####018003460#### AGUS76 KRSA 021713 HMDRSA Hydrometeorological Discussion National Weather Service / California Nevada RFC / Sacramento CA 830 AM PST Sat Mar 2 2024 ...WIDESPREAD PRECIP AND MOUNTAIN SNOW AND ISOLATED THUNDERSTORMS TODAY THEN PRECIP TAPERING OFF SUNDAY AS A COOL TROUGH MOVES THROUGH THE REGION... ...PRECIP CHANCES CONTINUE MAINLY OVER SRN OR AND NRN AND CENTRAL CA AND NRN NV MONDAY AND TUESDAY AND SPREADING SOUTH WEDNESDAY... .METEOROLOGICAL CONDITIONS (SAT AM - FRI AM)... Upper level trough over the region with associated low pressure centered off B.C. coast and cold front draped over the region around Point Conception and NE into the Central Sierra and into North Central NV. Showers moving through the region this morning and will continue through out the day. Isolated Thunderstorms possible today, mainly over Nrn and Central CA and into far western NV and over Eastern NV. Precip will taper off overnight into Sunday with scattered showers. Heaviest precip is expected in the Srn Sierra with 2-5 inches and San Bernardino Mtns 1-4 inches today. Precip amounts will be variable due to convection. Precip amount over the weekend are generally expected to be around 2-5 inches for the Central and Southern Sierra and 1-3 inches for the Nrn Sierra and NW CA coast and 1-2 inches for the Central CA coast and generally 0.5- 1.5 inches over Eel and Russian Basins and most of NV and Srn CA except locally up to 4 inches possible in the mtns, mainly San Bernardino Mtns and around 0.1-0.75 in the Central Valley. HREF exceedance probabilities are about 10-40% for 0.50"/hr rainfall rates possible for CA into this evening, especially over the Srn Sierra and NW CA coast. Another upper trough moves into and through the Pac NW on Monday and Tuesday bringing more precip to Srn OR and Nrn and Central CA and Nrn NV. Precip amount and southern extent of precip varies with the models and ensemble members with the GFS mainly drier and farther north than the EC. A low in the Eastern Pacific moves southeast to around 130W offshore of the CA coast Tuesday and off Point Conception and the Srn CA coast later Wednesday and into Baja Thursday morning. This may bring some showers to the region Wednesday. Models vary with the details of this low and how close it will be to the coast. High pressure from the Eastern Pacific builds in on Thursday for drier conditions. Freezing levels generally around 1500 ft near ORCA border and around 2500 ft near I-80 and around 4500 ft for Srn Sierra and 5000-7500 ft for Srn CA this morning and fluctuate before rising to around 2500 ft near ORCA border and 3500 ft near I-80 and 5000 ft for Srn Sierra Sunday afternoon. Max temperatures forecast to be around 5 to 20 degrees below normal today into Monday then near normal to 15 degrees below normal for mid-week. Overnight temperatures around 5 to 15 degrees below normal for Srn OR and Nrn CA and near normal to 10 degrees below normal for most of NV and Central and Srn CA Sunday morning and below normal to around 15 degrees for most of the region Monday morning and near normal for Tuesday and Wednesday morning (except north up to 15 degrees below normal on Wednesday and Thursday mornings). QPF graphics are available at www.cnrfc.noaa.gov/qpf.php Osborne $$