Avalanche Forecast

There is quite a bit of change in the snowpack as you go up in elevation in the North Cascades. There is barely a snowpack near 3000 feet. As you move higher, the snowpack increase noticeably around 4500 ft and again near 5500 ft.  Recent heavy rains have only amplified this characteristic. Despite the lack of low elevation snow, areas above 5500 ft have a deep winter-like snowpack.

January 5, 2019: The dark timber in the coast range highlights the lack of snow at lower elevations and the deep winter-like snowpack near and above treeline. Photo: Simon Trautman

January 4, 2019

The first few days of 2019 were active here in the Northwest. A strong weather system impacted the region bringing warm temperatures, heavy precipitation, and strong winds. This weather system did not impact the forecast areas equally. Even within the same forecast zone we can see wide discrepancies in precipitation numbers. The snowpack you encounter this weekend will be largely dependent on where you go and the elevation at which you travel

Storm Precipitation Totals as of Friday Afternoon

Hurricane Ridge: 2.41”

Mt Baker: 6.52”

Stevens Pass: 2.58”

Snoqualmie Pass: 2.27”

Crystal Mountain: 0.52”

Paradise: 2.23”

White Pass: 0.55”

Washington Pass: 1.05”

Mission Ridge: 0.31”

Mt Hood Meadows: 0.51”

A few big stories stand out in the current snowpack: recent avalanche warnings in the northern zones, persistent slabs in the western areas, and a complex and weak snowpack in the eastern zones.

The northern zone experienced the brunt of this latest weather system. This led to two days of avalanche warnings and at least one large natural avalanche cycle. It's tough to say what the snowpack looks like in areas near and above treeline, but we know those areas received substantial new snow.

Photo: Large triggered avalanche at Mt Baker Ski Area during the recent storm. -Mt Baker Ski Patrol

Earlier in the week we began forecasting a new persistent slab in our west-slope zones. A layer of buried surface hoar produced avalanches last Saturday, Sunday, and Monday. How did that layer fair after this recent round of weather? In locations like Mt Baker and Paradise, it was well tested with heavy precipitation. In other locations, less water may not have adequately stressed the weak layer. As visibility improves and more observation come-in the picture may become more clear.

Photo: Large remotely triggered persistent slab avalanche in the Crystal backcountry: Jeremy Allyn

In the eastern zones a complicated and weak snowpack exists. Several persistent weaklayers have plagued these regions most of the winter. Don’t expect this to change anytime soon. Snow profiles and snowpack test can give you a glimpse into the persistent layer. Remember, snow profiles cannot prove the absence of a weak layer or that a layer has “healed.”

Photo: Large remotely triggered slide on buried surface hoar from Christmas above Leavenworth on 12/31: Matt Primomo