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

7:30, Saturday April 12, 2008

Hello and good morning, this is Toby Weed of the Utah Avalanche Center with your Logan Area backcountry avalanche and mountain weather advisory.  It’s Saturday April 12th, at 7:30 in the morning. Today’s advisory is brought to you in part by the Friends of the Utah Avalanche Center in Logan with help from Import Auto.

Current Conditions:

If you get out early this morning you might find some nice dry powdery snow up high on shady slopes, but it probably won’t stay that way for long. Mountain temperatures will begin to rocket us into the spring melt down, and it’ll be significantly warmer today than it was yesterday. You’ll find remarkably good snow coverage across the region for this time of year, especially at lower and mid elevations. Only a little new snow fell below about 7500’ in the Central Bear River Range and cold temperatures solidified the snowpack nicely, while upper elevation slopes picked up a good deal of snow in the last week, with the Tony Grove Snotel reporting around 1.5 inches of water equivalent gain. There’s 97 inches of total snow on the ground and 109% of average water equivalent for the date… Thursday’s somewhat strong northwest winds caused extensive drifting in exposed terrain at high elevations, and we’ve seen steady northwest winds again overnight. The CSI weather station on Logan Peak shows a northwest wind currently averaging around 20 mph, and I’m reading 17 degrees this morning at 9400’.

Avalanche Conditions:

We’ve received numerous reports of triggered wind slabs in the mountains of Northern Utah from the past couple days, and the recently formed slabs remain active. We triggered a few soft slabs on steep slopes where fresh snow was cross-loaded into and around west and north facing gullies at upper elevations, (new photos). Wet avalanches involving the fresh snow are quickly becoming the greatest concern with significant warming and intense high angled sunshine…. But, recent drifts and wind slabs around a foot deep could still be active on steep slopes at upper elevations today.

Wet avalanches will rapidly become our greatest concern with this weekend’s warm up. Solar warming from the intense, high angled spring sun could well cause the fresh or surface snow to quickly become saturated and prone to wet avalanching. Warming will intensify in the next few days and snow that’s stayed dry up until now will start to melt; a scenario which will certainly increase the avalanche danger. This weekend you should avoid and stay out from under steep slopes with saturated surface snow, especially in the heat of midday.

Large cornices could be sensitive to your weight today and may break further back than you expect, and they’ll start to sag and deform with the heating. Some are likely to collapse in the next couple hot days, and it is always a good idea in the spring to stay off of and out from under these monsters.

Bottom Line:

There’s a MODERATE danger in the backcountry, and you could trigger wind slab avalanches on steep slopes in exposed upper elevation terrain. Solar warming will cause pockets of CONSIDERABLE danger of wet avalanches on steep sunny slopes at mid and upper elevations, with point-release type avalanches becoming likely. Rapidly and significantly warming temperatures in the next couple days will cause the danger of wet avalanches to rise and become more widespread. Avoid and stay out from under large cornices and steep slopes with saturated snow, especially in the heat of the day…..

Mountain Weather: A high pressure ridge will be over the region today and we can expect warmer temperatures in the mountains. Highs at 8800 feet will approach 40 degrees today and 60 degrees tomorrow…Monday looks like the warmest day in the series, with clouds and a weak storm cooling things off early next week.

General Announcements:

Even though you can ride anywhere these days, you should be sure to keep motor vehicles in terrain that’s open. Riding on public lands designated as “closed to motor vehicles” or as a National Forest Wilderness only jeopardizes the future of our sport, and fines for motor vehicle trespass have been recently increased. (MV wilderness trespass photos)

Check out the images page for photos of some of this season’s 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.