Mountain Weather Forecast

Weather Synopsis

308 pm minor updates and corrections

Daytime showers are starting to gain steam over the region this afternoon. Showers will peak later this afternoon and begin to wane overnight. We can expect another downright chilly mid-April night, with widespread 5000' temperatures in the teens.  A developing frontal system off the California coast will lift NE into Oregon tonight.  This should spread light snow to Mt Hood before daybreak, and along the southern Washington Cascades during the morning. There is high confidence that a period of east or southeast winds will occur ahead of the developing low pressure system Friday night and Saturday morning. 

The cold upper level trough that has been parked over the region for the week producing unseasonably cold temperatures and snow showers, will finally begin to shift inland Saturday afternoon. This should once again spark widespread shower activity in the afternoon. However, there will be a switch to westerly winds later Saturday afternoon and evening, bringing a period of moderate west winds to the Washington Cascades south of Stevens Pass and strong west winds to the Mt Hood area. If you see a few sunbreaks Saturday morning or mid-day, don't be fooled, dark convective showers and clouds will dominate the landscape in the afternoon. Some showers may of course contain graupel and the odd lighting strike can't be ruled out. 

A Puget Sound Convergence Zone may focus on the Mt Loop Hwy corridor with scattered showers elsewhere Saturday evening.  An upper level ridge will begin to slide over the area later Saturday night and move inland on Sunday. This should be a dry day, but not one without caveats. Low clouds may linger along the west slopes of the Cascades, especially near and north of Snoqualmie Pass. E-SE ridgeline winds and high clouds should increase Sunday afternoon ahead of the next Pacific frontal system.