Dangerous cold snap slugs Minnesota

Three weeks ago, National Weather Service meteorologist Mike Griesinger's forecast called for highs in the 70s.

Then he moved to the Twin Cities.

"I've mostly been staying indoors," said Griesinger, who moved from Peachtree, Ga., just before Christmas and this week has been issuing forecasts for 18 below. "I've got a thick jacket, but I haven't been outside enough to see if I need more."

Tuesday might have been a bit of a shock, even for longtime Minnesotans. In the Twin Cities, the low of minus 18 made it one of the two coldest days this decade, second only to Jan. 30, 2004, when the temperature bottomed out at 24 below.

In Embarrass, the low Tuesday was 44 below, and International Falls set a record for the date at 40 below. Giants Ridge Golf and Ski Resort near Biwabik shut down Tuesday because of the cold.

Cities around the state reported deep cold at 5:30 a.m. today. It was 6 below in Minneapolis, 36 below in International Falls, 15 below in Duluth, 13 below in Moorhead,  11 below in Brainerd and 4 below in Albert Lea.

A windchill warning is in effect until noon Thursday for northern, central and south central Minnesota.

After today's expected "warmup" to 1 above in the Twin Cities, the overnight low is expected to hit 18 below again.

Tuesday's cold, following Monday's 4.7 inches of fresh snow -- another extreme for this season -- led to more than 200 crashes and rollovers in the metro area over the morning rush hour, as exhaust from slow-moving vehicles put a fine polish of black ice on roads. That figure does not include the vehicles that slid off roads and ended up in the ditches and medians. An afternoon accident on Interstate 94 near Rogers involving a helicopter evacuation tied up homebound traffic. With another inch or two of snow expected overnight Tuesday, Don Zenanko, of the Minnesota Department of Transportation's Traffic Management Center, offered this traffic forecast for today:

"More of the same. Slow down and give yourself plenty of distance to the vehicle in front of you."

AAA Minneapolis received 865 calls for help Tuesday, mostly for tows and jump-starts, compared with a high of 300 on a "normal" day, said spokeswoman Dawn Duffy. Flat tires were also an issue, she said, since cold air contracts, making under-inflated tires even more vulnerable.

Along with the cold, St. Paul declared a snow emergency, which began at 9 p.m. Tuesday. But Minneapolis did not.

Minneapolis winter operations manager Mike Kennedy said plows had kept main streets clear Tuesday. Also, the snow on the picnic table at the Public Works Department office didn't quite reach the 4-inch mark, the informal threshold for calling a snow emergency, Kennedy said.

St. Paul's threshold for a snow emergency is 3 inches of snow. Kennedy said plows will continue to work in Minneapolis to clear snow to the curbs where they can, but he acknowledged parking lanes will remain sloppy in densely populated residential areas. Snow predicted for overnight could raise the chance of a snow emergency, he added.

After this cold snap, another weather shock looms: The predicted high for Tuesday is 34 above. That would be 52 degrees higher than tonight's low, and could result in an epidemic of misplaced hats and gloves.

"I'm always blown away by how good freezing feels after something like what we've been through," said meteorologist Paul Douglas.

In the winter, such swings are far more common than in the summer, because in the summer months arctic air recedes and warm air spreads further across the continent. In the winter, there is little buffer between warm air from the south and frigid arctic air as in other seasons, meteorologists say. As fronts move, they can open the door or slam it on pools of warm air or cold air.

Roseville meteorologist Frank Watson noted a 47-degree swing in just a one day last month, from 6 below Dec. 25 to 41 above Dec. 26.

Griesinger, who grew up in southwestern Michigan, said Tuesday's air was the coldest he had ever felt. He tried jogging earlier in the week, but skipped it Tuesday.

"I guess today I'd have to find a treadmill," he said.

Bill McAuliffe • 612-673-7646 Tim Harlow • 612-673-7768