Wayne Flann Avalanche Blog: April 7, 2022

YESTERDAY:

Ipsoot under clear skies.

Great light in the am.

Cloud coverage increased by the afternoon.

Great looking turns in the pm.

Dark overcast to the West later in the afternoon.

Weather Observations for April 7, 2022 taken at 06:00 Hours.

2240 meters -6, Winds were 50-60 KPH S--Horstman Hut

2180 meters -6, Winds were 50-60 KPH S--Whistler Peak

1860 meters 0, Winds were 10-25 KPH SE--Rendezvous

1835 meters +1, Winds were 20-30 KPH ESE--Round House

1650 meters -2, 0 cm in 12 Hrs, 0 cm in 24 Hrs. Base 302 cm --Pig Alley

1570 meters -1, 0 cm in 12 Hrs, 0 cm in 24 Hrs. Base 225 cm. Catskinner

660 meters -1, Valley Temp, Max temp Yesterday was +9.3, 0.0 mm of precip yesterday

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

FORECAST:

Dirty ridging this am with overcast skies in a warm Southerly flow aloft. The freezing level is hovering just below surface this am rapidly rising to 3000 m by this afternoon. Warm air loft at around 1800 m. The low will send some light precipitation tonight with a cold front arriving Friday am with an impulse of moderate precipitation early Friday am. The precipitation will ease to periods of light amounts with a mix of sun and cloud with the freezing level dropping to surface by Friday night. Cool upper trough with unsettled weather arrives on Saturday with periods of light precipitation. Weak ridging on Sunday with unsettled weather and some flurries. Ridge strengthens Monday with sunny skies. Guesstimates: 12-18 cm by Friday am, 4-6 cm by Saturday am, 1-4 cm by Sunday am, trace-1 cm by Monday am, 0 cm by Tuesday am.

GOES IR image from this am.

Goes 17 ABI Image 2022/04/07. 05:00 Hrs.

. Low to the North, High to the South with warm temperatures. High overcast for today.

Precipitation is North of our zone, clouds will spill in from the low. Light precipitation tonight.

Warm Southerly flow aloft.

Low will send a cold front for Friday with seasonable temperatures.

Impulse of moderate precipitation early Friday, eases to light precipitation later in the am.

Low and associated upper trough will bring unsettled weather with a cool Northerly flow Saturday.

Mixed bag on Saturday with periods of light precipitation.

Unsettled Sunday with a mix of sun and cloud with some showers.

Ridge strengthens Monday with mostly sunny skies.

AVALANCHE ACTIVITY:

Blackcomb, Some wet loose on solar aspects. One Sz 2 Sa with images and information below.

Boot hiker initiated this avalanche in Blackcomb Glacier.

The boot path and where it likely initiated the slide. 70-90 cm crown line.

One skier caught lookers left near the top on traverse. lost 1 ski, 1 pole. No Injuries.

The crown line.

Avalanche mitigation on Whistler produces some Sz 1-2 Xc (cornice results) Sz 1.5 Sa cornice.

Powder Mountain Zone. Sz 2.5 Remote trigger. MIN Report Below. Reid Pic

Sz 3 Na Mt Rohr. MIN Report Below. Apeplowball Pic

Ma Sz 2 Grizzly Lake. MIN Report below. Andy Messner pic

Ma Sz 2 near Longspur. NE Aspect 2000 m. April 6, 2022. Al Collis pic

Different perspective near Longspur. Al Collis Pic

Na Sz 1.5 2400 m Squamish Glacier. Al Collis Pic

West Facing 1850 m Sun Triggered wet loose to wet slab. Ice cap Al Collis Pic

Russet Ridge. April 6, 2022. Greg Newton Pic

FROM AVALANCHE CANADA-SEA TO SKY:

Avalanche Summary

On Tuesday, skiers triggered a few avalanches including a size 1.5 storm slab on a steep west aspect at 2000 m, a size 1 avalanche in a steep north aspect couloir at 2150 m, and a remotely triggered size 2 storm slab from 2 m away. A ski cut triggered a size 1.5 cornice release on a northwest aspect at 1900 m. Explosives triggered numerous size 1-2.5 storm slabs and cornices up to size 2.5. The storm slabs were typically up to around 60 cm thick and many were sliding on the underlying melt-freeze crust. Several of the cornice releases triggered slabs on the slopes below.

A variety of older avalanches were also reported on Tuesday which had occurred during the storm including evidence of a natural size 2 storm slab cycle. A natural cornice release was observed which triggered a size 3 storm slab and a few other natural cornice releases which triggered size 2 storm slabs.

Snowpack Summary

The recent storm produced 60-80 cm of new snow in the Whistler area. This storm snow has buried a firm crust which extends to mountain top on solar aspects and to around 2200 m on northerly aspects. This crust has been the sliding surface for many of the recent storm slab avalanches. Strong to extreme southwest wind has redistributed the new storm snow in exposed, high elevation terrain forming wind slabs up to 150 cm thick and developing large cornices. Windward slopes have been scoured down to the crust and the alpine snow surface is expected to be highly variable. A new sun crust was reported to be forming on the snow surface on Tuesday.

The middle and lower snowpack are generally strong and well bonded.

INFORMATION & OBSERVATIONS:

Wolverine Tracks on the Horstman Glacier.