Snowy mess Tuesday; 2-6 inches possible across Twin Cities region

Here we go.

A significant shot of snow is on the way Tuesday for much of Minnesota and northwestern Wisconsin. Winter weather advisories are posted and will expand in coverage Monday afternoon to include the greater Twin Cities area. Winter storm warnings are possible.

There are facets of this storm we know with confidence, but forecast models are still split by 20 to 50 miles on the storm’s track. The final track will make a big difference in snowfall totals on the northern side of this storm near the Twin Cities.

Here’s what looks most likely at this point:

• Snow will likely break out in southwestern Minnesota in the very early hours of Tuesday and reach the greater Twin Cities area between 3 a.m. and 6 a.m. It may be light at first, with heavier bursts between 9 a.m. and 3 p.m.

• Morning and afternoon rush hours in the Twin Cities will likely feature snow and slick roads.

• Snow will end from west to east between 6 p.m. and 9 p.m. in most of Minnesota. Snow in northeastern Minnesota along the North Shore likely favors afternoon and evening hours.

Snow bands in the system

A moderately strong low-pressure system will track from near Kansas City, Mo., to La Crosse, Wis., Tuesday. Precipitation will be all snow from the Twin Cities northward.

There may be some mixed ice and even rain in far southeast Minnesota. The National Oceanic and Atmospheric Administration’s NAM 3 km model lays out the general notion of light to moderately heavy snow bands within the system.

Snowfall totals

Most forecast models favor laying out the heaviest snowfall bands just southeast of the greater Twin Cities area, with a sharp cutoff in snowfall totals on the north side. That’s a forecasters’ nightmare for eventual Twin Cities totals.

Depending on which forecast model is correct, we could see anywhere from 1 to 2 inches to more than 6 inches across the Twin Cities from northwest to southeast.

Models from the European Centre for Medium-Range Weather Forecasts and NOAA’s Global Forecast System lay out the heaviest snow to the south with a general 1 to 4 inches across the greater Twin Cities from northwest to southeast.

Here’s the latest European Centre for Medium-Range Weather Forecasts model on Monday afternoon.

Here’s the NOAA Global Forecast System model:

Note the sharp cutoff in snowfall totals on the north edge of the system.

NOAA’s North American Mesoscale Forecast System model and the Environment Canada model bring the storm farther north. They pump out some 6-inch totals for the Twin Cities area.

The bottom line is to expect snowfall Tuesday from southwest and south-central Minnesota, through the greater Twin Cities south and east into Wisconsin.

The North Shore also looks likely to get some snow Tuesday. Be prepared for snowfall and slick roads most of the day Tuesday.

The most likely outcome for snowfall totals at this point seems like a range of between 2 and 6 inches across the greater Twin Cities from northwest to southeast.

Let’s see if the Monday evening forecast model runs can find greater consensus on storm track and snowfall totals.