THIS AVALANCHE ADVISORY EXPIRED ON February 15, 2016 @ 6:48 am
Avalanche Advisory published on February 14, 2016 @ 6:48 am
Issued by Brandon Schwartz - Tahoe National Forest

LOW avalanche danger continues for all elevations and aspects. Human triggered loose wet avalanches may occur this afternoon in isolated areas on E-SE-S-SW aspects on slopes 37 degrees and steeper. 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: Loose Wet
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    Certain
    Very Likely
    Likely
    Possible
    Unlikely
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    Very Large
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A decent snow surface refreeze is expected to have occurred again last night due to a combination of below freezing air temperatures in some locations and radiational cooling in other areas where air temperatures were above freezing. More upper elevation locations are reporting below freezing air temperatures this morning than has been the recent trend. Many of the mid elevation locations were still in the upper 30s overnight with radiational cooling allowing the snow surface to refreeze. Last night's refreeze is likely to be similar to what was observed yesterday morning.

Supportable conditions are expected through the morning hours today. Sometime during the mid day to afternoon hours conditions will become less supportable and loose wet snowpack instability will increase. Human triggered loose wet avalanche activity could occur this afternoon in isolated areas on E-SE-S-SW aspects. Some amount of cloud cover, slightly cooler air temperatures, and NE winds will help to keep the snow surface from melting too rapidly today.

Once several inches of wet snow form on the snow surface and body weight boot penetration approaches 1 foot deep or more into surface wet snow, it is time to take active measures to avoid avalanches. Change to a more northerly or westerly aspect and/or move to slopes less than 35 degrees in slope angle without steeper terrain above. Planned timing of travel in avalanche terrain is critical for the preferred mix of frozen to melting, but still supportable snow surface conditions.

recent observations

Across the forecast area, the snowpack on E-SE-S-SW aspects has for the most part adjusted to the post storm warming over the past 11 days. Widespread melt-freeze conditions are well established on E-SE-S-SW aspects. Areas of dry snow, unaffected by melt freeze linger on northerly aspects above 8,000'. Surface crusts exist on northerly aspects below 8,000'. Observations made yesterday on the north side of Carson Pass and received yesterday from the south side of Jakes Peak indicated that a strong snow surface refreeze had occurred in both areas the night before. The top 6 to 8 inches of the snowpack had formed a thick dense melt freeze crust on E-SE-S-SW aspects. Between 8,000' and 9,500' snow surface melt was noted to occur fairly gradually during the mid morning hours, with conditions remaining supportable during the late morning hours.

Weather and CURRENT CONDITIONS
weather summary

A weather system passing to the north of the forecast area today is shifting winds from the WSW to NE this morning. Wind speeds are forecast to increase to moderate in speed with ridgetop gusts in the 35 to 45 mph range through tonight. Air temperatures at 6 am this morning are in the upper 20s to upper 30s above 8,000'. This is a few degrees colder than yesterday with more locations reaching below freezing last night. Maximum daytime air temperatures are forecast to be slightly cooler today, but still above average. Some high level cloud cover will exist today. A warming trend and clearing skies is expected for tomorrow. High pressure will remain in place through Tues with the next storm system expected to impact the forecast area Wed-Thurs.

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: 48 to 53 deg. F.
Average wind direction during the last 24 hours: WSW
Average wind speed during the last 24 hours: 16 mph
Maximum wind gust in the last 24 hours: 26 mph
New snowfall in the last 24 hours: 0 inches
Total snow depth: 60 to 76 inches
Two-Day Mountain Weather Forecast Produced in partnership with the Reno NWS
For 7000 ft. to 8000 ft.
Sunday Sunday Night Monday
Weather: Partly cloudy skies. Partly cloudy skies, becoming clear. Sunny skies.
Temperatures: 43 to 50 deg. F. 26 to 34 deg. F. 46 to 53 deg. F.
Wind Direction: N to NE NE E
Wind Speed: 10 to 15 mph, increasing to 15 to 25 mph with gusts to 35 mph in the afternoon. 15 to 25 mph with gusts to 35 mph. 10 to 15 mph. Gusts up to 25 mph in the morning.
Expected snowfall: 0 in. 0 in. 0 in.
For 8000 ft. to 9000 ft.
Sunday Sunday Night Monday
Weather: Partly cloudy skies. Partly cloudy skies, becoming clear. Sunny skies.
Temperatures: 39 to 46 deg. F. 24 to 31 deg. F. 43 to 50 deg. F.
Wind Direction: N to NE NE E
Wind Speed: 15 to 20 mph with gusts to 30 mph, increasing to 20 to 30 mph with gusts to 45 mph in the afternoon. 25 to 30 mph with gusts to 50 mph, decreasing to 20 to 25 mph with gusts to 40 mph after midnight. 15 to 20 mph with gusts to 30 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.