Wednesday, June 07, 2006

Summer rain

The weather here is a little strange – water seems to be falling from the sky! And the sky is not bright blue – there are strange things blowing around up there that look like dirty cotton or something.

Las Vegas usually gets around three and a half inches of rain. The weather section in the paper lists rainfall to date, and so far this year (it’s June, remember) we’ve had 0.27 inches of rainfall. That’s not this week’s rain, that’s since Jan 1. According to the same weather section we should have had 2.25 inches by now, which in itself still is not very much. Even though we looked at Portland when picking a place to move to from San Diego I am really glad that we did not move there. I don’t think I could stand all that water, and the lack of sunshine. I know, you really appreciate a sunny day when it happens, but I really appreciate a sunny day following a sunny day following several months of sunny days. I have no complaint about the lack of rain.

We get most of our drinking water from the Colorado River, what’s caught up behind that big dam just east of here. That water comes from snow that falls in the Colorado mountains, not from local rain. So I’m more interested in how much snow falls up there than rain that falls here.

But it is nice walking between buildings. The sun is brightly shining, yet drops of water are pattering around. Not very much, but predictions for the next three days show 20% chance of thunderstorms. Southwest thunderstorms are different than the ones I remember back in New Jersey. Back there the whole sky would be filled with clouds, usually for several days. Rain would periodically fall, and lightning and thunder would also happen once in a while, usually right at bedtime for some reason.

Out here most of the sky is bright blue, with groupings of clouds that blow by. In Phoenix the summer thunderstorms were more noticeable, as the mountains were farther away. You could see a thunderhead cloud off in the distance, blowing in your direction. If you were paying attention to it, it could take up to a half hour from when you first saw it until it was overhead. The lightning inside was visible all the way, as was the rain falling underneath, and thunder got louder as the cloud got closer. It would suddenly be right over you, and the rain would just be pouring down. That usually lasted for five minutes, then you would be back in sunshine watching the cloud recede in the distance, dropping more rain along the way. After an hour all the water would be gone, and you would never know it rained. It did cool off a bit while it was raining – dropping from the Phoenix standard summer temp of 115f down to maybe 100f, then back up again after it passed.

The affect here is about the same, but with the mountains close by you don’t have as far a vista. Driving in this morning I could see bunches of clouds to the east and the north, and see the rain falling underneath them. I used to sit under my covered porch (when I’m not at work) and watch the clouds roll in, and enjoy the sudden downpours. Now I just get wet walking between buildings, then have to sit inside under the air conditioner until I dried off. Humidity is a little higher, but still under 20%.

With so few plants the desert soil itself is a lot different than what we had back east. There is almost no organic matter in the soil, it’s mostly sand and rock and some clay. The sun bakes a hard shell on top of the soil, so when it rains the water does not soak in but just rolls off. That’s why we get flooding when it rains – all the water just runs downhill, and if a housing tract has been built in between the mountains and the watershed all that water runs down the streets, stranding people in their cars. Water might collect in the low areas, and if the soil had a lot of clay in it you might end up with a real slick patch, if there was enough it could be enough to grab your car.

There is a low spot in the street just a few houses down from us. It becomes a big puddle, about three inches deep. That water does not soak into the soil, but sits around for a few days until it evaporates. The dry lake beds do the same thing – there is a big one just south of Primm on the California border. It’s a low spot surrounded by mountains, and collects water when it rains. There is usually less than six inches of water, but there is so much clay in the soil the water does not soak in. Coming down from the mountains the water collects minerals, and it eventually evaporates, leaving behind a big flat white ‘lakebed’. This is what it looks like driving up from the south

Just a big light area down at the bottom. Up close it looks white, from the mineral crust. I’ll have to do some close-ups next time I drive south. That’s what created the Bonnyville Salt Flats up in Utah, all the water flowing down from the mountains, collecting in the flat low area, evaporating and leaving a thick salt crust behind. It dries really hard, with a crust on top that’s like asphalt, so cars can drive really fast on the very smooth very flat lakebed.

Oh, that rusty red thing in the bottom of the photo - it's the hood of my old truck, coming back from my Fresno turnaround last weekend. I've got lots of pics for that post, to come soon.

You can also tell when it rains here from the auto parts stores. They all suddenly have 55 gallon drums scattered around the parking lot for trash cans. Can you guess why? Of course, with no rain for months, bright sunshine and 110f weather everybody’s rubber windshield wipers turn dry and don’t work very well to keep the windshield clean. So a thunderstorm hits, people turn on their wipers and six months of dust and oil and whatever is just schmeared around on the window, making it even harder to see. So they quickly pull into a parts store and buy new wiper blades, slide them in out in the parking lot standing in the rain, and need to discard the packaging and the old blades. Of course, I notice this when I’m running into the store, seeing all the wiper blade packages overflowing from the trash containers. If I was smart I’d stop at a place now, and put the new blades in my trunk, to await the rainfall. No, I wouldn’t install them, as the sun and heat would soon turn the new ones into non-wiper but schmearing blades.

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