Avalanche Advisory Archive Pre-2016

Date Issued:2010-01-08
Danger:2
Trend:3
Probability:3
Size:2
Problem:0
Discussion:

Hello and welcome to the Juneau Avalanche Advisory for the 2009-2010 season.

THE NATIONAL WEATHER SERVICE FORECASTS- TODAY...RAIN. PATCHY FOG IN THE MORNING. HIGHS 36 TO 42. EAST WIND TO 15 MPH. TONIGHT...CLOUDY. RAIN IN THE EVENING...THEN A CHANCE OF RAIN
AND SNOW LATE. NO SNOW ACCUMULATION. LOWS AROUND 34. EAST WIND
TO 15 MPH. CHANCE OF PRECIPITATION 90 PERCENT. SATURDAY, CLOUDY. A CHANCE OF RAIN AND SNOW IN THE MORNING...THEN RAIN LIKELY IN THE AFTERNOON. NO SNOW ACCUMULATION. HIGHS AROUND 38. EAST WIND 15 MPH. CHANCE OF PRECIPITATION 60 PERCENT.

We have received very little snow recently and .5\" or rain in the last 24 hours. This storm came in at near freezing temperatures and rapidly turned into rain. At summit elevations there may be a few areas of windloaded new snow that are now rain saturated and placing stress on the pack.

If the high temps and rain persist we will want to be careful and watch out for the potential of larger slab avalanches due to the multiple weak layers still remaining deeper in the snowpack.

Tip:

It was above freezing with quite a bit of rain around Christmas. This has caused quite a bit of settlement within the snowpack. Although we still have a few weak layers remaining deeper in the snowpack, most areas are fairly stable at this time.

If rains come in slow the snow has time to absorb it and soon the snowpack develops drain channels for the water.

If the rain comes in too rapidly then as it penetrates through the pack it often finds ice layers. If the water starts running down the mountian above or below that ice layer it has the potential to cut the slab above it loose and start an avalanche.

The longer the temperature stays above freezing and the more rain we get the more we start to look at the potential of full depth avalanches.