Hydrometeorological Discussion National Weather Service / California Nevada RFC / Sacramento CA 705 AM PDT Thu May 28 2026 ...COOL AND UNSETTLED TODAY SHIFTING EAST TOMORROW... ...BECOMING WARMER AND DRIER INTO NEXT WEEK... .METEOROLOGICAL CONDITIONS (THU AM - WED AM)... Radar imagery this morning shows the best area of precip currently impacting the SF Bay Area down across the central CA coast...as well as the adjacent locations of the southern Sacramento and northern San Joaquin Valleys this morning. Precip gauge reports since 28/12Z show widespread light to locally moderate precip falling over these areas with anywhere from a few hundredths of an inch to just shy of 0.20-inch. This is all associated with a disturbance rotating around the nearly stationary upr low spinning just south of Lake Tahoe this morning...very close to its location at this time yesterday. Through today...look for this embedded disturbance over the SF Bay Area to rotate southward and then inland across central CA around the primary circulation...increasing precip over the southern Sierra later this afternoon and evening Sierra. Also...a second disturbance currently located over central NV will make its way northward before arching across the upper Klamath River basin this afternoon and evening. Most recent models are in good agreement with this area seeing widespread moderate to locally heavy precip under any convective precip that does once again develop. SPC is actually pinpointing an area of Marginal Risk for severe storms today over the upper Klamath...indicating the potential for convective storms. Into Friday...a kicker system moving toward the Gulf of Alaska and the northeast Pacific will finally start to shove the upr low eastward as an open wave crossing the Wasatch on its way toward the northern Rockies. Precip will become more scattered and lighter on Friday...focusing on the upper Klamath River basin down across the Pit River basin to the northern Sierra as well as the northern two- thirds of NV. With the flow becoming a bit more westerly across the region...a weak disturbance moving through the flow may touch off a few showers on Saturday mainly over the Sierra and northern NV. However...coverage and amounts will be minimal. Heights then begin to rise for next week with an upr ridge just off the west coast...sitting between a deep upr low over the east-central Pacific and a system over the northern Rockies. Freezing levels this morning are very similar to yesterday given the stagnant pattern...around 7500-feet near the core of the upr low and increasing as distance from the primary circulation becomes greater. As the system opens and kicks to the east...freezing levels this weekend will generally range from 10000- to 13500-feet...bumping up even more into next week up to 12000- to 15000-feet by early Wednesday. 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. |