What to expect on the drive home with snow in the Cascades

Many motorists will be returning home Sunday after the long holiday weekend and the Apple Cup in Pullman. The weather heading out of town was rather tranquil, but that will not be the case coming home tomorrow, particularly for those driving on Cascade highways.

A strong Pacific frontal system diving southeast from the Gulf of Alaska is expected to move ashore tonight through Sunday, bringing rain to the lowlands of western Washington, but also heavy amounts of snow in the Cascades.

Lowland snow looming for Seattle region early next week

The passes will start out as rain with snow levels near 4,000 feet this evening but tumble to around 1,500 feet overnight and Sunday. Snow accumulations in the passes will pile up to between a foot and a foot and a half by midday Sunday.

Washington State Dept of Transportation (WSDOT) crews will be ready to tackle the onslaught of snow. Yet, given the expected elevated traffic volumes combined with the rate of falling snow, traffic delays are inevitable.

WSDOT reminds motorists that they must carry chains when crossing the Cascades passes and be ready to use them if conditions warrant.

For those returning from eastern Washington, consider Interstate 84 through the Columbia Gorge as a solid alternative to driving any snowy Cascade pass highway. Rain is expected through the gorge and even though the trip is longer in distance, that route will avoid any snow-related delays in the passes.

In western Washington, this incoming weather system will produce rain tonight into Sunday before the precipitation turns to showers with some partial clearing periods during the afternoon, in time for the Seahawks game. Highs will be in the 40s.

This weather system will also usher in the coldest air mass of the season thus far, with snow levels falling below 1,000 feet the rest of the week. High temperatures will struggle to reach even 40 degrees and lows will dip into the 20s to mid-30s.

With this colder air in place, the question then becomes, will there be any moisture to accompany it? The next cool Pacific weather system arriving Tuesday night into Wednesday will offer that moisture and a good threat of lowland snow, with snow levels hovering on either side of 300 to 500 feet.

More details will be forthcoming as this event approaches.