Winter Storm — East Sweetwater County, Wyoming

2021-03-13 to 2021-03-14 · East Sweetwater County, Wyoming

Event narrative

A trained spotter measured 6 inches of snow in Wamsutter, Wyoming. The snow and wind led to the closure of Interstate 80 for a couple of days, severely effecting transportation across southern Wyoming.

Wider weather episode

Lee cyclogenesis occurred over Colorado and low pressure moved slowly into the Plains states. Favorable east to northeasterly upslope flow brought heavy snow to portions of central Wyoming. The heaviest snow fell in the Casper area. Mesoscale banding developed in the area and brought extremely heavy snowfall rates on the morning of March 14th. A total of 15 inches of snow fell between 6 am and noon. There were widespread reports of over 15 inches of snow around Casper with a total storm total of 26.3 inches at the Casper Airport. This total was the 3rd largest storm total snowfall in station history and the largest storm total since December 1982. Heavy snow also fell in portions of Fremont, Sweetwater and Johnson Counties. The heavy snow closed many major roads, including Interstates 25 and 80 as well as US 20 26 and US 287. Some closures stretched for 3 days, stranding many travelers.

Source: NOAA Storm Events Database, event_id 950451. Narrative written by the NWS forecast office that issued the report.