A Shot in the Dark

I saw a flash in the night sky Sunday at around 0525 UTC. The rough location was between Arcturus and the front foot of Ursa Major, if you're familiar with the H.A.Rey star maps. After a little research, I conclude that it was pretty much in the direction of the Messier globular cluster M3. I only caught it for a fraction of a second out of the corner of my eye, it was blue white, and it was about twice as bright as Sirius. I also live in Hollister California, with lattitude/longitude coordinates of roughly 37.82N and 121.37W. Anyone have any ideas?