Provo Avalanche Advisory

Forecaster: Evelyn Lees

BOTTOM LINE

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


Danger Rose Tutorial

There avalanche danger is MODERATE for new snow sluffs and soft slabs, with human triggered avalanche possible. Any direct sun or heating this afternoon will increase the danger to MODERATE for wet loose sluffs on steep slopes. There are very isolated places where old, hard wind drifts hidden beneath the new snow could be sensitive.


CURRENT CONDITIONS

The seemingly endless parade of spring powder storms dropped another solid foot of snow above about 9,000’ in the upper Cottonwoods and along parts of the Park City ridge line, with 6 to 9” of new in the Provo mountains. The Ogden mountains have only managed to squeak about 3 to 6” of snow out of the storm so far. The winds have been from the southwest most of the night, and rather well behaved with speeds of less than 15 mph, except for the highest peaks, and even these gusts only into the low 30s. Temperatures are steadily dropping, currently in the upper teens at 10,000’ and the mid 20s at 8,000’. The new, dense, right side up powder is landing on crusts on all but the mid and upper elevation northerly facing slopes.


RECENT ACTIVITY

Yesterday, most of the action was roller balls and a few wet loose sluffs, all occurring before noon, when increasing clouds cut off the heating. In the Ogden mountains, skier triggered hard slabs were released on control routes, on E and SE facing slopes above 8500 ft. Most were less than a foot deep and less than 100’ wide, but one pulled out up to 2' deep, and triggered an additional mid slope pocket. A few shallow stiff slabs were triggered in upper Little Cottonwood with explosives. Interesting profile from the Provo area mountains.


THREAT #1

WHERE PROBABILITY SIZE TREND
      Over the next 12 hours.

Today, the new snow will be most sensitive this morning, especially during the any periods of high precipitation rates. Anytime it snows one to two inches per hour where you are, it will be easy to trigger sluffs, and natural avalanches will be possible. However, once the snowfall rates taper off, the new snow will rapidly stabilize. Literally within hours, the transition from natural avalanche activity to hard to trigger avalanches can occur. On some slopes, the new snow is landing on slick crusts, and may be a bit more sensitive.

While the new snow not too wind drifted, any old hard wind drifts will be completely hidden. These hard drifts seem more widespread and sensitive in portions of the Ogden mountains. Cornices throughout the range are being described as frighteningly large, and will break back much further than expected.


THREAT #2

WHERE PROBABILITY SIZE TREND
      Over the next 10 hours.

An afternoon concern is wet avalanches. This time of year, even a ½ hour of direct sun or a period of thin clouds is enough to heat up the snow. So with partial clearing in the forecast for this afternoon, watch out for wet loose sluffs on mid and lower elevation slopes of all aspects, and on any steep, sunny slope. Roller balls may be the first clue, followed by easily triggered sluffs that can pile up deeply in gullies and below road banks.


MOUNTAIN WEATHER

Heavy snow fall could continue for another few hours, before becoming more showery for the rest of the day. An additional 2 to 4” are possible today. Temperatures will cool at the upper elevations into the mid teens, and be in the upper 20’s at 8,000’. Winds will switch to the northwest, and remain light, generally in the 5 to 15 mph range. Clean off the storm boards this afternoon, as wrap around moisture in a northwest flow could bring as much as another foot of snow tonight into Saturday morning. Then high pressure will move in over the area Sunday, with temperatures rapidly warming through Tuesday.


GENERAL ANNOUNCEMENTS

Wasatch Powderbird Guides didn’t get out on Thursday and won’t be out today. 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.

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).

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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.

Brett Kobernik 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.