It’s the very beginning of fall and the northern Rocky Mountains are bracing for a significant winter storm that could pummel the mountains with feet of snow and blizzard conditions this weekend.
“This has the potential to be a historically significant early-season snow event,” the National Weather Service in Great Falls, Montana, said.
A cold front with strong winds and near-record cold air will move through Idaho and Montana on Friday. It will be followed by another low-pressure system that will stall over the region Friday night through Sunday.
With unseasonably cold air already in place, wet, heavy snow is likely from the valleys to the mountain tops.
The forecast for this storm looks eerily similar to a storm that struck Montana in 1934. That storm produced prolific amounts of snow in late September over North Central Montana.
Feet of snow forecast for the highest elevations
This weekend, a few inches to feet of snow could fall across the region. The impacts will start tonight along the Continental Divide.
By Monday, the mountains will have storm totals being measured in feet. Areas near Glacier National park will see two to three feet of snow.
Snow won’t start to accumulate in most of the valleys until Saturday night.
Since this is an early season storm and the ground is still warm, most of the first snow to fall will likely melt. In some lower elevations, it may not even accumulate.
Winter storm warnings will be in effect for portions of Montana from 6 p.m. (MDT) Friday to 6 p.m. (MDT) Sunday.
National Weather Service meteorologists say they’re confident in the forecast.
With strong winds in place, any snow that falls will likely lead to possible blizzard conditions.
Strong winds will lead to blizzard conditions and rare waves on mountain lakes
Wind speeds are no longer forecast to be hurricane strength, but they will be very dangerous and problematic.
Sustained winds will be near tropical storm-force (over 39 mph+) with gusts possible over 60 mph. These winds, combined with the snow that is forecast will lead to whiteout conditions.
With winds this strong and the sudden cold air interacting with the warmer mountain lake water, there is the chance for damaging waves across Flathead Lake.
“It’s very rare to have waves 6 feet or more on Flathead Lake, but it’s possible this Saturday,” said the National Weather Service in Missoula.
There are other hazards with an early-season storm of this magnitude
Given the expected wet nature of the snow, a host of potentially dangerous impacts could result.
Widespread tree damage and downed power lines are possible, resulting in power outages. Agricultural damage could be caused by the record cold temperatures.
Livestock is also at risk and the National Weather Service warns, “make sure livestock and pets also have the essentials that they will need during the storm.”