Wasatch Cache National Forest
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 Salt Lake County.

“keeping you on top”

AVALANCHE ADVISORY

Sunday, February 24, 2008 7:30 am
Good morning, this is Drew Hardesty with the Forest Service Utah Avalanche Center with your backcountry avalanche and mountain weather advisory. Today is Sunday, February 24, 2008 and it’s about 7:30 am.

Current Conditions:

It already seems like we’ve closed the chapter on yesterday’s book. The southerly winds, ahead of what looks to be a complex, impressive system, picked up overnight and have been blowing 30-45mph with gusts to near 80. Ahead of the trof, temperatures continue their steady march into the upper twenties and mid 30’s and we can expect an initial rain/snow line of about 7000’ with at times heavy snowfall favoring the Ogden, Park City and Provo mountains. It all shakes out to be a warm, wet, windy event. Yesterday’s face shots and over-the-hood riding is already a distant memory.

Snow and Avalanche Discussion:

Yesterday’s activity centered around continued sluffing and human triggered soft slabs of less than a foot in steep upper elevation terrain. At least one skier took a ride and bumped through some rocky terrain after triggering a pocket in steeper terrain off the Cardiac ridge in upper Cardiff Fork of BCC. My own ski/slope cut produced debris that ran over 1000’, but that was only the first of a series of increasingly unfortunate events. More on that here. Others, on the steep sunny exits, triggered wet sluffs “with every turn” as they descended back to their cars. 3^rd hand info had a couple people forced into ‘unintentional hip-checks’ with the excitement. Preserved cold, low density stellars on a multitude of hard, underlying bed surfaces were to blame for the activity, and are likely to be overwhelmed again by today’s onslaught of wind and snow. An outlier report of a skier triggered hard slab came in from southeast facing McDonald Draw. It was reported to be 8-12” deep and 100’ wide, triggered in the high terrain there at 9500’, and the skier avoided capture.

It’s not rocket science. The strong southerly winds will have already whipped up some sensitive new wind drifts in and below the standard starting zones in lee terrain. The northerly aspects will be more prone, but crossloading and eddying will put all deceleration zones at risk in complex terrain. I do not expect the new snow to bond very well to the old bed surface, but with potentially high snowfall rates, and storm totals approaching 16-20”, it may all be academic. Some avalanches are likely to step down about a foot or so to the older bed surfaces on the preserved stellars. Low elevation wet avalanches will be likely on the shadier aspects with a 7000’ rain/snow line and roof-alanches are a distinct possibility.

Bottom Line for the Ogden, Salt Lake, Park City and Provo area mountains:

It’s going to be a tricky and complex bottom line today. Due to the strong winds, Pockets of CONSIDERABLE danger exists in steep wind loaded terrain this morning in the Central Wasatch. The danger of storm snow avalanches will also rise today to CONSIDERABLE, and will initially be more pronounced in the Ogden, Provo, and Park City mountains, areas favored by a strong southwesterly flow.

Mountain Weather:

A powerful trough packing strong winds and dynamics suitable for high water amounts for the Wasatch is approaching northern Utah at this moment. Moisture out ahead of the trough has begun to drop snowfall up around 10,000 ft this morning. Ridgetop south/southwest sustained winds are in the 30-40mph range, frequently gusting to the 60s and 70s. Expect them to stay quite strong through the day, and slacken only slightly into the evening as they veer around to the west/northwest by evening. Temps are currently in the low 30s to low 20s and shouldn’t change too much through the day. We should see heavy snow through the day today and into Monday. Totals by evening will be around a foot or more, with totals approaching 2 feet in favored areas. A slight ridge will build in midweek with another storm on tap for the weekend.

Announcements
The Wasatch Powderbird Guides did not fly yesterday due to weather and won’t get out today. 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.

Brett Kobernik will update this advisory by 7:30 on Monday morning.