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Polar Vortex or Just Winter As Usual In Wisconsin?

S Bence

The story that is on almost everyone’s mind is the return of the snow and arctic cold to Wisconsin.

Cold weather was reported to be a contributing factor in the deaths of two people in the Milwaukee area in recent days, and temperatures have been falling below zero overnight. In fact,today's high temperature may only reach the zero marker.

"We are quite a bit below the normal – average highs should be 28, 29 degrees," meteorologist Mike Westendorf says. "And so we have a legal right to bellyache about this. But in terms of last year – we’ve got nothing too bad to really complain about."

Credit NOAA/ESRL
This map illustrates why the Polar Vortex is a pet peeve of Innovative Weather's Paul Roebber's. "The outer limits of the polar vortex are indicated by the yellowish lines, just brushing the northern reaches of Lake Superior on this date. It turns out that this was a special day. July 24, 1935, a day on which the temperature in Milwaukee, WI reached 105°F, the highest recorded temperature ever in our city," he says.

Last winter, the so-called 'polar vortex' was to blame for the bitterly cold temperatures.

However, Westendorf, who is also the director of operations for UWM'sInnovative Weather, says that the polar vortex is always there - it just got stuck over the Great Lakes region last year.

"There is always a cold core of polar air that's around, it's just a matter of where is it going to be and how long it is going to be," he says. "That was the thing that happened last year, it did not budge."

Thanks to El Niño, this winter will likely be else extreme than the cold we faced last year.

Generally, the trends for an El Niño year in the Great Lakes region tend to be - over a 3 month average - warmer than normal, and a little dryer than normal, Westendorf says.

"The forces that govern the jet stream location and persistence change from year to year and this year it is more progressive and further north on average," he says."The lack of snow pack increases the impact of warmth from the sun and that allows for the warming of colder air as it moves south out of Canada."

So, if we can't blame the polar vortex for this week's weather, what can we blame? Winter in Wisconsin. As Westendorf points out, it often gets cold in Wisconsin in January.

Mike Westendorf's hunch is that "this is probably going to be a two to three week cold snap and it'll warm back up again and it'll just kind of move on to more of a normal winter."

Let's hope his assumption is correct.

Audrey is a WUWM host and producer for Lake Effect.