Avalanche Advisory Archive Pre-2016

Date Issued:2012-03-06
Danger:3
Trend:4
Probability:4
Size:3
Problem:0
Discussion:

The National Weather Service Forecasts-

TODAY...SNOW...MIXING WITH RAIN LATE IN THE AFTERNOON. ADDITIONAL SNOW ACCUMULATION 3 TO 5 INCHES. STORM TOTAL SNOW ACCUMULATION 9 TO 15 INCHES. HIGHS AROUND 35. EAST WIND 10 TO 20 MPH.

TONIGHT...RAIN AND SNOW IN THE EVENING...THEN RAIN. SNOW
ACCUMULATION UP TO 1 INCH. SNOW LEVEL INCREASING TO 1200 FEET LATE. LOWS AROUND 33. EAST WIND 10 TO 15 MPH.

WEDNESDAY...RAIN...POSSIBLY MIXED WITH SNOW IN THE MORNING. LITTLE OR NO SNOW ACCUMULATION. HIGHS AROUND 38. SOUTHWEST WIND 10 TO 15 MPH.

Temperatures at the beginning of this storm started out at about 21f at both the Mt Roberts Tram and the Eaglecrest Summit. Since that time they have only warmed about 2 degrees. Look to see temperatures continuing to rise over the next 48 hours.

We received about 10mm of precipitation in the last 18 hours. This delivered 20cm of really light fluffy low density snow.

Winds ranged from 10-25knots out of the SE-SW. Watch to see easily triggered windslabs on N facing slopes.

The forecast for the next 24 hours calls for as much as another 7\" of snow, continued warming, and moderate winds. Avalanche danger is CONSIDERABLE at this time.

Natural avalanches possible, especially during the warming to warmest part of the day.

Potentially destructive avalanches may come near or reach developed areas. Notably along Thane Road, and the Flume and Perseverance Trails. Thane is quite filled in and wont take much to hit the road.

Human triggered avalanches probable, especially in steep open areas and in windloaded pockets near summit and ridgeline.

Danger levels will continue to rise over the next 24-48 hours as temperatures continue to rise and the precipitation accumulation rate increases greatly tomorrow night into Thursday.

The avalanche sizes will be determined by how much additional new snow we get between now and the time the slopes relieve themselves.

Recent tests along Mt Juneau and Mt Roberts show there are multiple weak layers in the snowpack that are also questionable in stability. They are holding well now but the question is how much new snow or rain would it take to reactivate them. Should these lower weak layers become reactive once again the avalanche sizes could become quite large.

It looks like tomorrow night into late in the day on Thursday is the greatest concern at this point, yet with this low density snow on the ground and winds we may see activity sooner.

Use caution out there. Things look like they are getting interesting.

Have a great day.

Tip:

Its always nice to see lots of new snow in the spring. Please remember, the glide tracks are much more filled in now. The anchors are all covered up. Many of our south facing slopes will start to ice on sunny days. The sun is having a much greater affect... Its early spring... but danger will be with us for quite some time. Please continue to pay attention to the conditions and stay safe out there.