Uintas Avalanche Advisory

Forecaster: Craig Gordon

BOTTOM LINE

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


Danger Rose Tutorial

In the wind zone at mid and upper elevations the avalanche danger is CONSIDERABLE today and human triggered avalanches are likely, especially in steep, wind loaded terrain.

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.

With strong afternoon winds on tap, be aware of rapidly changing avalanche conditions.


CURRENT CONDITIONS

Skies are mostly cloudy and light snow is still falling as yesterday’s storm shifts east of the region. Storm totals are pretty evenly distributed across the range and 8” of ultra light Utah fluff seems to be the norm, though some favored locations received nearly a foot. Temperatures are in the mid teens at 8,000’ and right around 8 degrees at 10,000’. Northwesterly winds are blowing 15-25 mph along the ridges. Riding and turning conditions have vastly improved in the past 24 hours.


RECENT ACTIVITY

Yesterday’s new snow was very sensitive to slope cuts and it was easy to trigger shallow soft slabs and sluffs. Click here for recent state-wide observations.


THREAT #1

WHERE PROBABILITY SIZE TREND
      Over the next 24 hours.

Winds have been all over the map the past 24 hours. Yesterday morning they gusted into the 30’s out of the south and southwest, then switched to the west late in the day and blew in the 40’s, now this morning they finally turned around to the northwest and are dying down into the teens and low 20’s. As you might’ve guessed, there’s no shortage of light fluffy snow to blow around and wind drifts formed all over the place. While mostly confined to mid and upper elevation terrain, these wind drifts are easy to detect and very manageable. You’ll find drifting along the leeward side of ridges, in chutes and gullies and around mid slope terrain features like sub-ridges and breakovers. The good news is these are manageable avalanches conditions and the slab will predictably break at or below your skis or machine. The bad news is you can trigger a deeper slide especially in steep terrain with a weak shallow snowpack, quickly creating an unmanageable avalanche. Remember to tweak small test slopes and road cuts and see what kind of avalanche dragon you’re dealing with before center punching your favorite bowl or chute. In addition, winds are expected to increase this afternoon and you’ll need to re-evaluate your slope and terrain choices as the day wares on.


THREAT #2

WHERE PROBABILITY SIZE TREND
      Over the next 24 hours.

Yesterday’s very light density snow wasn’t enough to insult our problem child- the weak, rotten snow near the ground- but these temperamental persistent instabilities aren’t going away anytime soon. Snowpit stability tests indicate 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. However, we tend to trigger deep dangerous slides in areas with weak shallow snow and if you don’t have a pair of avalanche goggles, it’s gonna take a lot of detective work to figure out an overall snowpack stability trend. In addition, if you haven’t done your homework and happen to misjudge our structurally challenged snowpack, it isn’t very forgiving and the consequences of making a mistake are serious. Steep, rocky upper elevation terrain remains a likely suspect where you’ll encounter this unmanageable avalanche condition.


MOUNTAIN WEATHER

After a few early morning snow showers, a ridge of high pressure builds over the area today, producing partly cloudy skies. Highs at 8,000’ will reach into the mid 20’s and at 10,000’ in the upper teens. Clouds increase tonight keeping overnight lows tolerable… in the mid 20’s. Ridge top winds are gonna be an issue, switching to the west and southwest later today and gusting into the 50’s along the high ridges and peaks, before dying down late tonight. The pattern remains relatively active the next couple of days as a series of weak systems impact the region.


GENERAL ANNOUNCEMENTS

The information in this advisory expires 24 hours after the date and time posted. I will update this advisory with a special holiday forecast by 7:00 AM on Friday, January 1, 2010.

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.