Where can I find a detailed map of weather patterns in the Bay Area?

I don't know a place for that (but I'm excited to find one). SF Ports has a lot of the data you're looking for: http://sfports.wr.usgs.gov/sfports.html
(You can do a time-series plot of two stations in various locations)

Also, the very cool modeled wind field over the SF Bay area: http://sfports.wr.usgs.gov/cgi-bin/wind/windbin.cgi

have you been to the National Oceanic & Atmospheric Administration website?
http://www.nws.noaa.gov/

Another one I’ve found:

http://weatherbonk.com/weather/powerMap.jsp?where=%5B37.4519672738549%2C38.17883049854014%2C-122.95623779296876%2C-121.8109130859375%5D%3A10&showWeather=on&_booleanHelper_showWeather=showWeather&showCams=on&_booleanHelper_showCams=showCams&webCamCategory=+&_booleanHelper_alerts=alerts&_booleanHelper_allowOverlap=allowOverlap&iconMode=BIG&_id=&_className=weathermaps.weather.user.PowerMapWeatherRequest

The live cloud overlay will show you fog. Doesn’t do historical stuff, but you can watch it and figure out the weather patterns =)

I am not sure how detailed it is but check out http://en.wikipedia.org/wiki/San_francisco