Major winter storm this weekend! 6″ to 12″ totals?

Friday late PM update:

The latest NAM run suggests that though we may see a few snow showers Saturday, the bulk of the accumulating “system snow” may hold off until after midnight. It still looks like the heaviest snow will fall during the morning and daytime hours Sunday.


******Original post 2:50pm Friday******

Whoever hit the “pause” button on winter a few weeks ago just hit “play” again.

It looks like our break from winter storms will end abruptly this weekend.

After a week of differing solutions on the potential for weekend rain or snow, forecast models Friday have come into agreement that a major winter storm is likely in much of central & southern Minnesota this weekend.

Winter storm watches have been hoisted for much of Minnesota. They will likely be upgraded to warnings by Saturday morning.

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Winter storm watches posted.

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Here’s the latest thinking from the weather lab on the timing, duration and intensity from this weekend’s winter weather event.

The System & Track:

A deep trof of low pressure in the Rockies will spin up a surface low in Colorado Saturday. The low is forecast to deepen near Omaha, then move quickly east into Iowa late Sunday. This is an excellent track for producing heavy snow in Minnesota given the right temperature profile.

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Precipitation Timing & Type:

It looks like snow will begin to bust out in patchy fashion Saturday PM in Minnesota, with a more widespread consistent snow shield developing and expanding Saturday evening and overnight. The bulk of the heaviest snow should come after midnight Saturday night/ Sunday through the day Sunday.

The latest model trends indicate the storm’s thermal profile will yield mostly snow in Minnesota, with some ice/sleet mixing in from the metro south at times, and maybe some rain near the Iowa border and along the I-90 corridor.

There is still the potential for a shift in the storm’s track that could bring more ice into southern Minnesota and even the metro…which could reduce overall snowfall totals accordingly.

Snowfall Totals:

We’re still a good 24 to 30+ hours out from the bulk of the steady snowfall in the metro area, so there are still 3-4 “critical” model runs before the snow flies that will (hopefully) help nail down snowfall totals. But here’s my best estimate at this point.

The peak snowfall intensity appears to be slated from about 2am Sunday to 3pm Sunday, with snow tapering off Sunday evening. During this window there could be several hours of 1″+ per hour snowfall rates. Isolated thundersnow is possible with this system.

I expect a broad area of 6″ to 12″ snowfall totals by Sunday evening in much of central and southern Minnesota. Within this broad area, there could be some higher totals to 14″.

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Modles cranking out 6″ to 12″ totals for MSP Airport.

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Cities included in the potential 6″ to 12″ (with isolated 14″) snowfall range include The Twin Cities, Redwood Falls, Willmar, Mankato, St. Cloud, Hinckley, Eau Claire and maybe as far south as Rochester.

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NAM model paints heavy snowfall band right through central Minnesota.

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A general area of 3″ to 6″+ is possible from Fargo east through Brainerd & Duluth. Also a band of 3″ to 6″ mixed with ice is possible along the I-90 corridor and into northern Iowa. Anybody planning travel south into Iowa should be prepared for significant icing conditions on roads!

Primary Impacts:

This will be a wet snow (7:1 snow:water ratio) Saturday night into early Sunday, and may be drier late in the event. Travel will become increasingly difficult either way overnight Saturday and especially Sunday. Expect strong winds Sunday from the northeast at 15 to 25 mph+ which will produce a wind-driven snowfall event with reduced visibility in open areas.

Bottom Line:

The first major winter storm in weeks will slam Minnesota Saturday night & Sunday.

Prepare accordingly!

We are staffing up and will have extra blog posts and weather updates on MPR News stations with me and Craig Edwards through the weekend.

Be safe!