Mountain Weather Forecast

Weather Synopsis

In the short term, the Pacific Northwest remains wedged between a northern branch of the jet stream directing moisture into northern British Columbia and a series of cutoff low-pressure systems gravitating towards northern California. The first of these low-pressure centers spins just off the northern California coast as of Thursday afternoon, with associated moisture moving into the Sierra Nevada and southern half of Oregon. A stronger cutoff low tracks toward the first low Thursday night through Friday. As this stronger low takes over, it pushes the lingering moisture from the first low northward. Initially, this translates to high clouds moving into our region on Thursday evening, gradually increasing overnight. By Friday, clouds lower and thicken through the morning hours, with a slight chance of a stray shower as an initial weak band of showers moves into drier air. Better chances for precipitation arrive late Friday afternoon around Hood as a more substantial rain band lifts northward over Mt Hood and then into Washington State Friday night. 

Freezing levels generally range from 8000-10000 ft Thursday night through Friday, with the warmest temperatures in the southern portions of the Forecast area Friday afternoon. 5000 ft Temperatures will approach and could surpass 60F in areas of the West South Cascades favored by downsloping of light SE ridgeline winds.

As precipitation and moisture increase, temperatures gradually cool from south to north. Snow levels should drop to 6000-7000 ft Friday night, then hover around 6000-6500 ft. Ridgeline winds start the day light and variable, but gradually increase out of the WSW by the afternoon. Expect mostly cloudy skies Friday night through Saturday, with light rain and higher-elevation snow at times. The focus of precipitation gradually shifts from the E to the W slopes of the Cascades.