Wayne Flann Avalanche Blog: January 5, 2017

AVALANCHE ACTIVITY:

No avalanches to report locally, avalanche control on the Duffy yesterday produced Sz 1-2.5 Xh.

Through the grape vine 2 sledders caught on Monday in a Sz 2.5 buried to their necks on Ogre.

YESTERDAY:

Early morning, Wednesday January 4, 2017.

Some great colour before sunrise.

Lenticulars to the North over Ipsoot Mountain.

Gusty winds Wednesday morning on Seventh Heaven.

Wide spread Sastrugi.

Image from Wednesday morning.

Big picture Wednesday afternoon. Oregon and California are getting snow.

Sunset was at 16:24 yesterday.

WEATHER OBSERVATIONS:

Weather Observations for January 5, 2017: taken at 06:00 Hours.

2240 meters -11, Winds were 20-30 KPH SSE --Horstman Hut
2180 meters -11, Winds were 20-30 KPH SSW--Whistler Peak
1860 meters -8, Winds were 15-25 KPH SE --Rendevous
1835 meters -8, Winds were 5-10 KPH SW --Roundhouse
1650 meters -9, 0 cm of new snow, 0 cm in 24 hrs, 190 cm Base, RH 90% --Pig Alley
1550 meters -9, 0 cm of new snow, 0 cm in 24 hrs, 98 cm Base, RH 78% --Catskinner

660 meters -14, Valley Temp, Max Temp Yesterday was -2.8, 0.0 mm of Precip recorded yest

Northerly winds have stripped some of the snow out of the Catskinner weather plot.

As of 07:00 Hrs this am we have clear skies, unlimited visibility and we have an inversion.

FORECAST:

The persistent cold high pressure will begin to slowly move away today with moderating temperatures and a North Flow Aloft. A weakening upper level low will bring flurries this evening, transitioning to light snow by Friday. Saturday is looking unsettled with light flurries. The flow will eventually switch to Southwesterly as the low moves down the coast with a freezing level remaining near surface for the weekend. A moist Southwest flow will continue from Sunday thru Wednesday with a couple of weak frontal systems. Difficult to determine snow amounts with the duration and intensity of the bands of moisture being produceded by the approaching low. Guesstimates: trace-2cm by Friday morning, 5-10 cm by Saturday morning, 3-5 cm by Sunday morning, 15-20 cm by Monday morning. These numbers likely to change!!

Another sunny day with some cloud development as the low starts to send cloud our way.

Light snow on Friday.

Weakening low will bring flurries for Saturday with light/moderate snow for Sunday.

ARTICLES:

New Svalbard avalanches revealed by satellite: Phys.Org

Avalanche Danger High as Heavy snows move in: Colorado

Workshop on Avalanche Processes in condensed matter physics and beyond: CRM

Breck Ski Patrol hosts Free Avalanche Seminar-Jan 5: Colorado

Ski Guide Injured in Helicopter roll over on X-Mas Day: Blue River, B.C.

OBSERVATIONS:

Lee Lau

January 4 at 10:07am

This isn't representative of anything other than a windslab issue but appropriate enough following a classic artic outflow.

There'll now be variable depths, stoutness and weakness of slab present. Because the winds have been so gusty and due to the nature of SW BC micro terrain the N and NE facing winds will have slabbed up all sorts of terrain. But it will slab opposite to the standard typical storm winds we get so the slabs can catch parties who're unaware.

Some things I think about following an artic outflow.

The storm slab can propogate a lot and tends to be at the start zones of typical paths (but not always). The typical bro ski cut or cornice bomb the start zone and happily gut full path might not be the best call.

You got to flip what you think about aspect 180 degrees. Which can be really hard but not impossible.

A return to typical SW storm snow on deposited NE wind slab is particularly tricky as everything looks so enticing. But now the N facing goods have potential trigger points all over the place.