Heavy Snow — Northern Aitkin, Minnesota

2020-12-23 to 2020-12-24 · Northern Aitkin, Minnesota

Wider weather episode

A strong area of low pressure brought heavy snowfall and very strong winds to much of the Northland starting on Wednesday the 23rd and lingering into Thursday the 24th. This storm was unique in that widespread blizzard conditions occurred across the upper Midwest, including areas from the Brainerd Lakes east towards the North Shore, Twin Ports, and Interstate 35 corridor with many observed wind gusts between 50 and 70 mph. Very strong frontogenesis occurred along a trowal axis that extended across much of northern Wisconsin west into Minnesota. Warm air advection caused temperatures across most of east-central Minnesota to rise above freezing and produce mixed precipitation for several hours during the day. As the cold front gradually moved east, temperatures very quickly dropped and caused treacherous road conditions as mixed precipitation changed over to snow. Narrow bands of heavy snow set up over the Brainerd Lakes northeast towards the Iron Range during the early morning and early afternoon, and then translated east towards the Twin Ports, North Shore, and Interstate 35 corridor. The heavy snow bands coincided with the strong mid-level frontogenesis, which also produced very strong northwest winds that caused the widespread blizzard conditions. A maximum gust of 70 mph was recorded at the Bay of Grand Marais during the height of the storm. Damage was reported to buildings and other infrastructure, in addition to some power outages and widespread whiteout conditions that made travel difficult if not impossible.

As the cold front swept rapidly eastward, bitterly cold air moved into the region and led to the development of a topographically-forced gravity wave during the night of the 23rd that dropped several more inches of snow from Two Harbors to Superior to Holyoke. The eastern half of northeast Minnesota received 6 to 10 inches of snowfall with lesser amounts further west in addition to the widespread blizzard conditions.

Source: NOAA Storm Events Database, event_id 933663. Narrative written by the NWS forecast office that issued the report.