The bottom line? A big ridge of high pressure sets up shop across the western U.S. leading to inversion haze, bad air quality ...

The bottom line? High pressure ridge continues to build with declining air quality in northern valleys but rebounding ...

The bottom line? A big ridge of high pressure has set up shop across the western U.S. leading to inversion haze, bad air quality, and cooler valley temperatures.

KOIN 6 Chief Meteorologist Josh Cozart explains why this week's temperature inversion is reducing Portland's air quality.

A long stretch of humid heat followed by intense thunderstorms is a weather pattern historically seen mostly in and around ...

With that, an inversion will form with air stagnation, so be on alert for air quality alerts this week. Winds will also be ...