Relief!

Doug writes:

It happened.

Deborah writes:

AHHHHHHHHHHH--we left for 2 hours to go to class and when we get off the freeway all of Ahwatukee is floating in water. Rivers flow down the street as we speak. Ah well, it rained at home, it smells marvelous and YOU WERE RIGHT!!

Yay! I've been worried! I feel almost as much relief as if it had rained here!

Watching the radar and IR images has been instructive. Nothing could get going until the dry patch along the Gila/Salt River valleys got filled. It was as if the two cogs of the spinning wheels, Colorado Plateau (high) and Sierra Madre (low) couldn't engage.

Once the sun went down, a lot of the thunderstorms up on the Rim and the Colorado Plateau collapsed, and the cool, discarded moisture began flowing off the Rim into the Salt River Valley. At the same time, remnant Emily circulation was persistently pushing moisture into the Salt and Gila River Valleys from the south. So, finally, the cogs began to engage!

Also interesting is that the storm that hit you tonight is at cloud/moisture discontinuity line of some sort: almost like a miniature "dryline", with drier air to the north. These storms seem to initiate best at these drylines. Also interesting is that the storm didn't come directly from the peaks of the Superstitions, but rather the southern flank of the mountains: the dryline was more important than the mountain!

Still, it's an amazingly complex flow of air. At the AZ-NM border, the air is flowing north. A few miles away, to the west, the air is flowing south. Amazing! Whirls and curls everywhere!

It's not clear what will happen later tonight. Your storm may be self-regenerating to some extent, so repeated showers may occur. Plus, even though down south, the air flow is from the north, for hours now, the Sierra Madre mesoscale convective complex has been steadily but relentlessly propagating north. It may attempt to engulf you from the south in the early morning hours! Or not.... It's hard to say...

Yay! I'm happy! I hope the cats can cope!