The Nature Writers of Texas

The best nature writing from the newspaper, magazine, blog and book authors of the Lone Star State . . .

Saturday, January 29, 2005

Snow in South Texas!
By Ro Wauer

What a strange topic! Snow in South Texas. And what a beautiful scene this Christmas morning to look outside from a warm, cozy setting and see a sea of white. There is no better timing for me and others that might have grown up in snow-country, but are now safely tucked away in the warmer climes of South Texas. Until I was 14, I lived in southeast Idaho where winters were cold and icy. Even now, seeing snowy conditions on TV in various parts of the country still makes me shudder. But a snowstorm for Christmas is different; it is acceptable and even preferable. One of my earliest memories as a child is walking home from church on Christmas Eve with huge flakes of snow slowly descending onto the world around me. Over the years, I have missed snow on Christmas!

At my house near Mission Valley, snow began in the afternoon on Christmas Eve; larger flakes were evident after dark. By Christmas morning, I measured almost ten inches of fresh snow in my yard. Knowing that the sun would melt it fast, Betty and I spend an hour or so taking pictures. We might use them on next year's Christmas card, or if not they can be a handy topic with relatives and friends. We both put on boots to trudge through the snow, taking pictures from all angles and with a special interest in the backyard bird feeders. Then I dug out (literally) my ancient snow shovel and cleared off an area on the deck where I spread lots of birdseed. There was a very good reason not to have discarded that hateful tool. It took the cardinals, sparrows, and goldfinches less than ten minutes to find their new feedlot. The 30-plus cardinals that had been sitting around looking hungry and forlorn were soon chowing down.

The snow was surprisingly light weight, containing less water than much of the snow I had shoveled in such foreign places like Utah, New Mexico, Tennessee, and Washington, D.C. Snow is less dense than rain, 10 inches of snow normally equals one inch of rain. The larger snowflakes are filled with air, while the smaller flakes that we experienced early on yesterday afternoon were mostly crystallized rain. Most snowflakes are about 90 percent air, and this fact makes them excellent insulators and mufflers of sound. It is that muffling characteristic that often is so endearing. I can remember and appreciate how silent it was after a heavy snowfall. Even this year, with less than a foot of fresh snow, the entire neighborhood was quiet. Until, that is, we all started driving around gawking and photographing our changed environment.

What causes snow? Rainy conditions and cold temperatures, of course. But there is more to it than that. When temperatures in a cloud are sufficiently low enough, its moisture content may be released, not as rain, but as feather-light snowflakes. This happens because the water in clouds behaves in strange ways. At very low temperatures cloud droplets become super-cooled, which means that they remain liquid even though their temperature is below freezing. Under certain conditions the supercooled droplets evaporate and the vapor then freezes directly into minute ice crystals. As more vapor freezes on the tiny crystals, they grow into snowflakes.

Developing flakes take on different shapes, depending on the temperature and the amount of moisture in the air. All snow crystals possess a six-sided pattern, although they are noted for the infinite variety of their forms. The most beautiful are the delicately symmetrical starlike flakes. Others may take the form of flat, hexagonal plates, needles, columns, cups, spools, or even irregular masses that produce extra large flakes, perhaps like those I remember from that Christmas in Idaho.

It is doubtful that we will ever again be blessed with a white Christmas like that we enjoyed in 2004. But may that nature experience lead you to appreciate the entire outdoors throughout 2005.


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