AREAS AFFECTED : EAST SLOPES OF THE OREGON CASCADES; KITTITAS VALLEY; YAKIMA VALLEY; SIMCOE HIGHLANDS; UPPER SLOPES OF THE EASTERN WASHINGTON CASCADES CREST; LOWER SLOPES OF THE EASTERN WASHINGTON CASCADES CREST
Another active weather pattern with a moderately strong
atmospheric river is expected in the Cascades, especially the
Washington Cascades, beginning Monday and Tuesday. Moderate to
heavy rain is possible at the Cascade crest with amounts
decreasing away from the crest. By Tuesday night, snow levels drop
to around 2500 feet and mountain rain will turn over to snow.
Snoqualmie Pass and White Pass have a 45 to 65 percent chance of 2
feet of snow from Tuesday through Thursday night, while Santiam
Pass has a 30 percent chance of 2 feet of snow in the same period.
This precipitation will lead to river rises and potential additional
flooding on the Yakima and Naches Rivers as well as an increased
risk of rock and mud slides in areas of steep terrain and near
burn scars. However, the transition to snow is expected to keep
flooding at lower levels than the past few days. While the Yakima
and Naches Rivers are forecast to reach minor flood stage by
Tuesday and Wednesday, other rivers in the area are expected to
remain below bankfull. Also, windy conditions are expected Tuesday
night and Wednesday which may lead to difficult mountain driving
conditions. Those living or having travel plans through the
Cascades should be prepared for impactful weather next week.