Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sat Dec 10 2022 19:39:45 AWUS01 KWNH 101939 FFGMPD CAZ000-110600- Mesoscale Precipitation Discussion 1149 NWS Weather Prediction Center College Park MD 237 PM EST Sat Dec 10 2022 Areas affected...Central California Concerning...Heavy rainfall...Flash flooding possible Valid 101930Z - 110600Z Summary...Areas of heavy rainfall will translate south and east this afternoon and evening in association with a cold front and atmospheric river. Localized rainfall rates may occasionally reach 0.5-1.0"/hr. Flash flooding and debris flows are possible in burn scar areas. Discussion...An anomalous longwave trough (normalized anomalies of 500 mb heights ranging from -2 to -3) located off the West Coast is driving a cold front and associated atmospheric river into Central CA late this morning. Areas of heavy rainfall will continue to progress south and east ahead of the cold front as the atmospheric river continues push farther inland from the southwest, bringing with it impressive low-level moisture transport and moisture flux convergence. As the trough continues to dig southward this afternoon (with a strengthening upper-level jet streak and associated downstream diffluence), additional embedded elements of convection are expected to develop (with MU CAPE up to 100 J/kg near the coastal interface of the front). This may allow for localized rainfall rates to occasionally reach 0.5-1.0"/hr, which may lead to isolated instances of flash flooding and debris flows over burn scar areas (with particular concerns for the San Lucia Mountains and associated Dolan, Colorado, and River burn areas). Farther inland along upslope portions of the Sierra Nevada, localized rates may occasionally approach 0.50-0.75"/hr (which should also generally limit any isolated flash flooding to burn scar areas). Within the San Joaquin Valley itself, rainfall rates are generally expected to peak between 0.25-0.50"/hr. Rainfall totals through late this evening (06z) are expected to generally range between 1-3 inches, but may reach as high as 3-4" along upslope portions of the San Lucia Range (and may be as low as 0.1-0.2" along downslope portions of the San Lucia and Diablo Ranges). Heavy rainfall may also begin to reach the San Gabriel Mountains of Southern CA towards the late evening and overnight. Churchill ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!_4Xl4ZQ8bQB-1AeYcuGpEbeImOiBElib4p5foeHutgG67wqKxc8l4UvdD4e3mGeNnQs2= bb_u0OF7IPRgyvvlR_Y9bwo$ for graphic product... ATTN...WFO...HNX...LOX...MTR...STO... ATTN...RFC...CNRFC...NWC... LAT...LON 39612131 39282100 38782075 38432060 38102042=20 37912027 37662004 37391994 37291977 37121952=20 37001934 36831917 36591905 36401899 36321899=20 36131907 35961921 35571975 35171975 34931939=20 34821876 34471861 34251891 34261953 34332031=20 34582085 34972100 35572164 35972209 36322249=20 36942267 37182279 37592251 37702222 37852195=20 38142172 38242166 38432151 38512145 38682141=20 38802145 38932156 39262153 39412149=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) .