Island Park

We rode to the top of Sawtelle to de-rime the anemometer (wind sensor) and then down into Rock Creek Basin under all the big north facing avalanche paths.

Key findings:

1. New snow amounts ranged from 6-8" at lower elevations and 18" at higher elevations
2. We did not observe any cracking or collapsing on non wind loaded slopes.
3. We observed two very recent natural storm slab avalanches about a 1.5 feet deep. One of them entrained a significant amount of snow an ran a long ways.
4. There has been minimal wind effect except at ridgetops
5. Extended Column tests on north facing slopes continuously broke and propagated after 12 taps (ECTP12) just under a soft crust in snow that fell last weekend. These appeared to be breaking on broken stellars/snowflakes. On other aspects, the crust was much thicker and harder.

Conclusions:

The likelihood of triggering a soft slab avalanche about 1.5' deep seemed low on non-wind loaded slopes. Any amount of wind affecting a slope whether loading a slope or just stiffening the new snow, dramatically increased the odds of triggering a slide. We felt comfortable riding in avalanche runout zones and even climbing into the paths some. The main strategy was to stay out of the upper starting zones that are steeper and have seen some wind. HOWEVER - we carefully limited our exposure in big runout zones where a falling cornice could have triggered a slide that could have crashed down onto us. We did not think that we would trigger an avalanche from below  

Looking ahead  - Strong winds Sunday through Monday will have plenty of snow to transport along with additional snow that will fall. This should increase the danger and the size of possible avalanches.