Uintas Avalanche Advisory

Forecaster: Craig Gordon

SPECIAL ANNOUNCEMENT

A SPECIAL AVALANCHE ADVISORY HAS BEEN ISSUED FOR ALL THE MOUNTAINS OF NORTHERN AND CENTRAL UTAH. HEAVY SNOWFALL AND WIND WILL OVERLOAD A VERY FRAGILE AND WEAK SNOWPACK...RAPIDLY CREATING DANGEROUS AVALANCHE CONDITIONS. THOSE WITHOUT EXPERT AVALANCHE TRAINING AND BACKCOUNTRY SKILLS SHOULD AVOID TRAVEL IN AVALANCHE TERRAIN.


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 will quickly rise to CONSIDERABLE this morning as the new snow piles up and wind drifts become more widespread and sensitive. Human triggered avalanches are likely, especially on steep, mid and upper elevation leeward slopes.

A MODERATE avalanche danger still exists for scarier avalanches, which break into deeper buried weak layers of snow near the ground. Dangerous, human triggered avalanches are possible today, especially in steep, rocky, upper elevation terrain that faces the north half of the compass with a shallow weak snowpack.


CURRENT CONDITIONS

A fast moving storm is slated to enter the region this morning. Along the high ridges southwesterly winds increased into the mid 20’s last night, ushering in its arrival. Two inches of medium density snow fell in the past 24 hours, increasing average snow depths to just about 33 inches above 9,500’. Currently, temperatures are in the mid teens at the trailheads and we’re barely crawling out of the single digits at 10,000’. Riding and turning conditions are a mixed bag and overall snow depths remain quite thin. However, you can find soft snow in sheltered terrain and if the upcoming storm verifies, soon we should have a little more room to roam.


RECENT ACTIVITY

No significant avalanche activity to report. However, many thanks go out to Ted Scroggin and Grant Helgeson for all their hard work and awesome observations... you guys rock!


THREAT #1

WHERE PROBABILITY SIZE TREND
      Over the next 24 hours.

New storm snow coupled with fresh wind drifts, particularly at the upper elevations is today’s most obvious avalanche concern. Yesterday, Ted stomped around Double Hill and found shallow wind slabs forming on the leeward side of ridges and terrain features. While only about 6”-8” deep, they were sensitive to the weight of a person, failing on recrystalized snow that grew weak and sugary during our recent dry spell. Though manageable in size and breaking at or below a person’s skis or sled, today’s wind drifts will be deeper and more widespread, and may pack more of a punch than you might expect. In steep rocky terrain even a small slide could break into deeper buried weak layers of snow, creating a large, unmanageable avalanche.


THREAT #2

WHERE PROBABILITY SIZE TREND
      Over the next 24 hours.

Speaking of unmanageable avalanche conditions, yesterday Grant and I set out looking for terrain that didn’t slide during the mid December avalanche cycle and found our nemesis, the weak faceted snow near the ground, alive and quite reactive to snow stability tests. Here’s where it gets tricky- while it’s getting harder to trigger a slide that breaks into weak snow near the ground, especially where the snowpack is thick and relatively strong, our structurally challenged Colorado-like snowpack isn’t very forgiving and the consequences are serious. As if that’s not enough to think about it’s also getting more difficult to tell what slid earlier in the month and what remained intact. You’re best bet is to carefully analyze each slope on an individual basis and if you don’t have a good handle on the history of the slope, avoid steep, upper elevation terrain altogether.


MOUNTAIN WEATHER

A decent looking storm system crosses the area today and we can expect 3”-6” of snow during the day with another 3”-6” possible tonight. Southwesterly winds should remain fairly well behaved at lower elevations, but will gust into the 30’s along the ridges and high peaks. Winds switch to the northwest in the afternoon and increase into the upper 30’s, before dying down early Thursday morning. Today’s high temperatures reach into the mid 20’s at 8,000’ and upper teens at 10,000’. Overnight lows will be near zero. The storm moves east tonight and we should see a partly cloudy New Years Eve with warmer temperatures. A warm front crosses the region late Thursday with a very moist westerly flow continuing Thursday night into Saturday when another cold front arrives. High pressure returns for Sunday.


GENERAL ANNOUNCEMENTS

The information in this advisory expires 24 hours after the date and time posted. I will update this advisory with a holiday forecast by 7:00 AM on Thursday December 31st.

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.