Observation: NWAC Forecaster

All Observations

Basic Information

Observation Date:

March 13, 2023

Submitted:

March 14, 2023

Observer:

NWAC Forecaster - Joe Dellaporta

Zone or Region:

Mt Hood

Location:

Vista Ridge

Recent Avalanches?

None Observed

Cracking?

Isolated

Collapsing?

None Experienced

Isolated cracking on wind loaded test slopes.

Advanced Information

Cloud Cover:

Obscured

Temperature:

32°F

Wind:

Strong , W

New/Recent Snowfall:

HN: 10 cm

Rain transitioned to snow just below trailhead elevations. Snow conditions were wet and sticky for the lower 500 ft of the tour. Above 5,500 ft W winds ramped up into the strong range and the snow became drier. Due to this we started observing heavy drifting at treeline.

We went out searching for buried surface hoar in the Vista Ridge area. Fortunately, we were unsuccessful at locating the 3/2 layer of buried surface hoar in the locations we dug. The main takeaways are wet surfaces that extend up to 5500 ft (that will likely have a crust after today) and stubborn firm wind slabs in the ATL.

Winds were actively blowing in the strong range once we reached treeline at 6000 ft. Test slopes produced shooting cracks in firm pockets of drifted snow. These slabs were typically (1F-P) and would likely pack a punch if triggered in bigger terrain.

We observed a deep and relatively strong snowpack in this zone. HS ranged from 300-360 cm above 5500 ft. The 2/21 freezing rain crust (K hard) still acts as a prominent marker in the snowpack. We were finding this crust about 130cm below the surface here. Snowpack test produced unremarkable results.

Problem	Location	Distribution	Sensitivity	Size	Comments
Wind Slab	N E S W	Isolated Specific Widespread	Unreactive Stubborn Reactive Touchy	D1 D1.5 D2 D2.5 D3 D3.5 D4 D4.5 D5	Layer Depth/Date: 4-8 inches Comments: The long duration of high wind speeds have made for some firm, stubborn slabs ( 1F-P hard) in more exposed NTL/ATL terrain. I suspect slabs forming further down slopes than usual.

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