Mountain Weather Forecast

Weather Synopsis

The Pacific Northwest sits on the backside of a broad upper trough that stretches across most of the contiguous US and Canada.  This pattern won't change much through Friday morning and either will the weather.  

Weak upper level disturbances and orographics will help squeeze out snow showers along the west slopes of the Cascades near and north of I-90, with a few inches of light snow possible every 12 hrs. Further south of I-90 and along the west slopes, low clouds will be present with the occasional light shower. The low clouds will squeeze through mountain gaps and push east of the Cascade crest, again especially north of I-90.  The further you travel east from the crest, the drier, clearer, and milder it is, thanks to strong W winds and downsloping. South of the Columbia River Gorge, conditions are even drier with mostly clear conditions expected. The highest peaks, except in the north Cascades, will generally be above the cloud tops. By Friday, low clouds will still be present but will begin to recede, and persistent showers near the Canadian border should start to taper in the afternoon. 

A slow warming trend will take place over this time, with Mt Hood on the southern edge of a tight gradient, and seeing the most warming as freezing levels rise to 8000-9000' by Friday.  The Olympics and WA Cascades will see a much slower warming trend. 

Finally the winds, leaving perhaps the most impactful piece to the end.  Westerly winds will be ripping through this period.  A strong jet core is set up over B.C. will spill those strong winds southward over WA throughout the short term. Look for strong W winds in all areas, strongest near and east of the Cascade crest and at upper elevations where periods of extreme winds are possible.