Provo Avalanche Advisory

Forecaster: Bruce Tremper

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 on all slopes as the new snow accumulates, especially in areas with recent wind deposits. Be sure to test the snow as you travel by jumping on test slopes and practicing slope cuts. If more than a foot of snow accumulates today, or if the wind comes up, or if the precipitation intensity increases dramatically, the danger will quickly rise to CONSIDERABLE.


CURRENT CONDITIONS

4-5 inches of very light, 4 percent, new snow fell this morning so far in the upper elevations of the Salt Lake area mountains and the wave is moving north this morning. We’re expecting as much as 8 inches of light snow today in favored areas. Winds have thankfully remained light, around 15 mph from the south on most of the ridge tops with winds of 20 mph on the highest, exposed peaks. The pre-existing snow was a foot-or-more of powder that provided fabulous riding conditions this past week. The south facing slopes got damp yesterday and south winds yesterday afternoon drifted snow along the upper elevation ridges.


RECENT ACTIVITY

People seemed to jump into most everything this past week with only a few slabs and sluffs triggered. Yesterday, someone was able to trigger some shallow wind slabs in Mineral Fork of Big Cottonwood Canyon that were running long and entraining snow, but they described them as manageable. Someone reported that cornices were breaking farther back than expected and that they were sensitive. Finally, a snowmobiler triggered a slab on a road cut on the Alpine Loop Road on the east side of Timpanogos and we don’t know what weak layer was responsible for this but I suspect surface hoar from a week ago.


THREAT #1

WHERE PROBABILITY SIZE TREND
      Over the next 24 hours.

The main problem today will be the new snow as it accumulates. Yesterday, we were more worried about it, but it now appears like it is coming in with less wind and less snow amounts than originally forecast, so I’m hoping we can squeak through the weekend with relatively, well-behaved snow. My avalanche advice for new snow always resembles the if-then statements we use in computer programming. IF more than about a foot of snow falls OR wind has deposited the new snow into drifts, OR if the precipitation intensity jumps up, THEN you may be able to trigger an avalanche within the new snow. IF you are getting avalanches on test slopes and slope cuts on safe slopes, THEN you will get avalanches on dangerous slopes. In other words, you need to use observations and tests throughout the day as you travel to assess the changing hazard as the snow accumulates.


THREAT #2

WHERE PROBABILITY SIZE TREND
      Over the next 24 hours.

The winds from the south came up yesterday afternoon along the upper elevation ridges and began to drift snow. The tricky part is this new snow will cover them up so they will be hard to see. So I would be very cautious of jumping into upper elevation northerly facing slopes today, even if the surface snow seems safe. As always, avoid steep slopes with recent wind drifts.


THREAT #3

WHERE PROBABILITY SIZE TREND
      Over the next 24 hours.

We now have two layers of slippery, buried surface hoar that may be sensitive, especially if it was overloaded by the south winds blowing yesterday afternoon along the upper elevation ridges. One layer of surface hoar was deposited a week ago and we have seen localized avalanches on this layer, mostly outside the Salt Lake mountains. The more recent layer was deposited a couple days ago and is now covered by this light, new snow. It may become sensitive as weight piles up from new and windblown snow. Again, be sure to jump on test slopes and practice slope cuts. Snow profile from the Provo area mountains - UFOBowls on Timp.


MOUNTAIN WEATHER

We’re expecting snow this morning and tapering off by mid day. It should accumulate 4 – 8 inches of low density snow depending on your location. Since it is coming from the south, favored areas include the upper elevations of the Cottonwood Canyons, the Provo area mountains, and the Wasatch Range near Ogden. The winds are expected to remain reasonable today 10-15 mph from the south and ridge top temperatures should remain in the teens.

This afternoon and Sunday should be a great day to get out with better visibility but still some high and mid level clouds. You should enjoy this snow while you can because a vigorous storm is supposed to arrive Tuesday with strong winds, and denser snow.


GENERAL ANNOUNCEMENTS

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

Wasatch Powderbird Guides flew yesterday in Cardiff and Mineral. They will not get out today because of weather. 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.

Bruce 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.