Skier caught, carried and buried. They were buried under 2.5' of debris for 2 minutes.

Advisory for February 17, 2003

Avalanche Conditions:

Yesterday strong winds and new snow caused a marked increase in the avalanche danger. Backcountry observers noted that the fresh wind drifts were a bit sluggish on 30 degree slopes, but didn’t need much encouragement on slopes approaching 40 degrees in steepness.

A group in Cardiff Fork triggered a fresh wind drift about a foot deep and 50’ wind on a northeast aspect. In the Wolverine Circ a skier was able to trigger several wind drifts, but one in Huge Chute broke about 30” deep and 70’ pulling out snow to the ground on one side. That slope faces northeast and is near 40 degrees. Also a skier in Big Cottonwood Canyon was caught and was briefly buried in a slide about 1’ deep and 40’ wide.

The main avalanche concern today will be the wind drifts that formed with southwest winds yesterday and northwest winds overnight. The winds were quite strong so look for mid-path wind pillows and drifts in other odd places. They could be stubborn today, but you will still be able to trigger then on the steeper slopes. Also with an inch of water in the last 24 hours and 2 inches in the last three days, the chances of triggering a deep slab avalanche have increased. The areas where you can trigger a deep slab remain localized, but as we saw on Saturday the consequences can be severe. Remember that wind slab avalanches are great triggers for deep slab avalanches.

Lastly, the cloud cover will be increasing today, but direct sun could trigger sluffs in the new snow this morning.

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Advisory for February 18, 2003

Avalanche Conditions:

We heard about a couple backcountry avalanches from yesterday. First, some snow boarders went out of bounds from Brighton and the third boarder down the west side of Millicent Peak triggered a soft slab avalanche about 100 feet wide and 1- 2 1/2 feet deep on a 38 degree slope, which ran about 300 vertical feet. Luckily, the boarder had his speed built up and was able to outrun the slide. It broke below the rain crust from February 13th and the boarder triggered it from the deepest part of the fracture, probably in a pool of graupel that rolled off the cliffs. The second avalanche occurred in the backcountry on the east side of Clayton Peak near Brighton, which was triggered remotely by explosive avalanche control at Brighton. It broke 3-4 feet deep, 100 feet wide and broke into deeper layers of faceted snow.

Today, we’re worried about two different avalanche problems:

First, you may be able to trigger some localized avalanches within the new snow. For instance, the graupel snow which fell on Sunday tends to roll off of cliffs and steep slopes and pool on the flatter aprons underneath steep slopes. So you should continue to watch out for places like because they have an unusually heavy load of new snow. Also, wind from Sunday and also last night created localized deposits of wind drifted snow. As always, you should avoid steep slopes with recent wind drifts.

Second, is our old problem, the weak layers of faceted snow and depth hoar near the ground, which formed during clear weather in December and January. We have had a coupe inches of water weight added over the past week and this is enough to stress some of these deeper weak layers enough to make them sensitive to human triggers. We’ve had three different avalanches break into these deeper weak layers in the past three days including the fatal Gobbler’s Knob avalanche on Saturday, Wolverine Cirque on Sunday and the east side of Clayton Peak yesterday. Especially watch out for steep, slopes with a thin snowpack above about 9,000’ in elevation.