Weather across interior Northern California is being dominated by an upper level ridge now situated over the Great Basin. A bit of marine stratus has begun to thicken across the far northern CA coast, but has yet to reach the Bay Area. Also factoring in a weak Delta breeze, temperatures across the interior are running warmer than 24 hours ago.
A series of shortwave troughs will pass through the Pacific Northwest starting late today and continuing through the middle of the week. This will bring about both synoptic cooling along with enhanced onshore flow through the Delta. Temperatures will beg into cool off Monday continuing through the middle of the week, with high temperatures floating within a few degrees of seasonal normals.
Extended discussion (Thursday through Sunday)
West-southwest flow aloft expected to predominate later in the week as the upper ridge shifts east into the Rockies and a weak trough develops along the West Coast. Pattern is dry for interior NorCal with deeper moisture and instability further to the north and east. Temperatures expected to be close to average with onshore flow through the Delta.