Logan Avalanche Advisory

Forecaster: Toby Weed

BOTTOM LINE

Danger by aspect and elevation on slopes approaching 35° or steeper.
(click HERE for tomorrow's danger rating)


Danger Rose Tutorial

On many slopes in the region there's a LOW danger and avalanches are unlikely.  However, a MODERATE danger exists and you could trigger avalanches on some wind-drifted slopes steeper than about 35 degrees, mainly at upper elevations.  Wind slab avalanches are possible in steep exposed terrain consisting of stiff, previously wind drifted snow.  Although the danger of deadly deep slab avalanches is gradually diminishing, the continued existence of weak sugary or faceted snow near the ground indicates that they're still possible, mainly in upper elevation areas with a thinner snowback.    

Evaluate the snow and terrain carefully, and use wise travel techniques....


CURRENT CONDITIONS

Most slopes in the region are now sun-crusted, wind-blasted, or rimed. (1-15-09 photos)  But the process of water vapor sublimation is re-crystallizing the snow surface and you can find some nice “loud powder” conditions in sheltered shady terrain. Boon docking is good at all elevations on generally supportable snow, but there are numerous shallowly buried obstacles and whips down low...

It's currently 27 degrees at the Campbell Scientific weather station on Logan Peak at 9700', and the wind sensor is reading a consistent 15 mph north breeze.   And, it's 29 degrees the Tony Grove Snotel... Recording 59 inches of snow, containing 18 inches of water, which is 96% of average for January 16th....

 


RECENT ACTIVITY

No significant new avalanches have been reported or observed in the Logan Area in the last week....


THREAT #1

WHERE PROBABILITY SIZE TREND
      Over the next 24 hours.

There are hard wind slabs on many slopes in the region, and the vast majority of these are solidly bonded to the underlying snow...But, there are probably some exceptions, mainly on very steep, exposed slopes and in or around terrain features like gullies or cliff-bands....

You should avoid obvious drifts or hard slabs on steep slopes as these will sometimes trick you, allowing you to get well out on them before releasing....


THREAT #2

WHERE PROBABILITY SIZE TREND
      Over the next 24 hours.

The danger of deadly deep slab avalanches is gradually diminishing, but weak sugary or faceted snow is still present at the very bottom of the snowpack...In many areas this weak snow has been compacted and compressed into the terrain by the tremendous load of the overlying slab.  But there are likely to be exceptions, especially in shallower areas and where the faceted basal layer makes up a higher percentage of the overall snowpack.  Since the slab layer is so deep and strong, you probably couldn't trigger an avalanche in most places anymore....But there may still be exceptions, most likely on very steep slopes and in areas where the slab layer is generally shallow.


MOUNTAIN WEATHER

Expect sunny conditions in the mountains today, with high temperatures near 40 degrees at the mountain tops...Haze and smog will become trapped in Cache Valley as a temperature inversion strengthens under a solid high pressure system.   The inversion will only get stronger in the next few days, with fair and mild weather in the mountains and cold fog and smog in the valleys...  The next possibility of a storm hols off until around Wednesday night or Thursday of next week.


GENERAL ANNOUNCEMENTS

New***   Click HERE for the online version of the Know Before You Go video.

The Utah Avalanche Center depends on contributions from users like you to support our work....You can support the Utah Avalanche Center and get discount lift tickets to  Beaver Mountain (here).  All proceeds from sales will support us through the Friends of the Utah Avalanche Center....

Also the friends still have a few items left over from the Logan fundraiser and you can pick up a few killer deals right now..Here are the items that are still available: -

(2) One day passes to Park City Powder Cats to be used during January or March and before April 15th, 2009.  Retail value is $449 each. Suggested Donation: $225 each

-Men's Medium Patagonia Figure 4 Jacket Grey    Suggested Donation: $95

-Yamaha Leather Snowmobile Jacket Men's Medium     Black with Blue marks   Suggested Donation: $100

100% of your donation will support the Utah Avalanche Center.  Email loganavalanche@gmail.com if you are interested in any of these items.

The information in this advisory is from the U.S.D.A.  Forest Service, which is solely responsible for its content.  This advisory describes general avalanche conditions and local variations always occur. 

I will update this advisory by 7:30 tomorrow morning.


This information does not apply to developed ski areas or highways where avalanche control is normally done.  This advisory is from the U.S.D.A. Forest Service, which is solely responsible for its content. This advisory describes general avalanche conditions and local variations always occur.


This advisory provided by the USDA Forest Service, in partnership with:

The Friends of the Utah Avalanche Center, Utah Division of State Parks and Recreation, Utah Division of Emergency Management, Salt Lake County, Salt Lake Unified Fire Authority and the friends of the La Sal Avalanche Center. See our Sponsors Page for a complete list.