


Hydrometeorological Discussion
Issued by NWS California-Nevada RFC
Issued by NWS California-Nevada RFC
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454 AGUS76 KRSA 131607 HMDRSA Hydrometeorological Discussion National Weather Service / California Nevada RFC / Sacramento CA 905 AM PDT Mon Oct 13 2025 ...WIDESPREAD PRECIP HEAVY AT TIMES IS EXPECTED ACROSS ALMOST THE ENTIRE REGION TODAY THROUGH TUE WITH COOLER TEMPS... ...GENERALLY DRY FOR THE SECOND HALF OF THE WEEK... .METEOROLOGICAL CONDITIONS (MON AM - SUN AM)... Satellite imagery shows the upper low near the southern OR coast this morning, while a front stretches to the south. Widespread precip is affecting much of NW CA into southern OR, with showers into mainly the Sierra and portions of northern NV. Heaviest amounts in the past 6 hours or so have been 0.5-0.9" and locally wetter in northern Del Norte County in the Smith basin. Expect the low to track south just off the coast for the next 24 hour or so before turning east and moving inland over the central coast of CA. With the track a bit further offshore for longer compared to yesterday, forecast storm-total precip amounts decreased around 0.3-1" across much of northern and central CA, while increasing 0.3-2" in portions of the transverse ranges of southern CA, especially eastern portions. With good dynamic support aloft and H85 onshore flow peaking around 25 kts and PW values peaking around 1-1.2" near the central and southern coast, expect a round of heavier precipitation to spread across much of CA into western NV, with highest overall totals expected from the SF Bay area and the northern Sierra through portions of SW CA into the southern Sierra and western NV, with a general gradient toward higher precip in the southern portion of the areas mentioned. Expect freezing levels around 6000-9000 ft near onset of precip, then falling to generally 6500-8000 ft behind the front (little change in freezing level is expected for far southern CA). Cooling temps and strong forcing aloft could lead to heavier shower/thunderstorm development at times the next couple days. Overall precip totals 0.5-1.5 inches are expected on the north coast, with 0.7-2" on the central coast and 1- 3" southern coast, except only 0.3-1.5" far SW CA. In the central valley, amounts 0.7-1.4" are expected, with 1-2 in the northern Sierra and 1.5-2.5" in the central and southern portions. Generally 0.5-1.5" are expected in NV with 0.1-0.6" in far northern/NE CA and southern OR. Please Note: This product may NOT be routinely updated this summer. Please refer to the following product issued by the CNRFC www.cnrfc.noaa.gov/Daily-Briefing for a graphical summary of weather and hydrologic conditions. QPF graphics are available at www.cnrfc.noaa.gov/qpf.php Lerman $$