THIS AVALANCHE FORECAST EXPIRED ON February 16, 2019 @ 6:49 am
Avalanche Forecast published on February 15, 2019 @ 6:49 am
Issued by Brandon Schwartz - Tahoe National Forest

HIGH avalanche danger continues for all elevations. Travel in or below avalanche terrain is not recommended. Maintain awareness of your location relative to avalanche terrain and keep a wide margin for error. Remain clear of avalanche runout zones.

4. High

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Above Treeline
Very dangerous avalanche conditions. Travel in avalanche terrain not recommended.

4. High

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Near Treeline
Very dangerous avalanche conditions. Travel in avalanche terrain not recommended.

4. High

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Below Treeline
Very dangerous avalanche conditions. Travel in avalanche terrain not recommended.
    Very dangerous avalanche conditions. Travel in avalanche terrain not recommended.
Avalanche Problem 1: Wind Slab
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Continued snowfall and gale force SW winds are drifting snow and keeping the wind slab avalanche problem ongoing. The vast majority of wind slabs exist near treeline and above treeline on NW-N-NE-E-SE aspects. Wind slabs may be encountered to a lesser extent on other aspects or in below treeline areas due to the strength of the wind and amount of recent snowfall. Avalanche size up to D3 is expected (could bury a car, destroy a house, or break a few trees).

Be aware of the potential for avalanches from above running down into lower angle treed areas. Route plan carefully, anticipating low visibility obscuring overhead avalanche start zones when avoiding travel below avalanche terrain.

Avalanche Problem 2: Storm Slab
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Storm slab avalanches remain likely from high intensity snowfall and varying snow crystal types (including graupel) creating weak layers within the new snow. Storm slabs form in wind protected areas mainly near and below treeline and may be encountered on any aspect. Avalanche size up to D2 is expected (could bury or injure a person).

Route plan carefully to avoid avalanche terrain. If areas of questionable slope steepness are encountered during travel, use an inclinometer to measure slope angle in order to assist in data based decision making. Allow a margin for error. Be aware of the potential for steeper slopes above.

recent observations
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* Snow levels peaked Thursday morning up around 8,500' to 9,000'. Rain soaked snow exists below the new snow from the past 24 hours in most areas.

* Several widespread graupel weak layers were reported yesterday within the new snow that accumulated during the past 24 hours.

* Signs of unstable wind slabs have been present in field observations during the past several days.

* Visibility in the backcountry has been poor with limited ability to see into avalanche start zones and assess for natural avalanche activity.

Weather and CURRENT CONDITIONS
weather summary

A powerful winter storm continues to impact the region. Snow levels that peaked around 8,500' to 9,000' have fallen over the past 24 hours and are now back down below 4,000'. High intensity snowfall is expected this morning. Snowfall intensity is forecast to ease this afternoon before increasing in intensity again tonight. Ridgetop winds remain out of the SW and are expected to continue at gale force through tonight. Winds begin to slow down a little bit tomorrow afternoon but will remain strong. Snowfall is forecast to continue into Sunday morning.

CONDITIONS ALONG THE SIERRA CREST BETWEEN 8200 FT. AND 9200 FT. IN THE LAST 24 HOURS
Weather Station Map
Weather Station Table
6am temperature: 13 to 21 deg. F.
Max. temperature: 33 to 35 deg. F.
Average ridgetop wind direction: SW
Average ridgetop wind speed: 67 mph
Maximum ridgetop wind gust: 143 mph
New snowfall: 12 to 26 inches
Total snow depth: 110 to 148 inches
Two-Day Mountain Weather Forecast Produced in partnership with the Reno NWS
For 7000 ft. to 8000 ft.
Friday Friday Night Saturday
Weather: Cloudy. Snow. Snow levels below 7000 feet. Chance of precipitation is 100%. Cloudy. Snow. Snow levels below 7000 feet. Chance of precipitation is 85%. Cloudy. Snow. Snow levels below 7000 feet. Chance of precipitation is 90%.
Temperatures: 23 to 28 deg. F. 14 to 20 deg. F. 22 to 27 deg. F.
Mid Slope Winds: Southwest 30 to 45 mph decreasing to 20 to 30 mph in the afternoon. Gusts up to 50 mph. Southwest 15 to 30 mph with gusts to 45 mph. Southwest 15 to 30 mph. Gusts up to 45 mph.
Expected snowfall: 80% probability of 10 to 18 inches. 20% probability of 15 to 25 inches. | SWE = 0.55-1.05 inches. 80% probability of 4 to 10 inches. 20% probability of 8 to 15 inches. | SWE = 0.25-0.50 inch. 80% probability of 4 to 10 inches. 20% probability of 8 to 16 inches. | SWE = 0.20-0.45 inch.
For 8000 ft. to 9000 ft.
Friday Friday Night Saturday
Weather: Cloudy. Snow. Snow levels below 7000 feet. Chance of precipitation is 100%. Cloudy. Snow. Snow levels below 7000 feet. Chance of precipitation is 85%. Cloudy. Snow. Snow levels below 7000 feet. Chance of precipitation is 90%.
Temperatures: 18 to 24 deg. F. 11 to 16 deg. F. 18 to 24 deg. F.
Ridge Top Winds: Southwest 40 to 60 mph with gusts to 120 mph decreasing to 30 to 45 mph with gusts to 90 mph in the afternoon. Southwest 30 to 50 mph with gusts to 85 mph. Southwest 30 to 50 mph with gusts to 85 mph decreasing to 25 to 35 mph with gusts to 65 mph in the afternoon.
Expected snowfall: 80% probability of 12 to 20 inches. 20% probability of 20 to 30 inches. | SWE = 0.75-1.25 inches. 80% probability of 5 to 11 inches. 20% probability of 8 to 15 inches. | SWE = 0.25-0.50 inch. 80% probability of 5 to 10 inches. 20% probability of 8 to 16 inches. | SWE = 0.25-0.50 inch.
Disclaimer

This avalanche forecast is provided through a partnership between the Tahoe National Forest and the Sierra Avalanche Center. This forecast 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 forecast applies only to backcountry areas outside established ski area boundaries. This forecast describes general avalanche conditions and local variations always occur. This forecast expires 24 hours after the posted time unless otherwise noted. The information in this forecast is provided by the USDA Forest Service who is solely responsible for its content.

For a recorded version of the avalanche forecast call (530) 587-3558 x258