Великая котловина блокирует осадки и создает уникальные погодные условия в долине Тетон

Time after time, we’ve seen the huge influence our geography has on Teton Valley’s weather. When storms approach the upslope sides of our surrounding mountains, they gain uplift and grow stronger only to rain themselves out, become disrupted, weaker, warmer, and drier on the downhill run into the valley. This effect, often simply called mountain shadowing, is responsible for many short-term, minute by minute changes in the precipitation forecast as each storm tries its hand against our mountainous defenses, usually while you have some great outdoor activity planned. But did you know that on a larger scale of both time and distance, there is another obstacle course that areas of precipitation must navigate before they get close enough to Teton Valley for our surrounding mountains to matter. In terms of blocking out a lot of our precipitation, it’s not just a good basin, it’s a Great Basin. Despite its name, the Great Basin is not just one valley surrounded by mountains, but its a series of valleys and ridges. To a storm trying to cross, these ridges, one after another, are what a vegetable grater is to a spud. A storm hits the windward side of a ridge, looses moisture, gets disorganized, then pulls itself together and moves on to the next ridge where it happens all over again. Depending on its heading, a storm might have to fight its way to survive against 400 to 500 miles of this kind of treatment and cross half a dozen mountainous ridges, give or take. By the time the spud gets out of the grater with whatever moisture it has left, the hash browns move into SE Idaho and maybe toward us in Teton Valley. Why we have no Waffle Houses here I’ll never know. Because precipitation from what’s known as the North American Monsoon rises up from the tropical Pacific Ocean, across Mexico, and then north and east toward us, the Great Basin stands directly in the path between the Pacific and Teton Valley. What a deal, huh? If the Great Basin were not in the way, we’d certainly have a lot more rain in the summer and a lot more snow in the winter. Case in point, most of Wyoming. Storms coming up from the south can do an end run around the eastern side of the Great Basin and reach Wyoming unscathed. That’s a good part of the reason that places like the Beartooth Highway get slammed with snow while we in Teton Valley are left with a flurry by comparison. To make matters worse, the Great Basin is water-greedy; it doesn’t share. The precipitation it wrings out of storms trying to cross it stays in the Great Basin; there are no outlets to the sea. All that water stays trapped in the Great Basin’s lakes, marshes, and mud flats. Evaporating or becoming groundwater are its only hope for escape. So the next time you find yourself wishing for more rain or more snow, don’t blame it all on relatively innocent bystanders like El Nino, the Jet Stream, or the North American Monsoon. The Great Basin is a major conspirator, too. And unlike the others, it’s always there, 24/365, a mine field, unchanging and waiting for the next storm to go ahead and make its day.