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, Friday April 11, 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 Friday April 11th, 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’re still trying to decide whether or not to head into the backcountry today, let me help.  Although we’re well into spring by the calendar, today is likely to be the last day of a prolonged and powdery winter.   Today you’ll be able to find nice cold and dry snow, especially on north facing slopes at upper elevations, but it’ll warm up drastically over the weekend which will send us face-first into the spring melt down… The mountains picked up a couple inches of new snow overnight, with the Tony Grove Snotel reporting 2/10ths of an inch of water.  The station picked up a bit more than a half inch of water in the last 72 hours, and with 99 inches of total snow on the ground it’s reporting 108% of average water content for the date.   Yesterday’s somewhat strong northwest winds caused fairly extensive drifting in exposed terrain at high elevations, but they diminished overnight.  The CSI weather station on Logan Peak shows a north wind currently averaging around 10 mph, and I’m reading 11 degrees this morning at 9400’.

 Avalanche Conditions: 

We’ve received numerous reports of triggered wind slabs in the mountains of Northern Utah from yesterday.  Ski area snow safety and highway crews had good success with explosives and slope cuts, triggering freshly formed wind slabs…East and southeast facing slopes appeared to be the most active…Despite the windy conditions in the Central Wasatch backcountry, a number of people made it up into exposed upper elevation terrain and several triggered sensitive wind slabs.  One escaped a potentially nasty ride by grabbing a small tree and arresting his descent, (Wasatch advisory)…..   Locally, with less new snow for the wind to drift and fewer people to trigger slabs it’s been quiet and no avalanches have been reported since last week…

  Wind slabs formed Wednesday night and yesterday will likely be the biggest threat in the backcountry, with dry sluffs and cornice falls also possible at upper elevations.  Recent drifts and wind slabs up to around a foot deep will be fairly stiff today, and they would normally be fairly easy to identify and avoid, except they’re now obscured by a couple inches of fresh snow from overnight.  The huge cornices in the region now present an obvious danger, especially when it’s stormy, windy, or warm.  Large cornices could be sensitive to your weight today and may break further back than you expect.  Wind slabs often form on the slope just below cornices.   It is always a good idea in the spring to stay off of and out from under these monsters.

Wet avalanches will rapidly become our greatest concern with this weekend’s intense warm up.  Air temperatures should stay fairly cool today, but 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. 


Bottom Line: 

  There’s a MODERATE danger in the backcountry, and you could trigger wind slab avalanches on steep slopes in exposed terrain mainly at upper elevations.  Solar warming may cause a MODERATE danger of wet avalanches on steep sunny slopes, with point-release type avalanches possible.  Rapidly and significantly warming temperatures over the coming weekend will cause the danger of wet avalanches to rise and become much 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 cool northerly flow will keep air temperatures down today, but a ridge of high pressure will move over the region tomorrow and temperatures will begin to climb drastically.  Expect a daily 10 degree increase in both high and low temperatures until they peak on around Tuesday…Models disagree beyond that point, but a weak and splitting storm appears possible mid-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.