Avalanche Forecast

Archived

Dec 6th, 2015–Dec 7th, 2015

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely, human triggered possible.

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely, human triggered possible.

Regions

Olympics.

Monday should become a wet day at Hurricane. Careful snow evaluation and cautious route finding should be essential if you venture into the alpine.

Detailed Forecast

A warm front on Sunday night will be rapidly followed by another warm front on Monday. Strong southwest to west winds should be seen in the alpine with moderate to heavy rain or snow Sunday night and by Monday midday with further warming. Snowfall so far in December by Monday morning at Hurricane will probably be about 1. 5 feet.

New wind and storm slab will be the focus on Monday at Hurricane Ridge where snow should change to rain. Careful snow evaluation and cautious route finding should be essential if you venture into the alpine.

With little snow near and especially below treeline at Hurricane, wet loose snow avalanches will not be in the forecast. But change your plans if you find wet snow deeper than a few inches or see signs of wet loose activity such as pin wheels or natural wet loose avalanches.

Snowpack Discussion

We have not received any snowpack observations from Hurricane Ridge so far this season, but given the warmer temperature regime over the Olympic Mountains lately, we don't expect any persistent weak layers problems like those seen in the Washington Cascades.

Problems

Wind Slabs

Wind Slab avalanches are the release of a cohesive layer of snow (a slab) formed by the wind. Wind typically transports snow from the upwind sides of terrain features and deposits snow on the downwind side. Wind slabs are often smooth and rounded and sometimes sound hollow, and can range from soft to hard. Wind slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.

Storm Slabs

Storm Slab avalanches are the release of a cohesive layer (a slab) of new snow that breaks within new snow or on the old snow surface. Storm-slabs typically last between a few hours and few days (following snowfall). Storm-slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.