Avalanche Advisory Archive Pre-2016

Date Issued:2010-12-24
Danger:1
Trend:4
Probability:1
Size:1
Problem:0
Discussion:

This is my favorite forecast of the year... as I know Santa is checking out conditions for his big deliveries tonight. Welcome to Juneau Santa... Conditions are just fine...

If I may request... All I want for Christmas is snow...

THE NATIONAL WEATHER SERVICE FORECASTS-

TODAY...INCREASING CLOUDS WITH A CHANCE OF SNOW THROUGH THE DAY. LOCALLY BREEZY. HIGHS AROUND 23. EAST WIND 10 TO 20 MPH. HIGHER GUSTS NEAR INTERIOR PASSES.

TONIGHT...SNOW LIKELY. SNOW ACCUMULATION 1 TO 2 INCHES. LOWS
18 TO 26. EAST WIND 15 TO 20 MPH.

CHRISTMAS DAY...SNOW LIKELY. SNOW ACCUMULATION 1 TO 2 INCHES.
HIGHS 27 TO 33. SOUTHEAST WIND 15 TO 20 MPH.

SATURDAY NIGHT...SNOW AND RAIN LIKELY. LOWS 25 TO 33. SOUTHEAST WIND 15 TO 20 MPH.

Things should be interesting to watch as the new snow comes in and starts to accumulate.

Currently there is much spatial variability in the snowpack. Some areas have been wind scoured and do not have much snow in place or surface hoar. Some places have windloaded pockets sitting on multiple weak layers that currently are fairly supportive yet may start to fail under the presence of new snow load. And last but not least some areas of the backcountry that have seen less wind have a fair amount of surface hoar that may not be too supportive of the new snow loads as they start to accumulate.

With the warm weather from 2 weeks ago, the rain and heavy dense snow, the lower snowpack has settled and bonded quite a bit.

There are still multiple weak layers lower in the snowpack but the heavy dense snow above them appears to be supportive at this time. Be cautious as new loads are placed on these already weak layers by new snow or even by additional wind loading.

Look to see continued areas of wind loading as the snow in place and new snow is affected by winds of 10+ MPH throughout most of the next few days.

With very little snow on Mt Juneau in the urban starting zones avalanche danger is LOW at this time. Yet some of the gullies are starting to see fair snow accumulation due to crossloading from the winds.

Remember- Long periods of cold temperatures build weaker snow, which isn?t a problem until the next significant snowfall.

When temperatures stay well below freezing for long periods of time and high and low temperatures never rise above 15?F (-10?C) day and night, weak layers may develop on the surface or near the ground in a shallow snowpack; this can create a weak layer that fails with the next load of new snow. (We have seen a fair amount of these conditions this fall. Be aware that weakness in the snowpack this year my be further down than simply reactive surface layers. Make sure you are taking a good look at conditions in your favorite backcountry areas)

Please remember this is not a Backcountry Forecast-
Backcountry danger levels could be considerably higher.

Tip:

Nobody should spend time in the backcountry without a few simple tools.

Avalanche Transceiver, Avalanche Probe, and Shover.

As well as a partner trained in Companion rescue.

with one last day for christmas shopping please remember these items make perfect Christmas gifts for the mountain enthusiast in your party, or for your backcountry partner!

Happy Holidays and Be Safe out there Juneau!