Winter Storm — Northeastern Yellowstone, Montana

2021-02-05 to 2021-02-07 · Northeastern Yellowstone, Montana

Event narrative

Snowfall of 7 to 10 inches was reported across the Pompeys Pillar area.

Wider weather episode

The seasons first, widespread winter storm occurred across most of the Billings Forecast Area from February 5th through February 7th. This was also the first and only arctic airmass of the season that impacted the Billings Forecast Area.

An arctic front blasted through the area on the 5th. Following the front, a moist Pacific flow aloft moved over this arctic airmass which resulted in a prolonged period of heavy snow. Many areas received 8 to 12 inches of snow with some locations reporting well over a foot of snow. After the snow ended and skies cleared, overnight lows of -20F to -40F were common. Many areas stayed below zero for 7 consecutive days.

Major impacts occurred with this storm as warm roads initially melted the snow. These wet roads then quickly froze resulting in icy and hazardous driving conditions. As a result, many accidents occurred across the area. In addition to the snow, strong winds resulted in blowing and drifting snow, as well as significantly reduced visibilities. US-191 was closed near Harlowton due to severe driving conditions as visibilities were a half mile in snow with wind gusts to 43 mph.

Two major crashes occurred on I-90 near Park City just a day apart. The first incident occurred on Saturday the 6th and was a 20-vehicle pileup on the eastbound lanes of I-90. Responders were dealing with a semi stuck in the median when another semi traveling east failed to slow down and yield to road signage. That semi nearly struck a Stillwater County deputy before jackknifing and causing the pileup of vehicles behind it. The Montana Highway Patrol reported only minor injuries with this incident. Another major crash occurred on Sunday the 7th. A pickup truck was hauling a camper that jackknifed. A second pickup truck hauling a camper then crashed into the jackknifed pickup. Shortly after the initial crash, multiple semis crashed into each other as they tried to slow down on an icy bridge deck ahead of the pickup trucks. In one instance, a semi collided with the cab of another semi that was sandwiched in the middle of everything. The driver of the semi that was struck had to be extricated from the vehicle. All five semis were disabled by the crash and two of them caught fire. Just east of this crash, two other semis crashed, including one that went into the median.

Source: NOAA Storm Events Database, event_id 942207. Narrative written by the NWS forecast office that issued the report.