Mountain Weather Forecast

Weather Synopsis for Wednesday night through Monday

The Pacific Northwest remains in a cool and active spring pattern. An E-W oriented frontal system is dropping southward across northern Washington State spreading significant moisture ahead of it (to the south). The front has not progressed southward as much as originally anticipated, so temperatures will be slightly warmer than expected early Wednesday evening. The front is expected to stall over the central Washington Cascades, so expect moderate to heavy snow (and low elevation rain) to continue from around Stevens Pass southward, overnight. The heaviest snow is expected to be in the Mt. Hood area where the winds and orographic forcing is strongest, but Paradise and White Pass should get a good wallop of heavy, wet snow. Stevens and Snoqualmie passes will be influenced by convergence zone activity during the evening hours. Temperatures are expected to cool with snow levels lowering during the evening hours, but snow levels should be slightly warmer than originally expected.

Another system arrives on a NW flow on Thursday, helping to sustain the snow (and low elevation rain) throughout the day as a ridge builds offshore and turns the upper-level flow NWerly. This flow direction will favor heavier precipitation further south over Oregon with lighter precipitation from the central Washington Cascades Northward. Strong winds over the Mt. Hood area Wednesday night will finally gradually decrease into the moderate range after days of strong winds.

Moist NW flow will continue shower activity Thursday night with a ridge offshore building and cutting off most of the moisture supply by Friday. Only a few rain and snow showers will linger Friday morning, but it is expected to be partly cloudy with plenty of sunshine east of the Cascade Crest.