Mountain Weather Forecast

Weather Synopsis

Our little taste of spring is about to change...A broad area of high pressure drifts east tonight as a trough establishes itself over the region. The trough is initially fairly narrow but extends down to the PNW from a low pressure in the Gulf of Alaska. This will snap us back into winter with a cold and snowy pattern into the weekend.

Tonight, increasing cloud cover and light snow and rain showers accompany a weak pre frontal disturbance. As the front drops down from the NW, it'll bring increasing south westerly flow to Washington, and westerly flow to Mt Hood. Precipitation will initially favor the west slopes of the Cascades overnight. Cold air slowly filters into the region with this initial disturbance, but its effects won't really be felt at the Cascade Crest and East Slopes until frontal passage sometime late in the afternoon on Thursday. 

Light and scattered snow and rain will increase in coverage and intensity during the day on Thursday as the front approaches the mountains. Winds and precipitation will gradually increase with the front, slated to cross Mt Hood mid-day on Thursday, and mid afternoon for the Cascades. Expect snowfall to begin accumulating rapidly with snow levels dropping fairly quickly Thursday afternoon into the evening. 

Thursday evening into the night we'll be under cold, moist and unstable post frontal flow which bodes well for continued snowfall for most of our mountain areas, favoring the west slopes of the Cascades south to Mt Hood. Chances seem decent for convergence zone banding, which could enhance snowfall rates and amounts for the above mentioned areas. With strong westerly winds, we're likely to see some snowfall spill over the east slopes of the Cascades as well. 

On Friday the trough axis sits over the PNW and we'll see continued stormy weather. Snow showers and winds increasingly focus on the Southwest part of Washington State and Mt Hood. It's likely the passes will continue to pick up modest snowfall, while precipitation becomes more showery for areas further north and east as the day draws to a close.