Salt Lake Avalanche Advisory

Forecaster: Drew Hardesty

AVALANCHE WARNING »

Dangerous avalanche conditions are occuring or are imminent. Backcountry travel in avalanche terrain is not recommended.
Notice:

I've issued an Avalanche warning for the Central Wasatch and the danger will be widespread across the range and most pronounced in the upper cottonwood canyons. A special avalanche advisory has also been issue for the logan, ogden, and provo mountains, to include the western uintas and the wasatch plateau.


BOTTOM LINE

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


Danger Rose Tutorial

Well, if we never use Extreme, and perhaps we should, then the danger is likely going to rise to HIGH if it keeps snowing and blowing. Natural and human triggered avalanches are probable with these conditions. Sensitive drifting is widespread and not limited to upper elevation terrain. Those without skill and training should play on or underneath slopes more gentle than 35 degrees – or head to the ski areas.


CURRENT CONDITIONS

There are those moments in life when you’re outside with good friends, or even alone, and you realize something has changed. The sun shines more brightly, the colors are more vibrant, the powder snow bottomless. It’s like a momentary glimpse of a rainbow just after a hard rain – and everyone looks at one another with smiles – and nothing needs to be said. We mark our lives by days like these. This was yesterday in the Wasatch.

By the afternoon, the door began to close, the clouds rolled back in and snow began again, in earnest. Snow totals are now 9-12” in the Cottonwoods, and 3-6” in the outlying areas. Densities average 7% with temps generally in the teens. The west to northwest winds picked up with the precipitation, blowing 25 gusting to 45, with even base elevation anemometers registering speeds of nearly 20mph with gusts to near 40. All of this on top of a settled 12-24” is a game changer. Things are starting to become more interesting.


RECENT ACTIVITY

Those with good avalanche (read avalanche, not skiing or riding) ability easily initiated the localized pocket wind slab or loose snow sluff in steep terrain yesterday. Periods of high sun dampened the snow in some terrain, which – as a good rule of thumb – will often become result in this. Few of us like, or welcome change, but it’s of critical importance to recognize when things just “aren’t like they used to be” – even if it was minutes ago. What was manageable yesterday is rapidly becoming less so today.


THREAT #1

WHERE PROBABILITY SIZE TREND
      Over the next 24 hours.

The danger will rise in lock step with the snowfall intensity and winds - It’s right out of Avalanche 101. Natural avalanching is likely occurring in the high alpine terrain in these conditions. I expect sustained snowfall and winds – and an initially poor bond to yesterday’s snow surface. Choose lower angled terrain or walk around the steeps on the ridge and sub-ridges. Cornice development will also be healthy – and drifting is occurring mid-slope and at the mid-elevations. Any encatchment area, particularly in cross-loaded areas, will be sensitive for triggering.


THREAT #2

WHERE PROBABILITY SIZE TREND
      Over the next 24 hours.

Most of the intra-storm weaknesses and sensitive wind pockets from Monday/Tuesday have likely sintered and gained strength – with the outlier being areas where it “graupled”. This “bean-bag” stuffing, while dense, has little internal cohesive strength and may be a “non-persistent” weak layer into today. Hand shears and pole-isolation tests should reveal its presence, or lack thereof. It does not, however, support remote triggering or “hard slab” tendencies, such as pulling out on the 3rd skier.


MOUNTAIN WEATHER

Heavy snowfall and strong and gusty winds are expected throughout the day. Temps will be in the mid to upper teens and we may see another 6-10” throughout the day, with another round of heavy snowfall expected around dinner time into the overnight time frame. Despite much colder air with the system, the storm shifts northerly, with poor orographic support for tomorrow.


GENERAL ANNOUNCEMENTS

Wasatch Powderbird Guides got out briefly into Cardiff and Toledo yesterday. Check their operations planning page is here.

Our web site is now formatted for iPhone. You can also download a free iPhone application from Canyon Sports to display the Bottom Line. Search for Utah Avalanche on the Apple's iPhone Apps page or in iTunes.

The North American Avalanche Danger Scale is being revised for next winter. Our friends in Canada have created a short survey found at the following link. Please help ensure the new Avalanche Danger Scale is effective by completing a survey. http://surveys.globalepanel.com/wix/p319164581.aspx

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).

Donate to your favorite non-profit – The Friends of the Utah Avalanche Center. 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 can save someone’s life. 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.

Evelyn 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.