Windstorms, monsoons, flash floods, no tornados. In northern Arizona they do have snow quite often and do get blizzard warnings.
Flash floods are probably the worst in the Phoenix area; there's slow drainage, so a lot of rain coming down can cause the washes (low spots) to fill up and they look deceiving shallow, but they can be deep enough to submerse a car. Some of them are on roads and people have died by going through them. Most roads that have them have warning signs that say not to proceed through if raining. There is actually a "Stupid Motorist Law" that says a driver can be cited for driving across a flooded wash when warning signs are posted. The fines and rescue costs can be steep!
Check this out: http://www.azfamily.com/news/local/S...-78731557.html