In partnership with: Utah Division of State Parks and Recreation, The Friends of the Utah Avalanche Center, Utah Department of Emergency Services and Homeland Security and
“keeping you on top”
December 29, 2007 7:30 am
Good morning, this is
A warm front moving languidly through the area continues to produce precipitation at less-than-alarming rates; nonetheless, who can really complain with the additional 4” of smoke. Mountain temperatures are warming with the disturbance, but most stations are still in the single digits. Winds are west to northwest and generally less than 20mph. Skiing and riding conditions are epic on all aspects, though there has been some wind damage in the highest terrain. Coverage has drastically improved for many lower elevation exits and snow machines should have little trouble off the packed roads.
I was not alone in finding and triggering small pockets of wind slab yesterday from the intermittent and inconsistent winds. I found mine half way down a northwest facing slope on Gobbler’s Knob, just at a rollover - a result of the up-slope fetch. Other observers and control teams initiated the odd pockets of a foot or less in steep, gently drifted terrain. Most were less than a foot deep. These storm snow, loose snow and wind drifted avalanche ‘problems’ encountered today and, more likely tomorrow, can be mitigated through the usual offensive tactics. Ski cuts and cornice drops will be effective with these, while simple test slopes and ‘column-isolation’ tests offer the even the most guileless the right information. No sense getting too technical with these issues. Consequences with these? Minor, unless the terrain plays a role with cliffbands, trees, or a steep gulley at the bottom.
On the other hand, I look forward to when we can lay our deep slab problem to rest. It should be soon. If you dissect the issue into structure, strength (stability test scores), and energy (propagation potential or shear quality), you’ll find that each of these are showing marked improvement on the whole. Still, irregularities in terrain and snowpack account for those isolated areas in the high shady terrain where a rider or snowmachine could still potentially trip the switch. Consequences? Likely fatal.
Most of us love to go
into the backcountry because, among many other things, we’re anarchists. We hate the rules, we go where we want, we do what we want.
Yep – freedom - it’s great – it’s what
Bottom Line for the
The avalanche danger is MODERATE on slopes steeper than about 35 degrees with new or old drifts of wind blown snow, which will be most widespread along the higher ridgelines. Watch for sluffing in the smoke on the steeper slopes.
There is also a MODERATE danger on steep, shady slopes facing northwest, north and northeast, above about 9,500’, where it is possible to trigger a deep, dangerous slide releasing near the ground.
With more snow and winds forecast tonight and tomorrow, the danger will be on the rise for the remainder of the weekend.
A warm front pushing through the Wasatch will likely continue the snowfall today into tonight ahead of a cold front tomorrow in the early afternoon. We can expect 3-6” today with light to moderate westerly winds, with totals of 10-16” perhaps by late Sunday/early Monday. Temperatures will reach into the upper-teens at 8000’ and low teens at 10,000’. Rapid warming sets in immediately under a shortwave ridge of high pressure for most of the week, with a warm and wet storm track lined up for next weekend.
Yesterday the Wasatch Powderbird Guides did not fly due to weather. Today if the weather allows they will be in Days, Silver, Grizzly Gulch and American Fork.
For an avalanche education class list, updated 12/22/07, click HERE.
If you want to get this avalanche advisory e-mailed to you daily click HERE.
The UAC has temporary job openings for doing avalanche outreach in more rural areas. Click HERE for info.
UDOT highway avalanche control work info can be found HERE or by calling (801) 975-4838.
Our statewide tollfree line is 1-888-999-4019 (early morning, option 8).
For our classic text advisory click HERE.
If you’re getting out and see anything we should know about please let us know. You can leave a message at (801) 524-5304 or 1-800-662-4140, or email us at [email protected]. (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.
I will update this advisory by 7:30 on Sunday morning.