Avalanche Advisory Archive 2016 – 2018

Date Issued:2017-01-26 06:47:01
Primary Trend:1
Primary Probability:7
Primary Likelihood:3
Primary Size:2
Primary Description:

With continued warming around the region our upper mountains are now seeing rain as well.

This rain is coming to rest on windslabs we formed over the last 4-5 days.

This will add tremendous stress to the slabs in place and rapidly erode the bonds in the snowpack.

Be aware these warm winds also play a role. Warming is one thing but warming driven by 30-40mph winds really effects the snowpack a great deal more.

These slides depending on elevation and rain will be someplace between a rain triggered windslab and a wet slab if saturation continues.

Secondary Trend:2
Secondary Probability:9
Secondary Likelihood:1
Secondary Size:2
Secondary Description:

Be aware these continued warm temps, winds, and rains increase the glide activity and rate of glide. If you are seeing any glide cracks be aware these areas remain questionable and weak until they finally fail at the ground.

Avoid spending time both above and below glide cracks.


The National Weather Service Forecasts-

Today- Windy. Rain. Highs around 42. Southeast wind 15 to 25 mph. Wind gusts increasing to around 40 mph in the morning.

Tonight- Windy. Rain showers in the evening, then rain heavy at times. Lows around 39. Southeast wind 10 to 15 mph increasing to 20 to 30 mph with gusts to around 45 mph late.

Friday- Windy. Rain. Highs around 43. Southeast wind 15 to 25 mph. Wind gusts up to 40 mph in the morning.

Temperatures remain quite warm around the region. Eaglecrest is showing 38f at the base, 34f at mid mountain and 32f on top. Mt Roberts is also showing 35f.

For the most part we are seeing mostly rain. There is perhaps a little new snow near summit and ridgeline. Yesterdays totals were quite light. Eaglecrest received only 1mm of precip while the tram received 2.mm or 1/10\". We lost a little snow in the process but not much.

Todays forecast calls for continued warm temperatures, high winds and continued rain with around .8\" of precipitation.

This is considerable loading once again and will keep avalanche danger to MODERATE to Considerable today. Natural avalanches are not likely but possible... and human triggered avalanches remain likely in isolated locations near summit and ridgeline that were previously loaded.

This fair amount of moisture coming to rest in an already saturated snowpack will continue to eat away at the bonds in the snow. Use extreme caution in steep convex unsupported areas. Continue to avoid terrain traps.

Wet loose avalanche also remain a concern... be aware until the snow cools a great deal this will continue to be on our radar.


Here is a great article written by my high school friend John Stimberis titled: Glide avalanche response to an extreme rain-on-snow event, Snoqualmie Pass, Washington, US


Forecaster:Tom Mattice