Wasatch Cache National Forest
In partnership with: Utah Division of State Parks and Recreation, The Friends of the Utah Avalanche Center, Utah Department of Emergency Services and Homeland Security and Salt Lake County.

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Friday, April 25, 2008  11:30 am
Good afternoon, this is Bruce Tremper with the Forest Service Utah Avalanche Center with your backcountry avalanche and mountain weather advisory.  Today is Friday, April 25, 2008 and it’s about 2:30 pm. 


Special Announcement: 

This will likely be our last advisory of the season.


Current Conditions:

We had a pleasant weather surprise yesterday.  We were expecting less than 6 inches of new snow but upper Big and Little Cottonwood Canyons ended up with over a foot and as much as 16 inches in some places.  By today, most of the new snow has settled out to about 8 inches and about a foot at the highest elevations.  The snow is slightly stiff, if you’re a snow snob, because there was some graupel in the new snow, but otherwise quite delightful, especially for the end of April.  Today’s sun put a thin sun crust on most slopes except for the upper elevation north facing slopes, which should be the only ones with decent powder for Saturday morning.  Temperatures this morning were around 10 degrees and it warmed up to the mid 30’s on the ridgetops with a moderate wind from the northwest. 


Snow and Avalanche Discussion:

Yesterday when the snow rained down fast and furious during the snow squalls that moved through, the snow was sensitive and several people were able to make the snow crack and occasionally kick off some shallow, soft slab avalanches.  Last night at 7:00 pm in the evening someone was caught and carried in an avalanche they triggered in Little Cottonwood Canyon on the south side of Little Superior.  They rode the avalanche 200 feet and got out before it ran 2/3 of the way to the road below.  The avalanche was 100 feet wide and 18-20 inches deep.  Someone also noticed a small natural slab, which probably released yesterday, in Ivory Flakes in Cardiff Fork of Big Cottonwood Canyon. 

The snow has settled out quite a bit by today and it was much less sensitive.  I suspect that since the old snow surface was so warm and wet, combined with a little sun, it caused rapid settlement and bonding in the new snow.   Even in this morning’s sun, there was surprising few wet sluffs on the steep south facing slopes.

For those heading out on Saturday and through the weekend, the snow should be fairly well behaved but you will need to watch for a couple of the usual avalanche problems we have with spring storms:

First, watch for a few, lingering,  sensitive wind drifts especially along the upper elevation slopes from northwest winds.  Be sure to practice slope cuts, jump on test slopes and dig down with your hand to test the snow.

Second, as the strong spring sun warms up the snow you should watch for wet sluffs on the steep, sun exposed slopes, especially in the heat of the afternoon.  The snow usually starts producing rollerballs (pinwheels) before it starts producing larger sluffs.

Mountain Weather:

The weekend should be mostly sunny with ridge top high temperatures near the mid 30’s and a 15-20 mph wind from the northwest.  On Sunday the high should be near 44 and near 52 on Monday. Overnight lows should be in the mid 20’s, rising to near freezing on Monday.

The extended forecast calls for continued nice weather with the chance of another shot of snow about Thursday.

You can easily monitor the weather yourself by using the following links:
Alta Forecast Graph from the National Weather Service (I love this product).
48-hour weather charts of past temperature and wind (a product produced by our own Brett Kobernik.)
Cottonwood Canyons Forecast from the National Weather Service.

If you see any avalanches or interesting snow conditions, please leave us a message at (801) 524-5304 or 1-800-662-4140, or email us at [email protected]. (Fax 801-524-6301).

UDOT highway avalanche control work info can be found by calling (801) 975-4838.

Watch video tututorials and fieldwork from UAC staff at our YouTube channel.

The UAC depends on contributions from users like you to support our work.  To find out more about how you can support our efforts to continue providing the avalanche forecasting and education that you expect please visit our Friends page.

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 will likely be our last advisory of the season.  I will put on an end-of-season message on Monday.