South Coast

As the last Pacific storms move through we`ll be changing from a storm slab to a persistent slab regime. Check out this great overview of the problem on the forecasters blog.

Fair - Forecast snowfall amounts are uncertain on Sunday

Forecast models disagree on precipitation amount in the next few days, but there are a couple of Pacific systems that may tag the south coast and into the southern interior.Friday night: Freezing level at valley bottom, cloudy, but no precipitation in the forecast, ridge top winds light 20Km/h.Saturday: Freezing level around 400m,  scattered flurries, ridge top winds from the west  10-20Km/h.Sunday: Freezing level around 100m, another pulse of moisture with a possible 10 to 15 cm of precipitation,  ridge top winds north-20 Km/h.Monday: Freezing level at valley bottom, no precipitation in the forecast, light ridge top winds

Lots of natural avalanches running in the forecast region, with the Coquihalla having a large natural avalanche cycle in the past 72 hrs . Some of these avalanches were in places not normally seen to run except on a 10 to 15 year cycle. Popular ski routes have had natural activity as well. A cornice failure earlier in the week triggered a size 2.5 slab avalanche on the slope below and explosives control has produced numerous very large avalanches.  Pay close attention to solar radiation as  the days get clear and sunny.

In the last week, the northern parts of the region have received over 1m of new snowfall and the Southern areas have seen almost 2.5m. The Coquihalla has received another 45cm of new snow in the past 24hrs with high winds, adding to the existing storm slab now100 to 200cm deep in some parts of the region. In the southern portion of the region the slab sits on a crust/facet combination along with old wind slabs on lee slopes. In the northern part of the region one can add surface hoar to the crust/facet/slab combination. The storm slab seem to be unusually reactive at tree line and below tree line elevations. Whumpfing and widespread natural avalanche activity are a sign of a poor bond between the new snow and these old surfaces. Strong to extreme winds are redistributing the new snow into deeper, reactive wind slabs on the lee side of ridge tops.The mid and lower snowpack are generally strong and well-settled. Although basal facets and depth hoar are likely to exist in the north of the region, giving us a low probability, but high consequence of a large destructive avalanche.