Mountain Weather Forecast

Weather Synopsis

It's been a fairly calm night across the Cascades, with some continued light showers along the west side and in the mountain passes. Temperatures have cooled, with snow levels hovering near 3000-3,500 feet. Winds are generally light ahead of the impending system.

Tuesday will be a busy day in terms of weather for the Cascades. Today, a low-pressure system will move south over British Columbia, delivering a strong stream of moisture to the region. Strengthening southwesterly flow will bring precipitation first to the Olympics and the West North zones this morning. Moisture will gradually spread south, reaching Mt Hood midday, and eventually providing moderate spillover east of the crest. During the daytime hours, the greatest precipitation intensity will be focused on the westerly zones north of I-90. Overnight, intensity will shift to the southern volcanoes and into the mountain passes.

Snow levels will hover near or above the mountain passes through the day on Tuesday, with a quick drop overnight, reaching as low as 1000 feet in some areas. The east side of the Cascades will be slower to cool with this system, so expect a delay in the snowfall compared to everywhere else. As snow levels drop, expect an increase in snowfall intensity across the Cascades.

Winds will ramp up quickly with the arrival of the system, forming a barrier jet along the west slopes. Most ridgelines will see strong wind speeds through the day, with extreme speeds possible on the volcanoes, and especially Mt Hood. Winds will ease gradually overnight, as the flow direction shifts more westerly.

Snow showers will continue on Wednesday as the low center moves over Washington. Cool air in place will maintain relatively low snow levels. That being said, it's springtime, and it doesn't take much for temperatures to climb during the day. Unstable air aloft may allow for some isolated thunderstorms around the Olympics in the afternoon.