Wayne Flann Avalanche Blog

5 Mar 2021

March 5, 2021

YESTERDAY:

Red sky in morning, sailors warning. Sunrise Thursday was 06:49 Hrs. -3 with a 30-80 KPH E wind.

Spindrift was obvious from the valley early Wednesday am.

Very obvious at 1860 meters. Max gust at 2180 meters yesterday was 140 KPH at 14:00 Hrs.

Pre-frontal clouds early in the am.

Frontal clouds moved in quickly.

Great snow conditions in the am.

Whistler did have the alpine lifts open for a while.

Strong winds and a dark front eventually moved in.

Eventually all alpine lift were forced to close.

Thursday March 4, 2021. 14:00 Hrs. -3 with a 30-80 KPH East wind. +7 in the valley.

Satellite image from the same timeframe as above.

Snowing 2 cm per hour by 14:30 Hrs.

Storming by 15:00 Hrs. 60-85 KPH winds at 1860 meters.

Raining in the valley at 15:00 Hrs. +7 Deg C.

Weather Observations for March 5, 2021 taken at 06:00 Hours.

2240 meters -4, Winds were 100-150 KPH S--Horstman Hut

2180 meters -4, Winds were 95-115 KPH ENE--Whistler Peak
1860 meters -2, Winds were 30-60 KPH SE --Rendezvous

1835 meters -2, Winds were 30-65 KPH ESE--Round House

1650 meters 0, 40 cm in 12 Hrs, 40 cm in 24 Hrs, Base 280 cm --Pig Alley
1570 meters -1, 32 cm in 12 Hrs, 32 cm in 24 Hrs, Base 206 cm--Catskinner

660 meters 0, Valley Temp, Max temp Yesterday was +9.3, 8.1 mm of precip yesterday.

Winds were 100-150 KPH early this am at 2240 meters.

Winds were 100-130 KPH early this am at 2180 meters.

As of 07:00 Hrs this am we have obscured skies, limited visibility and it is snowing.

Snow ruler at Pig Alley this am.

FORECAST:

Low will send several impulses today with periods of light to heavy precipitation in a Southerly flow aloft. The FL is around 1600-1200 meters and should slowly drop to around 800 meters by tonight. An upper level trough will bring periods of light precipitation for Saturday with a brief drying trend around midday. Light precip expected Saturday evening as another weaker front pushes through into Sunday. Monday at this time is looking overcast with some flurries. Tuesday will see some sunshine with ridging with a dry seasonal weather pattern next week. Guesstimates: 30-35 cm by Saturday am, 5-10 cm by Sunday am, 5-10 cm by Monday am, trace-2 cm by Tuesday am.

The FL spiked yesterday at around noon to 1800 meters but quickly dropped back down to around 1500-1000 meters for most of the storm cycle.

GOES IR image from this am.

Warm front with trailing cold front and light-heavy precip for Friday.

Southerly flow aloft.

An upper level trough will bring some light snow, and unsettled weather.

Low will send a weak front through with seasonal temps on Sunday.

Periods of light precip with a drying trend in the afternoon.

AVALANCHE ACTIVITY:

. Avalanche mitigation produced some Sz 1 10-40 cm slabs Sc/Sa on Whistler.

On Blackcomb no new avalanches were observed. Alpine closed all day.

From Sea to Sky avalanche advisory:

Avalanche Summary

Natural and human-triggered avalanches are likely on Friday.

There continue to be reports of both natural and explosive-triggered cornice falls (see this MIN report near Rainbow Mountain).

Snowpack Summary

As much as 30-50 cm of snow could accumulate above 1400 m by the end day on Friday. Strong south winds will contribute to rapid slab formation, making natural avalanches likely. The combination of wind and snow has the potential to weaken cornices, which can act as triggers on slopes below.

In isolated areas with a shallower snowpack in the region, a layer of facets, spotty surface hoar, and/or crusts buried in mid-February may still be preserved. There have been no avalanches reported on this layer; however, large triggers, such as an avalanche in motion, cornice fall, or intense loading from snow and wind have the potential to this deeper layer in areas where it may still exist.

The mid and lower snowpack is well settled and strong in most areas.

INFORMATION & OBSERVATIONS:

It was a nice morning with little signs of a major storm.

Always keeners.

Whistler eventually got the alpine lifts open, but not for long.

Harmony Express was open before noon.

Peak to Peak was free on any cabins.

By 13:30 Hrs all alpine lifts were closed.

Snow started at around 13:45, by 14:15 hrs it was a full on Blizzard.

Storm skiing in the afternoon.

Last night we received 32 cm at 1570 meters. Base 206 Cm.

Yesterday at 660 meters we received 8.1 mm up to Midnight.

FROM SEA TO SKY MIN REPORTS:

Rainbow Mtn: March 3, 2021

Chief Pascal: March 4, 2021

VIDEOS:

Parks Canada Avalanche Control: March 3, 2021

Loose wet avalanches Y-Not Couloir: Utah

Powder Picker March 4, 2021: David Jones

ARTICLES:

Voluntary Pieps Beacon Recall issued in Europe, plans for U.S.: WildSnow

Tahoe skier survives avalanche by jumping off a 100 Ft cliff: California

Massive avalanche warning and new ice climber info: Gripped

Ski Patrols discuss avalanche safety through the spring season: Western USA

Avalanche control booms over Juneau & Douglas Island: Alaska

Submit your best avalanche photo for a pair of Goggles March 1-31, 2021. Sea to Sky Area.

Thanks to Volkl Canada for sponsoring.

4 Mar 2021

March 4, 2021

YESTERDAY:

Sunrise Wednesday March 3, 2021 was at 06:51 Hrs. -8 with a 25-40 KPH South wind.

Overcast with flurries early in the am.

Some breaks off in the distance.

Power flurries in the am. Isolated flurries most of the day.

Nice light in the afternoon.

. Cornice debris in Blackcomb Bowl.

Bright enough to make shadows.

Wednesday March 3 2021. 14:00 Hrs. -4 Deg C with a 10-25 KPH ESE wind. +5 in the valley.

Satellite image from the same timeframe.

Nice light on Triplex Funnel. Later in the afternoon.

Breaks at dusk.

Weather Observations for March 4, 2021 taken at 06:00 Hours.

2240 meters -6, Winds were 50-75 KPH S--Horstman Hut

2180 meters -5, Winds were 65-80 KPH ESE--Whistler Peak
1860 meters -2, Winds were 25-50 KPH SE --Rendezvous

1835 meters -1, Winds were 20-45 KPH E--Round House

1650 meters 0, 0 cm in 12 Hrs, 1 cm in 24 Hrs, Base 244 cm --Pig Alley
1570 meters -1, 0 cm in 12 Hrs, trace in 24 Hrs, Base 175 cm--Catskinner

660 meters -3, Valley Temp, Max temp Yesterday was +5.9, 0.0 mm of precip yesterday.

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

FORECAST:

Overcast early this morning with the approaching front bringing light-moderate precipitation in a South Westerly--Southerly flow aloft before noon. The FL might rise to 1800 meters (let's hope for 1500) with winds 80-100 +KPH possible. An upper level trough associated with a deep low will continue to bring periods of moderate to heavy precip into Friday. Trailing cold front will bring the FL slowly down to surface by Friday night into early Saturday morning. Weakening upper level trough with some weak ridging Saturday will bring unsettled weather with a mix of sun and cloud with some afternoon flurries. Ridge shifts Sunday with a weak front bringing periods of light snowfall for Sunday with a chance of some sunny breaks in the afternoon. Drying trend next week with ridging, bring sunny skies for Monday. Guesstimates: 30-35 cm by Friday am above 1700 m, 30-35 cm by Saturday am, 1-2 cm by Sunday am, 5-10 cm by Monday am.

GOES IR image from this am.

Red sky in morning, sailors warning.

Deep low will send a warm front with trailing cold front our way later this morning.

South Westerly-Southerly flow aloft.

. Low will bring moderate-heavy snow on Friday. Cooling down!

Cooler temps by Saturday with unsettled weather.

AVALANCHE ACTIVITY:

Detailed report on the avalanche that killed a snowboarder on Feb 18, 2021. Article below.

Avalanche mitigation on Whistler yesterday produced some small soft wind slabs Sc.

No new avalanche activity observed on Blackcomb yesterday.

From Sea to Sky avalanche advisory:

Avalanche Summary

Large cornices (size 2) continue to be reactive to explosives. Explosive mitigation since Monday has also triggered a small (size 1) loose dry and storm slab avalanche. Minor pinwheeling has been observed on steep solar aspects in the afternoon.

Snowpack Summary

A slight rise in temperature and 5-10 mm of precipitation beginning in the afternoon on Thursday may increase the potential for wet loose avalanche activity on slopes experiencing warming for the first time. Watch for pinwheels and roller balls, as they are a clear indication of this problem. You can avoid them by staying off steep slopes when the snow becomes wet or slushy.

Strong winds from the south at upper elevations have formed shallow wind slabs in lee terrain features that may be possible to trigger. Recent winds have varied in direction, so watch for wind slabs on a variety of aspects.

In sheltered areas, 20 cm of recent snow sits over a layer that may consist of of facets, spotty surface hoar, and/or crusts on steep solar aspects and below 1500 m. A weak layer buried in mid-February is composed of a crust, facets or spotty surface hoar depending on elevation/aspect, and is now down 50-80 cm. There have been no recent avalanches reported on this layer. Large triggers, such as an avalanche in motion, cornice fall, or intense loading from snow, wind and/or a rapid rise in temperature could awaken these deeper weak layers.

The mid and lower snowpack is well settled and strong in most areas.

INFORMATION & OBSERVATIONS:

. Cornice debris in Blackcomb Bowl.

Rimed statue top of 7th Heaven.