Avalanche Advisory Archive Pre-2016
| Date Issued: | 2014-04-08 |
|---|---|
| Danger: | 2 |
| Trend: | 3 |
| Probability: | 0 |
| Size: | 2 |
| Problem: | 0 |
| Discussion: | From the National Weather Service: TODAY...RAIN SHOWERS. SNOW LEVEL 1400 FEET. HIGHS AROUND 44. SOUTHEAST WIND 10 TO 20 MPH DIMINISHING TO 5 TO 15 MPH IN THE AFTERNOON. TONIGHT...RAIN SHOWERS. SNOW LEVEL 1200 FEET DECREASING TO 700 FEET LATE. LOWS AROUND 33. SOUTHEAST WIND 10 MPH. WEDNESDAY...SNOW IN THE MORNING...THEN RAIN IN THE AFTERNOON. SNOW LEVEL 200 FEET IN THE MORNING. HIGHS AROUND 41. SOUTHEAST WIND 5 TO 15 MPH. The last 24 hours saw precipitation values about half of what was forecast, with 1.4? of rain on Mt. Roberts spread out through the day as opposed to in an intense pulse. Temperatures at Roberts remained above freezing with a high of 39 and we lost about 5? of snow. Similar precipitation is expected today with somewhere between .5?-.75? expected over the forecast period. It is possible that some of this will fall as snow in some locations. Freezing levels are currently near 2000'. Todays cooler temperatures should stay below 40f on Mt. Juneau. Winds will remain below 20mph. Larger natural slides are possible as we continue to put more stress into the snow, but drainage channels have likely had time to form to help sluice some of this weight away. A smaller wet slide may trigger the spatially variable but much deeper persistent weak layer. Numerous smaller wet slides and point releases were reported yesterday. Fieldwork today will look at how deeply water has penetrated in the snow pack and how well developed the drainage is. Todays urban hazard is MODERATE with some natural activity possible. Size should remain small and would not likely reach urban structures. The 24 hour trend is the same. |
| Tip: | Glide Avalanches: This is the time of year we are usually tracking glide cracks in the urban start zones. As the snow pack deforms downhill due to gravity and topography, it can break out to the ground in large cracks. This process often happens very slowly, and may or may not culminate in a natural release. When it does release, it can be a very large amount of dense snow. Below are a few links with further reading (cut and paste). USFS definition: http://www.fsavalanche.org/encyclopedia/glide.htm A great 2012 Juneau Empire article on Glide avalanches by Kensington Mine forecaster Ron Simenhois: |
| Forecaster: | Peter Flynn |