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

Monday, April 14, 2008 7:30 am
Good morning, this is Evelyn Lees with the Forest Service Utah Avalanche Center with your backcountry avalanche and mountain weather advisory. Today is Monday, April 14, 2008 and it’s about 7:30 am.

Special Announcement:

Today, Monday, is the last in a string of extremely warm days. Both human triggered and spontaneous avalanches are expected today, some of which could be quite large, running long distances down drainages and gullies. Parts or all of the roads in the Cottonwood Canyons may be intermittently closed during the heat of the day. Backcountry travel on and below steep snow covered slopes is not recommended on Monday. The avalanche danger will gradually decrease Tuesday as temperatures cool.

Current Conditions:

We have now switched to intermittent updates, as needed, for the remainder of April. Thank you very much for all the backcountry observations we received this winter, and if you’re still getting out, keep them coming.

Under starry skies, a few of the low mountain drainages managed to cool into the 20’s and 30’s last night. However, most mountain stations are in the mid 30’s to mid 40’s this morning, a full 5 to 10 degrees warmer than this time yesterday. Winds are from the southwest, averaging less than 15 mph. With clear skies overnight, the snow on some slopes will have a shallow surface refreeze this morning. But any supportable surface snow will be very short lived, with the snow surface rapidly becoming wet and sloppy on almost all aspects and elevations once the sun rises and the day heats up.

Snow and Avalanche Discussion:

Small to medium sized wet loose naturals were the only avalanche activity reported from the backcountry Sunday.

Today, Monday, heat related wet snow sluffs and slabs are once again the avalanche concern. With warmer overnight temperatures, the avalanche danger will rise more rapidly today, with human triggered avalanches becoming probable and natural avalanches possible. The sun is high in the sky this time of spring, heating all aspects, including northerly facing slopes. Any hard snow surface you find may have wet snow beneath, so dig down and investigate. There is the potential for long running slides that could pile debris low in gullies, possible reaching down to dirt trails. So Monday, it is best to put off any mountain travel on and below steep snow covered slopes. Due to the multi day heat wave, cornices are very sensitive, and could break back further than expected, or fail naturally, possibly triggering a slide on the slopes below.

Tuesday there will be a welcome cool down with the arrival of a cold front. While the air temperatures will cool fast, it will take a bit more time for the snowpack to cool, and the new snow will actually insulate the warm, wet snow beneath, slowing it’s cooling. So on Tuesday, it will still be possible to trigger wet sluffs and slabs during the day, until the old snow cools.

Mountain Weather:

One more sizzling day of high pressure is in store for northern Utah. Temperatures Monday will climb to near 60 at 8,000’ and near 50 at 10,000’. The light southerly winds will gradually increase throughout the day, into the 10 to 20 mph range, with gusts to 40 mph across the most exposed terrain. Clouds and winds will increase Monday night, with a cold front arriving Tuesday morning. 3 to 6 inches of snow are expected by Tuesday afternoon, with temperatures dropping back down into the 20’s and 30’s. Cool temperatures will continue Wednesday and Thursday, with 8,000’ lows in the teens and 20’s. Temperatures will gradually warm into the 40’s by Friday.

Announcements

For information on Wasatch Powderbird Guides … please call (801) 742-2800 or go to their daily blog.

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.

We’ll do intermittent updates as conditions warrant through April.