Well we are finally breaking free from the grip of the Arctic air mass. The frigid air is retreating back up into Canada and some much milder days are on the way. Temperatures began their plummet this last Saturday (January 4th) with our coldest day being on Monday (January 6th). Temperatures were some 30 to 35 degrees below normal. Below are the high and low temperatures through the duration of this cold snap going back to January 4th. Even though Monday was the coldest day; we still had some pretty frigid mornings to endure during the following days. The coldest morning actually occurred today on January 9th with a low temperature of -24 degrees in Eau Claire.
Temperatures stayed at or below zero this week between 48 to even over 80 hours in some places this week. It was quite the cold snap. This air mass originated in Siberia and found its way down into the Upper Midwest. It was some of the coldest air the country has seen in nearly 20 years. The last big Arctic blast like this was back in early February of 1996. Below, the image is a look at the Arctic air mass invading the United States. The animation is from the La Crosse National Weather Service Office. The colors represent surface temperatures below 0 degrees.
A big chunk of the country was under some kind of Wind Chill Warning or Wind Chill Advisory. Below is a look at all the advisories across the country on the morning of January 6th. Seven states including Wisconsin were covered in a Wind Chill Warning. And for good reason…wind chills on that morning of the 6th were between -40 to -55 degrees. Brrr!!!
(Photo Courtesy of the La Crosse National Weather Service)
The La Crosse NWS Office did some digging and looked back at how often we see these kind of frigid wind chills. The link below shows percentages of time spent with wind chills below -20, -30 and -40 degrees. Here’s a look at the probabilities for Eau Claire.
% of time with wind chills -20 or colder: 3.2%
% of time with wind chills -30 or colder: 1.2%
% of time with wind chills -40 or colder: 0.3%
During this cold snap we experienced wind chills in all three categories. So even though we didn’t break any temperature records in Eau Claire or La Crosse, this was still a pretty impressive Arctic blast.
Enjoy the break from the Arctic air over the next several days. Since the start of meteorological winter on December 1st, we've had 23 days with sub-zero low temperatures. The average during a whole winter for us is 30 days. Unfortunately, this winter is far from over, and there are signs of some more pretty frigid weather for later next week. Of course, we’ll keep you posted.