June Mountain Area Snowpack Summary - 2015-03-06 07:00

THIS ADVISORY EXPIRED ON March 8, 2015 @ 8:00 am
Avalanche Advisory published on March 6, 2015 @ 7:00 am
Issued by Sue Burak - Inyo National Forest
Avalanche Character 1: Normal Caution
Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features. Use normal caution when travelling in the backcountry.
Snowpack Discussion

Winds are light this morning, blowing from the northeast at 10 to 15 mph on Mammoth Mountain. No avalanche activity has been observed or reported over the last two days. Reports from a few public observers point to generally stable conditions at mid and high elevations. Cold dry, faceted surface snow with little wind affects or sun damage on open slopes and a generally stable snowpack are bringing many skiers and riders out to enjoy the best conditions of the winter. Conditions in steep narrow gullies are variable, ranging from bottomless facets to very hard crampon snow.  

I am probably the only person thinking about this but I am seeing and skiing on a lot of near surface facets on open slopes during this period of high pressure- it's called recycled powder because dry fresh snow becomes faceted during periods of clear, mild days and very cold nights. Its fun, it's good skiing but it's a thick layer and could be a real problem when the next storm arrives. 

At mid elevations, the sun is heating snow surfaces by mid-day. Slopes with direct exposure to the sun are getting wet for the first time after the storm- watch out for damp snow below rocks and ridges. 

The deep instability observed over the weekend is still showing up occasionally at mid elevations (9,300 to around treeline) on north aspects in the Lakes Basin and San Joaquin Ridge area.  Stability tests are inconclusive but the situation requires monitoring- just bring a sharp saw and enthusiasm to saw through the thick early February layer.  

recent observations

Observations made over the last few days in alpine terrain show soft and unconsolidated snow and recycled powder on north facing slopes. Areas of wind scour are found at the top of the crest and in sheltered high elevation gullies, snow is shallow and faceted in some places and very hard in others. The storm snow has bonded well to the old snow surface in the Lakes Basin. 

A pit dug in the un-compacted part of Climax Waterfall by ski patrol showed weakness on graupel overlying the old snow surface-a melt freeze crust that formed two storms ago near the end of February. This result confirms the high variability in this season's snowpack. Similar results have not been seen on the Mammoth Crest but snowpack structure this year is wildly variable and nothing will surprise me. 


CURRENT CONDITIONS Weather Observations Between June (10,000 ft.) and Mammoth (11,000 ft.)
0600 temperature: 14 deg. F.
Max. temperature in the last 24 hours: 28 deg. F.
Average wind direction during the last 24 hours: NE
Average wind speed during the last 24 hours: 10-15 mph
Maximum wind gust in the last 24 hours: 25 mph
New snowfall in the last 24 hours: 0 inches
Total snow depth: 30 inches

High pressure building AGAIN over California and Nevada  continues to bring mild and dry conditions for the remainder of the week. Low pressure may reach the west coast next week bringing a chance of precipitation to our area. 

The dry air mass associated with the ridge means nights will continue to be very cold- in the single digits and low teens at mid and high elevations. Daytime highs reach the mid 40's above 10,000 ft. for the rest of the week with light northeast winds. Mid-elevations will reach the upper 40's today and the low 50's over the weekend. 

Two-Day Mountain Weather Forecast Produced in partnership with the Reno NWS
For 8,000 ft. to 10,000 ft.
  Friday Friday Night Saturday
Weather: clear clear sunny
Temperatures: 48 deg. F. 26 deg. F. 51 deg. F.
Wind direction: NE E E
Wind speed: 5-10 5 5
Expected snowfall: 0 in. 0 in. 0 in.
Over 10,000 ft.
  Friday Friday Night Saturday
Weather: sun clear sun
Temperatures: 46 deg. F. 24 deg. F. 48 deg. F.
Wind direction: NE NE NW
Wind speed: 5-15 5-15 5-10
Expected snowfall: 0 in. 0 in. 0 in.

This snowpack summary applies only to backcountry areas outside established ski area boundaries. This snowpack summary only describes general avalanche conditions and local variations always occur. This snowpack summary expires 24 hours after the posted time unless otherwise noted. The information in this snowpack summary is provided by the USDA Forest Service who is solely responsible for its content.

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