Winter outlook: Bitterly cold, snowier for upper Midwest
The weather outside is going to be frightful this winter, according to forecasts from the National Oceanic and Atmospheric Administration and accu-weather. com.
Forecasters expect above-normal snowfall and below-normal temperatures, possibly including daily high temperatures below zero in December, according to Jack Boston, senior meteorologist with accuweathercom.
Thanks to the La Nina weather pattern, the jet str-eam will set up out of the northwest and will bring very cold air into the region from northwest Canada, Alaska and Siberia.
"You are going to get an Arctic outbreak," Boston said. "December and January are going to be the most extreme cold months cold-wise."
Those Alberta clipper winds will bring multiple light snows, likely between 3 and 5 inches each, which will constitute most of the snowfall in those months, Boston said.
According to NOAA, the La Nina isn't the only climate factor in play. The lesser-known and less predictable Arctic Oscillation could produce dramatic short-term swings in temperatures this winter.
The La Nina returned in August and is expected to gradually strengthen and continue through the winter.
"The evolving La Nina will shape this winter," said Mike Halpert, deputy director of NOAA's Climate Prediction Center. "There is a wild card, though. The erratic Arctic Oscillation can generate strong shifts in the climate patterns that could overwhelm or amplify La Nina's typical impacts."
The Arctic Oscillation during the last two winters caused cold and snowy outbreaks, including the "Snowmaggedon" storm of 2009. According to NOAA's forecast, the oscillation's episodes are difficult to predict more than one or two weeks in advance.
As for temperatures, accuweather.com expects the thermometer readings to be 5 to 6 degrees below normal in December, pushing the average 25-degree highs and 8-degree lows even lower.
January will continue the colder trend, with average temperatures about 4 degrees below the average high of 22 degrees and average low of 4 degrees. The Alberta clipper winds will keep the smaller snowfall events coming, Boston said.
Then in February the weather pattern will flip, with the jet stream turning to come from the west and southwest. The change means temperatures will be only 1 to 2 degrees below the average 27-degree high and 9-degree lows, but that change also will bring significant snowstorms. The storms will form over the Rockies and then proceed to drop one-foot snowfalls on this region.
The significant February snowfall will represent more of the winter's snowfall than the December and January snowfalls. Accuweather.com expects 56 inches of snow this winter for Minneapolis, up from the 45-inch average, but well below the 87-inch deluge that was measured last winter at the Minneapolis-St. Paul airport.
Last spring, it really did seem like winter never ended and just wouldn't give up and let the warm spring winds take over. Expect some of that this spring, Boston said, but not quite to the same extent.
"You will not have to wait quite as long as last spring," he said. "But winter will be stubborn to leave and allow spring to come into the upper Midwest."
As a whole, the winter temperatures will be 3 to 4 degrees below normal and the precipitation level will be above normal, Boston said, with record low temperatures a possibility in December and January.