A pair of systems are bringing a taste of winter to the Midwest tonight and with another round coming Sunday night. The feature that has really already occurred in the Upper Midwest is a classic Clipper feature coming right out of Canada. There was a solid 2-5″ in a stripe north of the Twin Cities, and forecasts were pretty consistent on it.

A larger feature moving in this weekend from the central Rockies promises to make for more interesting weather, starting Sunday afternoon and lasting through at least Monday. But how much snow will come out of this system? That’s the big question, and there isn’t really a solid answer, but I’ll do my best to get us there.

My friends started messaging me earlier this week, exclaiming that their weather apps were calling for nearly 2 feet of snow! That seemed ridiculous, and I looked at the various weather models that I use, and ultimately, I came to the conclusion that yes, the forecast of 2 feet of snow in Minnesota was ridiculous. At the time, the feature looked like, at most, a producer of 7-10″ of snow. It now projects as a stronger storm, but 2 feet still seems pretty absurd.

It’s not that there won’t be enough moisture. It’s spring now, and there aren’t any features in the Gulf blocking moisture, but all of the things one looks for in a system that sees snow totals stack up aren’t there in the Twin Cities. Despite the snow that fell overnight last night, there is no snow on the ground for most of the region, and the ground is quite warm.

Also warm: the atmosphere. This system is going to be rising from the south and pulling some warm air northward. This will change some of the precipitation to rain, and failing that, will reduce the moisture to snow ratio. Water crystallizes as it gets colder, so the amount of liquid water it takes to get to an inch of snow becomes less and less. The snow this weekend will fall in temperatures that will be flirting with, if not exceeding, freezing.

There will be a gradual ratio through Minnesota, and some bright bands of heavier and lesser snow owing to some local effects, but not everywhere will hit over 10″. Some places sure will surely avoid the heaviest precipitation and see less accumulation, and some areas will see heavy precipitation that falls more as rain than snow. Somewhere between, there will be a stripe that gets 12+ inches of fresh, wet snow.

Now, where will that area of heaviest snow be? Let’s see the NWS’s best guess:

Well, that narrows it down. These are the most likely totals, according the NWS forecast, but I also think we should expect the low end of these ranges, especially on the north and south parts of the forecast area.

A two day severe weather marathon stretched from Kansas to Ohio with tornadoes starting near Topeka, and becoming increasingly more destructive, ultimately leaving lives turned upside down across Indiana and northwest Ohio in particular.

The system came into being in an almost textbook manner. There was a stationary boundary in the PLains that needed only be given the energy of an upper level trough to get moving. That was when the severe storms started in Wednesday, with discrete super cells cropping up in northeastern Kansas. In addition to the tornadoes around Topeka, there was very large hail seen in the Kansas City suburbs.

The system got more organized as Wednesday turned to Thursday, and the warm sector we look for in a severe weather outbreak showed up in the southern Great Lakes. Severe weather developed all the way southwest to near Dallas, with strong winds and large hail reported in many locations. It will be the tornadoes found in northeast Indiana and northwest Ohio that will be remembered, though.

Storms rotate the most near the center of an area of low pressure, as a general rule of thumb. There is enough built in vorticity that any storm specific helicity is just added to the mix, and can both make tornadoes and very large hail likely. The low tracked through the Great Lakes, and ultimately, destructive tornadoes followed.

The two areas that were most directly impacted were Winchester, Indiana, where an estimated EF-3 tornado left a swath of destruction throughout the city, and in Logan County Ohio, north of Springfield, were three people were killed by a tornado.

This is the beginning of the severe weather season, lest we forget, and we have at least three more months of the particularly busy part of the year. Fortunately, we are coming off a quiet year for severe weather, and this part of the country is having a quiet spell to recover. Let’s hope this is as bad as it gets this year, but I fear it won’t be.