These are good general reference sites to a variety of natural disasters, both weather based, or geologic.
Weather Wiz Kids - hurricanes, winter storms, tornadoes, flooding, thunder/lightning, wind, fire, earthquake, volcanoes
eSchool - Natural Disasters - hurricanes, tornadoes, volcanoes, fire, flooding, wind, droughts
Ontario Natural Disasters - list of the types of natural disasters that occur in Ontario
BBC Animated guides to Natural Disasters - hurricanes, tornadoes, earthquakes, volcanoes, tsunamis
Severe Storms - blizzard, hail, heavy rain, ice storms, lightning/thunder, wind