Snow began to fall in the northern Cascades and Rockies in the first major snowstorm of the season, prompting people to break out their winter coats, gloves, boots and snowshoes after a warm fall in many places.
The U.S. National Weather Service has warned of hazardous travel on snow-covered mountain passes and icy conditions on some highways as the snow begins to melt and then freezes as road temperatures drop.
The storm is expected to come in waves, starting with precipitation that fell Tuesday as rain at low elevations in Washington state and as snow in the mountains. Snow is then expected to extend into northern Idaho, Montana, northwest Wyoming and North Dakota through Friday.
Cold air descending from northwest Canada combined with a humid Pacific weather system, bringing freezing temperatures and snowfall of up to 14 inches to the northern Cascades of Washington and 46 cm in the mountains of Montana, according to the National Weather Service forecast. Some high elevation areas in the northern Rockies could receive more than 2 feet of snow.
The most dangerous storm
According to Matt Ludwig, a meteorologist with the National Weather Service in Great Falls, central Montana will receive the most snow.
“We’re kind of in the crosshairs,” he said.
The first snowfall of the season “is always the most dangerous because people haven’t gotten used to it yet” after months of driving on mostly dry roads, Ludwig said. Drivers are not used to having less traction, going slower and longer braking distances, he added.
Snow fell across northwest Montana, including Glacier National Park, midday Tuesday and began falling in Helena overnight Tuesday into Wednesday. Northwest Wyoming, including Yellowstone National Park, was also under a winter storm warning, the National Weather Service said. Light snowfall was easing Tuesday evening in Alberta, Canada.
The forecast prompted residents to make appointments to have winter tires installed on their vehicles and some realized their underground sprinkler systems needed maintenance.
The storm brings a drastic change in weather. Late last week, Helena broke temperature records in the high 20s, about 25 degrees warmer than average for this time of year, Ludwig said. Great Falls also had a day in the high 20s late last week, and now those towns could get 8 inches of snow by Wednesday.
“If that’s not a shock to your system, I don’t know what is,” Mr. Ludwig said.
Snow is expected to move across northwest and north-central North Dakota overnight Tuesday into Wednesday, said Nathan Heinert, a meteorologist with the National Weather Service in Bismarck.
The Williston, Watford City and Minot area in the North Dakota oil patch could receive the heaviest snowfall, 8 to 12 inches, Heinert said. Bismarck could receive 4 to 6 inches of snow late Thursday, following Wednesday’s rain.