The Twin Cities might be spared the wintry blast that dumped as much as 6 to 8 inches of snow on the Red River Valley this weekend, but not the bitter cold that whooshed in behind it.

After a mild Saturday, when the high hovered just below freezing at 31 degrees, forecasters predicted subzero temperatures for most of Sunday and Monday in the metro area with the chance of small snowfall amounts. Meteorologist Paul Douglas said a roughly 40-degree swing in temperatures from Saturday to Sunday will be the start of what could be the coldest week of the winter — with anywhere from 72 hours to 96 hours of subzero temperatures.

"I'm not sure it's going to be school-closing cold," Douglas said, "but certainly with outdoor activities, you need to think twice when the windchill gets to 35 below zero or colder."

Astute Minnesotans seemed to be cramming in their outdoor exercise ahead of the cold front. The Nordic trails at Three Rivers' Hyland and Elm Creek park reserves in Bloomington and Maple Grove, respectively, were jammed Saturday.

Bob Pacieznik arrived in the morning to find cars parked all the way out to the security gate at Hyland, where snow-making has preserved a 5-kilometer loop. He estimated there were 1,000 skiers trying not to step on one another's skis and poles.

"If it wasn't the beginning of the year and I didn't have a New Year's resolution to keep," he said, "I would have turned around and gone home."

The January bite following a warmer December also evoked memories of the 2013-2014 winter when schools were closed or ordered to start late on multiple days due to frostbite fears for children awaiting their buses or walking to school.

Douglas said Wednesday is shaping up to be the coldest day, when even the high might not rise above zero.

The week could offer the first test for the new school cancellation policy adopted this fall by St. Paul public schools. If the forecast for 6 a.m. on a school day predicts air temperatures of 25 below zero or lower, or windchills of 40 below zero or lower, the district will inform parents the night before that schools will be closed.

"As far as I know, we will follow the guidelines this week," said district spokeswoman Toya Stewart Downey.

Downhill ski operators in the Twin Cities expected to remain open Sunday, but Spirit Mountain in Duluth is shutting down for the day due to the low temperatures, and Trollhaugen in Dresser, Wis., is closing early.

The cold spell in the Twin Cities followed blizzard conditions in northwest Minnesota. Tom Grafenauer with the National Weather Service in Grand Forks said winds between 30 and 40 mph were blowing snow that fell Friday night in the Red River Valley, resulting in near zero visibility at times. Snowfall near the Canadian border reached 6 to 8 inches of snow, but was only half that amount in Grand Forks and Fargo.

Windchills near the northern North Dakota-Minnesota border could reach 50 below zero today.

The Associated Press contributed to this report.

Jeremy Olson • 612-673-7744