Professional Observation

Basic Information

Observation Date:

April 21, 2023

Submitted:

April 22, 2023

Observer:

Everett Phillips | ESAC Forecaster

Zone or Region:

Mammoth Lakes

Location:

Winuba (Mount Tom) - Wet Snow in the Alpine

Recent Avalanches?

Yes

Cracking?

None Experienced

Collapsing?

None Experienced

Went up and over Winuba (Mount Tom) today from Pine Creek to the east headwall. We wanted look at transitioning snow above 12,000′ and assess wet loose conditions.

In the afternoon surface snow was wet on steep south through northeast faces up to 13500′.
Northeast facing snow in the alpine has yet to consolidate and it is prone to wet loose avalanching.
By 12:30 PM it was easy to trigger wet loose avalanches up to size 1 on NE aspects steeper than 45 degrees.
West and northwest facing aspects have been wind-hardened and present strong surface snow. Below 11,0000′ west aspects are transitioning to melt-forms.
Steep north facing snow above 11500′ is still soft. It saw some warming by air temperature in the early afternoon, but moist daytime snow is “drying out” (recrytsallizing) overnight.

Snow surface W, 10,000'. Boot pen. 5cm, rough surface.

Surface snow was wet on steep NE and E faces at all elevations even up to 13,000'. Ski sunk in to boot-top in the ealry afternoon.

Overhanging cornice on the north ridge of WInuba. 4/21/23

Melting root of an overhanging cornice on the north ridge of WInuba. 4/21/23

Advanced Information

Cloud Cover:

Mostly Sunny

Temperature:

Not Obs

Wind:

Light , SW

#	Date	Location	Size	Type	Bed Sfc	Depth	Trigger	Comments	Photo
5	Today	Mt Tom East Headwall NE 12800'	D1	WL		15cm	AS-Skier c-Intentional