Winter weather on the way to Northwest Montana

While fall may be less than a week old a significant weather system may make it seem more like winter across Northwest Montana.

While the heaviest snow accumulation - 2 to 3 feet - could occur along the Continental Divide, the National Weather Service is predicting possible record-breaking temperatures - highs and lows - across the region.

There is a winter storm watch for Libby from Friday through Sunday.

Heavy snow is expected to impact travel across Marias and Homestake passes Saturday night and Sunday. Two to 3 feet of snow is possible for places like Logan Pass in Glacier National Park above 6,000 feet.

“This is something that is definitely very abnormal for this time of year,” National Weather Service meteorologist Jenn Kitsmiller said. In a press briefing Thursday, Kitsmiller noted that Missoula has not received snowfall in September since 1983.

The storm will hit the area in three phases, Kitsmiller said, beginning with gusty winds and rain, followed by snow and then near-record cold temperatures.

The first punch is expected Friday night into Saturday morning. Heavy snow, with potential for blizzard conditions are anticipated for mountainous terrain, especially along the Divide.

Road closures were put in place across Glacier National Park Thursday in preparation for the storm.

Going-to-the-Sun Road from Jackson Glacier to Logan Pass closed Thursday morning. The Many Glacier Campground was to close at noon Thursday, while the Two Medicine Campground was to close Friday morning.

The St. Mary Campground will remain open but “camping not advised” signs were in place.

The Weather Service warned that impacts to sensitive plants are possible.

In the mountains, conditions will be raw, with lows bottoming out in the teens.

Trent Smith, a forecaster with the Weather Service in Missoula, said the temperatures will cause a significant impact to agriculture across the region and to gardeners.

“Travel over passes will be difficult and damage to trees with leaves on them could be significant, possibly causing damage to the power infrastructure,” Smith said.

Smith said the weather along the Divide could be dangerous to those not prepared for it - particularly for hunters and others recreating outdoors.

“If you are not prepared for these conditions, it could become a life-threatening event,” Smith said.

Snow totals in Libby could be 1-2 inches and West Glacier 4-6 inches.

The snow will be wet and heavy, which could cause further damage to power lines and bring down tree branches.

In the Libby area Friday night, there is a 90% chance of rain with as much as one-half inch possible. The low temperature will be about 32 degrees with light northeast wind increasing to 13 to 18 miles per hour in the evening and gusts as high as 25 mph.

Saturday, NWS forecasters are predicting snow as low as 3,100 feet but little or no accumulation is expected. The chance of rain and snow is 80% with a high near 46 and breezy conditions.

Saturday night, rain and snow is likely, mainly before midnight. Snow level is at 2,800 feet and lowering to 2,200 feet after midnight. Temperature are expected to drop to 27. The chance of precipitation is 60% and new snow accumulation of about an inch is possible.

Sunday, there is still a chance of rain and snow. The high is expected at about 45 with mostly cloudy conditions.

Sunday night, there is still a chance of rain and snow before midnight, then a slight chance of snow. Mostly cloudy, with a low around 24.

Monday and Tuesday, conditions will moderate a bit with no rain or snow in the forecast.

But it will remain chilly with highs from 50 to 53 and lows from 23 to 26.

In Troy, the forecast is about the same for the same time period.

Friday night, the temperature is expected to dip down to 33 degrees with an 80% chance of rain and a light northeast wind increasing to 15 to 20 mph in the evening. Winds could gust as high as 28 mph. As much as one-half inch of rain is possible.

Saturday, rain is likely with a 70% chance. The high will be near 45 and it will be breezy. New precipitation amounts between one-tenth and one-quarter of an inch are possible.

Saturday night, as it gets colder, the snow level will go from 2,800 feet down to 2,100 feet after midnight.

The chance of precipitation is 50% with a low of about 29. Little or no snow accumulation is expected.

Sunday, there is a chance of rain and snow with the snow level rising to 2,400 feet in the afternoon. The high will be near 50.

Sunday night, there is a slight chance of rain and snow before midnight. It will be mostly cloudy with a low of about 24.

Monday and Tuesday, the weather will improve with highs in the mid to high 50s and sunny conditions.

But overnight lows will still be in the mid to upper 20s, about 20 to 25 degrees colder than normal for this time of year, the National Weather Service predicted.