Another day, another day of deep marine layer at the beaches and coastal valleys to start the day. Like the pattern has been all week, there was clearing in the coastal valleys and the marine cloud deck backed up to the beaches where it lingered with some scattered openings in the cloud field. Temperatures at the beaches and coastal valleys were largely unchanged in the 50s and 60s at the beaches with 70s in the coastal valleys. As expected the interior valleys warmed quickly again into the 90s after a one-off cooling event yesterday.
Saturday looks like Friday with similar cloud conditions, winds and temperatures.
Sunday however looks dramatically different for the interior valleys. An upper low now positioned just off the Pac NW will dive into northern California and Nevada. This upper low is connected to a significant mid-level trough. This will allow much cooler air to get inland. Sunday morning clouds likely reach the interior. Now, those clouds likely clear or mostly clear with a developing afternoon NW winds up to 25mph. The largest impact however will be temps. Inland highs drop into the 70s and low 80s Sunday and Monday. Coastal conditions will also cool slightly, but a much muted difference since the marine layer there was already present. The clouds will likely clear or mostly clear at beaches and coastal valleys Sunday thanks to the breeze and the lack of a strong temperature inversion (wiped out by the trough).
Sunday night and Monday morning the clouds are back and modeling indicates that some mist/drizzle are likely. Temps will continue to be generally mild.
Tuesday through the rest of the week temps will rise again but not to extreme levels, maybe just a tad above average. The second half of next week looks like a return to "No Sky July" at beaches with the return of a stubborn marine cloud deck.