Wayne Flann Avalanche Blog: February 23, 2022

YESTERDAY:

Smooth surfaces on Ipsoot.

The only cloud in the sky Tuesday am.

Some cloud to the South in the afternoon.

Groomers were fun.

The wind has stripped the snow off some aspects. Down to the crust!!

16:30 hrs Tuesday, -20 Deg C with a 25-35 KPH East wind at 2240 m.

Weather Observations for February 23, 2022 taken at 06:00 Hours.

2240 meters -13, Winds were 10-15 KPH N--Horstman Hut

2180 meters -14, Winds were 10-15 KPH NW--Whistler Peak

1860 meters -13, Winds were 5-10 KPH NNE--Rendezvous

1835 meters -12, Winds were 0-5 KPH SSW--Round House

1650 meters -15, 0 cm in 12 Hrs, 0 cm in 24 Hrs. Base 228 cm --Pig Alley

1570 meters -14, 0 cm in 12 Hrs, 0 cm in 24 Hrs. Base 162 cm. Catskinner

660 meters -11, Valley Temp, Max temp Yesterday was -4.2, 0.0 mm of precip yesterday

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

FORECAST:

A weak shortwave trough will bring unsettled weather this am in a North Easterly flow aloft. Increasing cloud cover by noon with overcast skies by this afternoon. Good chance of some snow flurries this evening. Winds have abated. Temperatures have moderated. The freezing level will remain below surface. Ridge strengthens for Thursday with sunny skies and slightly warmer temperatures. Friday will also see sunny skies with some clouds moving in Friday night into early Saturday am. A Pacific front will bring periods of light/moderate snow Saturday, with strong winds and seasonable temperatures. Looking potent as of now compared to a few days ago. A series of weak fronts will push through into early next week with a more zonal flow. Guesstimates: trace-1 cm by Thursday am, 0 cm by Friday am, 0 cm by Saturday am, 15-25 cm by Sunday am, 5-10 cm by Monday am.

GOES IR image from this am.

GOES 17 ABI Image 2022/02/23.05:00 Hrs.

Low will spill some cloud over the top of the High today. Still cold!!

Overcast in the afternoon today.

North Easterly flow aloft.

High pressure with sunny skies, moderating temperatures Thursday.

High pressure Thursday.

High still dominant on Friday but low pushing hard from the North.

Low moving down the coast for Saturday with some much welcome snow.

AVALANCHE ACTIVITY:

Sz 1 Sr on Rainbow, 2000 m. MIN Report below. Adam Venner Image

Sz 1 stiff slab Sa yesterday on Disease Ridge. MIN report below. RichardK76 Pic

Wind slabs were forming on lee terrain.

Some recent wet loose on solar aspects.

Sc produced a few isolated pockets of windslab on Whistler yesterday.

A few isolated pockets of windslab could be found. No new avalanches observed on Blackcomb.

FROM AVALANCHE CANADA--SEA-SKY:

Avalanche Summary

On Monday, a natural size 2.5 cornice release was observed on a north aspect at 1900 m which pulled a small slab on the slope below. One natural size 1 wind slab was observed and skiers triggered several size 1 wind slabs. One of these was on a north aspect while the rest were on southeast through southwest aspects.

On Sunday, natural size 1 wind slabs were being observed as well as some isolated natural loose activity. A natural size 2 cornice was also reported which did not trigger a slab.

On Thursday, a natural icefall triggered a size 2.5 slab avalanche on the slope below. This avalanche was on a northeast aspect at 2100 m. Details were limited but we expect this may have been a persistent slab avalanche.

Snowpack Summary

The weekend storm produced 5-10 cm of snow with strong southwest wind that likely formed thin wind slabs in exposed terrain. On Monday, the wind switched to a northeast direction causing reverse loading and thin wind slabs may now exist on all aspects in exposed terrain.

The mid-February crust is down 10-30 cm. This melt-freeze crust is reported to exist on all aspects and elevations, except for some of the highest elevation polar aspects. Facets have been observed above the crust on polar aspects.

The late-January crust/facet/surface hoar interface is buried down 40-100 cm. This layer was most reactive between 1700 m and 2000 m. While this layer now appears to be dormant through most of the region, it may still be possible to trigger it at upper treeline or lower alpine features on polar aspects with a large load like a cornice or in shallow snowpack areas.

INFORMATION & OBSERVATIOS: