The questions to answer if you are traveling in the backcountry today are (1) how much new snow has fallen, (2) does it have a slab character and (3) how is it adhering to the underlying surface(s)?
(1) There have been significant differences in snowfall totals around the region (see mt. weather section below). The more snow the bigger the avalanche problem.
(2a) Right now temperatures are cold – single digits – which is keeping much of the new snow loose (see secondary concern). However, winds picked up yesterday and last night from the NW and it does not take much to create soft wind slabs with this low density snow. Slabs have the potential to be very sensitive to humans and remotely triggered avalanches are possible. Watch for these on all slopes, rollovers and cross loaded gullies as terrain channeled winds can load every aspect.
(2b) If the sun comes out and begins to warm the surface, watch for the loose snow to become more cohesive and form a soft slab. This is a concern on southerly aspects later in the day.
(3) The old surface is a combination of slick sun crusts on the southerly half of the compass and a mixture of wind crusts and near surface facets (old loose powder) on the northerly half. The new snow is having a difficult time bonding with these surfaces. It will be prudent to give the new snow some time to settle and adjust.
Today is a tricky situation with the variety of underlying surface conditions. One person may ski a slope with only sluffing while the next person 30ft away may trigger an unmanageable slab.
Human triggered sluffs in the new snow will be likely today on all aspects. Expect these to entrain significant amounts of snow and run fast, especially on slopes with a sun or wind crust underneath. They also have the ability to trigger slab avalanches on the way down so be mindful of your terrain choices. Good sluff management techniques will be required and exit routes necessary.
We have received our March refresher. Snow quality was excellent yesterday from all reports and should remain so today.
Snowfall shut off late last night in most areas around the Eastern Turnagain Arm. Below are totals from the past couple days:
24 hr totals 48hr totals
Turnagain Pass SNOTEL (1900′) 5 € (.4 € water) 7 € (.6 water)
Turnagain Pass manual obs (2,500′) 6-8 € 9-14 €
Summit Lake (1400′) 5 € (.4 water) 7 € (.5 water)
Alyeska (upper mountain) 20+ € 25-30 €
Anchorage area €“ up to 18 € on the upper hillside, official numbers HERE.
Hatcher Pass €“ up to 3’+ storm total, details HERE.
Winds associated with the snowfall were from the east during Sunday’s 6 € then backed to the NW on Monday morning bringing in cold air and the majority of the snowfall. Overnight the NW to westerly wind picked up with hourly averages in the teens and gusts to 30mph. Skies are clearing this morning and temperatures are plummeting. Ridgetops are around 0F while sea level and treeline temps are in the single digits.
Today the low pressure centered over our region will head out with clearing skies. Temperatures should stay in the single digits and may climb into the teens at 1000′. Winds look to be in the 5-15mph range from the NW.
Tomorrow, the break in storms will continue but winds look to shift back to the southeast with warmer air moving in. Thursday, another system heads into the Gulf that should be a bit warmer.
Kevin will issue the next advisory tomorrow morning, March 27th.
|01/24/21||Turnagain||Observation: Pete’s||Mike Records|
|01/24/21||Turnagain||Observation: Triangle bowl||Cooper Street|
|01/24/21||Turnagain||Avalanche: Eddies||Johnston-Bloom / Moderow Forecaster|
|01/24/21||Turnagain||Observation: Corn Biscuit||Troy Tempel|
|01/23/21||Turnagain||Observation: Seattle Ridge||A Schauer Forecaster|
|01/23/21||Turnagain||Avalanche: Tincan Trees||Matti Silta|
|01/22/21||Turnagain||Observation: JOHNSON PASS||Anonymous|
|01/20/21||Turnagain||Observation: Sunburst||Johnston-Bloom / Roberts Forecaster|
|01/19/21||Turnagain||Avalanche: Cornbiscuit||Schauer/ Johnston-Bloom Forecaster|
|01/19/21||Turnagain||Avalanche: Sunburst and Tincan||CNFAIC Staff|
Status of riding areas across the Chugach NF is managed by the Glacier and Seward Ranger Districts, not avalanche center staff. Riding area information is posted as a public service to our users and updated based on snow depth and snow density to prevent resource damage at trailhead locations. Riding area questions contact: email@example.com
|Area||Status||Weather & Riding Conditions|
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.