Courtesy Minnesota DNR State Climatology Office
A warm, wet, and fast-moving storm system covered much of Minnesota with moderate to heavy rain on Tuesday February 14th, 2023, before an intrusion of strong winds and cold air produced a short-lived but dangerous blizzard in western Minnesota and a "flash-freeze" over the rest of the state on Wednesday. The storm made it the wettest, rainiest Valentine's Day on record in some areas.
A low-pressure system formed in southeastern Colorado early on Valentine's Day 2023, and traveled over 1000 miles within 24 hours, with its center passing through the Twin Cities around midnight and crossing Lake Superior during the morning of February 15th. The path of the storm drew warm and moist air into Minnesota, leading to an unusually large shield of winter rain enveloping nearly the entire state during the day and into the night. Rainfall totals exceeding a half-inch were widespread across the southeastern 2/3 of Minnesota, generally east of a line from Pipestone to Granite Falls, to Long Prairie, to Leech Lake, to Kabetogama Lake. As the center of the system passed, strong northwesterly winds developed behind and pushed a strong cold front with rapidly-falling temperatures eastward across the state.
The advancing cold air changed the rain to wet snow in western and northern Minnesota, and winds gusting from 40 to 55 mph reduced visibilities and produced occasional whiteout conditions in open areas. Although snowfall accumulations were minor compared to other winter storms--just 1 to 4 inches-- the wind, snow, wet surfaces, and falling temperatures combined to produce dangerous conditions in western Minnesota for several hours, as visibility dropped to below 1/4 mile at times and wet surfaces became icy. The cold air charged eastward across the state on Wednesday, leading to a "flash-freeze" of the wet surfaces and standing water left behind by the heavy rain. Fresh sheets of ice blanketed much of Minnesota by Wednesday night.
The rain broke daily precipitation records at St. Cloud and the Twin Cities, as both stations recorded 0.68 inches of rain on February 14th. Oddly, Duluth and Rochester recorded 0.67 inches 0.66 inches, respectively. It's unusual to have such consistency in precipitation observations covering such a large area. The highest rainfall totals, general of 1 to 1.25 inches, were scattered in a horseshoe shape through the western, northern, and eastern Twin Cities suburbs, and then extending northeastward into east-central Minnesota.
This was a widespread winter rain event, but it was by no means the heaviest. A heavy rain event on December 24 and 25th, 1982, dropped over three inches of rain Farmington, and the Twin Cities recorded 2.47 inches of rain, followed by 1.4 inches of snow. Winter rain events of all sizes have become more common in Minnesota over the past few decades.
Updated February 27, 2023