THIS AVALANCHE ADVISORY EXPIRED ON January 25, 2015 @ 6:47 am
Avalanche Advisory published on January 24, 2015 @ 6:47 am
Issued by Brandon Schwartz - Tahoe National Forest

Avalanche danger remains LOW for all elevations and aspects. Minor surface wet snow instabilities are possible during the afternoon hours, but are not expected to present a significant hazard to backcountry travelers. Normal caution is advised.

1. Low

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Above Treeline
Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.

1. Low

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Near Treeline
Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.

1. Low

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Below Treeline
Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.
    Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.
Avalanche Problem 1: Normal Caution
  • Type ?
  • Aspect/Elevation ?
  • Likelihood ?
    Certain
    Very Likely
    Likely
    Possible
    Unlikely
  • Size ?
    Historic
    Very Large
    Large
    Small

Another solid overnight snow surface refreeze is expected to have occurred last night with near to below freezing air temperatures and radiational cooling under clear skies. Wet surface snow will form in sun exposed areas today in response to daytime warming. Convective cooling from increased NE to E winds is likely to slow the rate of snow surface melt in wind exposed areas. Small, minor wet snow instabilities are possible this afternoon in the form of human triggered roller balls, pinwheels, and/or small shallow loose wet avalanches. The size of any human triggered loose wet avalanche activity today is not expected to present a significant hazard to backcountry travelers.

Other hazards to manage include exposed rocks and difficult to travel firm icy surfaces on northerly aspects.

recent observations

Observations made yesterday on Castle Peak (Donner Summit area) revealed that the period of cooler air temperatures Wednesday night-Thursday-Thursday night had allowed for a solid full depth refreeze of the snowpack to occur. Snow surface melt on Friday was highly focused to SE-S-SW aspects. Between 10 am and noon, 0.5 to 2 inches of surface wet snow on top of very supportable melt-freeze crust was observed on these aspects. Light to moderate speed northeast winds were observed to slow the rate of snow surface melt on open slopes near and above treeline. Otherwise, recent observations from around the forecast area indicate that the snowpack is well bonded on all aspects and shows evidence of continued melt-freeze and/or rounding depending on aspect and elevation.

Weather and CURRENT CONDITIONS
weather summary

High pressure building over the forecast area will bring clear skies and well above average air temperatures today. Northeast to east ridgetop winds increased to strong in speed last night and are expected to continue at moderate to strong in speed through the weekend. Air temperatures this morning at the mid and upper elevations are in the upper 20s to mid 30s. Maximum daytime air temperatures are forecast to reach the mid 30s to low 50s today for areas above 7,000'. Very similar weather conditions are expected for Sunday.

Weather observations from along the Sierra Crest between 8200 ft. and 8800 ft.
0600 temperature: 28 to 37 deg. F.
Max. temperature in the last 24 hours: 36 to 42 deg. F.
Average wind direction during the last 24 hours: Northeast
Average wind speed during the last 24 hours: 38 mph
Maximum wind gust in the last 24 hours: 69 mph
New snowfall in the last 24 hours: 0 inches
Total snow depth: 23 to 32 inches
Two-Day Mountain Weather Forecast Produced in partnership with the Reno NWS
For 7000 ft. to 8000 ft.
Saturday Saturday Night Sunday
Weather: Sunny skies. Clear skies. Sunny skies.
Temperatures: 41 to 51 deg. F. 26 to 36 deg. F. 42 to 52 deg. F.
Wind Direction: E E E
Wind Speed: 10 to 20 mph with gusts to 30 mph. 10 to 20 mph with gusts to 30 mph. 5 to 15 mph with gusts to 25 mph.
Expected snowfall: 0 in. 0 in. 0 in.
For 8000 ft. to 9000 ft.
Saturday Saturday Night Sunday
Weather: Sunny skies. Clear skies. Sunny skies.
Temperatures: 35 to 45 deg. F. 29 to 36 deg. F. 35 to 45 deg. F.
Wind Direction: E E E
Wind Speed: 35 to 45 mph with gusts to 65 mph. 35 to 45 mph with gusts to 65 mph. 25 to 35 mph with gusts to 55 mph.
Expected snowfall: 0 in. 0 in. 0 in.
Disclaimer

This avalanche advisory is provided through a partnership between the Tahoe National Forest and the Sierra Avalanche Center. This advisory covers the Central Sierra Nevada Mountains between Yuba Pass on the north and Ebbetts Pass on the south. Click here for a map of the forecast area. This advisory applies only to backcountry areas outside established ski area boundaries. This advisory describes general avalanche conditions and local variations always occur. This advisory expires 24 hours after the posted time unless otherwise noted. The information in this advisory is provided by the USDA Forest Service who is solely responsible for its content.