Weather Picture for January 12-18 from Tornado Bob

1/16 update: moderate temps and light snow/flurries this weekend, thaw looking less likely next week.

Well, there has been some pretty warm air building over the Prairie Provinces of Canada, the Yukon, and Alaska. Any change from our cold, northerly upper air flow to a more westerly or northwesterly upper air flow would bring this warm airmass over Minnesota, but it looks like the northerly flow will be quite stubborn through Monday. The window of opportunity for a thaw will probably close about midweek as another surge of Arctic air descends to our latitude, and given the stubbornness of the northerly flow, it is conceivable that we could escape without a thaw and preserve our good snow conditions. We will have a chance of light snow or flurries throughout much of the weekend.

Thus, my earlier (worst case) prediction for melting snow and temperatures in the 40s is looking somewhat silly right now! As a skier, I find that to be good news.

(Original post) Bitter cold this week followed by a thaw early next week, then back in the deep freeze.

The cold airmass that has been residing in Canada for most of the winter so far will be getting "booted" out, so to speak, and will come blasting through the central U.S. A large amplification of the upper air pattern is occurring this week and is responsible for driving the coldest air in Alaska and Yukon southward toward us and replacing it with anomalously warm air (for Alaska and the Yukon). As this process occurs, our upstream air source becomes much warmer, and there is no way to avoid a warm spell.

Thus, we will have a fairly "typical" Arctic blast this week with some high temperatures near zero or in the single digits below zero and lows reaching the -20s and -30s (the coldest spots like Embarrass will probably reach -40). By this weekend, the warmer temperatures will begin to move in, and by Monday, we'll probably high high temperatures above freezing. It's rare to have this sort of pattern evolution without seeing temperatures reach into the 40s, so expect some melting to occur early next week. The warm spell will probably not last very long, as the medium range models are generally indicating a rapid return back to a cold and dry weather pattern by midweek. Often, these transitions happen a little more slowly than expected, so what I describe above may be delayed by a day or two.

As far as snowfall is concerned, we may have some light amounts Tuesday night as the last in a series of Alberta Clipper systems moves through southwestern Minnesota, immediately ahead of the coldest air, but we are generally in a dry pattern, and no major snowfalls are on the horizon.