Winter Storm — Southeast Johnson County, Wyoming

2015-12-14 to 2015-12-15 · Southeast Johnson County, Wyoming

Event narrative

A combination of moderate to heavy snow and winds gusting up to 45 mph led to near whiteout conditions that led to the closure of Interstate 25 for several hours.

Wider weather episode

A strong feed of moisture from the Pacific Ocean combined with favorable upper-level dynamics and low-level upslope flow to produce heavy snow across portions of western and central Wyoming. The heaviest snow fell in Natrona County with Casper Mountain receiving the most snow with as much of 32 inches reported. The city of Casper had 10 to 16 inches with higher amounts in the southern sections of town. Thermopolis and Lander also had favorable upslope flow and averaged around 10 and 8 inches of new snow, respectively. Less snow fell in other areas, but gusty winds combined with the snow to produce near white-out conditions that closed major roads including Interstate 25 and US 20/26. Across the west, the most snow fell in the vicinity of Jackson Hole with reports of 6 to 12 inches fairly common, especially north of the town of Jackson.

Source: NOAA Storm Events Database, event_id 607262. Narrative written by the NWS forecast office that issued the report.