When you think of the desert southwest, you typically think of scorching heat in the summers, mild winters, and not much precipitation. Thunderstorms are rare and severe weather is even more uncommon. That being said, an episode of severe weather struck portions of Arizona like the state hadn't seen in years.
A strong upper low was parked over the desert areas and this provided lots of instability and also added some spin to the atmosphere. There were several confirmed reports of tornadoes in north central Arizona, not far outside of Flagstaff. There was substantial damage to structures and some neighborhoods were heavily damaged. Preliminary reports show that four twisters touched down outside of Flagstaff -- this is roughly equal to the number of tornadoes that the entire state of Arizona sees in an average year.
In addition to tornadic storms, there were also reports of massive hail on Tuesday afternoon. Not far from Phoenix, there were reports of hail up to the size of tennis balls, or 2.50" in diameter. That ranks in the top ten for largest hailstones ever observed in the state of Arizona. On a good note, the weather appears to be clearing out in this area, but now the cleanup will begin for many in northern Arizona.
If you have any questions about severe weather, feel free to post them in the comments section and I'll answer them!