Winter Storm — Mille Lacs, Minnesota

2021-02-28 · Mille Lacs, Minnesota

Event narrative

Snowfall amounts of 4 to 7 inches fell in a 3-4 hour period across the southern part of Mille Lacs County.

Wider weather episode

This winter storm had a similar track of a Colorado/Plains Low developing in the Rockies, moving out into the plains, and into the Upper Midwest/Great Lakes region. There was even some evidence of gulf moisture interacting with this storm as low level moisture transport originated over the western Gulf 36 hours prior to the storm moving across the Upper Midwest. In addition to the evidence of deeper moisture, there was an elevated convective instability layer which led to an enhanced area of forcing and banding. This is where locally 6 to 9 inches of snow fell between Willmar and Mora. The heaviest snowfall was across northern Meeker, southeast Stearns, and northwest Sherburne Counties.

Initially, the focus of the precipitation was along the Minnesota, Iowa border, during the afternoon and evening of Saturday, February 27th. By the late evening, and early morning of Sunday, February 28th, a secondary area of forcing developed across central Minnesota as mentioned from the evidence of elevated convective instability, combined with stronger mid-level frontogenesis and an upper jet axis. This heavier snowfall band developed over eastern Chippewa, Kandiyohi, northern Meeker and southeast Stearns Counties between 1-2 AM CST. This band expanded farther to the northeast but remained nearly stationary for 3 hours. This led to localized snowfall rates of 1-2 inches per hour in a 50-75 mile-wide band. By 5-7 AM, the band shifted southeast and quickly ended shortly after sunrise. Snowfall ratios during this period were approximately between 15-1 to 30-1. Farther to the south of this band, these snowfall ratios were more consistent with a 10-1 average or less as a mixture of rain and snow developed during the onset of the precipitation.

Some of the higher snowfall totals included:

8.5 inches southeast of Pleasant Lake.

8.2 inches in South Haven.

7.5 inches northeast of Willmar.

7.5 inches north of Kimball.

Source: NOAA Storm Events Database, event_id 936526. Narrative written by the NWS forecast office that issued the report.