Wayne Flann Avalanche Blog: January 9, 2021

YESTERDAY:

Friday Jan 8, 2021. Sunrise was at 08:09 Hrs. -4 with a 15-30 KPH ESE wind. -1 in the valley.

09:30 Upload, walked on.

Snowing lightly in the valley.

Thin cloud cover but we did get 4 cm at 1570 meters by 14:00 Hrs.

Some breaks started before noon.

Blue to the North.

Friday Jan 8, 2021. 14:00 Hrs. -4 with a 10-30 KPH WSW wind. 0 Deg C in the valley.

GOES IR image from Friday afternoon.

17:00 Hrs Friday. -7 with a 15-30 KPH SSW wind.

Weather Observations for January 9, 2021 taken at 06:00 Hours.

2240 meters -10, Winds were 20-25 KPH SE--Horstman Hut

2180 meters -9, Winds were 20-35 KPH S--Whistler Peak
1860 meters -8, Winds were 5-10 KPH E --Rendezvous

1835 meters -7, Winds were 10-20 KPH ESE--Round House

1650 meters -9, trace in 12 Hrs, 5 cm in 24 Hrs, Base 236 cm --Pig Alley
1570 meters -9, trace in 12 Hrs, 4 cm in 24 Hrs, Base 158 cm--Catskinner

660 meters -3, Valley Temp, Max temp Yesterday was +1, 2.2 mm of precip yesterday.

As of 07:00 Hrs this am we have broken cloud and unlimited visibility.

FORECAST:

Weak ridge of high pressure will shift East today in a North Westerly flow aloft. Sunny breaks this am with increasing cloud cover this afternoon, a weak front arriving tonight with light precipitation. The FL will climb up to around 800 meters. Light precip continues into Sunday with a vigorous front arriving Sunday night. Atmospheric river arrives with moderate-heavy precipitation, strong winds, and warm temperatures into Monday. Likely a break in systems Monday afternoon before another wet event moves onshore into Tuesday. The FL on Tuesday could go up to 1600 meters, more on that in Monday's post. Guesstimates: 8-12 cm by Sunday am, 18-22 cm by Monday am, 35-45 cm by Tuesday am, 25-35 cm by Wednesday am.

GOES IR image from this am.

Low will push the high East today with a weak front arriving tonight.

Weak front for Sunday with a warm wet windy event arriving Monday. Warm air to the South.

Atmospheric river event for Monday. On the warmish side.

Plume of Moisture for Monday into Tuesday.

AVALANCHE ACTIVITY:

Three people have died after avalanche hits Russian Ski resort. Article below. Net Pic

Snowboarder killed in an avalanche near Park City, Utah. Article below. Net Pic

Recent controlled avalanche at Mt Baker. That is a lot of snow. Net Pic

No new avalanche activity observed on Blackcomb yesterday.

On Whistler some Sz 1 with Sc soft wind slabs. Some Sz 2 Xe cornice control.

From the Sea to Sky Advisory:

Avalanche Summary

On Thursday there was a report of a remotely triggered (from a distance of 20m) size 2.5 deep persistent slab avalanche on a west aspect at 1930 m on Cowboy Ridge. The fracture line was up to 200 cm deep. This avalanche subsequently sympathetically triggered an additional size 2.5-3 deep persistent avalanche about 50 m below on Cowboy ridge.

On Wednesday there were numerous size 2 explosives controlled storm slab avalanches reported running in the alpine and treeline. As well there were several persistent and one deep persistent slab size 2.5-3 ranging in depth from 100-150 cm.

Snowpack Summary

Over 150 cm of recent storm snow from the past week has seen extensive wind effect at upper elevations, with scoured windward aspects, wind slabs in lee features and growing cornices at ridgetop.

The snowpack is currently quite complex. The layer of greatest concern is a melt-freeze crust from early December, found around 100-200 cm deep in the snowpack. This crust may have surface hoar or sugary faceted grains sitting above it. There have been several recent large natural and human triggered avalanches on this layer and new snow loads as well as large loads from storm slab avalanches have potential to trigger these layers.

Goggles for who can get the best avalanche photo by Jan 17, 2021 in the Sea to Sky Corridor. Send pic to wwflann@me.com.

INFORMATION & OBSERVATIONS: