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

Slopes to avoid today:

Any slope approaching 35 degrees or steeper that is cracking or collapsing under your weight or snow that has an upside down, slabby feel. You will find these mostly along the upper elevation ridges on slopes that face the north and east quadrants of the compass.

Expect the avalanche danger to rise for Saturday with a couple inches of additional snow combined with stronger winds.


RECENT ACTIVITY

Yesterday, the intrepid observer, Mark White, was able to trigger shallow wind slabs easily by intentionally kicking cornices along the Park City ridgeline. Also, yesterday one of our most experienced observers noticed lots of cracking and collapsing in slabby snow along the Alta and Brighton periphery from wind deposits and denser, warmer snow on top of faceted snow. Many of these wind slabs did not have the typical rounded pillow appearance, which made them tricky to recognize except for the way they consistently cracked and collapsed. You can see these observations in the usual location--the Current Conditions section of our website.


THREAT #1

WHERE PROBABILITY SIZE TREND
      Over the next 24 hours.

The preexisting snow is extremely weak--the weakest, thickest layer of faceted snow I have ever seen in Utah in over a quarter century of avalanche forecasting. So it does not take much of a slab on top to make things interesting. With the combination of 3 inches of dense graupel yesterday morning combined with with a thin rain crust under the graupel and combine all that with some stiff winds yesterday, it has made some slabby conditions along the upper elevation ridges. Many of these are cracking and collapsing under your weight. Most are shallow enough to continue calling it a Moderate danger instead of something higher on the scale.

With the expected couple inches of new snow tonight combined with stronger winds, it should make the slabs more widespread and thicker for Saturday. Expect avalanche danger to rise a notch.


THREAT #2

WHERE PROBABILITY SIZE TREND
      Over the next 24 hours.

The snow below 8,500' is quite damp and the loose, faceted snow wants to sluff easily on steep slopes.


MOUNTAIN WEATHER

Today we have a warm front in advance of a cold front tonight and on Saturday. Temperatures at 9,500' will rise to near 40 degrees and winds will blow 20-30 from the west and southwest. Skies should be partly cloudy.

Tonight and on Saturday, expect a mostly dry cold front to push in from the west. We should get a couple more inches of new snow combined with stronger winds blowing 30 mph from the west and northwest and gusty winds.

But for the first week of 2012, we should return to high pressure with warm and clear conditions in the mountains and more chocking smog in the valleys.


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.

Subscribe to the daily avalanche advisory e-mail click HERE.

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

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.

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.