Mountain Weather Forecast

Weather Synopsis

This is the last Mountain Weather forecast of the season. NWAC will continue to monitor weather and avalanche conditions through May and issue additional safety products as needed. Have a great spring and summer! See y'all in the fall!!!

It may not be quite as hot out there as the past several days, but temperatures are still warm and well above freezing. In general, most weather stations show readings 10-15 (or even 20) degrees colder than this time yesterday. A deepening trough just offshore is pushing slightly colder air, clouds, and even a few showers into the mountains. This pattern should continue Sunday night as the trough nudges just a bit further eastward. Don't look for a major cool down, but you could see overnight lows dip back into the mid/upper 30's in many locations. Similarly, while you could encounter a passing shower, most of these sprinkles won't amount to very much and may not even record on our weather stations. 

As the upper-level trough deepens along the coast, a bit of moisture wraps around and will approach the region from the SE. This could bring a period of more organized rain and very high-elevation snow to areas along the east slopes of the Cascades late Sunday night and into Monday morning. Pinning down exactly where the bulk of the precipitation will occur is quite tricky. There is a wide spread in the weather models, but it looks like this pattern will favor locations from Lake Chelan to Washington Pass. 

Eventually, the low-pressure center of the trough cuts off from the main jet stream and wanders south to California. As it does so, we find ourselves positioned between the cut-off low to our south and a building high-pressure ridge to our north (Rex Block). Even if a few showers manage to linger into Monday evening, they should be shortlived. The trend will be for drying and warming. Look for freezing levels to quickly rebound Monday night into Tuesday as we settle back into a few days of sunshine and summer-like temperatures.