This week, extensive areas of fog (sometimes quite dense) will prevail in CA Central Valley--even into PM hours. This is a classic "tule fog" setup, w/a strong temperature inversion under a ridge trapping sfc moisture in CV but keeping nearby hills & mountains balmily warm/sunny.

Parts of the SF North Bay Area could also stay a bit chilly as fog "spills" westward from the Valley through the Carquinez Strait. But away from the CV and above the inversion, it'll be quite warm and sunny! Expect 60s in NorCal foothills/mtns and 70s (or warmer) SoCal. #CAwx

After this week, uncertainty reigns. A major stratospheric warming event and subsequent stratospheric polar vortex disruption *may* cause a pattern change-up in early Dec, but details (and even big picture) remain quite murky. In general, looks potentially active in California...