Thu, April 11, 2013 Turnagain Pass Avalanche Forecast

Thu, April 11th, 2013

Alpine

Above 2,500'

2 - Moderate

Treeline

1,000'-2,500'

1 - Low

Below Treeline

Below 1,000'

1 - Low

0 - No Rating

1 - Low

2 - Moderate

3 - Considerable

4 - High

5 - Extreme


Travel Advice	Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.	Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern.	Dangerous avalanche conditions. Careful snowpack evaluation, cautious route-finding, and conservative decision-making essential.	Very dangerous avalanche conditions. Travel in avalanche terrain not recommended.	Extraordinarily dangerous avalanche conditions. Avoid all avalanche terrain.
Likelihood of Avalanches	Natural and human-triggered avalanches unlikely.	Natural avalanches unlikely; human-triggered avalanches possible.	Natural avalanches possible; human-triggered avalanches likely.	Natural avalanches likely; human-triggered avalanches very likely.	Natural and human-triggered avalanches certain.
Avalanche Size and Distribution	Small avalanches in isolated areas or extreme terrain.	Small avalanches in specific areas; or large avalanches in isolated areas.	Small avalanches in many areas; or large avalanches in specific areas; or very large avalanches in isolated areas.	Large avalanches in many areas; or very large avalanches in specific areas.	Very large avalanches in many areas.

Avalanche Problem 1

Wind Slabs

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.

More info at Avalanche.org

Despite the light winds the past couple days, shallow and very sensitive slabs have been able to form in scattered areas along ridgelines (shown in the photo below). This is mainly due to the weekend’s snow being so light and easy to transport. They didn’t pack much punch yesterday but a bump in wind overnight with plenty of low density snow available for transport will likely have continued wind slab development. Watch for these to be 6-10″ thick and on a variety of aspects – winds have been blowing from various directions due to our region being in the heart of a low pressure system. Keeping an eye on the snow texture as well as for shooting cracks from your skies/board or sled will be key.

Avalanche Problem 2

Dry Loose

Dry Loose

Dry Loose avalanches are the release of dry unconsolidated snow and typically occur within layers of soft snow near the surface of the snowpack. These avalanches start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-dry avalanches include point-release avalanches or sluffs.

More info at Avalanche.org

Loose snow avalanches are expected to be prevalent again today. These are both in the dry snow category and the wet/damp snow category (pending clear skies):

Dry snow: The very cold overnight temperatures will add to the looseness of the surface snow (and to the good riding/skiing conditions). This should keep dry sluffs something to plan for on steep slopes.

Wet/damp snow: If the skies remain clear today, the sun should have ample time to warm southerly aspects. Watch for dampening of the snow surface to turn a small low volume dry sluff into a larger heavier damp sluff. Shallow slabs are also possible with daytime warming on southerly aspects. These sluffs and slabs have the potential to release naturally if we do get intense sunshine today.

Weather

Thu, April 11th, 2013

Under mostly clear skies this morning, temperatures have plummeted to the single and minus single digits. Winds have remained light from the north and west with a slight bump overnight to the 15-20 mph range. Yesterday, mostly cloudy skies limited much daytime heating and 24-hour average temperature at the Sunburst wx station was +1F while winds averaged 4mph with gusts to 16.

Today, a few clouds are likely to stream through but the sun should have time to warm things up a bit. Temperatures should reach the mid 20’sF at sea level up to treeline and the low teens on the ridgetops. Winds will be light and slowly backing to the SE where they look to pick up tonight to the 15mph range.

Beautiful spring weather consisting of sunny days, cold nights and light to moderate northerly winds are on tap for the remainder of the week and into the weekend.

Kevin will issue the next advisory tomorrow, April 12th.

Observations

Recent Observations for Turnagain Pass

Date	Region	Location	Observer
10/27/24	Turnagain	Observation: Tincan	Michael Kerst
10/21/24	Turnagain	Observation: Turnagain Pass Road Observation	Trevor Clayton
10/19/24	Turnagain	Observation: Tincan – Below Todds Run	Andy Moderow
10/18/24	Turnagain	Observation: Taylor Pass	Eli Neuffer
10/15/24	Turnagain	Observation: Tincan Common	John Sykes Forecaster
10/14/24	Turnagain	Avalanche: Tincan	CNFAC Staff
05/13/24	Turnagain	Observation: Eddie’s, Sunburst, Seattle, Cornbiscuit, Pete’s South	H Thamm
05/13/24	Turnagain	Observation: Turnagain Pass non-motorized side	Amy Holman
05/12/24	Turnagain	Observation: Warm up Bowl	Tony Naciuk
05/07/24	Turnagain	Observation: Turnagain Pass Wet Slabs	A S

Riding Areas

The riding areas page has moved. Please click here & update your bookmarks.