It’s extremely cold in the Midwestern United States, where forecasters warn of “life-threatening extreme cold.” During the early Wednesday morning hours, many of the Dakotas, Minnesota, Wisconsin, and Illinois are shut down with these “feels like” temperatures in the -40s, -50s, and even -60s (Fahrenheit) as winds from the west howl at 25 mph.
The region’s largest city, Chicago, is likely to set a record Wednesday for the coldest day in the city’s history. Temperatures at dawn in the city were -23°F and high temperatures today were predicted to reach just -14°. The coldest day on record in the city occurred on January 18, 1994, when the highest temperature reached just -11°C. The city even burns its railway lines so that trains can run on them. The battle against the cold is much the same in the upper Midwest.
The culprit behind this Arctic outbreak is the much-discussed “polar vortex,” which isn’t a storm per se, but a feature in the atmosphere. Normally this is a roughly circular flow near the North Pole, a kind of atmospheric river, which keeps cold air above the Arctic. Every so often, something disrupts or expels the vortex, allowing some of this colder air mass to move south into the mid-latitudes. Currently, a particularly cold and large portion of this air mass has flowed into Canada and the United States.
Predictably, this has led to some prominent climate skeptics dirty crying about climate science, confusing local weather with the broader climate.
It’s worth noting that just before the Arctic outbreak in the central United States, Australia suffered a severe heat wave Down Under in the middle of summer. The country’s Bureau of Meteorology reported that nighttime temperatures in the Noona region, in New South Wales, only briefly fell below 100°F, and Canberra and other locations set all-time heat records.
The science of climate change generally predicts more extreme weather in the coming years as the planet warms, the atmosphere becomes more humid and the climate a little more unstable, breaking down features like the polar vortex.
In any case, it is useful to have some perspective. High temperatures in Chicago are expected to recover by Monday in the mid-1950s, with a low that may only drop to about 50 degrees. If that prediction holds true, a 50-degree low on the morning of Monday, Feb. 4, would shatter the record for “record high minimum temperature” for that day, which is currently 37°.