Monsoons in Tucson, Part I

“We can never know about the days to come
But we think about them anyway. . .
Anticipation, Anticipation”

As my seventh monsoon season approaches this is exactly what I am feeling, anticipation!   Yes, I admit this sounds a bit odd but if you haven’t experienced a torrential rainstorm with over 1,000 lightning strikes across the city in one evening, you may want to visit Tucson between mid-July and early September. 

As I look back to 2001, I remember I was heading home in my new car and the skies had this ominous appearance.  Umm . . . what was that?   The thunderous, crackling sounds were only the precursor as the skies released bucketfuls of rain.  Wow what is going on?  I have never experienced anything like this in my 25 years in Alaska.  Yes, there are rainstorms in Alaska which can last days on end.  The buzz of hungry mosquitoes is the only noise you hear not the clapping of thunder and lightning. 

Needless to say my emotions went from utter excitement to go barefoot and jump up and down in the instant puddles to shear panic.  Will I make it home without crashing my car?

I called my friend, Marchelle, and she couldn’t contain herself.  She could barely talk over her laughter as I am asking her “What should I do”.   “Just keep driving, it will be all over in a few minutes” giggled Marchelle.  She was right, by the time I made it home, safe and sound, the sun was overtaking the skies creating a very humid afternoon.  It can’t be humid?  We live in the desert; it is suppose to be a dry heat!

With six monsoon seasons under my belt, I realize how important this season is to the desert.  The Old Pueblo is experiencing a seven year drought despite record rainfalls from last year’s monsoon season. 

What is a monsoon?

Wikipedia describes a monsoon as a rainy season which lasts for several months and has lasting climatic effects. 

The Sonoran monsoon season officially begins when the dew point is 54 degrees or greater for three consecutive days.   In general terms, our season may begin around the fourth of July and continue through the first week of September.

The three steps which bring moisture to the Sonoran Desert are: 

1. The warm waters of the Pacific and the Gulf of California evaporate.
2. Southeast winds bring the moisture into Arizona.
3. Heat-driven thunderstorms strip the moisture out of the air and drop it on our arid state.

How do you know a storm is on its way? 

You will start to notice white, puffy clouds appearing. This will continue for a couple of hours until it fills half the sky. Then the wind arrives, in front of the rain. Downdrafts within the storm spread out when they hit the ground, blowing up to sixty mile per hour gust fronts.
 
A crackling flash is followed instantly by a loud roar; the refreshing rain arrives. There is barely time to enjoy the coolness and the clean-washed air; the rain lasts only part of an hour. Then the storm moves out across the desert, filling arroyos and wetting the hot creosote, which now releases its perfume.   A lot of people love this aroma, I am not one of them.  Maybe it takes more than six years to appreciate it!

Finally, the sun reappears as you watch the snippets of rain, called virga, evaporate before they reach the ground.
  

”And stay right here,
’cause these are the good old days.
Anticipation . . .”

Watch for Part II - How to prepare your Tucson home for the monsoon season.