April 10, 2013

Advisory based on observational knowledge and weather forecast available at time of posting (12am).  Accuracy is subject to temporal and spatial variability and expires in 24 hours. Read the disclaimer and conduct your own assessment of conditions accordingly.

Wednesday:

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see the complete danger scale

What you need to know:

While the avalanche danger has dropped to moderate, current snow conditions still demand careful evaluation in order to determine the specific avalanche concerns and danger level in the area in which you’re traveling.  Dangerous avalanches conditions may still exist in certain areas.

Danger trend:

Decreasing gradually, in general.  Increasing later in the day if the sun breaks through and warms exposed aspects.

Primary Concerns:

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On Tuesday afternoon small soft slabs were observed to have occurred in the Monday-Tuesday storm snow.  With the addition of up to 5″ of light, dry snow in the upper elevations through Wednesday loose snow avalanches (sluffs) and small soft slabs should be expected.

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Although mountain winds have been relatively light some areas are loaded more heavily than others on varying aspects.  Wind directions were different between the Saturday-Sunday storm and Monday-Tuesday storm.  Between this and the channeling effect of terrain features, small and soft wind slabs may be found on all aspects in the upper elevations along ridge lines and near peaks.

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Even though the sun wasn’t out in force on Tuesday it broke through enough to warm and moisten southerly aspects.  Some small point releases and rollerballs were observed.  Although the sun isn’t currently forecast to be much of an issue until Thursday, if it comes out in force expect wet avalanches to be the primary concern on sun exposed aspects.

Travel Advice:

Visibility may be low with mostly cloudy skies and snow showers in the forecast.  Low visibility will demand more cautious route-finding and stability evaluation.

Be on the lookout for red flags of instability like recent avalanches, shooting cracks, collapsing or whumphing.  What do these signs tell you about the stability in the area through which you’re traveling and how should you adjust your plans accordingly?

In assessing the wind slab concern, be on the lookout for some of the typical characteristics like a rounded, pillowy look and/or hollow, slabby feel.  Wind slabs of concern will likely be in relatively obvious areas of deeper snow along ridge lines and near peaks.

Mountain Weather:

Wednesday is forecast to present us with mostly cloudy skies, up to 5″ new light and dry snow in the upper elevations through the day, temperatures in the mid teens to lower 20s, and variable light winds.

Avalanche Outlook:

Thursday, April 11

With the possibility of sunnier skies and warmer temperatures, wet avalanches will likely be the primary concern.  The wet avalanche danger will increase as the sun heats exposed aspects through the day.

Friday, April 12

Sunny skies and even warmer temperatures are forecast.  Wet avalanches should again be the primary concern as the sun heats exposed aspects through the day.

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