Significant storm to drop 2 to 3 feet of snow in Idaho mountains. What will Boise get?

Idaho Statesman

A significant snowstorm rapidly approaching Idaho is expected to dump 2-3 feet of powder in some locations north of Boise between Tuesday night and Saturday morning.

Although there probably will be only about half an inch in Boise, the National Weather Service is forecasting up to a foot of snow as close as Idaho City and up to 2 feet in Cascade and McCall.

“The heaviest snow that we’re looking at is going to be from pretty much north and east of Centerville and definitely around the Featherville area; Atlanta, they’re gonna get hammered,” Weather Service Boise meteorologist Stephen Parker told the Idaho Statesman.

“Warm Lake is going to get hammered. Donnelly and Banner Summit is a place that we often talk about; they’re going to get, right now, our forecast is over 30 inches of snow.”

The Weather Service is giving Boise a 2% chance of getting 4 inches or more of snow, with the expected amount from the multiday system just 0.4 inches and the high-end possibility only 1.9 inches.

This content is not available due to your privacy preferences.
Update your settings here to see it.

Parker said the Boise foothills can expect much more snow than the city — the altitude for heavy accumulating snow by Wednesday night will be about 3,000 feet, and Boise’s elevation is just below that, at 2,730 feet.

Many ski resorts, including Bogus Basin and Brundage Mountain, opened their slopes over Thanksgiving and are about to add healthily to their totals. Bogus Basin is forecast to receive 12 to 18 inches, while Brundage Mountain and Tamarack could see over 3 feet each.

The storm should pass through Idaho by the weekend, the weather service said.

“It’s going start moving in (Tuesday) evening and then really pick up after midnight,” Parker said. “All day Wednesday, it’s going to snow pretty hard into Wednesday night, even into Thursday up in the mountains, and into Thursday night.

“And then it looks like things will quiet down somewhat on Friday, but there will probably be a few snow showers up there Friday morning.”

Why isn’t Boise getting much snow?

For such a significant storm, why is Boise remaining virtually untouched?

Being situated at a lower altitude in the Treasure Valley, Boise and the surrounding cities typically don’t experience the same type of snowfall as other parts of the state. This storm system has winds blowing at two different heights in two different directions, keeping snow away from the City of Trees.

The storm is inducing a southeast wind into the Treasure Valley, Parker said, which will bring dry air over the valley. That dry air will make it incredibly difficult for snow to fall to the ground — and any snow that does fall will turn to vapor before hitting the ground, a process called sublimation.

A separate surface-level southeast wind will be blowing into the Boise area from the Twin Falls and Mountain Home areas, Parker said.

“The air that we expect to come in from the southeast is also going to be very dry,” Parker said. “So snow that does form aloft — and there won’t be much — but what does try to form aloft and fall to the ground, some of that is going to be eaten up by the southeast winds.”