Avalanche Advisory Archive Pre-2016
Date Issued: | 2011-02-22 |
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Danger: | 3 |
Trend: | 3 |
Probability: | 3 |
Size: | 3 |
Problem: | 0 |
Discussion: | The National Weather Service Forecasts- TODAY...PARTLY CLOUDY IN THE MORNING THEN BECOMING SUNNY. HIGHS AROUND 25. NORTH WIND 10 TO 20 MPH...HIGHER GUSTS OUT OF INTERIOR PASSES. TONIGHT...MOSTLY CLEAR. LOCALLY BREEZY. LOWS 1 TO 11. COLDEST WEDNESDAY...SUNNY...WINDY. HIGHS 23 TO 29. NORTHEAST WIND 20 TO 30 MPH DECREASING TO 15 MPH IN THE AFTERNOON. STRONGEST WINDS OUT OF INTERIOR PASSES. WIND CHILL TO 30 BELOW ZERO IN THE MORNING. WEDNESDAY NIGHT...MOSTLY CLEAR. BREEZY. LOWS 5 TO 13. NORTHEAST WIND 15 TO 25 MPH. We saw 55mm of precipitation and 40cm of snow in 36 hours at tram summit elevations from Friday to Saturday. Then another 12cm of snow on Sunday night. Winds averaged 20+ mph during the main part of the storm along the channel and closer to 30 mph on Douglas Island with gusts into the 50's. Then died down durning the last 12cm leaving light loose snow available for wind transport today. Temperatures warmed by 7 degrees during this snow event. These are all red flag indicators of Direct Action Avalanches. With direct loading wind in the forecast for today Avalanche Danger is Considerable at this time. Natural avalanches are still possible and human triggered avalanches remain likely in areas. The last two days quite a few people got a surprise as they surfed out avalanches around the region... Be Careful out there, danger is still there and waiting for you. The slab has had additional time to settle and bond yet pockets of instability still exist. These are dangerous avalanche conditions. Careful snowpack evaluation, cautious route finding, and good decision making are the rules for the day if your headed out to play. Recognize areas of great weakness exist and with the addition of the trigger (YOU) avalanches are quite possible. Heightened avalanche conditions on specific terrain features exist. Identify snow and terrain features carefully and identify features of concern. This light loose snow on top will be cleaning itself off of rocks, trees, and steep open pitches in the form of Point release avalanches. In areas these point releases can become quite large. Even creating the ability for a fracture to propagate down to the deeper weak layers in place. Small slabs will also be building with this wind and have the ability to trigger larger slabs should they release. |
Tip: | Learn how to: Identify Red Flags Mother Nature often provides clues or Red Flags when the snowpack is unstable. 1. Recent avalanche activity: Recent avalanche activity is the indisputable sign of instability. If you see recent avalanche activity the snowpack is unstable. 2. Wind: Wind creates dangerous slabs; if the wind is blowing or has blown recently it has probably created dangerous wind slabs and increased the avalanche danger. 3. Intense precipitation: Precipitation often increases the avalanche danger. The more snow that falls and the faster it falls the more apt it is to create dangerous conditions. And wet snow or rain falling on cold dry snow almost always causes avalanches. 4. Whoomping sounds or cracks: Cracks in the snow surface and/or \"whoomping\" sounds mean that a weak layer is collapsing and that the snowpack is unstable. This is a sure sign of instability; stay on low angle slopes. 5. Rapid temperature rise: If the temperature is rising; watch out! Often it will be cold powder skiing in the morning and then warm up significantly in the afternoon. This rapid warming can transform fluffy powder into a dangerous slab. This newly formed slab can change stable powder conditions into unstable slab conditions in a very short time. In a settled more spring-like snowpack, if you are sinking into wet snow 6\" or more, the snowpack surface is becoming saturated and wet slides could occur. Roller balls, snow snails and point releases all indicate wet unstable snow. |