Avalanche Advisory

Turnagain Area Avalanche Advisory Monday, March 16th 2015 6:54 am by John Fitzgerald ARCHIVED ADVISORY - All advisories expire after 24 hours from the posting date/time.

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The avalanche danger will climb to HIGH in the Alpine and CONSIDERABLE at Treeline by the end of the day.  Slabs up to 18” thick will be very sensitive to human triggers and could release naturally.  

Dangerous conditions exist and require advanced travel and snowpack assessment skills.  Avalanches have the potential to run through multiple elevation bands.  Because of this, awareness of terrain looming overhead will be critical today and is why the danger will be MODERATE below Treeline in big channeled terrain.

Show the Complete North American Avalanche Danger Scale

North American Public Avalanche Danger Scale Avalanche danger is determined by the likelihood, size and distribution of avalanches. Danger Level Travel Advice Likelihood of Avalanches Avalanche Size and Distribution 5 Extreme Avoid all avalanche terrain. Natural and human- triggered avalanches certain. Large to very large avalanches in many areas. 4 High Very dangerous avalanche conditions. Travel in avalanche terrain not recommended. Natural avalanches likely; human- triggered avalanches very likely. Large avalanches in many areas; or very large avalanches in specific areas. 3 Considerable Dangerous avalanche conditions. Careful snowpack evaluation, cautious route-finding and conservative decision-making essential. Natural avalanches possible; human- triggered avalanches likely. Small avalanches in many areas; or large avalanches in specific areas; or very large avalanches in isolated areas. 2 Moderate Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern. Natural avalanches unlikely; human- triggered avalanches possible. Small avalanches in specific areas; or large avalanches in isolated areas. 1 Low Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features. Natural and human- triggered avalanches unlikely. Small avalanches in isolated areas or extreme terrain. Safe backcountry travel requires training and experience. You control your own risk by choosing where, when and how you travel.

4 High Alpine / Above 2,500'

Travel Advice: Very dangerous avalanche conditions. Travel in avalanche terrain not recommended.

3 Considerable Treeline / 1,000'-2,500'

Travel Advice: Dangerous avalanche conditions. Careful snowpack evaluation, cautious routefinding and conservative decision-making essential.

2 Moderate Below Treeline / Below 1,000'

Travel Advice: Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern.

An avalanche accident involving a snowmachiner occurred over the weekend near Denali National Park.  Our thoughts are with the patient for a full recovery.  More details can be found HERE.

Avalanche Problem 1

Rapid loading as a result of new snow and wind will create unstable conditions today.  Slabs will vary in size and be thickest, up to 18” on leeward slopes.  With wind speeds over 40 mph expect loading to occur lower down on slopes and in areas that are normally protected from the wind.

The danger will be more in the MODERATE range in general this morning.  That will change quickly as the day progresses.  Becasue of this it will be important to pay attention to rapidly changing conditions and pick your terrain carefully.

Recent avalanches, shooting cracks, and collapsing are key indicators of unstable snow.  These signs should dictate where you travel today.  In other words, avoid avalanche terrain if and when you begin noticing these signs.

Travel in the Alpine elevations is not recommended for the latter part of the day.

Low pressure currently centered over the Alaska Peninsula has brought precip, wind and warmer temps to the area.  Temperatures over the last 24 hours have seen a dramatic rise with ridgetops moving from 0 to 20 deg F.  Winds have picked up in a similar dramatic fashion, with ridegtops reporting speeds in the 35-40mph range this morning.  Storm totals so far are in the 5”/.4” (snow/H20) range.

Today expect snow to be heavy at times with up to 10”/.9” (snow/H20) of additional accumulation by the evening.  Winds will be strong out of the East at 30-40mph.  Temperatures will be in the low 30s F at 1,000’.  Rain/snow line will hover between 500-1,000’.

Precipitation will taper off late this evening.  Cloudy and showery conditions will continue through Tuesday with another round of significant precipitation on Wednesday.

PRECIPITATION 24-hour data (6am - 6am)

RIDGETOP 24-hour data (6am - 6am)

This is a general backcountry avalanche advisory issued for Turnagain Arm with Turnagain Pass as the core advisory area (this advisory does not apply to highways, railroads, or operating ski areas).

Riding status is not associated with avalanche danger. An area will be open to motorized use in accordance to the Forest Management Plan when snow coverage is adequate to protect underlying vegetation. Backcountry hazards including avalanche hazard are always present regardless of the open status of motorized use areas.

(Updated: Dec 01, 2018 )

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