Wasatch Cache National Forest

In partnership with: The Friends of the Utah Avalanche Center, Utah Department of Public Safety Division of Comprehensive Emergency Management,

Salt Lake County, and Utah State Parks:

        

 

Avalanche INFORMATION

Wednesday, October 27, 2004  12:30 pm

 

Good afternoon, this is Evelyn Lees with the Forest Service Utah Avalanche Center with your backcountry avalanche and mountain weather information.  Today is Wednesday, October 27, 2004, and it’s 12:30 pm.  We’ll be issuing afternoon bulletins through the end of the month on an almost daily basis.  Don’t miss the annual Friends of the Utah Avalanche Center ski swap at REI on Saturday, November 6th.  Gear drop off will be on Thursday and Friday evenings.

 

Current Conditions:

While fashionable late, the Pacific storm system off the California coast is slowly moving inland, and the northern Utah mountains are forecast to receive snow this afternoon into Friday. Ahead of this storm, the weather continues to be cloudy, mild and breezy.  Overnight lows were near 30 at 9,000’ and temperatures have warmed to near 40 at many 8,000’ stations this morning.  The winds are from the south, in the 15 to 20 mph range across the higher ridges, with gusts 25 to 35 mph.  Surface snow conditions include dense powder on mid and upper elevation shady slopes, while low elevation and sunny slopes are crusted.

 

Avalanche Conditions

The storm on our doorstep is expected to bring strong southerly winds and a foot or more of snow by Thursday morning.  So if you are heading into the backcountry this afternoon or tomorrow, Thursday, expect a rising avalanche danger, with several problems to be aware of.   First, the warm temperatures may cause the rain/snow line to start as high as 8,500’.   If prolonged rain on snow occurs, it could initiate a natural, wet loose avalanche cycle.  Wet, loose slides could continue to be a problem at the mid and lower elevations through tomorrow or until temperatures cool.  At the colder, higher elevations, I expect most of the avalanche activity to be within the new snow or at the new snow/old snow interface.  On most slopes, the old surface snow is through warm and dense.  However, cold, light surface snow remains on upper elevation, shady slopes, and these are the slopes where the new snow may be the most sensitive.  And finally, avoid any fresh drifts of wind blown snow on steep slopes.  These new, sensitive wind drifts will be most widespread on northwest through northeasterly facing slopes, but watch for drifts around terrain features such as gullies, rocks and sub ridges. 

 

Whenever natural avalanche activity is possible, backcountry travelers, including hunters, need to be aware of the slopes above them and avoid travel below steep slopes and in runout zones.  The Provo area mountains have a lot of steep avalanche paths with long run outs, and these photos from this Monday’s slide cycle off Elk Point illustrate the dangers.  There were several natural avalanches with impressive debris piles 20 to 30’ deep that ran close to summer trails.  These are a good reminder that when there is natural avalanche activity, you don’t need to be in the starting zone or on a steep slope to be caught and buried.

 

Remember, the unopened ski areas are not doing control work, and are just as dangerous as the backcountry.  Also, some ski areas may start posting closures so they can prepare to open, so please obey all signs.  The Alta Ski Area is closed to backcountry travelers and uphill traffic for avalanche control work and construction, and the closure will last through the storm. 

 

Bottom Line:

The avalanche danger is MODERATE on slopes steeper than about 35 degrees with recent deposits of wind drifted snow, which are most widespread along the higher ridgelines.  Elsewhere, the danger is generally LOW.  Once the storm arrives, the avalanche danger will increase, rising to CONSIDERABLE on and below steep slopes, especially those with fresh wind drifts or in areas receiving heavy rain.  Considerable means natural avalanches are possible, and human triggered avalanches probable.  Wet snow sluffs may be possible on steep slopes in areas that receive prolonged rain on snow.  If the storm is as potent as forecast, the avalanche danger may be the higher and most widespread in the PROVO area mountains on Thursday.   

 

Mountain Weather:

Widespread snowfall should start falling in the northern mountains this afternoon, with 12 to 18” inches of snow possible by Thursday morning.  Winds will remain from the south today and tonight, increasing to near 30 mph across the ridges.  At 8,000’, highs will be in the mid 30’s to near 40 today and low’s tonight near 24.  The upper trough will cross the area late Thursday or Thursday night, bringing more snow to the mountains on a cooler northwest flow.  A break is expected Friday night and Saturday, followed by a colder system dropping in Saturday night that should bring snow through Sunday night.

 

If you are getting out, drop us a line or an email with any reports or observations from the backcountry.  You can leave us a message at 524-5304 or 1 800-662-4140.  Email us at [email protected], or a fax to 524-6301. 

The information in this advisory is from the US Forest Service, which is solely responsible for its content.  This advisory describes general avalanche conditions and local variations always occur.

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For more detailed weather information go to our Mountain Weather Advisory

National Weather Service - Salt Lake City - Snow.

For an explanation of avalanche danger ratings:

http://www.avalanche.org/usdanger.htm