Coldest stretch of weather in store for eastern North America

Latest atmospheric teleconnections and forecast model data are pointing toward an extended stretch of very cold weather from the Prairies to the eastern United States starting around Jan. 20 and persisting through the end of the month.

There will likely be several direct discharges of Arctic air into the regions due to what we call cross-polar flow, which is basically an open highway with no exits that sends very cold air straight from the polar region and through Canada and into parts of the U.S.

These air masses are also usually dry, thus big storms for the Prairies and Midwest are unlikely, but there can be significant outbreaks of lake-effect snow. We will also have to watch the East Coast closely for potential nor'easters which may bring heavy snowfall to Atlantic Canada.

On the flip side, this pattern likely brings more tranquil weather to the West Coast with milder temperatures.

Once we get into February, there is much higher uncertainty, and the pattern may revert more to what we have been seeing in December and early January.