An inversion is forming across the Inland Northwest as we head into the weekend. That means warm air is trapping cold/moist air down near the surface. When that happens fog and freezing fog becomes the norm down in the valleys, while the mountains bask in sunshine!
Under this weather pattern, expect fog and freezing fog to form each night, and linger through each morning. It might lift slightly in the afternoons, but it'll still make for a gray/gloomy stretch, with high temperatures in the 30s/low 40s and overnight lows in the 20s.
Poor Air Quality
The inversion is brought on by high pressure sitting over the Inland Northwest for days on end. Along with the fog, it also makes it hard for fresh air to reach us, meaning our air quality could get worse through the middle of next week. The National Weather Service suggests that people with breathing problems limit time spent outdoors, has the poor air quality could take a toll.
Next Storm System
The high pressure does do one nice thing for us though. It keeps any major storm systems from moving in. We'll stay dry through the middle of next week, but by Wednesday night/Thursday a storm system rolls in from the south with a wintry mix of rain, snow and possibly freezing rain. Long range forecast models indicate that several more storms could follow, bringing more rain and snow through next weekend.