Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sat Dec 03 2022 09:46:29 AWUS01 KWNH 030946 FFGMPD CAZ000-032100- Mesoscale Precipitation Discussion 1141 NWS Weather Prediction Center College Park MD 445 AM EST Sat Dec 03 2022 Areas affected...central to southern coast of CA Concerning...Heavy rainfall Valid 030937Z - 032100Z Summary...Areas of moderate to heavy rain will shift northward into the Santa Lucia Range throughout the morning into the early afternoon. Rainfall rates will likely increase with time and hourly totals will near 0.5 in/hr along with 12 hour totals in the 2-3 inch range through 21Z. Localized flooding will be possible in areas of sensitive terrain. Discussion...Loops of regional radar imagery through 09Z showed areas of light and moderate rainfall translating northward along the south-central coast of CA, near a quasi-stationary front that bisected San Luis Obispo County. Recent GPS observations along the coast near Point Conception were near 1.2 inches and VAD wind data from KVBX showed 850 mb winds from the south at 15-20 kt. Observed rainfall over the past 3-6 hours in southern Santa Barbara County was in the 0.5 to 1.0 inch range with hourly totals in excess of 0.25 inches just west of KSBA earlier in the night. The larger scale picture showed a mid-upper level trough centered just east of 130W with a 110-130 kt upper jet located downstream over the southern third of the CA coast. At the surface, a quasi-stationary front was located southwestward from the south-central CA coast into the eastern Pacific Ocean. While no evidence of a baroclinic leaf was seen in water vapor imagery, a developing area of low pressure was estimated to be on the front near 32N 126W based on its location just ahead of a vorticity max observed on water vapor imagery and as seen in RAP analysis data. Short term forecasts show the weak low along the front tracking northeastward through the morning toward southern Monterey Bay through 21Z, ahead of the advancing shortwave and broader southwest flow located to the southeast of a large closed low centered west of the Pacific Northwest. The axis of precipitable water along the CA coast is expected to continue lifting north through the morning, with 1 inch precipitable water values reaching Monterey Bay and 1.1 to 1.2 inch values along the coast of Monterey, San Luis Obispo and Santa Barbara counties. The axis of low level moisture transport is forecast to slow or even stall in the 15-21Z time frame into the Santa Lucia Range. Southerly to southwesterly 850 mb winds are forecast to increase to near 30 kt through 18Z with an orientation directly orthogonal at times to the axis of higher terrain. Rainfall rates are expected to steadily increase in intensity through the rest of the morning into early afternoon with hourly totals peaking near 0.5 in/hr. Peak/localized 12 hour totals of 2-3 inches will be possible and when combined with a broad 2-4 inches which fell over the 24 hour period ending Friday morning, localized flooding may occur. Any instances of flooding that occur would be most likely in areas of sensitive terrain, including any burn scars over the past 1-3 years that could be more sensitive to runoff. Otto ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!9dtV76Wt6yIel3XTd0bka9MgPM4GQAE9uTGUyUh5jFK21uVUzeehgQGcF5hPMdKxin-y= 2LZWsaa5SJKJv-YRkafzCVY$ for graphic product... ATTN...WFO...LOX...MTR... ATTN...RFC...CNRFC...NWC... LAT...LON 36632194 36612183 36522161 36372146 36262131=20 36152112 36032105 35842097 35792092 35692081=20 35572062 35432042 35272018 35122012 34952011=20 34792028 34792061 35142084 35462124 35982165=20 36262198 36522201=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) .