The same pattern could bolster the risk of additional storms for those on the East Coast, although it’s too soon to specify the timing and location of any threats. The leading edge of cold air will surge southeast into Thursday, claiming a stake in much of the country as its icy tongue laps south. Chicago will see subzero lows by this weekend, with Sunday’s high only forecast at 7 degrees.
In Minneapolis, Sunday’s high temperature could sit at minus-4, with lows as cold as minus-14 and wind chills down to 30-below.
That means the jet stream, or a river of wind that snakes through the upper atmosphere, will be slicing through the Northeast, tracing the sharp gradient between the contrasting air masses and providing the needed dynamics to generate repeated wet or wintry storms.
There are signs that the pattern could dominate most of February, with mixed signals about what lies beyond in March. “Although below normal temperatures are favored to persist across the north-central U.S. during the last 10 days of February, the magnitude of the anomalous cold is favored to be less severe than earlier in the month at the current time,” wrote Jon Gottschalck, a meteorologist at NOAA’s Climate Prediction Center, in an email.
He noted that through the majority of the month, “subzero minimum temperatures [are] probable as far south as northern Kansas and northern Missouri.”
The pattern is tied to a chain-reaction sequence that started at the North Pole in early January. A disruption of the polar vortex, a whirlpool of cold air and low pressure whirring above the Arctic, caused the icy eddy to split into two.