What if Mount St. Helens erupts?

Angela Brown, the About Guide to Seattle/Tacoma, has put together some advice on dealing with volcanic eruptions. I was just visiting Oakland's fire/quake preparedness site—an actual site, a building at Tunnel and Caldecott Roads—and the advice there was much the same. In fact, I'll bet Floridians would find it familiar even though their local hazard is hurricanes.