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Observation: Primrose Cirque

Observation Date
3/16/2024
Observer Name
Coyne/ Hartnett/ Bonfiglio
Region
Provo » Provo Canyon » North Fork Provo R. » Primrose Cirque
Location Name or Route
Primrose Cirque/ Emerald Lake
Weather
Sky
Few
Wind Direction
East
Wind Speed
Extreme
Weather Comments
SLC Valley winds were gusty and blowing out of the East at our morning rendezvous location in Millcreek, skies mostly clear throughout the day, with a few clouds forming from high winds off ridgelines. Winds were calm at the Aspen Grove TH at about 6:30am. Winds remained mostly calm until we reached near ridgeline on Timp. We did have a little moist layer rise through the cirque as the eastern valleys warmed up, inversion lifting and forming a quick 10 minute cloud bank as it condensed into the mtns.
Red Flags
Red Flags
Wind Loading
Red Flags Comments
Name of the game continued to be concerns about the winds.
Comments
I'll start by saying that usually I submit observations when my eye catches changing snow conditions, avalanche observations, or something of the matter. I submit today as we have had strong> extreme easterly winds for several days and we were pleasantly surprised by the lack of wind damage in the drainage from the event. More eyeballs and submissions during unique weather events, improves forecasting, builds our community, and ultimately helps us all make better and more informed decisions.
Tour today started at Aspen Grove Trailhead at about 6:45 am with a hope to ascend Primrose Cirque >Emerald Lakes> Timp Glacier travel south across the ridge line to ski the East Ridge. Travel was good, beginning on some low elevation smooth, refrozen snow which lead to softer powder snow at about 7,600ft on the more northern terrain in the shade of the climber's left wall. Based off of Kelly, et all's video from yesterday, the winds off East Peak had diminished greatly this morning. We were pleasantly surprised to find mostly soft powder snow ~8-10" through shaded aspects in Primrose with little wind effect. Southerly slopes donned a thin breakable crust that capped graupel from a previous storm. We noted several recent avalanche debris piles on shaded aspects likely from wind slab avalanches in the past few days. About a dozen loose wet slides peppered the southerly facing slopes between Bob's Knob and Roberts Horn, consistently sliding to the dust later.
We noted very little wind-affected snow until we reached the Timp Glacier which was heavily wind-jacked, a mixture of sastrugi and graupel deposits. Venturi-style winds were increasing in speed as we ascended to the pass below the South Summit of Timpanogos, likely gusting 70 mph on the ridge itself. Trying not to be turned into human kites, we tucked tail on our object and enjoyed a wonderful ski back down Emerald to Primrose.
We were again a bit surprised to find pleasant powder snow with little to no wind damage once we put the Glacier behind us. on a few test slopes a few "rounded pillows" we not quite slabbed up enough to make an avalanche. Snow remained cold in the shade until our 1 pm exit. A new wet loose snow avalanche in the upper pitches of Primrose covered our skin track, validating the early start before temperature rose.
Photo 1: Pleasant travel
Photo 2: Punishment
Photo 3: Reward for turning on the main objective
Today's Observed Danger Rating
Moderate
Tomorrows Estimated Danger Rating
Moderate
Coordinates