As promised, a nasty winter storm blasted its way into the Flathead Valley on Monday.

At noon, the sky was clear, winds were calm and it was 37 degrees in Kalispell.

Two hours later, snow was falling, the temperature had dropped 16 degrees and winds blowing at 25 mph (gusting to 40) created white-out conditions in many areas.

The storm hit the North Valley even earlier, with snow falling at a rate of 2 1/2 inches per hour in Whitefish.

Driving conditions became treacherous across the valley as the Arctic cold front caused “flash freezing” on roadways, according to the National Weather Service.

A two-vehicle accident on U.S. 93 south of Montana 40 around 1:30 p.m. caused partial traffic blockage, while at the same time a disabled semi-truck blocked traffic on U.S. 93 west of Whitefish.

Reports of other accidents and slide-ins increased as the weather worsened.

A winter storm warning was to remain in effect until 1 a.m. Wednesday. Snow accumulations of 3 to 5 inches were expected in the Flathead Valley with 1 to 2 feet in the mountains.

Snow was forecast to taper off this morning in the Flathead Valley, although fierce winds are expected today. The National Weather Service predicts northeast winds of 30 to 34 mph with gusts as high as 50 mph today.

The high temperature today is expected to be 16 degrees with a low tonight of 5.

Wind-chill values were forecast to drop as low as 10 to 20 below zero today and tonight in the valley, with lower chill figures at higher elevations such as Marias Pass and the Big Mountain.

On Wednesday, the freeze will deepen, with a high temperature of 13 degrees and low of minus 4. Subzero nights are predicted to continue through Saturday with daytime highs in the teens.