Ogden Avalanche Advisory

Forecaster: Brett Kobernik

BOTTOM LINE

Danger by aspect and elevation on slopes approaching 35° or steeper.
(click HERE for tomorrow's danger rating)


Danger Rose Tutorial

The avalanche danger is MODERATE on slopes steeper than about 35 degrees. This includes northerly aspects along the ridges where drifts formed yesterday and may again form today as winds increase. This danger also includes southerly facing slopes that may become unstable do to direct sun. Also, watch all aspects at the lower elevations as things may become damp and unstable. Watch for snow falling off rocks and trees as well as producing rollerballs all of which can precede wet avalanche activity.


CURRENT CONDITIONS

OK people, human triggered avalanches will again be possible today with a MODERATE avalanche danger. Folks with good avalanche terrain assessment skills will have no problem mitigating the manageable issues with the newest snow. People with less experience could easily find themselves in the wrong place.

Snowfall during the day yesterday laid down another 6 inches of snow or better, some of it coming down rather fierce for a short period of time. Winds were better behaved then first anticipated but still picked up a bit mid day and drifted a little snow. This seemed more pronounced on the Park City side of the range where drifting from southerly winds is not an uncommon occurrence.


RECENT ACTIVITY

There were two snowshoers caught in a small avalanche following a collapse and “whoomp” in very steep terrain that completely buried them in the foothills near Layton on Saturday. They were able to dig themselves out of the soft debris and were not injured. But wait, wasn’t the avalanche danger MODERATE?!! Yes, it was, meaning human triggered avalanches were possible but it’s also easy to overlook additional information in the advisory such as “the danger will QUICKLY rise to CONSIDERABLE with any periods of intense snowfall and increasing winds.” We’ll go have a look at the slide but my gut tells me it was a result of the period of intense snowfall mid day yesterday. Scattered buried surface hoar could very well be the culprit as well. This period of intense snow also produced a very minor natural avalanche cycle in the mid and lower portion of Big Cottonwood Canyon where loose snow avalanches made piles of soft debris 3 to 4 feet deep below the steepest slopes and road cuts. A few fractures were visible on the road cuts as well indicating the presence of a slab. These may have been natural as well but most likely triggered from the snow plows below. A ski touring group in White Pine of Little Cottonwood experienced the new snow collapsing and “spiderwebbing” out a slope during this period as well. (PHOTO) This period of instability was short lived and became stable again for the most part by late afternoon.

(For a look at the period of intense snowfall, go to our archived RADAR LOOPS, set the date for 2-14-09, set the start time at 8 and duration for an 8 hour loop. You'll notice the band of snow from Ogden through Salt Lake at around 1800 UTC which is around noon.)

A few people reported some sensitive fresh drifts along the upper ridges in the Cottonwoods which were big enough to push a person around a bit. (PHOTO) Reports from the Park City, Deer Valley and Canyons snow safety teams all noted wind transport and sensitive soft slab conditions during Saturday. Thanks you guys for your continued observations.


THREAT #1

WHERE PROBABILITY SIZE TREND
      Over the next 24 hours.

While wind speeds did slow back down overnight, we are expecting them to increase as the day goes on. This directly relates to the stability of our newest layers of snow in that there still may be some recent drifts that formed yesterday along the ridges that will be sensitive to the weight of a person. With an increase in winds later today, the very light density snow may be transported and form more fresh drifts. Slope cuts will be an effective tool to use. Continue to monitor the snow surface throughout your travels today and watch for areas with pillows of stiffer snow and, as usual, cracking is the most obvious indicator.


THREAT #2

WHERE PROBABILITY SIZE TREND
      Over the next 24 hours.

A second concern for today may be avalanching as a result of solar radiation. The new light density snow will be very susceptible to its first taste of the sun today. On the upper elevation southerly slopes it will be more of a function of the direct sun rather than temperatures which will not get unreasonably warm. At the lower elevations, however, warmer temperatures may make the new snow become unstable on a variety of aspects.


MOUNTAIN WEATHER

We’ll see a few clouds today but the sun has a good chance to shine strong during the day. Ridgetop temperatures will be in the low 20s but may feel warmer with direct sun. Southerly winds may have a slight east component and will increase as the day goes on. They’ll start out in the 5 to 10 mph range and gradually increase. They probably won’t get out of hand but may be just the right speed for good snow transport. We’re looking at one more storm for Monday night into Tuesday then high pressure for the remainder of the week.


GENERAL ANNOUNCEMENTS

Our web page is now mobile-friendly for users of iPhone and iPod Touch.

Wasatch Powderbird Guides. Operations planning page is here.

Beacon training parks are up and running! There is one at Snowbasin, one on the Park City side at the top of Canyon’s gondola toward the Tombstone lift, one in Little Cottonwood near the Snowbird parking structure on the bypass road, and in Big Cottonwood a training park is at the west end of Solitude's lower parking lot.

If you want to get this avalanche advisory e-mailed to you daily click HERE.

For a text only version, the link is on the left side bar, near the top.

UDOT highway avalanche control work info can be found by calling (801) 975-4838. Our statewide toll free line is 1-888-999-4019 (early morning, option 8).

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 visitour Friends page.

Your snow and avalanche observations help everyone in the backcountry community. Please let us know what you're seeing by leaving a message at (801) 524-5304 or 1-800-662-4140, or email us at uac@utahavalanchecenter.org. (Fax 801-524-6301).

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.

Drew will update this advisory by 7:30 tomorrow morning.


This information does not apply to developed ski areas or highways where avalanche control is normally done.  This advisory is from the U.S.D.A. Forest Service, which is solely responsible for its content. This advisory describes general avalanche conditions and local variations always occur.


This advisory provided by the USDA Forest Service, in partnership with:

The Friends of the Utah Avalanche Center, Utah Division of State Parks and Recreation, Utah Division of Emergency Management, Salt Lake County, Salt Lake Unified Fire Authority and the friends of the La Sal Avalanche Center. See our Sponsors Page for a complete list.