Good morning. This is Wendy Wagner with the Chugach National Forest Avalanche Information Center on Wednesday, December 7th 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).
There will be no advisory issued tomorrow, Thursday, Dec. 8th. The next advisory will be on Friday, Dec. 9th at 7am. Look for “Thursday’s outlook” below.
Kevin will be presenting our final Fireside Chat tonight at 7pm at the Girdwood Ranger Station. Rescue will be theme for the evening. Come join us!
The avalanche danger is MODERATE for small fresh wind slab avalanches and storm snow sluffing in the 3-6 inches of new snow and increasing winds today. Pockets of CONSIDERABLE danger exist on steep leeward slopes in areas receiving more than 6″ of new snow. These pockets will be most likely found and triggered where the wind drifted snow collects, for example, rollovers, gullies and off ridgelines.
New snow and wind will increase the avalanche danger today and into Thursday. Around 3-6″ of snow is expected throughout the day, with more overnight. Unfortunately, winds are forecast to increase today and will accompany the new snow.
Although today’s snow amounts look to be modest, the strong winds should not have much trouble forming sensitive fresh wind slabs and pockets. These should be relatively small and manageable with good travel practices; however, they will be forming on a hard slick surface in many areas, providing a good bed surface for any snow that slides to run further than expected. These are likely to be found and triggered on leeward terrain features and slopes. Watch for cracking around you in the fresh wind drifted snow.
The new snow will fall on a variety of surfaces formed by last weekend’s rain, snow and wind event. Below 2000′, most locations sport a 1-4 inch, semi-supportable crust (depending on your mode of travel). Between 2000 and 2700′, the rain crust becomes thinner, until above around 2700′, where it disappears. Upper elevations became fairly wind hammered and have varying degrees of a wind hardened surface.
Increasing snowfall Wednesday night through Thursday, with steady strong winds, will increase the avalanche danger. Human triggered wind slab avalanches will be likely on all slopes receiving an additional 8+ inches of new snow overnight with strong winds. Constant evaluation of the new storm snow will be prudent on Thursday. This includes, how well the new snow is bonding to the old surface and how the wind drifts are cracking under your sled or boards.
Overnight, the leading edge of a system spinning in the Bearing Sea has brought cloudy skies, easterly winds and slightly warming temperatures. We should see a shot for 3-6″ of snow during the day as the system moves over us. Easterly winds have begun to blow in the 30’s overnight and temperatures have begun to rise slightly are around 30F at sea level, 20’s around 2000′ and mid-teens above 3000′. Easterly winds significantly increase today, possibly gusting to over 60mph on the ridges. Temperatures should remain fairly steady, in the 20’s at lower elevations and mid-teens at the upper elevations.
Expect an additional 6-10″ Wednesday evening through Thursday with continued strong winds. The snow should tapper off by later Thursday afternoon and winds decrease as well, blowing in the 20’s from a southerly direction. Temperatures look to increase slightly, into the 20’s at the upper elevations. Be sure the check out our weather page for up to date weather conditions!
CNFAIC Weather Page and the NWS forecast
Kevin will issue the next advisory Friday 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.