Avalanche Advisory Archive Pre-2016

Date Issued:2012-03-15
Danger:1
Trend:3
Probability:2
Size:2
Problem:0
Discussion:

The National Weather Service Forecasts-

TODAY...MOSTLY CLOUDY. SLIGHT CHANCE OF RAIN AND SNOW. HIGHS
AROUND 38. EAST WIND 10 TO 20 MPH.

TONIGHT...RAIN LIKELY IN THE EVENING...THEN SNOW LIKELY LATE.
SNOW ACCUMULATION UP TO 1 INCH. SNOW LEVEL 700 FEET IN THE
EVENING. LOWS AROUND 31. EAST WIND 10 MPH IN THE EVENING BECOMING LIGHT AND VARIABLE.

FRIDAY...SNOW AND RAIN LIKELY. SNOW ACCUMULATION UP TO 1 INCH. HIGHS AROUND 39. SOUTH WIND 10 MPH.

Yesterdays field work on Mt Juneau confirmed the presence of older persistant weak layers deeper in the snowpack.

The surface layers also had some weakness.

We saw pencil hard windslabs over 4 finger snow that failed in compression tests on isolation of the column at 20cm. We also saw a faceted layer under some old crusts that failed in tests at 100cm deep.

Temperatures rose at the Mt Roberts Tram Summit yesterday and hovered around -1c while the Eaglecrest summit stayed colder at -3c. We have received almost no new precip in the last 3 days.

Avalanche danger is LOW at this time for the most part.

The Tram and Eaglecrest sumit gauges showed 10-25mph winds yesterday out of the North East. But ground winds in the starting zones were actually much higher. We experienced winds approaching 50mph on the Mt Juneau ridgeline which were quite actively loading our urban starting zones.

I am growing somewhat concerned as to what the next snowfall will bring in our urban enviroment.

Last week the Cross Bay path had two avalanches. The skiers Right side slid to within 200 yards of Thane Road and the skiers left side slid to within 75 yards of the road. The center of the path has not released since early January and it is safe to assume it may have the same deeper weak layers present in the snowpack.

The snowslide creek path has not released significantly in quite some time as well. We did see some small results there with the recent blasting but have had quite a bit of new snow since that time. All three paths that converge on the snowslide creek drainage are quite loaded at this time. Winds over the last 3 days have continued to add to that load as well. The cornice on lookers right of the main chute is also quite large and overhanging. It could fail at any and become the trigger for a much larger avalanche.

The Behrands Ave Avalanche Path has had numerous notable slides this winter but all from the lower starting zones. The main upper starting zone is VERY filled in and has deep weak layers present. Time will tell how this persistant weak layer plays out.

With not much precip in the forecast I am going to keep the danger rating to LOW yet recognize in certain paths it may be more moderate.

Be aware of windloaded pockets on SW facing slopes on Douglas Island as well as along the channel...

Recognize that lots of direct sun, warming, wind, or heavy new snow loads could make these layers become reactive once again.

Remember if your in the backcountry in these places with windloaded pockets YOU are the trigger and could tip the balance sooner to cause avalanches.

Pick safe lines and enjoy another nice day!

Tip:

Skiers View- from the summit of a given mountain looking downhill...

Lookers view... from the base of a mountain looking up the hill...

This is often how mountain folks describe mountain features in a way their freinds can understand...