Observation: Mineral Fork

Observation Date
2/8/2013
Observer Name
Bruce Tremper
Region
Salt Lake
Location Name or Route
Mineral Fork, east facing
Weather
Sky
Overcast
Precipitation
Heavy Snowfall
Wind Direction
Southwest
Wind Speed
Moderate
Weather Comments
Cloudy and windy in morning and heavy snow started falling around 3:00 pm.
Snow Characteristics
New Snow Depth
2"
New Snow Density
Medium
Snow Surface Conditions
Powder
Faceted Loose
Wind Crust
Melt-Freeze Crust
Snow Characteristics Comments

Before the storm arrived, there was the usual mixed bag of snow surface conditions--wind blasted along the ridges, sun crusts on sun exposed slopes and still some soft, settled powder--somewhat recrystallized--on the shady aspects. New snow should dramatically improve conditions.

Red Flags
Red Flags
Wind Loading
Red Flags Comments
The southwest ridge top winds were transporting snow along the Mineral - Mill B divide creating wind slabs just a few inches thick.
Avalanche Problem #1
Problem
New Snow
Problem #1 Comments

In the morning, the main problem will be storm snow with the expected accumulation overnight. I would expect there to be fresh wind slabs along the ridges from the southwest winds, combined with new snow. The usual cautions for new snow such as wind slabs and density inversions within the new snow. I would expect it will bond to the old snow surface fairly well. I did not see any surface hoar along the creek bottoms but the old snow surface is somewhat recrystallized on the shady slopes so we should keep an eye on it but it seemed quite small-grained and immature.

Avalanche Problem #2
Problem
New Snow
Problem #2 Comments

Most of our persistent slab problems--perhaps they are deep slabs now--have settled down. I dug a couple snowpits, one on a northeast face around 7,500' and one on a northeast facing slope around 9,000'. both showed no propagation of fractures. The snow at very low elevations is quite shallow and weak with basal depth hoar and columns broke more easily in the shallow snowpack areas. If we get significant snow, we may see some slabs in low elevation steep slopes that could be persistent.

There is always the chance to reactivate the January faceted snow layer if we get significant amounts of water weight, especially with wind on the same slopes where we had so many problems last weekend--upper elevation shady slopes--but I'm guessing they will remain fairly well behaved with this storm with the forecasted addition of water weight.

Sorry no photos or video today because of time constraints.