Light precipitation develops later today into Saturday, mainly in the mountains. Breezy north to east winds develop Saturday and persist into early Monday. Another weak system Monday night into Tuesday will bring additional light precipitation followed again by breezy northerly winds into midweek.
Discussion
Light wind and clear skies overnight, along with higher dewpoints, will allow for some potential patchy fog development in the Central Valley. HREF showing best probabilities for development from about KOVE southward. Any development should be short-lived.
Meanwhile, upstream Pacific trough forecast to deepen and close as it approaches today. 545 DM upper low progged just west of KACV this afternoon with models suggesting some light precip extending into the Coastal Range later today. Upper low progged to move south along the coast tonight into Saturday.
Light QPF forecast by the models, mainly over the mountains. Snow levels begin around 4500-6500 feet this evening, lowering to around 3500-4500 feet Saturday.
Storm total QPF showing majority of light precip falling in the Sierra Nevada with snow totals below mainly at or below 5 inches above 5000 feet with local amounts up to 7 inches. Slick roads and minor travel delays will be possible.
Gusty north to east wind develops Saturday as subsidence increases over the PacNW with tightening low level N-S pressure gradient over interior NorCal. 925 mb winds increase to about 30-40 kts over the Central Valley Saturday evening with the strongest wind over western portions of the Sacramento Valley.
Tightened pressure gradient continues Sunday for breezy conditions in the Central Valley, and in the northern and eastern foothills/mountains through Monday morning. Lighter wind expected Monday as short wave ridging moves through ahead of the next weak short wave trough progged in from the NW Monday night into Tuesday.
Extended Discussion (Tuesday through Friday)
Upper level trough will digging out of the PacNW into interior NorCal for the start of the extended period. This will bring cooler conditions and the chance for some light precipitation mainly over the Sierra and southern Cascade. Snow levels will be low with this system but precip will be limited. 1-3″ of snow will be possible above 4000 feet.
As the trough pushes into southern California and the Great Basin we will see increased northerly winds for Wednesday. Otherwise upper level ridge builds bringing quiet conditions for the middle part of the week with a gradual warm up.
Upper level trough will be digging over the Pacific late week into next weekend and may bring the return of some precip but ensembles are struggling with timing and placement at this point.