Extreme Cold/Wind Chill — Southwest Carbon County, Wyoming

2022-12-22 · Southwest Carbon County, Wyoming

Event narrative

Overnight low temperatures fell to around -22 F at multiple sites across southwestern Carbon County from 12/21 into 12/22. Sustained winds around 5-15 MPH resulted in a prolonged period of extreme wind chills under -30 F. The most extreme wind chills occurred between 8:00 AM and 7:00 PM MST on 12/22. Minimum observed wind chill values reached -47 F at COWW4 (Cow Creek, 19 N of Dixon) at 11:43 AM MST on 12/22.

Wider weather episode

An intense arctic cold front tracked rapidly from north to south across southeast Wyoming during the morning and afternoon hours on 12/21. Temperatures at the Cheyenne Airport (KCYS) fell from 43 to 7 degrees between 1:05 PM and 1:18 PM MST, before plummeting to a near-record -25 degrees F at 7:15 AM MST on 12/22. Numerous records were set for the most rapid and extreme temperature drops in history. Morning low temperatures fell to -20 to -40 degrees F across a large portion of southeast Wyoming on 12/22, with many sites remaining below zero through the day. Wind chills plummeted to between -45 and -65 degrees F for many. The cold frontal passage on 12/21 was also accompanied by scattered snow showers and locally intense snow squalls, resulting in a period of extremely low visibilities and dangerous travel conditions due to a flash freeze. Several inches of mountain snow were also recorded in the Snowy and Sierra Madre mountain ranges, along with reports of significant blowing and drifting snow.

Source: NOAA Storm Events Database, event_id 1062758. Narrative written by the NWS forecast office that issued the report.