Hydrometeorological Discussion National Weather Service / California-Nevada RFC / Sacramento CA 715 AM PST Fri Nov 13 2026 ...SERIES OF SYSTEMS TO IMPACT THE REGION INTO NEXT WEEK... .METEOROLOGICAL CONDITIONS (FRI AM - THU AM)... Two areas of precip straddling the coast this morning with the more impressive negatively tilted s/wv trof making its way toward the Pacific Northwest and northern CA coast...while a more compact disturbance is just off the southern CA and northern Baja coast. Radar imagery shows one solid line of precip making its way onshore along the north coast down to about Point Arena at the 13/15Z hour with several embedded lines of convective precip just ahead of the offshore cold front. Down south...the line of showers and thunderstorms moving onshore from about Orange and San Diego counties...but has shown a tendency to weaken as it continues to move toward the east. However...precip amounts over coastal southern CA with the onshore flow has brought widespread precip slightly higher than originally anticipated. Through the morning and afternoon hours...the s/wv trof moving toward the Pacific Northwest and northern CA coast will dig a bit more to the southeast before crossing inland. This will push the associated cold front inland...while displacing the moisture plume of approx 1.00-inch PW to the south and east. Heaviest precip will shift from the northern CA coast this morning to the northern and central Sierra back to the coast over the SF Bay Area down to Monterey County. After sunset and through the overnight...look for the system to continue to track inland before exiting the area to the east around sunrise. Precip will focus on the southern Sierra back southwest to near Point Conception during the evening and then finally eastern NV down to the coast between Los Angeles and San Diego. The majority of Saturday looks to be a break day between systems as a transitory upr ridge slides across the area ahead of the next s/wv trof riding east between 40N and 50N...on its way to the west coast...where it is anticipated to dig southward before shifting inland. Some timing difference amongst the models with both the 13/00Z and 13/06Z GFS lagging on the speed of the cold front across the region...while the 13/00Z EC is the quickest. The 13/00Z CMC is somewhere in between the two. For now...used the more compromise solution...which was supported by the latest WPC QPF. Precip will slide across northern CA from Sunday morning into the evening hours as the overall system slowly makes its way across the area...finally shifting toward central CA and weakening during the overnight hours into Monday morning. This thinking across central and southern CA is slightly different from yesterday...bringing a decrease to overall amounts on later Sunday into Monday. This second late weekend into Monday system will shift east of the area on Tuesday...while the region awaits the next system that is showing the lowest confidence in the track and strength. The s/wv trof looks to move toward the Pacific Northwest during the middle of the week...but then how the system evolves is up in the air. The EC is wanting to dig the system farther inland more over the Great Basin...while the GFS is wanting to drop the system south closer to the west coast. The CMC is somewhere in between...but overall is looking closer to the EC at this time. For now...a compromise approach was used with the NBM50Pct being included in a blend with the GFS and EC. Freezing levels are currently from 8000- to 10000-feet across the region...mainly from west to east. As the core of the system moves overhead later tonight...these will bottom out from 5500- to about 7000-feet for the northern tier of the region...before bouncing back with the upr ridge moving in on Saturday. The later weekend and Monday system will bring in some more cooler air across the majority of the region...dropping to 4500- to 7500-feet from north-to-south before fluctuating a bit from Tuesday into Wednesday from 4500-feet north to 10000-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. |