Eastern Sierra - Sun Mar 28 2010
Eastern Sierra avalanche advisory |
The avalanche danger rating for today is estimated to be LOW. Sunny skies and mild temperatures will continue, but winds are expected to be breezy out of the west. The main concern will continue to be wet snow activity on wind sheltered terrain on East to South to Southwest slopes at lower to mid elevations (9000’ – 10500’). Breezy winds help keep the snow surface cool and firm and safer in terms of wet snow instabilities. But firm slopes present their own non-avalanche hazard concerns. |
Mild temperatures and sunny skies will continue today, but winds will be on the increase from the calm conditions we had yesterday. Wet snow instabilities were the main concern yesterday. Observations made yesterday on Nevahbe Ridge in the McGee Creek area revealed variable snowpack conditions. Southeast aspects were of most concern, as we found some areas where boot packing penetrated 2’+ deep close to 12000’ around noon. Still we saw no evidence of wet snow slides or point releases today, only evidence from surface slides from several days ago before the winds picked up (most likely wed). Observations made 2 days ago around Red Cone Bowl with light to moderate winds revealed no wet snow concerns on any aspects. Most slopes were wind affected, with variable firm surfaces with some pockets of 1-2” of light freshly fallen wind deposited snow.
Today, the main avalanche concern will continue to be wet snow instabilities on sun affected slopes (East to South to Southwest). The expected breezy conditions should help keep snow surfaces cool and lessen the likelihood of the development of these wet snow instabilities. However, continue to be alert for snow softening deeper than surface layers on slopes which may not be exposed to these breezes. If you are heading out tomorrow expecting to find nice corn, be careful on some of those steep slopes which may not soften up and could lead to a long fall.
Spring conditions will definitely end by Tuesday for the remainder of the week. Very strong winds will be the precursor to stormy winter weather.
Expect more mild temperatures today, more sunny skies, but increased wind speeds. Breezy conditions will prevail, with gusts up to 45 mph out of the west at mid to high elevations. Temperatures will reach into the 40s at 9000’-10000’, and into the 50s below 9000’. The big news is a significant cold storm front moving into the area from the north beginning Monday afternoon. A High Wind Watch is in effect for Monday afternoon into Tuesday with wind gusts at 10000’ expected to easily exceed 100mph and reach into the 140mph range Monday night. Flurries expected to start Monday night, but the real snow is expected to start Tuesday into Tuesday night and Wednesday with continued unsettled weather throughout the remainder of the week.
Please note that the avalanche danger rating in this advisory expires in 24 hours. This advisory is our best interpretation of snow pack conditions and NWS forecasts issued today. Backcountry travelers should be aware that elevation and geographic distinctions are approximate and that a transition zone exists between upper and lower elevations. Avalanches do not happen by accident and most human involvement is a matter of choice not chance. Most avalanche accidents are caused by slab avalanches that are triggered by the victim of member of the victim's party. Even small slides can be dangerous. Always practice route finding skills and carry avalanche rescue gear. Remember that avalanche danger ratings are only general guidelines. Distinctions between geographic areas, elevations, slope aspects and slope angles should be made.
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