Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sun Dec 04 2022 05:56:17 AWUS01 KWNH 040556 FFGMPD CAZ000-041500- Mesoscale Precipitation Discussion 1143 NWS Weather Prediction Center College Park MD 1255 AM EST Sun Dec 04 2022 Areas affected...Coastal Ranges of central to southern CA Concerning...Heavy rainfall Valid 040554Z - 041500Z Summary...Rainfall rates are expected to decrease in magnitude along the CA coast as a plume of moisture translates south through 15Z. Additional rainfall totals of 1 and 2 inches are expected prior to rainfall coming to an end. Discussion...IVT values are likely near or just past peak for this event with 500-600 kg/m/s focused into the Santa Lucia Range of southern Monterey and northern San Luis Obispo counties as of 05Z. Earlier observed rainfall rates in the Big Sur region of the CA coast were in the 0.50 to 0.75 in/hr range near 02/03Z with 12 hour rainfall totals of 3 to 5+ inches ending 05Z. Looping GOES West infrared satellite imagery showed at least a temporary lull in colder cloud tops associated with the axis of greatest moisture flux pointed into the central CA coast but additional flare ups cannot be ruled out overnight. To the northwest, an elongated axis of colder cloud tops tied to a frontal band of rain (ahead of a large closed low centered north of 40N 130W) was seen to be making steady eastward progress along the 35th parallel. The eastward push of a shortwave on the south side of the large closed low to the north should help to support steady southward progression of the cold front currently analyzed through Monterey County. Peak precipitable water values of 1.2 to 1.3 inches and 850 mb winds of 30-40 kt over the Coastal Ranges are forecast to gradually wane with time. This combined with the progressive nature of the low level moisture axis should help to limit additional total rainfall through Sunday morning. However, 48 hour rainfall totals of at least 3-5 inches along portions of the central/southern CA Coastal Ranges have left soils saturated and the additional forecast of 1 to 2+ inches cannot entirely rule out the possibility of localized flooding. This would especially be true for the southern Santa Lucia Range and Santa Ynez and San Rafael Mountains where orographic ascent will help to boost additional rainfall totals. As the event wanes late Sunday morning, hourly rainfall totals are expected to drop to less than 0.25" beyond ~15Z for the entire south-central CA coast. Otto ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!_v-llt_IJUlv58UE1oS4J2057H2VFrtl6B-L4_YCDWEOJlfRoVaYdb-Mk8mEw7UzaXFe= KvzdU4zHz1h77bgMrLqsCoc$ for graphic product... ATTN...WFO...LOX...MTR... ATTN...RFC...CNRFC...NWC... LAT...LON 36422170 36392154 36252133 36012094 35702068=20 35502045 35352028 35091998 34931978 34701948=20 34621922 34531908 34251923 34191961 34302037=20 34512074 35052097 35442122 35692153 35992173=20 36262186 36402181=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) .