Observation: Emma Ridges

Observation Date
1/17/2019
Observer Name
Bill Nalli
Region
Salt Lake » Little Cottonwood Canyon » Emma Ridges
Location Name or Route
Emma Ridge
Weather
Precipitation
Moderate Snowfall
Wind Direction
Southwest
Wind Speed
Strong
Weather Comments
Warm and strong SW winds ramped up early morning causing S aspects to mostly get stripped and deposited new snow onto N-E slopes along the Emma Ridge. Conditions became intense by afternoon causing one to question the reasons for travelling in the backcountry.
Snow Characteristics
New Snow Depth
16"
New Snow Density
Medium
Snow Surface Conditions
Dense Loose
Snow Characteristics Comments
The new snow was getting blown into dense drifts on all leeward aspects. Todays dense snow began to pile up by mid day and was being deposited onto yesterdays lower density storm. Very slabby and upside down. Difficult trailbreaking. All leeward aspects now have a dense slab on top of lower density snow with a mixed bag of layers below. While the structure is complicated in most areas, the current status is simple. Lots of new snow and wind have created unstable conditions on all steep slopes. Avalanches are expected.
Red Flags
Red Flags
Recent Avalanches
Heavy Snowfall
Wind Loading
Cracking
Rapid Warming
Poor Snowpack Structure
Red Flags Comments
With the first steps into the backcountry today it was clear that we would find instability and create avalanches. Wise terrain choices were the only option for backcountry travel today.
Avalanche Problem #1
Problem
Wind Drifted Snow
Trend
Increasing Danger
Problem #1 Comments
Todays strong SW then NW wind created dense but stubborn wind drifts on all aspects. 1st photo is of wind transport along the Emma Ridge into Days Fork. This sensitive but tricky slab sits on top of yesterdays new snow that had an initial weakness about 2cm above the old surface. That new snow instability settled out yesterday but became active again with today's new load. Cracking and failure was found on most all slopes above 35 degreees.
Travel was up Flagstaff and east along the Emma Ridge. We stayed well left and west of the normal route today as we found spooky hollow slabs on all SE leaward aspects. My good ole patrollers feet kept sending me left away from punchy slabs on steep slopes. Once we gained the Emma Ridge it was hard to stay far enough away from the NE aspects not to trigger 1'-2' slabs into Days Fork. After triggering the second slide into Days east of Two Dogs we decided to call it quits due to very poor visibilty and increasing hazard. In these conditions its just not possible to ensure that there arent other parties below you. Best to pull the plug and retreat.
After choosing to descend the most gentle route down the subridge of Emma 1, I unintentinally triggered a D2 SS that nearly took me for a nasty ride. It was on a sublte terrain feature that was holding yesterday's storm snow instability and was now reloaded with a stiff slab. The slide travelled 1000' vertical stopping at the last transition above the summer road. It failed at a density change 2cm above yesterday's old snow surface.
Today's Observed Danger Rating
High
Tomorrows Estimated Danger Rating
Considerable
Coordinates