Every Nevada region shares one system — the same maps, the same live radar, the same climate record. Reno sits in the rain shadow of the highest stretch of the Sierra Nevada, and everything about its weather is that wall — seven inches of precipitation a year on the valley floor, forty feet of snow at the crest thirty miles west, and a west wind off it in the afternoon that Nevadans have called the Washoe zephyr for a hundred and fifty years. When an atmospheric river comes in warm enough to rain on that snowpack, the Truckee runs through downtown.