Outside my Porter Fork bubble the past three days.

Toured Murdoch Peak Sunday 12/29 and Mt. Aire Monday (12/30) and today (Tuesday 12/31). This is an update to the Zinn Wilson and Drew Hardesty ob of 12/29. Summited Mt. Aire and Snowdrift Monday and returned to Snowdrift Tuesday. The difference between Monday and Tuesday was the amount of faceting. This area was the site of an avalanche accident with a call to 911 January 25, 2017, involving buried surface hoar.

The Murdoch Peak/Summit Park/Lambs/Mt. Aire complex is notorious for surface hoar development in the local cold pool which has been shrouded in a cold mist the past two days, producing notable feathers in select areas and a generally weak snow surface. Isolated a column in the north facing trees about 200 feet below Zinn and Drew’s pit which failed on the October snow. The combination of weak surface snow and an obvious failure plane on the October snow leads me to believe this area could produce some big avalanches over the next few days if the New Years Day storm verifies. Skiers initiating slides in the storm snow which then step down to the ground (a depth of 4 feet adding new snow to the existing 3 foot base), seem distinctly possible.

It was interesting to observe the cold mist was centered on the Summit Park/Lambs area and didn’t seem to get into Milcreek or the Cottonwoods—Gobblers and Raymond were clear, I’m guessing the Alta perimeter was too.

Hazard during the day Tuesday 12/31 was low, but this should change dramatically during New Years Day if the forecast verifies.

Mean of the U’s short range ensemble for Upper Collins is almost 20 inches during New Years Day. The 95th percentile on water is almost 1 inch during the 6 hour period from 9am to 3pm New Years, with winds on Baldy possibly gusting above 80 mph during the afternoon. The combination of strong wind, high PI and weak surface snow makes me shudder.

I’m calling the hazard for Wednesday Jan 1 considerable because I expect it will start low or moderate in the morning and increase during the day, possibly spiking to where avalanches are certain in steep terrain during the height of the storm. I wouldn’t be surprised to see UAC tweeting lots of avalanches during the day with a high hazard call. Me? I’ll be in low angle terrain.