Winter storm update: 3 to 7 inches likely for much of Minnesota by late Friday

Here’s an update on our inbound storm system for Thursday and Friday.

• Latest advisories and warnings from the Twin Cities National Weather Service office

URGENT - WINTER WEATHER MESSAGE National Weather Service Twin Cities/Chanhassen MN 219 PM CST Wed Jan 13 2021

...WINTER STORM WILL IMPACT THE AREA THURSDAY THROUGH FRIDAY...

.A period of mixed precipitation is possible late tonight into Thursday morning, followed by a long duration of light to moderate snowfall for much of the area from Thursday afternoon through Friday. A storm system will drop southeast from Canada tonight, strengthen as it moves into Minnesota, then slowly weaken as it very slowly drifts into the lower Great Lakes Friday into Friday night. An area of precipitation will move into west central and central Minnesota tonight, then spread east into west central Wisconsin Thursday morning. This initial band of precipitation will be a mixture of rain, snow, and some freezing rain, with the best chance for freezing rain north of the Minnesota River valley. Any ice accumulation should be minimal, but a glaze of ice in some areas could make travel difficult for the morning commute on Thursday. A lull is expected behind the initial band of mixed precipitation until steady light to moderate snow develops Thursday afternoon and Thursday night. This snow will initially develop from central Minnesota into west central Wisconsin before spreading westward across the remainder of the area. Total snowfall accumulations of 4 to 9 inches are expected, but they will occur over a long duration of time, with snowfall rates expected to remain below an inch per hour for most if not all of the event.

Trends

The latest forecast model trends suggest there may be downward pressure on snowfall totals compared to Wednesday’s early forecast model runs. This storm is unusually warm, and the lack of cold air immediately behind the system may hamper intensification and the ability to produce heavier snowfall in many areas.

Still, expect a wintry mix to change to snow Thursday and Friday. Several inches is still likely, and this looks like a plowable, if not a major winter weather event. High winds will make travel very difficult in western Minnesota.

Here’s the latest snowfall thinking from the Duluth, Minn., National Weather Service office.

Impacts

NOAA’s Winter Storm Severity Index factors in weather parameters to assess impacts. This looks like a moderate impact event across much of eastern Minnesota.

High winds

If you’ve ever driven even an hour west of the Twin Cities in a winter storm, you know how quickly winter driving conditions can crater. High winds with gusts to 50 mph will cause blowing snow and reduced visibility and near blizzard conditions in western Minnesota.

Snowfall totals

It should be noted that a few models have eased off snowfall a bit. I’m still expecting a wide area of 3 to 7 inches across most of Minnesota, and that includes the Twin Cities area. Here’s NOAA’s NAM 3 km resolution model run from late Wednesday afternoon. Note the sharp snowfall cutoff north of Duluth.

Expect a wintry mix to turn to intermittent snowfall Thursday. Heavier steadier snow favors Thursday night into Friday morning.