CHEYENNE, Wyo. — Two years ago today, the city of Cheyenne was in the midst of a historic blizzard, according to the National Weather Service in Cheyenne.
In 2021, a slow-moving, upper-level disturbance strengthened on the weekend of March 13–15 and drew abundant moisture from the Gulf of Mexico, which was transported to eastern Wyoming.
The deep moisture combined with a strong east wind, and instability wrapping around the north side of this disturbance resulted in anomalously high snowfall amounts from southern Johnson and Natrona counties near Casper Mountain southeast along and east of the Laramie Range.
Wyomingites saw snowfall rates of 2–3 inches per hour occur at times on March 13 and continue through midday March 14.
The NWS in Cheyenne reported that 14 inches fell in a six-hour time period from 6 a.m. on March 14 to noon at the Casper International Airport, and 10 inches of snow fell in the NWS in Cheyenne’s region in a five-hour period from after midnight on March 14 to 6 a.m.
Thundersnow was reported and observed several times across Laramie County during this time frame of the most intense snowfall rates. The county experienced heavy, wet snow, followed by drier, more driftable snow.
Windspeeds also increased to 45–55 mph and caused significant drifting. Many area roads were closed for an extended period of time, including Interstate 80 between Rawlins and Cheyenne and I-25 between Casper and Cheyenne.
