Uintas Avalanche Advisory

Forecaster: Craig Gordon

SPECIAL ANNOUNCEMENT

Mirror Lake Highway is now officially closed.


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 today on steep slopes in upper elevation terrain facing the north half of the compass and human triggered avalanches are possible. Within this terrain and elevation band be aware there are pockets of CONSIDERABLE avalanche danger especially on slopes with recent deposits of wind drifted snow and human triggered avalanches are probable.

At mid and low elevations the avalanche danger is generally LOW.


CURRENT CONDITIONS

Monday night’s storm stacked up 4”-8” of very light density snow with the bulk of the moisture benefiting the southern half of the range. West and northwest winds picked up early yesterday morning and have blown steadily for the past 24 hours in the 15-25 mph range. A very cold airmass settling in over the region brought brutal overnight temperatures… hope you plugged the block heater in last night. Currently it’s -10 degrees at Trial Lake, -7 degrees at the trailheads and Lily Lake is slowly rebounding after an overnight low of -20 degrees.


RECENT ACTIVITY

Numerous test slopes avalanched easily yesterday, failing on weak faceted snow near the ground.


THREAT #1

WHERE PROBABILITY SIZE TREND
      Over the next 24 hours.

Our shallow, structurally challenged snowpack took a hard hit the past week as cold temperatures virtually ate away the crusts that gave the snowpack a bit of body and strength. Now, weak sugary facets make up the majority of our snowpack and these won’t take much of a load before slopes start to avalanche. As a matter of fact, yesterday Ted stomped around Hayden Pass, finding it easy to trigger small avalanches on safe test slopes and these slides are running on weak snow near the ground. If this isn’t a sign of things to come; our fragile snowpack is failing easily and we’ve hardly added any additional weight!

A cohesive slab is the biggest ingredient missing from this junk show cake, but today’s winds should take care of that. Westerly winds are expected to increase as the day progresses, gusting into the 50’s along the high ridges. With all the players into place today, avalanches will be bigger and deeper than you might expect, given the overall lack of snow. In addition, it’ll be easy to trigger avalanches from a distance and from the bottom of a steep slope. Remember to look for clues to unstable snow like shooting cracks, whoomphing sounds and the biggest clue of all- recent avalanche activity. Quick hand pits give you an idea of what we’re dealing with and slope cuts on safe test slopes are a good barometer of the snows stability… or lack thereof.


MOUNTAIN WEATHER

Yesterday’s storm is exiting the region, but residual moisture keeps light snow showers around, lingering into the afternoon hours. Temperatures will be hard pressed to rebound from this morning’s brain freezing lows. We’ll see highs in the low single digits and overnight lows near -10 degrees. Winds increase later today as a westerly flow develops this evening, drawing moisture back into the area for Thursday and Friday. Wind gusts along the ridges today reach into the 50’s by late afternoon. A series of disorganized weather disturbances are expected to affect the area over the weekend.


GENERAL ANNOUNCEMENTS

The information in this advisory expires 24 hours after the date and time posted, but will be updated by 7:00 AM Saturday December 12th.

If you’re getting out and about and trigger an avalanche or see anything interesting please drop me an email at craig@utahavalanchecenter.org or call 801-231-2170

Also, now is a great time to schedule one of our free avalanche awareness presentations for your group or club. Email or call me and we’ll get you booked before things get too crazy.


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.