South Coast

South Coast

Date Issued:

Valid Until:

Forecaster: shorton

Conservative terrain choices are critical. Although the chance of triggering large avalanches is decreasing, the consequences of doing so are high.

Mon, 25 FebTue, 26 FebWed, 27 Feb
Alpine2 Moderate2 Moderate2 Moderate
Treeline3 Considerable3 Considerable2 Moderate
Below Treeline2 Moderate2 Moderate2 Moderate
Confidence: Moderate -
Mon, 25 FebTue, 26 FebWed, 27 Feb
Alpine2 Moderate2 Moderate2 Moderate
Treeline3 Considerable3 Considerable2 Moderate
Below Treeline2 Moderate2 Moderate2 Moderate
Confidence: Moderate -

Persistent Slabs

Travel and Terrain Advice

  • Use conservative route selection, choose moderate angled and supported terrain with low consequence.
  • Minimize exposure to sun exposed slopes when the solar radiation is strong.
  • Be aware of the potential for wide propagations due to the presence of a buried weak layer.

Storm Slabs

Travel and Terrain Advice

  • If triggered the storm slabs may step down to deeper layers resulting in large avalanches.
  • Choose well supported terrain without convexities.
  • Use caution above cliffs where small avalanches may have severe consequences.

Forecast Details

Avalanche Summary

Several small (size 1) human triggered slabs were reported in the storm snow on Saturday and Friday. Loose dry sluffing was also observed in steep terrain.

Persistent slab avalanches on the buried crust layer are still a serious concern. One occurred naturally on a south-facing feature at treeline elevation on Wendesday (see MIN report here). Last Monday, a fatal avalanche occurred on a steep feature at treeline elevation in the Mount Seymour backcountry (see here for incident report). Avalanche professionals involved in the rescue indicated wide propagation consistent with a persistent slab problem. The crown depth was variable - 40 to 100 cm, indicating there was also wind loading in that area.

Snowpack Summary

Roughly 30 cm of new snow sits above a mix of sun crusts and possibly some weak faceted snow and surface hoar. A widespread crust layer is buried 50-100 cm deep with weak snow above it that has produced large natural and human-triggered avalanche over the past week. These videos from Wednesday demonstrate how easy it is to trigger this weak layer (here and here). The reactivity of this layer appears to be worse in the south of the region (i.e. the North Shore Mountains) since this part of the region has seen more snow and it has consolidated into more of a slab. Unusually for this region, we expect this layer to remain reactive for some time into the future. The lower snowpack is settled and strong.

Weather Forecast

SUNDAY NIGHT: Clear, moderate northeast wind, alpine temperatures drop to -5 C.

MONDAY: Sunny, light to moderate northeast wind, alpine high temperatures around -3 C.

TUESDAY: Sunny, moderate northeast wind, alpine high temperatures around -6 C.

WEDNESDAY: Sunny with cloudy periods, strong northeast wind, alpine high temperatures around -3 C.

Source: avalanche.ca

South Coast