Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Mon Feb 19 2024 16:06:03 AWUS01 KWNH 191605 FFGMPD CAZ000-200404- Mesoscale Precipitation Discussion 0066 NWS Weather Prediction Center College Park MD 1105 AM EST Mon Feb 19 2024 Areas affected...portions of southern California Concerning...Heavy rainfall...Flash flooding likely Valid 191604Z - 200404Z Summary...A landfalling atmospheric river will continue to impact portions of the discussion area with moderate to heavy rainfall (and attendant flash flooding) through at least 04Z Tuesday. Discussion...Areas of moderate to heavy rainfall continue across southern California currently - especially in portions of Santa Barbara and Ventura Counties. Numerous areas of 0.25-0.6 inch/hr rain rates have been observed along with reports of flash flooding and mud/debris flows. The rainfall continues as a result of a landfalling atmospheric river located on the southeastern periphery of a slow-moving mid/upper low centered near 40.4N, -130W. Strong southwesterly flow within the atmospheric river, orographic lift against coastal ranges, and 1+ inch PW values will continue to support the ongoing heavy rain/flash flood risk in the short term. Models/observations support a very slow, southeastward translation of this atmospheric river over the next 6-12 hours, with heavier rainfall eventually impacting more of the Los Angeles Basin and adjacent areas of the Transverse and Peninsular Ranges across southern California. As this occurs, a lengthy duration of 0.25+ inch/hr rain rates is expected in the aforementioned areas, continuing to support flash flood/debris flow potential. The greatest threat for heavy rainfall (and overall 2-4 inch rainfall totals) should exist from the 10Z-00Z timeframe. Thereafter, most models lessen rainfall rates although at least an isolated flash flood risk should continue given the preceding rainfall and wet soils. Cook ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!711EpiKRq00UhhXjbpd0IuHxMy0yqvnEQ1wmetF70XDNYe_hyEt_6kcfnnAh8VX71R5Q= R08cY4m6WzFy9tlZdMjRTT0$ for graphic product... ATTN...WFO...HNX...LOX...SGX... ATTN...RFC...CNRFC...NWC... LAT...LON 35431912 34631735 33491663 33011692 33071761=20 33901937 34492054 35022059 35342000=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) .