Ogden Avalanche Advisory

Forecaster: Drew Hardesty

BOTTOM LINE

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


Danger Rose Tutorial

POCKETS OF CONSIDERABLE remain in an otherwise MODERATE landscape. The likelihood of triggering 1-3’ deep 200’ wide avalanches is mostly confined to the steep, northwest through northeasterly facing slopes above about 8200’. Consequences of getting carried in one of these slides remain severe, even if you’re not buried. We'll see a heightened MODERATE danger of newly formed wind drifts in the steep mid and upper elevations. Wet and dry sluffs on the steeper slopes will also be a factor today as well.

Safer terrain does exist - slopes less steep than about 33 degrees that are not connected to steeper slopes directly above or to the sides, and slopes without the layer of buried facets – generally those at mid and lower elevations and those facing the south ½ of the compass.


CURRENT CONDITIONS

Skies are clear but the southwesterly winds make the headlines. Ahead of a couple weak going-through-the-motions storms, the winds have ramped into the 40-45mph range with gusts into the mid-60s. Mountain temps are in the low 30s at 9700'. Colder air pooling in the basins has many trailheads in the upper teens to low 20s. Surface hoar (the wintertime equivalent of dew - see Mark White's photos) was noted on most aspects and elevations yesterday, but sun and wind will conspire to destroy or erode the more exposed feathers of snow. Sun dampened the southerly and westerly aspects and they will be crusted over this morning.


RECENT ACTIVITY

Intentional cornice drops off the Park City ridgeline initiated some longer running sluffs in the new snow, with some reportedly packing a punch. We did not hear of any continued collapsing or human triggered slides into the old snow, but explosive control work in Little Cottonwood Canyon produced two more avalanches 2-3' deep in the high north facing terrain.

In the past couple weeks, we've suffered a fatality, a broken femur, and a caught and carried backcountry skier with bumps and bruises. It's something to have the intrepid men and women from Wasatch Backcountry Rescue and the County Sheriff's Departments, but consider becoming trained in Wilderness Medicine. It's all part of becoming self-sufficient and prepared for being in the mountains we so love.


THREAT #1

WHERE PROBABILITY SIZE TREND
      Over the next 24 hours.

The results from the control work in LCC as well as continued positive, if inconsistent, test results dictate continued caution in the steeper shady terrain. A word on snow pits. Statisticians will tell you that a sample size of 1 (N =1) is junk science. Perform multiple snow tests for a more complete picture (Evelyn looking for the distribution of weak layers in Ogden) and reach down and look for the presence of the buried sugary faceted snow (see Trent Meisenheimer's video from last week - two large skier triggered avalanches released in adjacent terrain on a day or two later.) With conflicting test results, I tend to put more stock in the ones that hint at "unstable" more than "stable". The consequences of being wrong may be too much to bear.


THREAT #2

WHERE PROBABILITY SIZE TREND
      Over the next 24 hours.

You can count on finding some shallow, but reactive new wind drifts formed from the stronger southwesterly winds. Sensitive drifts will primarily be found on the north and easterly aspects, but cross-loading may have them in the lee of sub-ridges, convexities, or gullies. The new drifts will bond poorly to the weak surface snow, even on terrain crusted over yesterday. It'll be critical to jump on test slopes and perform safe ski and slope cuts before committing to the line. Remotely triggered slides (slides triggered at a distance) are possible.

Triggered wind drifts may step down into the older faceted snow in the steep northerly aspects.


MOUNTAIN WEATHER

High pressure today will gradually give way to a couple weak disturbances on Thursday and again on Friday. In the meantime, temperatures will soar into the 40s again at 8000' and the mid to upper 30s at 10,000'. The southwesterlies will blow 45-55mph with gusts to perhaps 70. We'll have increasing clouds and perhaps a trace tomorrow with the potential for 3-6" on Friday. The cold front drops temps to the mid-teens Saturday, but they'll quickly rebound into the upper 30s at 10k by Sunday. I hate to say it, but the longer range models look bleak.


GENERAL ANNOUNCEMENTS

If you trigger an avalanche in the backcountry - especially if you are adjacent to a ski area – please call the following teams to alert them to the slide and whether anyone is missing or not. Rescue teams can be exposed to significant hazard when responding to avalanches, and do not want to do so when unneeded. Thanks.

Salt Lake – Alta Central (801-742-2033)

Ogden – Snowbasin Patrol Dispatch (801-620-1017)

Provo – Sundance Patrol Dispatch (801-223-4150)

Dawn Patrol Forecast Hotline, updated by 05:30: 888-999-4019 option 8.

Daily observations are frequently posted by 10 pm each evening.

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UDOT canyon closures UDOT at (801) 975-4838

You have the opportunity to participate in the creation of our own community avalanche advisory by submitting avalanche and snow observations. You can also call us at 801-524-5304 or 800-662-4140, or email by clicking HERE

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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.

We will update this forecast tomorrow morning. Thanks for calling.


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.