Observation: Silver Fork

Observation Date
3/7/2013
Observer Name
Bruce Tremper and Trent Meissenheimer
Region
Salt Lake
Location Name or Route
Quick trip from Alta to Silver Fork (East and West Bowls) return to Alta
Weather
Sky
Broken
Wind Direction
South
Wind Speed
Light
Weather Comments
Unsettled weather with variable, mid level clouds. Quite warm, light to moderate winds from the south.
Snow Characteristics
New Snow Depth
1"
New Snow Density
Medium
Snow Surface Conditions
Powder
Snow Characteristics Comments

Rather character-building snow surface conditions with a wide variety of sun and wind crusts and old tracks in often punchy snow. One mighty inch of new snow helped a bit. Not a lot of people were out. But I've been chained to the computer for the last few days and it sure felt good nonetheless. We actually found some ridable snow in places but I was jealous of Trent on a split board--at least on the downhills.

Red Flags
Red Flags
Wind Loading
Red Flags Comments
See below
Avalanche Problem #1
Problem
Persistent Weak Layer
Problem #1 Comments

Although most of the snow seemed rather well-behaved, the main problem is the lingering wind slabs from the strong southerly winds for the past couple days. I expected to see more wind slabs along the upper elevation ridges but it appears like the wind was so strong that it just scoured all the upper elevation terrain and most of the wind-slabbed snow was down lower on the slope and even in some of the upper elevation drainage bottoms--well down off the ridges. It was a tricky wind pattern and the wind seemed to swirl around a lot so the loading was on a variety of aspects.

Luckily, most of the wind slabs were settled out and we could not get any of them to crack. They are more tricky to recognize than usual because the inch of new snow hides the texture.

Very little activity occurred at the ski resorts today with the exception of one significant result from one of the Park City areas that typically loads with south winds. The avalanche was triggered by a controlled cornice fall. So they are out there, just a bit stubborn.

Avalanche Problem #2
Problem
Wet Snow
Problem #2 Comments

The lower elevation snow is still moist and isothermal. We noticed a couple small, wet sluffs on steep slopes but nothing major. I suspect wet activity will remain fairly well behaved until we get another big warm up or low elevation rain again.

Comments

We dug one snow pit on a northeast facing slope at 9,000' and found quite stable snow there with a total snow depth of 220 cm. There were no results with compression or Extended Column Tests.

Sorry, no video or photos due to lack of anything too interesting.