Avalanche Advisory Archive 2016 – 2018

Date Issued:2017-04-02 07:36:25
Primary Trend:1
Primary Probability:3
Primary Likelihood:3
Primary Size:1
Primary Description:

We ahve built out windslabs around the region over the last 5 days with winds of 20-50 from the SSE.

This wet new snow often packs and bonds well but be aware in areas with few or no anchors especially on steep convex slopes danger remains.

Secondary Trend:2
Secondary Probability:5
Secondary Likelihood:2
Secondary Size:2
Secondary Description:

The deep persistent slab remains weak in the region. Yesterday additional slides were noted in and around Juneau.

With the decrease in the temps and precip loading rates as well as in the winds this layer will start to gain strength again... but yesterday on Douglas Island showed this layer about a meter down and still very reactive in tests.


The National Weather Service Forecasts-

Today- Widespread rain showers. Snow level 500 feet. Highs around 41. Southeast wind 10 mph.

Tonight- Snow and rain. Snow accumulation to 1 inch. Lows around 36. Southeast wind 10 mph.

Monday- Cloudy. Chance of snow in the morning. Chance of rain in the afternoon. Highs around 42. Southeast wind 10 mph.

Temperatures are back below freezing at the Mt Roberts Tram for the first time in a week. Its currently 30f at the Tram summit and 28f mid mountain at Eaglecrest.

Winds blew steady from 20-40 gusting to 50 the last several days out of the SSE building windslabs.

Precipitation rates have declined this a.m. Yesterday we saw 10mm at Eaglecrest and 9mm at the Tram Summit. This only left around 2cm of snow at the tail of the storm. Much less than the previous few days. The forecast for today calls for less than 1/2\" precip in next 24 so reduced from last several days as well.

With cooler temps back in the region and a decrease in precipitation rates the chance of widespread natural avalanches has diminished.

With mid day warming and continued precip there is a possibility of seeing small wet loose avalanches. Especially at lower elevations.

With the winds and new snow at summit and ridgeline for the last several days there is a possibility of human triggered avalanches for windslabs on lee slopes.

And with small wet loose avalanches or human triggered slides you may also have enough energy to trigger the deeper persistent weak layer in place.

Over the next 24 hours I assume the snowpack will continue to stabilize but the wet surface layers created the last few days will take time to freeze back up.

Recognizing that Natural avalanches are possible today and human triggered avalanches remain possible avalanche danger is CONSIDERABLE today.

Continue to use caution in avalanche prone areas.

Forecaster:Tom Mattice