Subj : DAY1SVR: Day 1 Convective Outlook To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Tue Oct 10 2023 05:37:50 ACUS01 KWNS 100537 SWODY1 SPC AC 100536 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1236 AM CDT Tue Oct 10 2023 Valid 101200Z - 111200Z ....NO SEVERE THUNDERSTORM AREAS FORECAST... ....SUMMARY... Severe thunderstorms are not expected on Tuesday. ....Discussion... Large-scale mid-level height falls are forecast across the northwestern US during the day1 period as a strong 500mb jet digs toward northern CA late in the period. Downstream upper ridge that has dominated the southwestern US is breaking down and will be shunted east into the Plains. Isolated-scattered convection should develop ahead of the western US trough, primarily across the northern Rockies. It appears sufficient buoyancy will exist across this region for at least some risk for lightning. Weak southern-stream short-wave trough will eject across NM into the southern High Plains, along with substantial mid-level cooling. Strong surface heating/steep lapse rates will lead to an uncapped environment that should support a few thunderstorms across this region. Latest NAM guidance suggests LLJ will strengthen markedly during the latter half of the period across the central Plains. Strengthening corridor of low-level warm advection will evolve north of a warm front, primarily across the lower MO Valley. Forecast soundings suggest parcels lifted near 800mb will be uninhibited, and modest buoyancy is expected to support elevated thunderstorms. A few robust updrafts could generate small hail but large hail is not currently expected. Remnants of Hurricane Lidia are forecast to spread across Mexico late in the period. As this feature spreads northeast, NAM is the most aggressive model inducing significant surface development just southeast of BRO by 11/12z, while GFS is considerably offshore with this feature. Surface cyclone position will influence thunder potential across deep South TX late in the period. While forecast wind profiles/shear increase significantly with the near-land surface development, at this time severe probabilities will not be introduced due to uncertainly in low development. ...Darrow/Weinman.. 10/10/2023 $$ = = = 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) .