Mountain Weather Forecast

Weather Synopsis

Scattered showers will continue through this afternoon and begin to taper down during the evening. We'll have a brief break in the wet weather as an upper level ridge quickly moves east over the area tonight. A deep low pressure system will spread warm frontal precipitation over the Olympics, south WA Cascades and Mt Hood area during the early morning hours, with precipitation spreading further inland around sunrise.  A period of offshore flow and E-SE winds will have a subtle cooling effect, with snow levels starting over the Washington Cascades in the 2500-3000' range late tonight through tomorrow morning. Snow levels will gradually rise during the day, peaking in the 4000-4500' range in the afternoon, right around the time a weakening "cold" front pushes through the Cascades.  

This isn't a powerful storm by winter standards but it will deliver a decent wallop for late March.  We can expect 0.35"-1.00" of precipitation during the day tomorrow, with the Mt Baker area, the Crystal/Paradise/St Helens area, and Mt Hood receiving the higher totals in part due to the southerly orientation of the flow. Snowfall totals will be location and elevation dependent with rising snow levels. Above the rain/snow, look for 4-10" of new snow during the day Wednesday.  We'll see strong winds over the Olympics and Mt Hood, and more moderate winds over the Cascades.  

Showers will continue Wednesday night but they should be lighter. On Thursday, the weakening upper low will drift closer to our coast. An unstable air mass overhead will pave the way for afternoon convective showers over the mountains, with the most persistent showers reserved for the Olympic peninsula closer to the low. Some of the showers may be heavy at times and contain graupel.