Mountain Weather Forecast

Weather Synopsis for Tuesday & Sunday

A pair of fronts will bring a stream of clouds and moisture into our area over the top of a shallow ridge of high pressure just offshore. The first front is fizzling this morning as it brings some very light snow to the region. The second feature, a potent warm front, will bring increasing moderate rain and snow across the area, primarily during the afternoon. Through the evening hours, a battle will play out between the cool easterly flow and the warm air spreading in aloft. Snow levels will rise significantly during the day in some areas west of the Cascades such as Hurricane Ridge which is likely to experience a changeover to rain during the day, but most NWAC stations will remain snow because it will take time to wash out the low-level cold air due to that easterly flow. Many low and mid-elevation NWAC stations will experience significant snow totals before a changeover to rain overnight as the warm air ultimately wins the battle once the warm front moves through during the evening hours. SW flow during the evening hours will focus the moisture toward the North Cascades primarily Tuesday evening as the low slides along the coast of Vancouver Island and the warm sector of the storm provides a "relative" dry window south of Snoqualmie Pass. The cold frontal passage will bring the heavier precipitation back to all areas after midnight, including Mt. Hood which missed a lot of the heavier warm frontal precipitation.

On Wednesday, the surface low passes over central Washington State and will leave the potential for moderate convergence in the central Cascades amid the light to moderate showers that will decrease throughout the day across the Cascades. Snow levels will decrease gradually during the day, but they will remain above Stevens Pass level.