First major spawn with smaller ones within the last month in Tiburon, Sausalito and Alameda. The Bay Bridge spawn is usually major lasting at much as 4 days some years.
The major spawn is along the south tower of the Bay Bridge with the Chase Center, Mc Covey Cove/ Pier 52 and Agua Vista all areas of concentrated herring spawn.
Perhaps this particular school with head south to Candlestick, Oyster, and Coyote Point.