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Avalanche Advisory

Turnagain Area Avalanche Advisory
Forecaster:   Wendy Wagner  
Sunday, March 31st 2013
Created: Mar 31st 6:14 am
2 Moderate Alpine / Above 2,500' Travel Advice: Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern.
1 Low Treeline / 1,000'-2,500' Travel Advice: Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.
1 Low Below Treeline / Below 1,000' Travel Advice: Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.
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The John Byrne Family
Special Announcement

Today is the 2nd ANNUAL CORN HARVEST - come join us anytime between 3 and 7PM!! Motorized lot on Turnagain Pass - FREE FOOD, games, prizes, etc.


The Bottom Line

The avalanche danger will remain MODERATE today above treeline for both wind slab avalanches and wet loose snow avalanches. Wind slabs formed two days ago were still reactive yesterday and though on the decline, should still be watched out for today. Additionally, natural and human triggered wet sluffs will be possible where warm temperatures will again moisten the snow surface on south, east and westerly aspects predominantly. Last, cornices deserve a wide berth with continued warm conditions.


Primary Concern

Wind slabs formed during Friday, 3/29’s 8-10” of snow were still releasing yesterday. These were in the foot deep category and on all aspects above treeline. A few observed were: one natural that occurred on the east face of Seattle Ridge and one on the southerly tip of Tincan Proper. Check the obs page for a few more details from other observers. The sun and warm temperatures likely played a role in increasing the instability of the slabs.

Today I'm expecting these to be harder to trigger but still the primary concern due to their slab nature. The snowpack is quite variable currently with wind slabs sitting on crusts on south, east and westerly aspects (some of which have facets surrounding them) and on old wind crust/slabs on northerly aspects. Quick hand pits looking for easy shears between snow layers in the top 12-18” of the pack is one good tool to suss out any slab that has yet to heal.


Secondary Concern

Wet point release and damp point release avalanches should be expected today on south, east and westerly facing slopes approaching 40 degrees and steeper. Watch for rollerballing in the surface snow and be suspect of areas and aspects where the snow surface is warm and gloppy.

 

 

 


Additional Concerns:
Cornices. Warm temperature are known for contributing to the failure of cornices. A good thing to keep in mind when planning your route.

Surface Conditions:
Yesterday’s warmup affected the south, west and easterly aspects as well as below treeline locations. These areas that became damp or wet yesterday are likely undergoing a superficial refreeze now but should moisten through the day. Upper northerly aspects sport variable wind affected, but dry, snow.


Mountain Weather

It was a WARM day yesterday with temperatures reaching the 40deg mark at sea level and 30F at 3,000’. Skies were partly cloudy with a few flurries (drizzle below 1500’) late in the day. Winds were light from the east (5mph gusting 15mph). The last measurable snowfall was 8-10” on Friday 3/29.

This morning we are looking at mostly cloudy skies, fog and temperatures around freezing (32F) at 1,000’ and ~20F on the ridgelines. Temperatures should rise to the upper 30’s at 1000’ and upper 20’s at 3,500’. A chance for an inch of snow is on the radar (drizzle below 1000’) as instability showers are over the region. Winds are from the east currently, 10mph gusting ~15mph, and should remain today. I’m hoping the cloud cover will burn off a bit for the CORN HARVEST so cross your fingers.

Monday, and through the early part of this week, it looks as though a high pressure ridge will build over western Alaska. This should bring us light northerly wind and mostly clear skies.

 


Fitz will issue the next advisory tomorrow morning, April 1st.

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).

Winter snowmachine use open/closed status and riding conditions updates

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: Apr 11, 2017 )

AREA STATUS WEATHER AND RIDING CONDITIONS
Glacier District
Johnson Pass: OpenPlease park on road in and leave the turnaround (near outhouse) open for trailers to turn around.
Placer River: OpenWide swaths of open river in the Placer Valley. Travel with extreme caution!
Skookum Drainage: ClosedSKOOKUM DRAINAGE CLOSED TO MOTORIZED USE ON APRIL 1 annually as per the Chugach National Forest Plan document.
Turnagain Pass: Open
Twentymile: ClosedClosed for the remainder of the 2017 season.
Seward District
Carter Lake: Open
Lost Lake Trail: OpenPlease STAY ON existing and hardened trail surface through the lower sections of this route.
Primrose Trail: OpenPlease STAY ON existing and hardened trail surface through the lower sections of this route.
Resurrection Pass Trail: ClosedClosed for 2016/17 winter season. This is a non-motorized season. This alternates every other year and will open again during the 2017/18 winter.
Snug Harbor: Open
South Fork Snow River Corridor: Open
Summit Lake: Open

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The information in this advisory is from the U.S. Forest Service, which is solely responsible for its content. This advisory describes general avalanche conditions and local variations always occur. This advisory provided by the Chugach National Forest, in partnership with Friends of the Chugach National Forest Avalanche Information Center.


USFS SNOW AND AVALANCHE HOTLINE (907) 754-2369
If you have comments or questions regarding CNFAIC operations or winter recreation management, please email staff@chugachavalanche.org
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