Avalanche Advisory Archive Pre-2016

Date Issued:2013-03-19
Danger:2
Trend:4
Probability:3
Size:2
Problem:0
Discussion:

The National Weather Service Forecasts-

TODAY...SNOW SHOWERS. SNOW ACCUMULATION 3 TO 5 INCHES. HIGHS
AROUND 32. NORTH WIND 5 TO 15 MPH.

TONIGHT...DECREASING CLOUDS. SCATTERED SNOW SHOWERS IN THE
EVENING. LOCALLY WINDY LATE. LOWS 21 TO 27...EXCEPT AROUND 15 IN WIND SHELTERED AREAS. NORTH WIND 10 TO 20 MPH...EXCEPT NORTHEAST WIND INCREASING TO 25 MPH WITH HIGHER GUSTS NEAR DOWNTOWN JUNEAU AND DOUGLAS AND OUT OF INTERIOR PASSES LATE.

WEDNESDAY...PARTLY CLOUDY. SLIGHT CHANCE OF SNOW IN THE MORNING. HIGHS AROUND 31. NORTHEAST WIND 10 TO 20 MPH.

Temperatures have warmed by 5c degrees over the last 24 hours.

Winds picked up yesterday afternoon on Douglas Island from 15-30mph. Most of the time in the low 20's. The Mt Roberts Tram saw less wind with ranges from 10-20mph.

We received 3mm of precipitation at the Mt Roberts Tram Summit which left behind 6-7cm of really light dry snow.

The UAS site is showing slightly less snow with around 4cm.

The new Mt Juneau Station above the White Path is showing closer to the same 7-8cm of the tram.

With light winds and low snow volumes added to our current snowpack conditions during a moderate warming trend avalanche danger is Moderate today.

Natural avalanches unlikely, potentially destructive avalanches unlikely to come near or reach developed areas.

Human triggered avalanches possible. Use caution near summit and ridgeline where the wind had more effect. Look to the N-W slopes for additional wind loading and danger.

With 2-5\" of precip in the forecast today avalanche danger will rise a little as will the likelyhood of these human triggered avalanches.

If we should see more snow, warming, or wind than the forecast calls for avalanche danger could rise significantly more.

Please avoid the Flume and Perseverence Trails today. Limit your exposure by limiting your time in Avalanche terrain.

Tip:

Whumpf:

Whumph has actually been adopted as a technical avalanche term to describe the sound of a collapsing snowpack when you cross the snow. For instance, ?we got a lot of whumphing today,? or ?the snowpack whumphed like rolling thunder just before it released and caught us.? This is the sound of nature screaming in your ear that the snowpack is very unstable. Most snowpacks collapse onto a ?persistent? weak layer such as faceted snow, depth hoar or surface hoar, although occasionally whumphing occurs on very wet snowpack as well.

There are 5 red flag indicators of direct action avalanches can you tell us what they are? Stay tuned for tomorrow as we discuss those 5 indicators leading to direct action avalanche danger.