Cold, or really cold?

Weather models waffle over how bad it will be

Sunny winter days are a rare and precios gift in the Flathead, offering a kind of psychic balm to spirits bruised by the endless days of gray.

However, this might be a good time to pray for snow and clouds … lots and lots of clouds.

Otherwise, the National Weather Service says a cryogenic deep freeze could be in store next week, with temperatures in the valley dropping as low as 20 or 30 below zero.

Even with cloudy skies, the next several days aren't going to be a picnic. Temperatures across western Montana are expected to drop near zero on Tuesday and below zero beginning on Wednesday as an arctic cold front moves down from Canada.

"The overnight lows will certainly be below zero," said Peter Felsch, a National Weather Service meteorologist in Missoula. "The uncertainty is how low they'll be. Our long-range weather models have waffled back and forth on that."

Felsch said two computer models are predicting that the arctic front should hit the area late Tuesday, bringing snow flurries and strong winds - similar to the Pacific storm front that moved through on Friday.

Where the models disagree, he said, is about what happens after that: One says there will be clear skies and near-record cold temperatures beginning on Thursday; the other says it's going to be cloudy, with more snow and not quite as cold.

"If a clearing takes place after the cold settles in, temperatures could really bottom out," Felsch said. "We're looking at minus 20 to minus 30 in the valley, with colder temperatures elsewhere. In Polebridge, the potential is for 40 below."

It's only been a year since temperatures here dropped that low: Glacier Park International Airport recorded 29 below zero on Jan. 5, 2004; Polebridge was the coldest spot in the nation that day, with an official reading of 45 below.

However, those were the lowest temperatures recorded in the Flathead since 1990. The valley's all-time low is minus 38, set in 1950.

Felsch said cloudy conditions could moderate the weather somewhat, but overnight lows on Thursday and Friday could still be in the neighborhood of 10 below.

This kind of discrepancy in the long-range computer models tends to occur when global weather patterns are unstable, he said. Otherwise, they're often completely in sync.

"Right now, there's a lot of energy in the tropics that could play havoc with the jet stream," Felsch said. "That could explain the difference in the models."

The midweek cold snap would follow on the heels of Friday night's winter storm, which was expected to drop 4-8 inches of snow in the valleys and 9-14 inches of snow in the mountains by late this morning.

Once this storm clears, the weather service predicts three days with milder weather until the expected subzero temperatures arrive.

Reporter Bill Spence may be reached at 758-4459 or by e-mail at bspence@dailyinterlake.com