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”
February 23, 2008 7:30 am
Good morning, this is Evelyn Lees with the
Under mostly cloudy
skies, a few light snow showers are still being reported in the Cottonwoods. Temperatures are in the mid teens at the
10,000’ level, and the northwesterly winds are quite light, with most stations
less than 10 mph. Snow amounts varied
widely throughout the range, with storm totals of 12 to 16 inches in the upper
elevations of the Cottonwoods and the south end of the
Snow and Avalanche Discussion:
Yesterday, there were numerous observations of very sensitive new snow sluffs on all aspects, running unusually far, with a small natural cycle report midday. Most sluffs were manageable, but there was one close call when a party of three 2/3 of the way up the Y couloir was hit by slide, taking one member for the full 1,200' ride. In addition, in terrain catching the stronger southeasterly winds, drifts 1 to 2 feet deep rapidly formed, and were sensitive to slope cuts.
Today, the new snow could still be sensitive to people, especially on steep slopes. While most of the soft new snow sluffs and drifts are manageable with careful slope cuts, it will be possible to get into trouble. Good bed surfaces on many slopes mean once the snow gets going, it could run faster and farther than expected. Terrain will be the key - long, continuously steep slopes are the places where these shallow, soft sluffs could be a problem or any place where the snow could pile up deeply in a terrain trap such as a gully. Short test slopes, quick hand and pole pits and shovel tilt tests will help to evaluate this new snow instability. (Shovel Tilt “how to” video) Cracking within the new snow is a sign you’re in an area of sensitive wind drifts.
The second avalanche concern will be caused by the combination of warm temperatures and intermittent sun. If the steep sunny slopes heat up, wet snow sluffs will be possible. Again, they could be longer running than expected due to the hard bed surfaces. The mid and low elevation shady slopes could heat up if high thin clouds move through, and also have damp, loose snow avalanches. Roller balls will be an indicator of heating snow.
Bottom Line for the
The avalanche danger is MODERATE today on slopes of about 35 degrees and steeper, with easily human triggered sluffs and soft slabs possible. With daytime heating, avalanche activity could switch to damp sluffs, possible on both steep sunny slopes and the mid and low elevation shady slopes. Terrain that received less than about 5” of snow has a generally LOW danger. The avalanche danger will increase late tonight through Monday, as an approaching storm with strong winds and moderate to heavy snowfall is in the forecast.
A weak ridge will be over the area today ahead of a strong Pacific storm system that will start to impact the region tonight. Skies will be partly cloudy, with temperatures in the low 30’s at 8,000’ and the upper teens at 10,000’. The winds will slowly shift to the southwest today, and remain light, with only the highest peaks having speeds slightly stronger than 5 to 15 mph range. The southwesterly winds will increase after midnight, and periods of snow should give storm totals of 1 to 2 feet by Monday afternoon.
The Wasatch Powderbird Guides did not fly yesterday due to weather and if they can fly today, they will be in Mineral, Cardiff, Days, Silver, Grizzly, White Pine and American Fork. For more detailed information please call (801) 742-2800 or go to their daily blog.
If you want to get this
avalanche advisory e-mailed to you daily click HERE.
UDOT highway avalanche control work info can be found by calling (801) 975-4838.
Our statewide tollfree line is 1-888-999-4019 (early morning, option 8).
Watch video tututorials and fieldwork from UAC staff at our YouTube channel.
The UAC depends on contributions from users like you to support our work. To find out more about how you can support our efforts to continue providing the avalanche forecasting and education that you expect please visit our Friends page.
If you see any avalanches or interesting snow conditions, please leave us 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.
Drew Hardesty will update this advisory by 7:30 on Sunday morning.