It ALWAYS rains in the desert!
Every time I go desert hiking in the spring it rains. "Desert Dry" is a myth. In '08 four of us went to the Escalante river area. Camped on Egypt trail head and was awoken to the roar of waterfalls from the cliffs below. Two days later the river had subsided enough to allow us to go in Harris Wash. I swam several times in what should have been a knee deep river. Thanks to my pack liner, anything I was not wearing was nice and dry. (my pack is the little one)