Saturday, August 6, 2005

The Desert Forgets the Rain

The Sonoran Desert has a terrible memory for weather, especially this time of year.  When it rains as hard as it did last night, the desert forgets that's it's suffered through a decade-long drought, and fails to drink deeply of the water the clouds offer.  The next day, it forgets this, too, and drinks it after all, whatever the sun and clouds don't snatch away first.  Soon there is no sign that it rained recently, except for the deposits of dirt and debris, and the occasional fallen tree.

Still clogged with debris, but dry.Today I tried to find you photographic evidence of the storm I wrote about last night, but there was little to be seen.  The streets were dry, the stalled cars were long gone, and even the downed tree near Fifth and Wilmot was being hacked apart so it could be hauled away.  At least, I assume that was the meaning of the truck and workers I saw from a distance.  It didn't seem worth being late for work to go find out for sure.

I did find debris, though, some of it trash but most of it torn from trees and bushes by the wind and rain.  I was right about this storm drain next to St. Michael's, for instance.  It was clogged with palm leaves and twigs and such.  About two feet from this stretch of curb was where I saw the crashing waves of water last night.

Dry this morning.

By lunch time, the sky was mostly blue and the ground was mostly dry, but the debris was still there.

Last night's river returns briefly as a puddle.

Late this afternoon it rained again.  I was busy inside at work, and totally missed the shower, if that's what it was.  When I left work at 5:45, even the clouds had forgotten what they were about, and shook loose only the occasional drop.  The ground still vaguely remembered what had just happened, enough to still have small, rapidly drying puddles, mere shadows of last night's rivers running along city streets. 

A puddleat St.Michael's, 5:45 PM.

All this heat and then rain, wet and dry and wet again, cracks the pavement as it expands and contracts.  By the end of summer, most streets and parking lots are cracked like this.  That's probably part of why there always seems to be road work all over Tucson, but nothing ever actually improves much, or for long.

The wash is dry - until the next big rain.

Last night, John said I'd be able to go out today and get pictures of water in the washes and rivers.  The rivers are a little farther than I wanted to drive on my way home from work tonight, so I  went over to the wash behind the high school near 22nd and Kolb. It was dry, at least on the surface.

the roots of the trees know that water is there.  That's why washes are green.

Underground, though, it was probably a different story.  When they're not paved over, washes are the greenest places in the city.  Most of the runoff sinks into the pebbly soil, feeding the tree's thirsty roots.  The result is an arid approximation of a river ecosystem, almost a "riparian habitat."

The sign is ready, just in case.

Dry as this wash was, the road hazard sign was still up, in case it rained again.  And indeed it did, an hour later, for about five or ten minutes.  When I went outside, it stopped.  There were puddles at Safeway, but nothing dramatic.  And I knew that the desert would quickly forget this rain, too, and leave us dry again - and perhaps longing for another storm, one big enough to leave benign evidence of its passage.



rap4143 said...

Reading blogs, is an education learning about the different climates, weather conditions around our country. Thanks for sharing.
The east coast we have a lot of rain but right now in dry spell.

gotomaria said...

Yes, it is quite an education seeing this pictures. We have relatives in Arizona and get some desert reports from time to's been very hot there. Also have some relatives in Oklahoma where the winds get pretty crazy with tornados and the like.

Although it rains alot here in Seattle on the West Coast and we sometimes have flooding when the rivers rise it's mostly very temperate and mild.  July and August are the nicest times to be in Seattle with the sunniest skies and warmest temperatures. The morning fogs begin to roll in early in August....signaling the coming of a change to cooler and more humid weather not far off into the future.  The fog began this morning...:)

ryanagi said...

Interesting about the pavement. You'd think they would come up with a solution to the heat/wet/heat thing and make asphault that can take the expansion and contraction.