Utah Avalanche Center
New member
March 11, 2007 - 7:22 am
SUMMARY >>> Danger by
ASPECT & ELEVATION
BOTTOM LINE
on slopes over 35 degrees
The danger of wet sluff and slab avalanches may rise to CONSIDERABLE today with daytime warming on the sun-exposed slopes. The danger of triggering a remnant soft slab or deeper slab remains MODERATE, although the consequences for the two are miles apart. Remotely triggered slides remain possible. Forecaster: Drew Hardesty LINKS: -Danger scale- -Encyclopedia- -Text only- CURRENT CONDITIONS >>> LINKS TO MORE INFO: NWS SNOW PAGESNOTEL MAP
Skies are clear with light northwesterly winds. Mountain temperatures dipped to the low to mid-twenties and may be our last decent refreeze for the next couple of days. Mid and upper elevations are excellent, with off and lower elevations crusted.
RECENT AVALANCHES AND SNOWPACK INFO >>> LINKS TO MORE INFO
AVALANCHE LISTPHOTOSACCIDENTSSNOW PROFILES Gustier a.m. conditions produced a host of garden variety soft slabs intentionally and unintentionally triggered by backcountry skiers in upper elevation north through east facing terrain. Most were 6-10" deep and 40' or 50' wide, with one in upper Days breaking out 150' wide. We heard about 6 of these scattered across the central Wasatch, and give it another day, and many of these will become less sensitive and widespread.
Of greater interest, however, were the two and perhaps three larger hard slab avalanches stepping into old snow. The first, which may have been just a new-snow-only avalanche, involved a snowmachiner in the upper American Fork drainage. He triggered a slab near a rocky outcrop 1-3' deep and 50' wide in steep Mary Ellen at 11,000'. Apparently his machine ragdolled a few dozen times with the debris, but the rider reportedly came out ok. Over along the Park City ridgeline above Lake Desolation, a very experienced backcountry skier triggered a hard slab 1-3' deep and 40' wide on a steep north to northwest facing roll at 9600'. He hit a thinner part of the slab pulling out the pocket, which, incidentally was adjacent to the large natural that pulled out on the 2nd. Far luckier was the party in the upper starting zone of the Cabin Run on Gobbler's Knob, a classic northwest facing slope at 10,100'. A party of three collapsed the slope and remotely triggered a hard slab 1-3' deep and 300' wide, failing on very weak faceted snow in terrain holding a thinner slab and weaker basal depth hoar. One of our observers had been in the terrain an hour earlier and spooked from the snow stability tests, left the area for lower angled terrain. See plenty of new photos on the link to the left.
AVALANCHE CONCERNS >>> WHERE PROBABILITY SIZE TREND Likely
Unlikely Large
Small Increasing
Danger Same Decreasing
Danger over the next 8 hrs Daytime warming, light winds, and a high sun should have the new snow moving well when saturated on the steep sun-exposed slopes. Shallow wet slabs up to 10" may be triggered from other wet sluffs or human activity. WHERE PROBABILITY SIZE TREND Likely
Unlikely Large
Small Increasing
Danger Same Decreasing
Danger over the next 24 hrs While likely less sensitive than yesterday, today's rapid warming may still enhance human triggereing of the newer storm snow and soft slab avalanches in upper elevation north through east facing terrain. Same story for the hard slab avalanches into older snow. They'll be most suspect in steep rocky terrain or in areas with a thinner snowpack on the shady end of the compass. Simple probe or ski pole tests will give some clue to the structure here. With the natural cycle long done, it's becoming even more critical to dig snowpits and perform stability tests to get more information.
MOUNTAIN WEATHER >>> LINKS TO MORE INFO
UAC COMPILATION
NWS ZONAL FORECAST
SEASONAL Wx CHARTS Sunny skies, light northwesterly winds, and rapidly rising temps into the mid-40's at 8000' and mid-thirties at 10,000'. Even warmer tomorrow.
GENERAL ANNOUNCEMENTS >>> See yesterday's archive. Computer issues today. 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.
This advisory provided by the 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
The post was created using an automated process maintained by First Tracks! Online.
SUMMARY >>> Danger by
ASPECT & ELEVATION
BOTTOM LINE
on slopes over 35 degrees
The danger of wet sluff and slab avalanches may rise to CONSIDERABLE today with daytime warming on the sun-exposed slopes. The danger of triggering a remnant soft slab or deeper slab remains MODERATE, although the consequences for the two are miles apart. Remotely triggered slides remain possible. Forecaster: Drew Hardesty LINKS: -Danger scale- -Encyclopedia- -Text only- CURRENT CONDITIONS >>> LINKS TO MORE INFO: NWS SNOW PAGESNOTEL MAP
Skies are clear with light northwesterly winds. Mountain temperatures dipped to the low to mid-twenties and may be our last decent refreeze for the next couple of days. Mid and upper elevations are excellent, with off and lower elevations crusted.
RECENT AVALANCHES AND SNOWPACK INFO >>> LINKS TO MORE INFO
AVALANCHE LISTPHOTOSACCIDENTSSNOW PROFILES Gustier a.m. conditions produced a host of garden variety soft slabs intentionally and unintentionally triggered by backcountry skiers in upper elevation north through east facing terrain. Most were 6-10" deep and 40' or 50' wide, with one in upper Days breaking out 150' wide. We heard about 6 of these scattered across the central Wasatch, and give it another day, and many of these will become less sensitive and widespread.
Of greater interest, however, were the two and perhaps three larger hard slab avalanches stepping into old snow. The first, which may have been just a new-snow-only avalanche, involved a snowmachiner in the upper American Fork drainage. He triggered a slab near a rocky outcrop 1-3' deep and 50' wide in steep Mary Ellen at 11,000'. Apparently his machine ragdolled a few dozen times with the debris, but the rider reportedly came out ok. Over along the Park City ridgeline above Lake Desolation, a very experienced backcountry skier triggered a hard slab 1-3' deep and 40' wide on a steep north to northwest facing roll at 9600'. He hit a thinner part of the slab pulling out the pocket, which, incidentally was adjacent to the large natural that pulled out on the 2nd. Far luckier was the party in the upper starting zone of the Cabin Run on Gobbler's Knob, a classic northwest facing slope at 10,100'. A party of three collapsed the slope and remotely triggered a hard slab 1-3' deep and 300' wide, failing on very weak faceted snow in terrain holding a thinner slab and weaker basal depth hoar. One of our observers had been in the terrain an hour earlier and spooked from the snow stability tests, left the area for lower angled terrain. See plenty of new photos on the link to the left.
AVALANCHE CONCERNS >>> WHERE PROBABILITY SIZE TREND Likely
Unlikely Large
Small Increasing
Danger Same Decreasing
Danger over the next 8 hrs Daytime warming, light winds, and a high sun should have the new snow moving well when saturated on the steep sun-exposed slopes. Shallow wet slabs up to 10" may be triggered from other wet sluffs or human activity. WHERE PROBABILITY SIZE TREND Likely
Unlikely Large
Small Increasing
Danger Same Decreasing
Danger over the next 24 hrs While likely less sensitive than yesterday, today's rapid warming may still enhance human triggereing of the newer storm snow and soft slab avalanches in upper elevation north through east facing terrain. Same story for the hard slab avalanches into older snow. They'll be most suspect in steep rocky terrain or in areas with a thinner snowpack on the shady end of the compass. Simple probe or ski pole tests will give some clue to the structure here. With the natural cycle long done, it's becoming even more critical to dig snowpits and perform stability tests to get more information.
MOUNTAIN WEATHER >>> LINKS TO MORE INFO
UAC COMPILATION
NWS ZONAL FORECAST
SEASONAL Wx CHARTS Sunny skies, light northwesterly winds, and rapidly rising temps into the mid-40's at 8000' and mid-thirties at 10,000'. Even warmer tomorrow.
GENERAL ANNOUNCEMENTS >>> See yesterday's archive. Computer issues today. 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.
This advisory provided by the 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
The post was created using an automated process maintained by First Tracks! Online.