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Major Arctic outbreak to bring bone-chilling air to Central U.S.

Temperatures will drop 40 degrees below average in spots

A look at low temperatures Sunday morning as forecast by the National Weather Service. (Pivotal Weather)

A bitter Arctic blast is set to plunge much of the Central U.S. into a frigid deep freeze, with subzero temperatures from the northern Rockies and Great Lakes to parts of the Plains and Midwest. Temperatures some 40 degrees or more below normal will be likely, with wind chills in some spots reaching minus-30.

Behind the Arctic blast that’s about to plunge into the U.S.

Chicago, Minneapolis and Des Moines are all in line for frigid readings below zero, with highs barely climbing out of the single digits over the weekend. A second, potentially more significant shot of reinforcing cold is possible next week, part of a pattern that favors bitter cold weather along the nation’s northern tier, and gradually extending farther south, through at least mid-February.

The leading edge of the cold air mass was met with blizzard conditions in the Corn Belt, while strong winds along the front kicked up shoreline flooding on the eastern sides of Lakes Erie and Ontario.

In Iowa, blustery winds combined with briefly moderate snowfall to bring localized whiteout conditions Thursday. That contributed to a 40-vehicle pileup on Interstate 80 east of Des Moines, which resulted in several injuries but fortunately no deaths. Speed and slick roadways were likely factors.

The same cold front brought winds that blew lengthwise along Lake Erie on Friday morning, pushing a six-foot wall of water into the eastern shoreline of the lake. Buffalo was under a lakeshore flood warning with pockets of inundation possible along Route 5. The so-called seiche, which is a wind- or air-pressure-driven oscillation in water levels across a lake or pond, featured a drop in water levels along the western rim of the lake.

Behind the front, cold air was pouring south into the Lower 48. It has origins as far as the high Arctic and Siberia.

Bismarck, N.D., started its morning at just 2 degrees Friday, part of the same wave of cold air that’s bleeding south across the International Border. It paves the way for a more potent lobe of cold, which arrives out of Alberta and Saskatchewan on Friday night. Bismarck will drop to minus-11 on Friday night, rebounding to highs a degree or two below zero Saturday. Average highs there this time of year are in the mid-20s.

By Saturday afternoon, the cold will slosh south through most of Montana, eastern Wyoming and northeast of the Palmer Divide in Colorado, as well as over the central and northern Plains, with highs about 20 degrees below average. The cold won’t quite reach Wichita, which will sit in the upper 30s, but extreme northern Kansas will hover in the teens. Lincoln, Neb., will crest at 13 degrees.

The core of the cold will ebb over the Upper Midwest, plunging Minneapolis to minus-4 on Friday night. Saturday’s high is forecast at zero degrees. A low of minus-15 is possible Saturday night. Despite the bone-chilling readings, lows would have to drop into the minus-20s to even begin challenging daily records in the Twin Cities.

Another painfully cold day is in the cards Sunday before a high potentially above freezing Monday. The current forecast calls for a high of 1 degree. Most of next week looks to offer lows around minus-10 and single-digit highs.

In Sioux Falls, S.D., single-digit highs are forecast every day next week as well; the city hasn’t seen a stretch of single-digit weather lasting more than five days since 1996.

Milwaukee will awaken to potentially subzero lows Saturday morning, while Chicago has to wait until Sunday morning to share in the below-zero readings. The Windy City’s low is forecast at minus-3 degrees, 21 degrees below average.

Initially it appeared as though the cold would charge all the way to the Appalachians, but recent computer model runs have been more limited in their simulations. It’s now likely that the cold will sort of run out of oomph after surging past Lake Michigan and south into the mid-Mississippi Valley, still bringing anomalously cold weather to places like Detroit, Indianapolis and St. Louis but probably not much farther south or east, at least not initially.

By Monday into Tuesday, a storm system will begin to form along the dividing line between frigid Arctic air and milder Gulf air to the south, potentially bringing unsettled conditions to the Interstate 10 corridor Wednesday before more widespread rainfall across parts of the South late week.

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Meanwhile, another Arctic high-pressure system could slide southeast out of Canada late next week. That could potentially bring a second batch of temperatures plummeting up to 50 degrees below average, perhaps to a significantly more widespread area across the central United States.

Looking ahead, it’s likely that this cold pattern will dominate through at least the next 10 to 14 days, with stormy conditions favored in the Mid-Atlantic and New England.