Good morning. This is Wendy Wagner with the Chugach National Forest Avalanche Information Center on Monday, November 28th at 7am. This will serve as 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).
Our next advisory will be issued Wednesday, November 30th, at 7am.
Tuesday, the much anticipated storm will move into our area. Heavy snowfall looks to begin in the afternoon along with an increase in southerly winds. The avalanche danger will rise rapidly with: (1) increased snowfall, (2) increased wind, and (3) warming temperatures. If this storm arrives earlier than scheduled, natural avalanches will be possible and human triggered avalanches likely. Wednesday, expect the danger to rise one more notch. Stay tuned for Kevin’s advisory Wednesday morning at 7am.
Yesterday, Sunday, there was a report of three natural wind slab avalanches produced by the rapid increase in wind. Additionally, several folks getting out were able to initiate 10-100′ wide wind slabs on the steeper slopes. Most of these were fairly shallow, 4-10″ deep. Here is one example sent in to us.
Today, Monday, the primary concern is for wind slab avalanches on wind loaded slopes that formed yesterday and last night. These are likely “touchy” to the weight of a person and, even more so, to the weight of a snowmachine plus a person. Watch for how and where the 4-5” of new snow from yesterday and the loose old snow have been deposited. These loaded areas include rollovers, ridgelines and gullies. Also watch for cross-loading (gullies are a prime suspect).
Bull’s eye clues will be cracking in the snow around you, stiff snow with a hollow feel and smooth textured snow indicating a wind pillow. Steer clear of any slope that, if released, would funnel and deposit snow in a pile below, such as gullies, chutes or benches. An CNFAIC Staffwise small and ‘manageable’ wind slab can have high consequences in this terrain.
Balmy temperatures (20’s) have the potential to form soft slabs in the new snow and the underlying old, loose snow, that have not been wind damaged. These are most likely to be found on low and mid-elevation rollovers.
Around 4-5″ of snow fell Sunday, mostly just after dark. Winds peaked in the early evening as well, gusting into the 40’s, or higher, from the east on the ridges. Mid-elevations got their fair share with 30mph winds. Temperatures also increased yesterday, into the upper teens around treeline. Overnight, the winds have decreased while the temperatures remain warm, in the upper teens. Today, Monday, winds remain light and variable and temperatures increase into the 20’s. Skies should be mostly cloudy and there is a chance for a trace of snow.
Tuesday, a low pressure system moves into the Gulf and by afternoon snow should start falling with increasing southerly winds. The brunt of the storm looks to be Tuesday night through Thursday morning. The rain/snow line will rise above sea level throughout the storm. Snow totals look to be in the 1-2′ range. Stay tuned HERE for updated weather forecasts for our region.
CNFAIC Weather Page and the NWS forecast
Kevin will issue the next advisory Wednesday morning at 7am. If you get out in the backcountry we want to know what you are seeing. Please send us your observations using the button at the top of this page or give us a call at 754-2369. Thanks and have a great day.