Dad, official late dad of NewMexiKen, provided this report on seasonal change in Tucson back in 2004:
Those of you familiar with the desert know that after two or three months of no rain we expect thunderheads to build up every afternoon south east of us. These are the rain clouds from the Gulf of Mexico, pushing up into the Sierra Madres in Mexico. Day by day they creep closer to us.
Yesterday while reading I was surprised by a loud clap of thunder. Glancing out the window it was true….. Rain………
I raced to the kitchen to gather my rain gauges and ruler; ran out the door and proceeded to record the event.
Taking numerous measurements, I concluded the drops averaged two inches apart and the rain had lasted four minutes…..a 2/4 rain.