Good morning backcountry travelers. This is Jon Gellings with the Chugach National Forest Avalanche Information Center on Wednesday, April 6th 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).
The avalanche danger today is MODERATE with pockets of CONSIDERABLE. Recent wind slabs on steep leeward terrain could still possibly be triggered by a skier or snowmachiner. The pockets of elevated danger will become increasingly obvious as the sun begins to warm this surface layer of previously non-sun-affected snow, if the sun acts as forecast.
We will hopefully be able to see the extent of recent avalanches today, pending whether or not the obscure skies lift for once. I suspect a new layer of surface hoar has formed last night due to clear skies, low temperatures, moist snow, and light breezes. If the approaching storm comes in overnight and drops a significant amount of snow on this, expect anCNFAIC Staff increase in avalanche activity.
The weak layers of surface hoar and small facets from the end of March are currently the most concerning layer in our snowpack. Steep alpine slopes facing North which lack crusts in upper snow layers have a more concerning setup than lower elevations which now have a rain crust, and alpine South aspects which have sun crusts from previously sunny days last week.
The secondary concern, which may become a higher concern in the afternoon dependent on sun, is that South aspects will start shedding snow in the form of point releases near rock outcroppings. As these roll down the slope, they could naturally start pulling out wet and/or soft slabs further downhill. Clues to this instability include increasing temperatures, which manifest in seeing roller balls, as well as upper layers of snow settling and creeping, and becoming saturated with water.
If you hear any “whumpf” sounds, see shooting cracks, feel collapses, or see any recent avalanches, please let us know about them by submitting an observation at the top of this page. These clues help us determine what type of instability we are dealing with, and where more concerning areas are located. Plus, you get entered to win a beacon of your choice on April 15th!
For the next 12 hours, the winds are not forecasted to be strong enough to transport snow, therefore will not increase the avalanche danger. Temperatures are not going to be as warm as they were yesterday, which has already started freezing up the recently saturated snow at lower elevations. Expect a surface crust… Precipitation will likely not be falling at a significant rate today, as radar, satellite, models and forecasts all point to semi-clear skies. Winds and precipitation rates will increase later on tonight, affecting tomorrow’s avalanche danger.
MPH BY LATE THURSDAY AFTERNOON AFTER FRONTAL PASSAGE.
WEATHER EVENT SHOULD BEGIN NOW.
.TODAY…PARTLY CLOUDY. HIGHS IN THE MID 30S TO LOWER 40S.
BECOMING 10 MPH IN THE AFTERNOON.
16 degrees. N wind 4mph gusting to 13mph.
26 degrees. Winds are not being recorded due to an iced-up anemometer. This should correct itself when the winds pick up tonight.
23 degrees. 2-3 inches new snow.
