Winter Storm in Southwest Big Horn Basin, Wyoming

Around Thermopolis 6 to 8 inches of snow was measured.

The combination of a slow moving upper level low passing over Utah and Colorado, powerful jet dynamics, and favorable northerly upslope flow produced very heavy snow across portions of western and central Wyoming. Fremont and Natrona counties were the hardest hit areas. Around two feet of snow fell in Lander and the surrounding foothills with 12 to 18 inches around Riverton. The 15.4 inches of snow measured by the cooperative observer in Riverton was the most in a single storm since 1999. In Natrona County, 10 to 18 inches fell in and around Casper with up to 30 inches on Casper Mountain. More impressively, most of the snow in Natrona County fell in a 12-hour period. Widespread snowfall totals of 12 to 20 inches were recorded in the Wind River, Salt River, Wyoming, and Absaroka mountain ranges. The heavy snow, falling temperatures, and gusty wind of 15 to 25 mph combined to close several roads at the height of the storm. These roads included interstates 25 and 90, US Highway 20/26, and State Highway 28 over South Pass.