Boise just experienced a snowstorm not seen in nearly 120 years. Here’s what happened

Boise residents woke up Thursday morning to a fresh, thick layer of snow covering their cars, trees and roads.

Snow is not an uncommon sight in Boise, except when it happens so late in March. In fact, the City of Trees had not seen a snowstorm of this magnitude in late March since 1905.

As of 10 a.m. Thursday, Boise had picked up 2.8 inches of snow, National Weather Service meteorologist Stefanie Henry told the Idaho Statesman. Henry said she expected the snow to transition to rain around noon, after another tenth of an inch or so of snowfall.

That would bring Boise incredibly close to the daily record snowfall total of 3.2 inches for March 30, set in 1905.

“It’s really rare to have snowfall this far late (in the season),” Henry said.

Bogus Basin has benefited from the late-season snowfall. The Weather Service had recorded a fresh 13 inches of snow at the ski resort at 9 a.m. on Thursday, and Henry expected the higher elevations to receive at least 2 more inches before the storm passed through.

If that isn’t enough, a second storm system this weekend could drop up to 2 feet of snow on Bogus Basin. Snow will likely fall in Boise on Sunday evening, but the Weather Service forecasts less than half an inch for downtown.

A snowy and cold March

Including the 2.8 inches that fell on Boise through Thursday morning, the city has picked up 9 inches of snow in March, Henry said. That ranks this March as the sixth-snowiest on record, with the potential to climb and leapfrog fifth-place 1906 (9.1 inches) and fourth-place 1952 (9.2 inches).

A couple of early-March snowstorms helped get the month off to a flying start: 2.1 inches fell in Boise on March 1, and a week later, a rare squall dropped 1.5 inches of snow in about 30 minutes.

Thursday’s snowstorm also extended another March record: the most days with at least 0.1 inches of fresh snow. Thursday’s snow extended that record to 11 days, pulling away from 1904, 1917 and 1951, which all experienced nine March snow days.

It’s also been much colder than average this winter in general. The city is on a streak of 148 days since temperatures last hit 60 degrees, bringing it just five days away from the record of 153 set in 1899.

There’s an excellent chance Boise will break that record, too. The highest forecast temperature through next Wednesday — the day Boise would break the record — is 51 degrees on Saturday.

Where’s all this snow coming from?

A low-pressure system, typically associated with stormy weather, is stationed over the southern part of Idaho, Henry told the Statesman.

“What’s happening is there’s a lot of moisture coming around the low-pressure system, and it’s moving into colder air behind the low,” Henry said. “And so it’s just generating a lot of snow, mainly in Boise and east into the mountains.”

The low-pressure system has been part of a larger pattern this month, associated with an active Pacific jet stream funneling moisture into the Gem State. An active Pacific jet is often associated with La Niña winters, typically representing below-average temperatures and above-average precipitation for Idaho.