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.


       The Utah Avalanche Center Home page is: http://www.avalanche.org/~uac/

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Logan area Avalanche advisory

Saturday March 31, 2007

Hello and good morning, this is Toby Weed of the Forest Service Utah Avalanche Center with your Logan Area backcountry avalanche and mountain weather advisory.  It’s Saturday March 31st 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 help from Simmons Flexi-ski of Providence.

The Franklin Basin Road is closed to wheeled vehicles due to muddy season conditions, and you must ride snowmobiles over snow and not mud or sagebrush.  Motorized access to the backcountry is severely limited if not impossible from this and other melted-out trailheads.  You can park up on the Tony Grove Road, but expect congestion….

Current Conditions:

Cloud cover kept the snow nice on many slopes, and you can find decent shallow powder conditions especially on sheltered slopes at mid and upper elevations.  A funky, breakable crust developed late in the day at lower elevations and on slopes that warmed up yesterday afternoon.  You can ride anywhere once you get up to snow, but watch out for numerous obstacles, which are only buried by a few inches of new snow.   A steady westerly wind overnight probably damaged exposed slopes with wind-crusts and stiff drifts.  It will be partly cloudy this morning, with more sunshine and warmer temperatures than yesterday.   This week’s fresh snow is likely to get moist and gloppy pretty quickly on sunny slopes.   Clouds should build-in again this afternoon and could trap heat, and greenhousing may be an issue in sheltered areas.  It will be breezy on the ridge tops, with west winds in the 20+ mph range expected.

Avalanche Conditions:

 I triggered a small fresh wind-slab yesterday in a steep mid-elevation gully facing northeast. I also noticed a few natural loose wet point-release avalanches down low on north and west facing slopes, which were triggered by snow falling from trees or cliffs.

 In addition to the expected lee slope loading zones near ridge lines, you might find more stiff drifts and wind slabs today in and around terrain features like rock outcrops, sub-ridges, and gullies. You should avoid any obvious drifts on steep slopes, and be cautious if you encounter stiff, wind blown snow.  

 Given the high sun angle, intense solar warming will quickly turn the fresh surface snow wet and sloppy, and loose wet avalanches will become more likely as slopes are heated up during the day.  These will entrain the new snow and could reach a significant size, especially on big slopes.  It’s a good idea to keep one eye uphill to watch for following wet sluffs, and to move well out of the way of any you initiate.  Although you can generally escape wet point-release avalanches, they can be quite dangerous to anyone in the line of fire.  Best to avoid problems and leave when the new snow on the slope you’re on gets sloppy or saturated.

Bottom Line:

This morning there’s a MODERATE danger in the backcountry, and you could trigger wind slab avalanches on drifted slopes steeper than about 35 degrees. You are most likely to encounter these in exposed terrain at upper elevations, on slopes near ridge-lines facing north through southeast, and near terrain features like gullies, sub-ridges and rock outcrops. With warming temperatures and periods of powerful spring sunshine likely today, the danger will rise to MODERATE on sunny slopes with saturated surface snow.  By afternoon, you might trigger loose wet avalanches entraining significant quantities of heavy snow, especially on steep sustained slopes.


Mountain Weather:

Expect significantly warmer temperatures today in the mountains, with periods of sunshine-or-cloudiness the determining wildcard.  A weak storm passing to our north will bring a threat of snow showers overnight and more clouds, mild, and breezy conditions tomorrow.  Another small storm may produce a few inches of new snow on Monday.

          General Information:

Check out photos of avalanches in the Logan Area on our images page.

Go to the Avalanche Encyclopedia if you have any questions about terms I use in the advisory.  I also recommend the recently-released Media Page, which shows the forecast danger for our coverage areas across the state.

Please e-mail me at [email protected] or leave me a message at 755-3638 if you see or trigger avalanches in the backcountry.  The information you provide may save lives...

 I will update this advisory on Sunday morning.

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.