Valid 072000Z - 081200Z ....NO SEVERE THUNDERSTORM AREAS FORECAST... ....SUMMARY... Organized severe thunderstorms are not forecast today, though a few strong gusts could accompany the more robust storms. ....20Z Update... The forecast remains on track, and only minor changes were made to the outlook with this update. In particular, the General Thunder line was trimmed behind the frontal rain band and associated wind shift in the Northeast, where cool post-frontal conditions have generally depleted instability. Updrafts within this band have remained too shallow/weak for an appreciable lightning risk thus far. However, an isolated strike still cannot be ruled out, especially over portions of eastern NJ and far southeastern NY/Long Island -- where filtered boundary-layer heating has occurred amid middle 60s dewpoints. Isolated/embedded strong gusts also remain possible (earlier 44 mph gust in eastern PA), though the weak/shallow updrafts (and associated downdrafts) should continue to limit the severe risk. Elsewhere, severe potential still appears too localized and/or marginal for severe probabilities. See the previous discussion below for details. ...Weinman.. 09/07/2024 ..PREV DISCUSSION... /ISSUED 1131 AM CDT Sat Sep 07 2024/ ....Northeast... A cold front will move steadily east across the northeast today, accompanied by showers and thunderstorms. Extensive cloud cover in advance of the front will tend to limit heating/destabilization, however modest MLCAPE (on the order of 250-500 J/kg) may develop from the northern Delmarva Peninsula north into southeast NY this afternoon. Ascent with an upper-level trough will continue to move east in tandem with the front, and scattered thunderstorms may develop this afternoon with some potential for locally gusty winds. Weak instability and poor low-level lapse rates should limit severe potential. ....Central High Plains... Low-level moisture will be generally modest east of a surface trough that will extend north-south across eastern portions of WY/CO this afternoon. Still, lower 50s surface dew points and steep mid-level lapse rates should contribute to MLCAPE of 750-locally near 1000 J/kg. Isolated thunderstorms may form and move southeast within a northwest mid-level flow environment late this afternoon/evening, and a deep/well-mixed boundary layer suggests some potential for localized strong wind gusts. Thunderstorm potential may extend eastward into western portions of NE/KS this evening as a low-level jet strengthens. The overall coverage of any severe potential remains too low to introduce severe probabilities. ....Interior Northwest... The potential for isolated thunderstorms, already ongoing this morning over south-central OR, will continue today as modest large-scale ascent associated with a mid-level trough overspreads inland areas of the Pacific Northwest. These storms may produce limited rainfall, exacerbating fire weather concerns. ....Lower Colorado River Valley and Vicinity... Strong heating will contribute to scattered thunderstorm development this afternoon, and 12z hi-res guidance suggests that a couple of stronger storms or small clusters may have the potential for gusty outflow winds within a hot/well-mixed boundary layer. $$ = = = 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) .