Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Fri Aug 02 2024 19:56:15 AWUS01 KWNH 021956 FFGMPD AZZ000-NVZ000-CAZ000-030153- Mesoscale Precipitation Discussion 0783 NWS Weather Prediction Center College Park MD 354 PM EDT Fri Aug 02 2024 Areas affected...Portions of the Central and Southern Sierra Nevada down into Southern CA...Southern NV...Western AZ Concerning...Heavy rainfall...Flash flooding possible Valid 021953Z - 030153Z SUMMARY...Locally slow-moving and heavy showers and thunderstorms are expected over portions of the central and southern Sierra Nevada and down into southern CA, southern NV and western AZ going through the afternoon hours. Isolated instances of flash flooding will be possible. DISCUSSION...The latest GOES-W visible satellite imagery in conjunction with regional dual-pol radar and LightningCast data shows CI underway across the higher terrain of southern CA with a specific focus on portions of some of the Transverse Ranges. SBCAPE values are already on the order of 1000 to 2000 J/kg over southern CA adjacent to the higher terrain as strong diurnal heating continues and couples with proximity of multiple differential heating boundaries for convection to develop. An increasingly favorable thermodynamic environment coupled with the favorable orographics and proximity of a well-defined mid-level low/trough over southern CA should favor an additional expansion of convective activity over the next several hours. Slow-moving and locally anchored areas of heavy showers and thunderstorms can be expected, and with PWs that are running as much as 2 to 3 standard deviations above normal, there will be concerns for the stronger convective cells to be highly efficient. Some rainfall rates with the stronger storms are likely to approach or even locally exceed 2"/hour, and where any storms tend to hang up over the higher terrain, some spotty rainfall totals may reach 3 to 4 inches. The convection over the next few hours will have a tendency to be focused over the higher terrain of the Transverse Ranges where stronger forcing/proximity to the mid-level low center/trough will be noted along with favorable differential heating. However, in time, there should be areas of locally heavy showers and thunderstorms that develop over portions of the central and southern Sierra Nevada adn potentially some of the adjacent deserts south and east into eastern CA and southern NV. Expect some generally isolated instances of flash flooding to be possible going through the afternoon hours, and especially where any of these storms impact any burn scar locations. Orrison ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!7nUgcdcLXuB_n0_zM0Hd-PRyTiZJHA9MXUxUkOoeAmoaJPsHBlH8hS9GBHyFROvhZyQW= oTad5ddpFe6v_CDTiptrnO0$ for graphic product... ATTN...WFO...FGZ...HNX...LOX...PSR...REV...SGX...STO...VEF... ATTN...RFC...CBRFC...CNRFC...NWC... LAT...LON 38411939 37971826 37011710 36691577 36241425=20 35621286 34681310 33891322 33601459 33531586=20 33621666 34031747 34291821 34421922 34741963=20 35101966 36061910 37131937 37961990=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 3.20-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .