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

Thursday, April 12, 2007 7:30 am
Good morning, this is Evelyn Lees with the Forest Service Utah Avalanche Center with your backcountry avalanche and mountain weather information. Today is Thursday, April 12, 2007 and it’s 7:30 in the morning.

Today is Thursday, April 12^th. We are issuing advisories on an intermittent basis for the remainder of April.

Current Conditions:

Under mostly cloudy skies, temperatures this morning are in the teens to low 20’s and a few snow flakes are drifting down in the mountains. The southwesterly winds are light, averaging less than 15 mph at all stations. Stashes of very nice powder exist on sheltered, easterly and northerly facing slopes between areas of wind scour and breakable wind crusts that are just waiting to trip you up when you least expect. Most southerly and westerly facing slopes received just enough sun to crust. Several days of cooler temperatures are in the forecast, so the shady slopes should retain cool, dry powder through Saturday morning, though another round of strong northerly winds tonight will drift and scour the snow.

Avalanche Discussion:
While most of Tuesday’s wind drifts settled out rapidly, backountry tourers were able to trigger a couple of 2 foot deep wind drifted pockets on Wednesday. These were in the closed for the season East Castle area of upper Little Cottonwood. Remember, as the ski resorts close, no control work being done in this terrain, and it needs to be treated as backcountry.

If you are heading into the backcountry today, Thursday, be alert for a few lingering wind drifts that could be triggered on steep slopes, mostly on northerly and easterly facing slopes. By Friday morning, strong northerly winds will once again be drifting snow into sensitive drifts, both along and well off the ridgelines. Sensitive drifts will build up around terrain features such as sub ridges and breakovers. Approach any steep, wind drifted slope with caution. While slope cuts should be able to handle most of these drifts, a mistake could take you for a dangerous ride. Watch for any direct afternoon sun that could heat up the snow, and create wet sluffs.

On Saturday, mostly sunny skies and rapidly warming temperatures will make wet avalanche activity the main concern. As the snow warms, it will be possible to trigger both wet sluffs and slabs on steep, sunny slopes, taking out all the new snow from this past week. A few natural slides may be possible. In addition, isolated sensitive wind drifts will linger on the shady slopes.

Mountain Weather:

A weak storm system moving across Utah today will bring a few inches of snow to the mountains through tonight. Temperatures today will be near freezing at 8,000’ and in the low 20’s at 10,000’. The winds will remain from the southwest, generally in the 10 to 20 mph range, with gusts to 30 in the most exposed terrain. Thursday night, strong northwesterly winds will pound the mountains, with hourly averages of 25 to 45 mph, and gusts into the 60’s across the highest peaks. On Friday, the winds will decrease and temperatures start to warm as high pressure builds in. Saturday will be sunny and much warmer, with 8,000’ temperatures in the mid 40’s. Another weak system is expected to bring light snow Sunday night into Monday.

Announcements:
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.

We appreciate all the great snowpack and avalanche observations we’ve been getting, so keep leaving us messages at (801) 524-5304 or 1-800-662-4140, or email us at uac@avalanche.org. (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.

We will update this advisory on an intermittent basis for the rest of April and thanks for calling.