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Sunday - March 23, 2008 - 7:53 am
SPECIAL ANNOUNCEMENT >>>
Saturday's advisory updated on Easter Sunday morning.....

Triggered avalanches are possible this weekend on steep slopes in the backcountry.....Happy Easter...

SUMMARY >>>
Danger by
 
ASPECT & ELEVATION
BOTTOM LINE
on slopes over 35 degrees
 
Thereís a MODERATE avalanche danger in the backcountry, and you could trigger avalanches on some slopes steeper than about 35 degrees.  Persistent slab avalanches are possible on very steep slopes at upper elevations.  Wet avalanches will become possible midday as the snow is warmed on sunny slopes especially at lower and mid elevations, and you should avoid and stay out from under all steep slopes with saturated snow.

Forecaster: Toby Weed
LINKS: -Danger scale- -Encyclopedia- -Text only-    
CURRENT CONDITIONS >>>
LINKS TO MORE INFO:
 Once again, Itíll be a bluebird day in the backcountry, with plenty of high angle spring sunshine and some fresh snow to play in.  The Bear River Mountains picked up a bit more powder yesterday and overnight, with the Tony Grove Snotel showing around 6 inches of new snow.  The station is currently reading 100 inches total snow on the ground containing 104% of average water weight for the date.  This could well be the highpoint since with significantly warmer temperatures forecast in the next few days Iíd expect to start seeing some melting.  Yesterday, we found really nice powder conditions on due north facing upper elevation slopes and a wide selection of sun or heat-created crusts elsewhere. The snow at lower elevations is saturated and slushy through and through and you can easily spin your track in or sink to the ground once surface crusts soften.  The Campbell Scientific weather station on Logan Peak recorded north winds averaging in the teens overnight, and itís 6 degrees at 9400í.

RECENT AVALANCHES AND SNOWPACK INFO >>>
LINKS TO MORE INFO

AVALANCHE LIST
PHOTOS
ACCIDENTS

On the second field day of the Avalanche Fundamentals class on Saturday we found a couple nice examples of recent persistent slab avalanches in the Naomi Peak Area, (new photos). These 1-2í deep slab avalanches on easterly facing slopes above 9000í, triggered by cornice-fall and snowmobilers, indicate the potential for more activity on similar, very steep upper elevation slopes.  In test pits I found a suspect weak layer consisting of graupel and small sugary faceted grains, which continues to produce clean and fairly energitic shears with slab propagation.

A skier reports triggering a small slab running on faceted snow on the front side of the Bear River Range above North Logan.  

A snowmobiler triggered a rogue deep slab in the Western Uinta Mountains yesterday and took a nasty ride with his sled but luckily survived. (Western Uinta) 

It was an active week locally, with a handful of natural wind slab avalanches at upper elevations on Tuesday and Wednesday (photos from 3-19) and extensive natural wet activity due to warmth and rain on Wednesday and Thursday, (photos).

  

AVALANCHE CONCERNS >>>
WHERE PROBABILITY SIZE TREND
Likely
 
Unlikely
r
q
Large
 

Small
Increasing
Danger
Same
Decreasing
Danger
e
over the next 24 hrs
Significant wet avalanches are likely on steep sunny slopes again today as solar warming turns the fresh surface snow into slush.  Some cornices could become active with heating.  You could find even smallish wet avalanches entraining lots of mass and traveling far.  Warming is likely to cause a more widespread problem in the next couple days even on shady low and mid elevation slopes  Continue to avoid and stay out from under steep sunny slopes with saturated snow at all elevations.

WHERE PROBABILITY SIZE TREND
Likely
 
Unlikely
r
q
Large
 

Small
Increasing
Danger
Same
Decreasing
Danger
t
over the next 24 hrs
Triggered wind or persistent slab avalanches 1-2' feet deep are possible on very steep upper elevation slopes.  Many areas are plagued by weak layers consisting of small sugary grains called near surface facets and a tricky overlaying slab.   Avalanche slide paths in the area are well filled-in and smooth, so even relatively small avalanches might run far or fast.

MOUNTAIN WEATHER >>>
LINKS TO MORE INFO

UAC COMPILATION
NWS ZONAL FORECAST

A high pressure system will build into the area today bringing fair weather and lots of sunshine.  It will be unseasonably warm on both Sunday and Monday.  A return to more stormy weather is a good bet for early next week, with a stalled front several inches accumulating by Tuesday evening.

GENERAL ANNOUNCEMENTS >>>
Todayís advisory is brought to you in part by the Friends of the Utah Avalanche Center in Logan with help from Black Diamond.  

Check out the images page for photos of some of this seasonís avalanches.

Go to the Avalanche Encyclopedia if you have any questions about terms I use in the advisory.

I'm very interested to know what you're seeing out there.  Please e-mail observations to me at [email protected] or leave me a message at 755-3638, especially if you see or trigger an avalanche in the backcountry. We keep all observations confidential.

This advisory will expire in 24 hours from the posting time.

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.

This advisory provided by the 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.