Avalanche

Herman

Lee LazzaraWest Slopes North
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Quick report

Looked for - but didn't really find - lingering weakness at the Jan 10th interface in the Baker BC as that was where the most reactivity was reported over the weekend. Most steep slopes with wet snow tried to produce wet loose avalanches but they were sluggish and didn't amount to much. However, it was easy to get wet snow moving where there was 15cm or less of new snow and the Jan10th crust was supportable and slick underneath. Avalanche danger was Low on slopes not seeing the sun, but somewhere out there there's probably a lingering slab that could fail on facets above the Jan 10th crust.

Instability limited to roller balls and triggering small wet loose avalanches on southerly, mid and lower elevation slopes.

Weather

Cloud Cover
clear
Wind Loading
none
Snow Avail For Transport
none

Mostly clear sky and quite warm. Light southerly winds through the day didn't prevent surface warming but may have kept it in check at upper elevations.

Snowpack

A very thin layer of moist snow topped the snowpack on shady aspects up to 6000'. Surface faceting (up to 2mm) was most noticeable on shady slopes near drainage/valley bottom where there was more shade and a mild temperautre inversion.  Crust on south aspects turned to mush by the afternoon.

15-70cm of recent new snow from last weened over the thin Jan 10th crust depending on exposure to wind. Small facets forming in the upper 10cm or so. Warmer temperatures seem to have kept extensive faceting in check so far. Weakest interface was still softer, faceted snow just above the crust. ECTN/X at Jan 10th interface, CTM-SP. The facets are generally rounded, but intact facets under 15cm of moist snow were found on an east aspect at 6000'.  The Jan 2nd interface was down 30cm on a shaded, wind sheltered slope at 5000' - CTH-RP at this interface.

Avalanche

Not a huge numbner of loose wet avalanches out there, but plenty enough out there to say there was a loose wet problem the past few days. Wet avalanches appeared to be greater in number at mid and lower elevations, but big alpine slopes (Larrabee, Goats, Sefrit) had some as well. Most were less than D2. The only recent slab avalanche was a human-triggered D1 a northeast aspect of Mazama Dome at 5500. Start zone > 40 degrees.