Hydrometeorological Discussion National Weather Service / California Nevada RFC / Sacramento CA 740 AM PDT Fri Apr 17 2026 ...DRY THROUGH THE WEEKEND... ...TURNING COOLER WITH INCREASING CHANCES OF PRECIP NEXT WEEK... .METEOROLOGICAL CONDITIONS (FRI AM - THU AM)... Dry northwest flow aloft across the west coast with an upr trof pushing across the Rocky Mountain states and an upr ridge shifting toward the region from the eastern Pacific. Dry conditions are anticipated through the weekend as the axis of the upr ridge reaches the immediate coast tonight...and then slides inland Saturday into Sunday. Afternoon high temperatures will rise above normal for much of the area with anomalies of plus 5- to plus 10-degF. Attention next turns to a disturbance moving off the Aleutian Islands this morning...expected to form a cutoff low over the northeast Pacific before slowing and settling off the northern CA coast generally along 130W. Timing of this system has slowed over the past several model runs with the GFS leading the way with a delayed onset of precip along the immediate coast. Light precip will begin to develop later Sunday...and then ever so slowly spread inland across northern CA and down the coast over central CA on Monday. Finally by Tuesday...the overall system is expected to shift inland...bringing widespread precip to northern/central CA with lighter totals south of Point Conception and inland over much of NV. With cyclonic flow remaining in place through Wednesday and early Thursday...shower activity will persist. Overall...trended slightly away from WPC QPF and NBM as the timing still seems too fast. Relied more heavily on the 17/00Z GFS and EC along with some influence from the 16/12Z WestWRF-EC. Freezing levels this weekend will peak anywhere from about 10000- to 13000-feet across the region...probably later Saturday as the upr ridge moves overhead. Then as the cooler airmass moves overhead with the upr low moving inland next week...look for freezing levels across northern/central CA anywhere from 5000- to 7000-feet...and for southern CA slightly higher where the cooler airmass does not impact the area as much with 8000- to 12000-feet. NV will generally range from 5500-feet northwest to 9000-feet south. Please Note: This product may NOT be routinely updated. 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. |