Avalanche Advisory Archive Pre-2016

Date Issued:2012-02-22
Danger:1
Trend:2
Probability:2
Size:2
Problem:0
Discussion:

The National Weather Service Forecasts-

TODAY...MOSTLY CLOUDY. SCATTERED SNOW AND RAIN SHOWERS. HIGHS
AROUND 37. LIGHT WINDS BECOMING SOUTHEAST 10 MPH IN THE AFTERNOON.

TONIGHT...CLOUDY. SCATTERED RAIN AND SNOW SHOWERS. LOWS AROUND 31. SOUTHEAST WIND 10 MPH.

THURSDAY...MOSTLY CLOUDY. SCATTERED RAIN AND SNOW SHOWERS. HIGHS AROUND 37. SOUTH WIND 10 MPH.

On Feb 15th we had a very hard and somewhat icy snow surface in places in the region after a long period of rains to summit and melt freeze conditions. This made the lower snowpack quite solid in place.

Since February 15th we have received 70mm of precipitation at the Mt Roberts Tram Summit Weather Station.

It has been below freezing almost the entire time since the 15th. It went just above freezing for a few hours on the 15th and again on the 17th.

This 70mm of precipitation delivered a total of 55cm(21.7\") of new snow at that elevation (approx. 12% density). We may have seen slightly more snow at higher elevations.

We have had a fair amount of snow settlement at these near freezing temperatures during this time as well. Currently the overall accumulation since the 15th at the tram weather station is 38cm(13.8\"). The UAS Gauge at Eaglecrest is showing slightly less but still near 35cm overall during this time.

We had a fair amount of wind during this event with 5 days of winds in excess of 25knots at summit elevations and 2 days where winds reached 50+knots.

Most of the wind has been our traditional SSE winds along the channel with 3 exceptions. From the 17th to the 18th we had West winds under 15 knots. From the 19th to the 20th we had East winds under 20 knots. From the 21st to the 22nd we had West winds at Eaglecrest and SW winds along the channel at under 20 knots. Most of the windloading would have occured primarily on NNW facing slopes yet you can assume there may be minor windloading on anything but South facing slopes.

Temperatures have cooled slightly over the last 36 hours and winds have died down to under 15mph in most locations.

The 24 hour forecast is calling for light winds, constant temperatures and very little precipitation. Avalanche danger is LOW at this time due to the lack of a trigger.

Natural avalanches very unlikely. Human triggered avalanches unlikely.

Most of the snowpack is solid in place yet be aware there may be windloaded pockets near summit and ridgeline in wind exposed locations that may be human triggered. Unlikely does not mean impossible. Every slope you choose to play on is an individual decision you must make.

Tip:

Everyone who plays in the mountains during snow season should take a level one avalanche course to be able to make educated decisions on what YOU are comfortable with.

We need to get away from the concept of safety gear saving lives and remember the only thing that saves your life everytime is an educated decision to not expose yourself to avalanche terrain during certain conditions.

It is important to remember that 25% of people who die in avalanches die from Trauma and all the tools and all the education in the world will not save you.

Here is a link to a great article on Avalanche Safety Tools:

http://www.adn.com/2012/02/19/2326372/snow-enthusiasts-split-on-use.html