Snow & Avalanche Weekly Summary
This will be the final weekly summary for Summit Lake of the 2014-2015 season. We will update this page as needed (i.e. storms, avalanche cycles). A season wrap up including weather history and springtime tips will be posted soon.
This past week brought little in the way of change to the snowpack around Summit Lake. Coverage remains thin to non existent below 2,000’. A storm that brought 1-2’ of snow to Turnagain and Girdwood deposited only 2” or less at Summit. With a lack of any loading and mild temps over the week the general danger is currently LOW.
Coverage at Summit Lake is thin. View of Summit Lake looking down from Tenderfoot Ridge.
The general snowpack structure between the road level and 3,500’ is comprised of a series of crusts and weak snow (see photo below). Pockets of very shallow slab that formed on Thursday’s 2” storm have made for good riding conditions in the Alpine. A continuation of mild temps, cloud cover and little in the way of precip will prevent weak layers from forming on the surface through the weekend.
Triggering an avalanche is currently unlikely around Summit Lake. Exceptions to this may be found in the following:
Wet Loose Avalanches
Warm temps and particularly direct sunshine will impact the small amount of loose surface snow. This will produce rollerballs and very shallow point releases. Volume will be low and speed will be slow to medium. This issue becomes greater when traveling on or below long sustained steep slopes. If the sun is hitting steep slopes, pay attention to the snow at your feet as well as any large terrain that may be overhead.
Very isolated pockets of shallow wind slab may be encountered in the highest elevations. Avoid terrain over 40 degrees that has stiff or hollow sounding snow. These slabs will only be found in pockets, but could create problems if triggered above terrain traps such as cliffs, gullies or trees.
While it has been a meager year in terms of snowfall, cornices still exist along ridgelines. Sun, warm temps and a lack of wind can quickly weaken these features in cirques and bowls that collect heat. Always give cornices a wide berth and approach from the side where you can see the underlying terrain. Pick routes on the way up that minimize time spent beneath these features.
The past week was mild in all three weather categories related to avalanches - temperature, wind and precipitation. Ridgetop temps remained in the high 20s F to low 30s F while valley locations were warm with Summit Creek SNOTEL recording averages over freezing for the past 3 days. Winds bumped up slightly ahead of an approaching storm on Wednesday night. That storm did not do much in the way of precip at Summit, with roughly 2” of new snow falling above 2,500’ and rain falling at road level.
A broad area of low pressure to our South will spin and continue to pump light amounts of precipitation to the area today. Another trace to 1” of snow can be expected today. Rain/snow line will rise to around the 1,800’ mark. Winds will be out of the East at 15-30 mph. Temperatures at 1,000’ will be in the mid 30s to low 40s F.
A continuation of unsettled weather will bring more of the same weather for the next several days. Warm Southerly flow associated with low pressure in the Gulf of Alaska will keep temps mild and precipitation coming in small doses.
As always check the nearby weather stations before heading out around Summit Lake:
Fresno Ridge for ridgetop winds and temps
Summit Creek SNOTEL for temps and precip at road level
This is a general backcountry avalanche advisory issued for Summit Lake Area 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: Mar 26, 2015 )
|AREA||STATUS||WEATHER AND RIDING CONDITIONS|
|Turnagain Pass:||Closed||Conditions do not look promising for a snowmachine season on the CNF this winter.... A first ever so far as we can tell. There is still a small glimmer of hope for a cold April storm but we are not holding our breath.|
|Lost Lake Trail:||Closed|
|Resurrection Pass Trail:||Closed|
|South Fork Snow River Corridor:||Closed|
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