Winter Storm in Southern Big Horn, Montana

Snowfall of 8 to 16 inches was reported across the area. Severe travel conditions were reported on Interstate 90 and Highway 212.

A very strong upper low and trough moved out of the Great Basin area northeast across Wyoming during this time period. At the same time, a surface low moved across Wyoming into South Dakota. As a result of all the above, a deep, easterly upslope flow was in place across the southern and south central portions of Montana. During the first 24 to 36 hours of the event, conditions were unstable with steep lapse rates. This resulted in periods of very intense snowfall during the evening and overnight hours of the 24th and through the day on the 25th.