Avalanche Advisory Archive Pre-2016

Date Issued:2011-12-24
Danger:1
Trend:3
Probability:2
Size:2
Problem:0
Discussion:

The National Weather Service Forecasts-

TODAY...RAIN SHOWERS MIXED WITH SNOW IN THE MORNING...THEN RAIN IN THE AFTERNOON. SNOW LEVEL RISING TO 900 FEET IN THE MORNING. NO SNOW ACCUMULATION. TEMPERATURES STEADY AROUND 39. SOUTHEAST WIND 10 TO 20 MPH IN THE MORNING BECOMING LIGHT AND VARIABLE.

TONIGHT...RAIN. SNOW LEVEL 1300 FEET. LOWS AROUND 34. SOUTHEAST WIND 15 MPH IN THE EVENING BECOMING LIGHT AND VARIABLE.

CHRISTMAS DAY...SNOW IN THE MORNING. RAIN. SNOW ACCUMULATION UP TO 2 INCHES. SNOW LEVEL 1000 FEET. HIGHS AROUND 36. SOUTHEAST WIND 10 MPH.

In the last 24 hours we received 12mm of precipitation and roughly 12cm of new snow at tram summit elevations and above.

Temperatures have come up by 2C degrees in the last 24 hours.

Winds have been from 15 to 35 knots out of the SSE.

The surface layers have been bonding and settling pretty fast at these near freezing temperatures.

There is a fair amount of spatial variability in the snowpack at this time on different aspects and elevations. Be aware that pockets of isolated danger may still exist.

In general with not much precip in the forecast. Steady, near freezing temperatures, and light to moderate winds avalanche danger is LOW at this time.

Yet be aware you may still be able to trigger slabs in isolated windloaded pockets.

Tip:

Learn how to: Analyze Snow Stability

Many experienced and skilled people get caught in avalanches because they base their decisions on subjective human factors like I want to rip this line rather than objective data like observations and stability tests. The best way to be sure you are basing your decisions on natural factors rather than human factors is to follow a systematic, accepted and repeatable snow stability evaluation process.

1) Begin gathering information before you leave home in the morning. Read or listen to your local avalanche advisory and weather forecast and gather beta from any friends that have been in the backcountry recently.

2) Get your Avalanche Eyeballs in focus as you drive to the trailhead. Watch for Red Flags or signs of instability like recent avalanche activity off cut banks and snow blowing across the road or off adjacent peaks.

3) Keep your Avalanche Eyeballs peeled as you leave your car and head out into the backcountry. Watch for recent avalanche activity, cracks emanating from your tracks, heavy snow or rain fall, and wind blown snow and listen for \"whoomping\" sounds.

4) Recent avalanche activity is a sure sign that the snowpack is unstable and any one of the other Red Flags is a very reliable indicator that the snowpack is unstable

5) Dig snow pits and perform stability tests on a variety of aspects and elevations: Look for signs of instability not stability. Dig lots of snow pits and perform lots of stability tests. The snowpack can vary wildly and widely from place to place; each snow pit you dig and test you perform increases the likelihood that your assessment will be accurate.

6) Choose terrain that matches your stability assessment. In other words, if you observe any Red Flags, the safest decision is to stay on terrain below 30 degrees.