News

Weekend conditions update — Friday Jan. 22

 | January 22, 2021

Every weekend SPIN will present the current avalanche forecast and weather for the Interior. As a reminder, we’ve pulled this information together for a convenient overview to help make your initial plans and recommend reading the full avalanche forecast, and checking and assessing conditions on your own specific to your unique location. Tune in at the end of each week to get the forecast before your weekend adventures begin!

Our ridge of surface pressure has yet to dissipate laying claim as to why the Interior has been covered by clouds with the odd sunny break as of late.

But don’t be weary! A little blue bird sky may start poking its head out today as the inversion breaks down. 

The Interior is under the spell of high pressure calling for mainly clear skies above 1500 metres according to Avalanche Canada’s mountain weather forecast. But be aware, the clouds won’t completely clear and are expected to reform overnight, tonight.

As the weekend kicks into full effect Saturday, our neighbours in the Coastal Mountain ranges will begin to see some light precipitation and Arctic air that may creep its way into the Cariboo and Southwest Interior ranges.

Sun Peaks Resort is forecasting sun with cloudy periods for Friday and Saturday. Sunday will see slightly more cloud and weekend temps will be cold with lows of -14C and highs of -11C. Winds are forecasted to be light and northerly. Monday teases the slopes with the chance of potential snow.

Avalanche Canada echoed a similar detailed weather forecast for the weekend in the Cariboos, North and South Columbia regions and South Coast Inland region.

Avalanche Forecast

The yellow brick road will be evident in the North and South Columbia and Cariboo avalanche region forecasts with a moderate rating for all elevations Friday and the same for Saturday, except for a ‘Low’ rating below treeline before dipping to low at all elevations Sunday in the Cariboo, North and South Columbia avalanche regions. But don’t let the fair weather lure you into a sense of complacency.

Avalanche Canada warned users to not let the low to moderate ratings as the “conditions are more complicated than meets the eye. Wind-drifted snow and a buried weak layer warrant careful evaluation in specific areas,” they said for the North and South Columbia and Cariboo areas.

Avalanche problems for the North and South Columbia and Cariboo regions have shifted slightly from last week. The storm slab has since turned into a wind slab problem as the main concern at alpine and treeline on all aspects except southwest facing slopes. The chances of triggering the wind slab is deemed possible and could release avalanches sized one or two. 

Avalanche Canada also warned of growing cornices which could fail thanks to recent wind in the alpine.

The second avalanche problem to watch for is that pesky persistent slab due to a weak layer of surface hoar that was buried on Jan. 11 by 40-60 cm of snow in the Cariboo and 50-70 cm in the North and South Columbia. This layer is possible to trigger size two to three sized avalanches and is more prevalent where the surface hoar was preserved. This problem has been documented on the Mountain Information Network (MIN) reports in the South Columbia region where human caused triggers released size 1-1.5 avalanches on the surface hoar layer on north, east and southeast aspects at and below treeline elevations.

The snowpack summary for the Cariboos, North and South Columbia regions also detail a couple of lower layers in the mid to lower snowpack. The first layer is down about 70-120 cm in the South Columbia and Cariboo regions and 100-140 cm in the North Columbia and consists of spotty surface hoard at shaded treeline and below treeline elevations. Another weak layer is down 120-190 cm in the South Columbia, 150 cm in the Cariboo and 150-200cm in the North Columbia which was formed early in December and is described as a decomposing surface hoar crust and faceted snow. However, results from tests on these layers are suggesting it’s heading towards dormancy.

Travel and terrain advice for the Cariboo, North and South Columbia regions are to evaluate steep lines for wind slabs, approach them cautiously at and below treeline as there may be buried surface hoar and avoid exposure to slopes that have cornices overhead.

The Coquihalla area boasts the solid green light for the whole weekend with all elevations forecasted as a low avalanche hazard after a moderate rating is forecasted for the alpine on Friday.

Avalanche problems from this region are mostly to do with wind which has created a wind slab at and above treeline on north to southeast aspects which are unlikely or possible to trigger sized one to two avalanches.

Cornices are the second culprit in the alpine on northwest to east aspects with a possible chance of triggering sized 1.5 to 2.5 avalanches.

The Coquihalla part of the region also saw fluctuations in freezing levels during the last storm, leaving a prevalent crust which may lay under 5-10 cm of new snow turned into wind slab in some areas where other areas the crust is exposed.

Terrain and travel advice by Avalanche Canada for the South Coast Inland region suggests watching out for wind-loaded pockets especially around ridge crests in consequential terrain, to pay attention to isolated alpine features as well as cross-loaded features at treeline and of course give cornices a wide-berth when travelling on ridge tops.

Read the full Avalanche Canada forecast here.

Comments

shares