32nd Annual Backcountry Benefit- Get Your Ticket Now!
Ad
The National Forest Service Logo
icon-add Observation
Forecasts
Logan Ogden Salt Lake Provo Uintas Skyline Moab Abajos Weather Archives How to read the forecast
Observations & Avalanches
Submit Observation Observations Explorer All Observations Avalanches Fatalities Weather Place Names Map Archives
Education
Avalanche Class List UAC Class List Online Classes Resources and Tutorials Avalanche Awareness Develop Skills
Events
Store
About
Contact Who we are Core Values Staff Board of Directors Past Forecasters Sponsors Annual Reports Sign In
Blog
icon-add Observation
Donate / Join

Observation: Snowbird periphery

Observation Date
3/28/2017
Observer Name
B
Region
Salt Lake » Little Cottonwood Canyon » Snowbird periphery
Location Name or Route
Snowbird Periphery
Weather
Sky
Broken
Wind Direction
North
Wind Speed
Moderate
Weather Comments
The weather forecast appeared to miss it's mark on the winds; and as a result the north winds were sustained in the high end of the Moderate range with gusts into the Strong category. Transport was Moderate with many cornices being eroded and reverse loading. Temperatures appeared to remain cooler as well with regard to the forecast, and with the increasing cloud cover during the day combined with north winds the snowpack did not warm up as much as possible for a late March day.
Snow Characteristics
New Snow Depth
9"
New Snow Density
High
Snow Surface Conditions
Dense Loose
Faceted Loose
Wind Crust
Melt-Freeze Crust
Damp
Snow Characteristics Comments

Due to high RH, the winds and the moderate temperatures the settlement of Mondays storm event was significant. New snow measurements of up to 13 inches appeared to be more around 9 inches for the day on the protected areas. And, the winds thinned this depth as well as the daytime heating and sun that was out for the morning hours. All that said, in the limited protected areas the riding was good in dense spring powder; and on the E, ESE and S aspects where the snow surface wasn't disturbed by the wind even the damp powder rode well on low angle terrain in the morning. Much of the upper elevation exposed terrain had dense wind laden snow, and slabs. Plus, the upper steep starting zones on many of the northerly facing shots was scoured and slippery. Interestingly, there were small/shallow deposits of Faceted Loose snow being sprayed and loaded on the southerly sides of the leeward ridges. By the end of the day all but the most northerly slopes with angles > 25 degrees were either damp and or already crusted.

Red Flags
Red Flags
Recent Avalanches
Wind Loading
Cracking
Poor Snowpack Structure
Red Flags Comments
Poor snowpack structure continues to be confined to the interface of the latest prestorm melt freeze crusts to the new snow from Monday. In the early morning hours S and SE facing steep terrain at mid slope elevations were experiencing sensitive wind slabs that were easily triggered with slope cuts. Cracking was observed on low angled slopes without initiation. During the afternoon hours with daytime heating and the associated solar influences it was possible to intiate small pockets of wet slabs on E and NE facing steep rollovers.
Avalanche Problem #1
Problem
Wind Drifted Snow
Trend
Same
Problem #1 Comments

See above, and it most likely was possible that this problem became more widespread on upper elevation steep terrain that was a little off the ridgelines due to the excessive wind velocities. At 2100 hours the winds are still very active at the upper elevation ridgelines and this problem may still be of concern and maintaining this isolated trend of Danger and Hazard for Wednesday.

Avalanche Problem #2
Problem
New Snow
Trend
Decreasing Danger
Problem #2 Comments

On the shady very steep northerly facing aspects that are still housing what is left Mondays storm the potential for this hazard was possible on Tuesday; and it there may still be very isolated pockets in this identified terrain on Wednesday, though this reactivity most likely will be decreasing.

On another note, due to the the cold temperatures and cloud cover the Wet Loose activity was minimal on Tuesday; and with the clear skies and warmer temperatures forecast for Wednesday this problem may be more active during daytime heating on Wednesday.

Finally, the Cornice situation continues to be of concern where these lingering large cornices still exist; and with the reverse loading and eroding may have weakened them on Tuesday.

Today's Observed Danger Rating
Moderate
Tomorrows Estimated Danger Rating
Moderate