Our Fall Auction is LIVE! Support avalanche forecasting by bidding TODAY! Ends Sept 26th.
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: Brighton

Observation Date
1/5/2017
Observer Name
B
Region
Salt Lake » Big Cottonwood Canyon » Brighton
Location Name or Route
Brighton perimeter
Weather
Sky
Overcast
Precipitation
Light Snowfall
Wind Direction
Northwest
Wind Speed
Light
Weather Comments
Light snowfall in the early morning with overcast skies, and Broken Skies in the pm. Winds were not a factor by mid morning. Temperatures remained cool and in the lower teens. No transport observed after mid morning.
Snow Characteristics
New Snow Depth
12"
Snow Surface Conditions
Powder
Dense Loose
Wind Crust
Snow Characteristics Comments

6 inches of Light Density Snow from overnight overriding the settled 6 inches of Dense Snow from during the day on Wednesday. Density inversion that was evident on Wednesday (due to Wednesdays Denser Snow capping the Light Density Snow from Sunday/Mondays Event) appears to be settling out significantly. Shears indicated a Strong over Weak Layer still observable, but as reported by others, the quality of these shears was not Clean. Riding conditions today were fast with the Light Density Snow providing good "silky" turning on Moderate and Low Angle slopes. Slopes 30 degrees and over that were not showing signs of Loose Dry Avalanches and or Slab Avalanches were excellent. There times it was essential to keep your tips coming back up out of the snow due to the lingering Buried Density Inversion. Even Snowboarders were needing to be careful. Trailbreaking was much improved today.

Exposed Ridge Lines and Leeward Deposit Zones facing NE and ENE were showing signs of Wind Sculpting and Loading respectively. Wind Slabs of up to 24 inches deep were observed.

Red Flags
Red Flags
Recent Avalanches
Heavy Snowfall
Wind Loading
Cracking
Poor Snowpack Structure
Red Flags Comments
The combination of the Density Inversion (as cited above), Heavy Precipitiation, and the Strong Winds from Wednesday appear to be enough Red Flags to believe there is still potential for Lingering Reactive Slabs. Of Note: Explosive Control in Upper BCC released Hard Slabs that were up to 3 feet deep. And reports stated that there were areas with "Spooky/Errie" feeling "drum like" Wind Loaded areas that were Stubborn and not reactive. Slope Cuts were easily releasing 20 inch/plus Wind Ladden Soft Slabs on Steep Convexities with Slope Angles > 37 degrees. Cracking was also evident in these same locales.
Avalanche Problem #1
Problem
Wind Drifted Snow
Trend
Decreasing Danger
Problem #1 Comments

See above for details; and the Winds did not appear to die down in the Upper Elevations until after 1200 hours today. These Hard Slabs may still possibly be reactive and Likely in very steep N and NE facing terrain on Friday. The Wind Loaded Soft Slabs may be possibly settling out by Friday and more Unlikely.

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

Early in the day the Storm Slabs, that were present due to the previously cited Density Inversion, were easily Triggered and Reactive on Steep Convexities. With the extreme Cold night forecast these may become significantly more Stubborm on Friday.

Buried NSF's from last weekend still appear to be the Wildcard out there, and in Very Steep Northerly facing terrain this Problem may still be Likely.

The morning appeared to start out with the Danger being Considerable with the Winds still active; yet by Mid Day the Danger appeared to lesson to Moderate. And, with the lack of Natural Activity observed this validates this reasoning. For Friday, there appears to be a High Consequence Moderate Danger with potential for Moderate Sized Hard Slabs in the previously cited areas.

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