Wasatch-Cache National Forest  In partnership with:  Utah State Parks and Recreation, Friends of the Utah Avalanche Center-Logan, and Utah State University College of Natural Resources.

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Logan area Avalanche advisory

 December 9, 2006

Hello and good morning, this is Toby Weed of the Utah Avalanche Center in Logan with your backcountry avalanche and mountain weather advisory.  It's Saturday December 9th, and it's 7:00 in the morning.  This advisory is brought to you in part by the Friends of the Utah Avalanche Center in Logan with the help of Avalanchetools.com. 

Current Conditions:

The winds picked up overnight and early this morning, and they're posting near 30 mph hourly averages with gusts around 50 from the south-southwest.  Temperatures at the Campbell Scientific weather station on Logan Peak reached a 24 hr low at 5:00 this morning, recording a balmy 27 degrees.  Clouds will be on the increase today, but the winds should back off a bit ahead of a series of progressively stronger storm systems, which will affect the region tonight into early next week.  You'll only find powder-like re-crystallized snow on very sheltered and shady slopes, with a mixed bag of surface wind and sun crusts elsewhere.  Your best bet may be at mid elevations, if you can find shady slopes with enough snow to play on.  Yesterday we found a wide variety of conditions, ranging from bullet-proof crusts to ankle-deep reconstituted powder. The snow in many shallow areas is punchy, especially around rocks, and sometimes you sink to your knees in nasty sugary snow.  This can make hill-climbing and turning in un-compacted terrain somewhat hazardous.

 Avalanche Conditions:

 Avalanches remain generally unlikely throughout the region today, but you still might find places in very steep and exposed terrain where you could trigger an avalanche.  I'd be most cautious on shallow, upper elevation slopes facing the northern third of the compass and around terrain features like gullies and rock outcroppings where drifts may have formed during this morning's wind.  We found a number of developing weak layers and crusts yesterday, and it will be interesting to see what happens when all this stuff is buried.  I'm growing much more concerned by the wide-spread presence of large sugary or faceted crystals we call depth hoar, which are rapidly growing near the bottom of the snowpack.  Many slopes developed a substantial layer of pretty feathery frost crystals called surface hoar.  Sunnier slopes sport surface sun crusts ranging from super hard and slick on south facing slopes to weak and zippery on east and west facing slopes where the time of direct sun exposure is more limited.  All of these could form dangerous persistent weak layers once a slab of stronger snow builds up on top of them.  The danger will begin to rise in the backcountry as new snow starts to pile up, starting tomorrow.

  Bottom Line:

There's a LOW danger and avalanches are unlikely on most slopes in the mountains around Logan.  You might find isolated exceptions and possibly trigger avalanches in very steep, wind-drifted terrain.   

Mountain Weather:

The inversion causing ridge of high pressure finally moved off to the east, and a series of progressively colder and more energetic pacific troughs will affect the region into early next week.  This morning's southwesterly winds should diminish during the day, but not before mixing up the atmosphere and cleaning much of the smog out of the Valley.  The wind will increase again tonight, and some light snow is possible in the mountains.  4 to 6 inches of accumulation is possible on Sunday, with enough wind to build drifts and cause an increasing avalanche danger.  Models are still disagreeing on the potency of a mid-week trough, but then that's still a ways off.

 General Information:

I'll give a free Avalanche Awareness Talk, open to everyone, at the Logan Ranger District offices on Thursday, December 14th at 6:30.

 The Tony Grove Road is not maintained in the winter.  That means, you can't quite drive a wheeled vehicle all the way to the lake, and you should be prepared to get stuck in a couple feet of snow if you try.  Turning around may be difficult. Snow and ice-covered road conditions are alright today, but could rapidly deteriorate tomorrow.  With limited access to upper elevation snow elsewhere, there's lots of snow-hungry people on the Tony Grove Road.   Motorized users need to be aware of this, and we need to keep our speed way down in the proximity of pedestrians.   

   I'll update my advisories on Tuesday and Thursday evenings and weekend mornings by about 7:00.    I'll update this advisory again on Sunday morning.  Logan Area advisories will be accessible through the new statewide toll-free avalanche info line; 1-888-999-4019.

If you're confused by some of our avalanche terms check out the cool new Avalanche Encyclopedia.  Please  send backcountry observations to [email protected] or leave us a message at 755-3638, especially if you see or trigger an avalanche in the backcountry.

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