Good morning backcountry travelers, this is Carl Skustad with the Chugach National Forest Avalanche Information Center on Thursday, April 22, 2009 at 9:30am. This will serve as a general backcountry avalanche advisory issued for the Turnagain Arm area (Turnagain Pass is the core advisory area). Local variations always occur. This advisory should be used as a general spring safety message and is less detailed than previous advisories.
*As we wrap up this season we would like to thank the Friends of the Chugach National Forest Avalanche Center. These guys and gals are amazing and are responsible for the improvements made to the Center this season. The countless hours of fund raising, web design, map making, and community outreach they put in make us proud to be part of such an organization. The Glacier Ranger District and the Chugach National Forest thank the board and all who helped support the Center. Join the team, check out the Friends Page on this web site.
* Skookum closed to snowmachining on April 1st*
MOUNTAIN WEATHER ROUND UP FOR THE LAST 24 HOURS
-General Weather Observations-
As spring tries to role up winters white carpet we need to remember a few things about spring travel. Spring storms come and go very quickly. Sunny one minute, rain and snow the next. Be prepared. If the temperatures refreeze the snow pack at night the early hours of the day are best for safe travel. Hard fast icy surfaces! Once the snow begins to soften on the surface it’s time to take advantage of great skiing and riding. After the sun has warmed the surface snow and you sink into your ankles, it’s time move off and away from steep slopes. Get early starts to your backcountry day and go ride you mountain bike or motorcycle later on sunny days.
Primary avalanche concerns
-From Sea Level to Rigdetops.
Multiple weak layers in the top 1-3 feet of snow ranging from crusts to buried surface hoar.
-Below 3000 feet.
The “January Hurricane” rain crust buried under 4-6 feet of surface snow. There is a layer of weak sugary faceted snow above and below this hard rain crust.
AVALANCHES AND SNOWPACK
EXTRA CAUTION is advised – this weekend avalanche hazard is still CONSIDERABLE. Use conservative decision making, careful route finding, and good travel habits. Training and experience are essential. Sustained temperatures above freezing and/or direct sun may increase the avalanche hazard to HIGH and possibly EXTREME very quickly.
The avalanche danger rating is only a starting point. YOU CONTROL YOUR OWN RISK by choosing where, when, and how you travel.
AnCNFAIC Staff human triggered avalanche was reported yesterday from the north side of Tincan. Very large propagation was reported. The avalanches that are happening right now have been propagating very wide and running pretty far. Large natural avalanches are STILL happening as well. Generally speaking, our snowpack is NOT very stable right now. It has been active for a couple weeks and we have not even seen the Spring Thaw yet. Late April and early May is usually the time when the temps stay above freezing for several days even at night. Some old-timers talk about how avalanches really start ripping out after 48-72 hours of sustained above freezing temps. The sun can also get intense really fast. If you find yourself in the mountains and you see the sun sluffing snow off rocks, then you can expect larger avalanches withing hours or minutes. Heavy rain will also rip out a lot of avalanches, but most people will not venture too far into the mountains if that is how the Spring Thaw presents itself.
On a personal note… I think this is a very strange late season snowpack, and I don’t trust it.
This concludes today’s avalanche advisory. Thanks and have a great day.