Yesterday birded Pt. San Pablo from 640am to about 11. There were a couple other birders out, including the Stephensons who met me at ~845. Almost no wind early morning, with a slight West breeze (2/3 mph?) picking up later in the morning. A thin fog first thing but it cleared up fast.
When I first arrived, I walked the switchbacks leading up from the marina like I normally do, and detected only 4 migrants--2 Wilson's, 1 Yellow warbler, and 1 Pac slope. I made my way up to the top of signal hill. Here there were 5 Savannah Sparrows and a curious warbler that went unIDed in the scrub. After a minute of going through them, they flushed off the hill and flew South. A slight breeze had started to pick up at this point (SW), and with it came one Yellow Warbler heading S over the hill. Then another, heading W across the bay. And more birds kept coming, sometimes landing briefly. I left the hill an hour and a half (?) later when the birds making the flight calls were too high for me to see. Highlights of birds flying over-- 30 Purple Finch (very high count here), 14 Tanager, 2 OC and 15-20 Yellow Warblers, 7 Savannah Sparrow, 4 Bluebird (these hung around up top for 5-10 minutes), 5 Vaux's Sw., 2 Say's Phoebe, 2 Willow Flycatchers (didn't actually see if these left over the bay but they disappeared heading W), a couple blackbirds, and 2 collared doves (rare here). Almost all heading West over the bay. Walking the switchbacks after I left the hill, the oaks were newly alive. 2 kinglets, vocalizing Swainson's Thrush, several more warblers, singing Fox Sparrow, waxwings, etc. Presumably all birds that had cycled in during the time I was skywatching.
Walking the railroad tracks with the Stephensons, Lucas flushed up a Spizella about 100 feet west of the marina. We saw it fly by, and it sat up for maybe 5-6 seconds in a stand of fennel ~30 yards away from us before taking off out of sight. They both think it was a Brewer's. I don't want to get into it too much--it certainly could have been a Brewer's--but several things I saw didn't convince me to that end.
Birded Richmond the rest of the day, decent migrant numbers, only highlight was an apparently continuing Lark Sparrow at Miller.