Wayne Flann Avalanche Blog: February 7, 2021

YESTERDAY:

Sunrise was at 07:39 Hrs on Saturday.

Typical Saturday morning?

Snowing in the valley Saturday am.

WB Patrol have been working hard getting terrain open early.

Sproatt Mountain.

There were some nice breaks in the am.

Saturday February 6, 2021. 14:00 Hrs. -4 with a 15-25 KPH West wind. +3 in the valley.

Image from same timeframe as above. Not looking good for more snow!!

Nice snow on Northern exposures.

Looking nice to the West.

End of the day for skiers/boarders.

Weather Observations for February 7, 2021 taken at 06:00 Hours.

2240 meters -11, Winds were 5-10 KPH NNW--Horstman Hut

2180 meters -10, Winds were 5-10 KPH NW--Whistler Peak
1860 meters -8, Winds were 5-10 KPH W --Rendezvous

1835 meters -9, Winds were 5-10 KPH SSW--Round House

1650 meters -7, trace in 12 Hrs, 1 cm in 24 Hrs, Base 250 cm --Pig Alley
1570 meters -7, trace in 12 Hrs, trace in 24 Hrs, Base 182 cm--Catskinner

660 meters -2, Valley Temp, Max temp Yesterday was +3.1, 1.5 mm of precip yesterday.

Failed on the forecast yesterday, all the precip stayed South of Whistler.

As of 07:00 Hrs this am we have overcast skies and unlimited visibility.

FORECAST:

A weak surface trough will bring periods of very light snowfall in a North Westerly flow aloft. The FL will remain below surface. Mostly cloudy today with some afternoon sunny breaks. Unsettled Monday with a mix of sun and cloud, flurries are possible. Colder as the artic air pushes onto the coast. Tuesday looks unsettled but could be mostly cloudy with the chance of some flurries. Guesstimates: 1-3 cm by Monday am, trace-1 cm by Tuesday am, trace-2 cm by Wednesday am.

GOES IR image from this am.

Surface trough with colder air moving in from the Arctic Front for today.

Arctic Front pushes cold air onto the coast with some flurries.

More of the same for Tuesday, getting colder.

AVALANCHE ACTIVITY:

Four skiers have been killed in an avalanche at Wilson Glade, Utah. Article below.

Wet loose below tree line later Saturday afternoon.

Avalanche control on Whistler produced Sz 1 soft slabs, 10 cm. Xe, Sc, Xc.

Avalanche control on Blackcomb produced a few Sz 1 soft slabs.

From Sea to Sky Avalanche Advisory:

Avalanche Summary

Explosive control work conducted over the last few days have produced size 2 cornice and storm slab avalanches. Skier triggered wind slabs up to size 1.5 were reported on Thursday.

Earlier in the week, many of the numerous size 1-2 natural, human and explosives triggered avalanches were reported to have failed on the recently buried persistent weak layer.

Snowpack Summary

Wind slabs on a variety of aspects are likely beginning to facet and lose cohesion in the cold temperatures. 50-100 cm of snow sits on a persistent weak layer that consists of facets at upper elevations, surface hoar in sheltered areas, a melt-freeze crust below 1900 m, and a sun crust on south-facing slopes. There could be more than 100 cm on this layer in wind loaded areas.

A crust from early December may be found around 200+ cm deep in the snowpack. Under the current conditions, it has been unreactive.

INFORMATION & OBSERVATIONS:

Lining up at 07:00 Hrs.