Re: spring morning flight
I also ended up doing a "morning flight" watch the last couple mornings from a hillside spot I found a short walk from my home, beginning a little after dawn. While Paul's spot is close to the coast mine is a bit further inland, a little north of Lake Hodges, near the edge of the Del Dios Highlands Preserve.
Like Paul, I saw a big jump in Black-throated Gray Warblers this morning with 34. While my numbers for Wilson's and Nashville Warblers were a bit lower than Paul's totals, I had many more Townsend's (17) and a decent number of Hermit Warblers (6) on the move at my site. I didn't start visiting this spot until this spring, so I don't have have a great sense of what expectations should be for high or low counts yet.
The lists include a portion of my walk to the location, and I didn't attempt to separate active migrants from local breeders, but the vast majority of the warblers were seen actively moving up and over the hillside, similar to what Paul described:
My list for April 14:
and April 15:
Source: SanDiegoRegionBirding Latest Reports