The radical "heat dome" over the Pacific Northwest is slowly sliding north and eastward but still producing much above-average temperatures for the region.
The Central Coast is far underneath this extreme feature but covered in the broader ridge over The West.
That ridge weakened locally and a deeper marine layer has ushered cooler temperatures inland, near the coast there isn't dramatic change since the marine influence was already in place the last several days.
The key factor thru Thursday is the lighter wind flow near the beaches and near coastal valleys, not enough to mix out the marine clouds in those areas fully. Some may continue to see little sun Thursday but many areas are just experiencing slower clearing than earlier this week, leading to cool beach temperatures.
As I have discussed this week there is a monsoonal airmass (humid and unstable) to our east. This has produced scattered thunderstorms across the Desert SW and parts of the higher elevations of California. This looks to continue. Locally just some high clouds and perhaps slightly higher dewpoints.
No huge changes into the weekend, the thing to watch on the 4th is the rate of marine cloud clearing. Looks like some stronger afternoon winds could aid in better clearing we are experiencing today and are likely to experience Thursday.
Otherwise, the temperature trend is rather flat, warming a bit into next week.