January 30, 2018 – Dry and mild for the next week with above average daytime temperatures.
Discussion
Varying amounts of high clouds continue to move across NorCal under westerly flow aloft. Holes in the higher clouds have allowed a stronger radiative inversion to develop overnight across portions of the Central Valley resulting in patches of shallow dense fog (the fog is expected to diminish by late-morning). Current temperatures are running around 2-5 degrees cooler across most of the area compared to 24 hours ago.
Little change is expected through mid-week as high clouds continue to stream into the region. The West Coast ridge is forecast to amplify a bit Thursday and Friday resulting in increased insolation, and northerly surface pressure gradients are expected to tighten a bit. The result will be even milder daytime temperatures with readings in the Central Valley expected to range from the mid 60s to mid 70s.
Extended discussion (Saturday through Tuesday)
High pressure over the eastern Pacific will continue to bring dry weather and above normal temperatures across the region. Some patchy fog will be possible during the morning hours in the valleys, but modest, drying northerly winds will likely limit the fog’s extent. Guidance continues to suggest temperatures surpassing the 70 degree threshold across portions of the Valley late this week into next week.