Mountain Weather Forecast

Weather Synopsis

Forecast updated 2:30 PM for 5000 ft temperature adjustments.

An unusually strong ridge of high pressure parked just offshore maintains a beautiful weekend of weather across the Pacific Northwest through early next week. It's hard not to sound like a broken record when the weather pattern remains stubbornly static. The ridge is bringing some of the warmest January temperatures we can remember to the highest elevations of the Pacific Northwest. The mercury rose to 44F at Camp Muir Saturday afternoon, confirming freezing levels well above 10,000 ft. Overnight low temperatures only dropped to 36F and we suspect that much of the daytime rise in temperature readings may be due to solar radiation and reflection. Still, these numbers are impressive for this station. 

Saturday is a strong candidate for the peak warming of this extended warm period as the high-pressure center drifts slightly northward through the weekend, then begins to weaken. Freezing levels in the 11,000 to 12,500 ft range Saturday night should drop by around 500 ft each 24 hours...aka, you probably won't notice.

With light N winds aloft not reaching the ridgelines, the 3D structure of the shallow pool of cold air east of the Cascade Crest will be more noticeable in most mountain areas. Stronger E winds on Friday sloshed this cold air up against the east slopes of the Cascades Friday night. The resulting deeper cold pool has been slower to warm at lower elevations on Saturday. Although these winds gradually decrease over time, we expect a similar diurnal pattern to play out Saturday night into Sunday, with a secondary low-elevation freezing level redeveloping over the passes and east slopes of the Cascades. By Monday, the ridgeline winds shift westward, begin eroding, and moderate the cold pool east of the Cascades.