|Location:||Taylor Pass, Sunburst below the weather station|
Route & General Observations
Toured up Taylor Pass to de-rime the weather station and to get a look at conditions on the South/Southwest face of Sunburst.
-6F at the parking lot at 10:45 am. Light N (cold) winds through treeline and when approaching the alpine. Winds died off and there was no wind at the saddle of Taylor pass or the ridge on Sunburst. Clear sunny skies throughout the day temps warmed to 11 degrees at the weather station around noon but conditions were nice and warm in the direct sun. 10F as we were leaving the Pass.
Layer of low density lightly wind blown snow at all elevations, thinner down low, 10cm of just off the ridge on Sunburst. As the day progressed sun exposed slopes began to show signs of minor surface warming.
Pit @ 3,750’, S/SW aspect, 28 degrees. February 9th buried surface hoar (6 mm-1 cm in size) was 85 cm below the surface.
HS:335 cm (Wind loaded area) average depth probing across the slope was 300 cm
Pit depth: 135 cm. The top 10 cm was new snow from the past few days. Below this was 20 cm of 1F snow that was the more recent wind slab. We got CT 16 and ETCN 15 at the interface with this layer and the Pencil hard (trending to Pencil +) wind slab below. The slab below was formed by the high winds during the Valentine's Day storm cycle and was 75 cm thick in our pit. The Feb. 9th buried surface hoar is laid over and was below this pencil + hard wind slab and sandwiched between another pencil+ hard wind slab below. We were able to get the surface hoar layer to fail when we pried on the blocks so we did a Deep Tap Test and a Deep Tap ECT and got a failure at DTT23 and DTT ECTP23.
These results fit well with the current, (scary) moderate, avalanche problem. In areas where the buried surface hoar is present it will require a lot of force to trigger but if you find a thin spot or are able to put enough force on the slope there will be very high consequence results, 3'+ thick slab.