Subj : MESO: Mesoscale Discussion 2017 To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sun Aug 20 2023 18:10:05 ACUS11 KWNS 201809 SWOMCD SPC MCD 201809=20 AZZ000-NVZ000-CAZ000-202015- Mesoscale Discussion 2017 NWS Storm Prediction Center Norman OK 0109 PM CDT Sun Aug 20 2023 Areas affected...Southeast CA...Southwest AZ...extreme southern NV Concerning...Severe potential...Watch possible=20 Valid 201809Z - 202015Z Probability of Watch Issuance...40 percent SUMMARY...A couple tornadoes are possible this afternoon as T.C. Hilary moves north-northwestward. Tornado Watch issuance is possible. DISCUSSION...Tropical Storm Hilary is quickly moving north-northwestward near the Baja California coast late this morning. While Hilary will continue to weaken through the day, strong low/midlevel flow associated with the broader circulation has already spread into parts of southern CA/AZ, and will move into a larger portion of southeast CA into western AZ with time. 0-1 km SRH of 200-300 m2/s2 (as noted on recent VWPs from KYUX and also from objective mesoanalyses) will be supportive of low-level rotation with any deeper convection to the east/northeast of Hilary's track.=20 Uncertainty remains regarding the coverage of deep convection within the favorable low-level shear regime. Convective banding may remain somewhat muted in closer proximity to Hilary's center as the surface circulation continues to decay, and widespread cloudiness will tend to limit destabilization. The greatest relative threat may materialize along and west of the lower CO River Valley, where richer low-level moisture will be in place and somewhat greater heating/destabilization is underway along the eastern periphery of the strongest low-level flow/shear. One or more arcs of deeper convection may evolve with time across this region, with embedded transient supercells and a couple of tornadoes possible. Tornado Watch issuance is possible, depending on short-term observational trends regarding destabilization and convective evolution. ...Dean/Grams.. 08/20/2023 ....Please see https://urldefense.com/v3/__http://www.spc.noaa.gov__;!!DZ3fj= g!5lUDS3htypTKZy_nkJjAkU2y5Y1WS4mZLLS_m71olpC9hUBTV2I9RXIdEm670yyYdZLw-4YCV= kaSDVdN2hP3Akuyphs$ for graphic product... ATTN...WFO...PSR...VEF...SGX... LAT...LON 32621629 33721664 34891669 35301623 35511564 35351458 34231421 32791410 32171410 32361496 32621629=20 =3D =3D =3D 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) .