THIS AVALANCHE FORECAST EXPIRED ON February 3, 2019 @ 6:45 am
Avalanche Forecast published on February 2, 2019 @ 6:45 am
Issued by Brandon Schwartz - Tahoe National Forest

Avalanche danger will increase to HIGH danger this morning. Natural and human triggered avalanches are very likely today. Travel in or below avalanche terrain is not recommended.

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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High intensity snowfall rates today combined with strong S to SSW winds will create new wind slabs. The vast majority of wind slabs will form near treeline and above treeline on NW-N-NE-E-SE aspects. More isolated wind slabs may form on other aspects or below treeline. Be aware of exposure to steeper slopes above where naturally occurring avalanches could run down into low angle terrain below treeline.

Avalanche Problem 2: Storm Slab
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High intensity snowfall today is likely to create problematic storm slabs. Unstable storm slabs could form on any aspect in wind protected areas near treeline and below treeline. Open or sparsely treed N-NE aspects where new snow is deposited on top of surface hoar could be very unstable. In these areas, avalanches may occur in atypical locations. Be aware of the possibility of avalanches occurring in relatively low angle terrain down around 28-30 degree slope angle and well below traditional ridgeline avalanche start zones.

recent observations

* Surface hoar was likely buried last night on many open wind protected slopes on N-NE aspects creating a problematic weak layer at the old/new snow interface. Surface hoar was reported prestorm on Stevens Peak (Carson Pass area), Jakes Peak (West Shore area), and on Tamarack Peak including in Hourglass Bowl (Mount Rose area).

* No problematic weak layers have been observed deeper in the snowpack below the old/new snow interface.

Weather and CURRENT CONDITIONS
weather summary

The first in a series of storm events expected to last through Tuesday is impacting the forecast area. Snow level around 6,500'-7,000' last night has lowered to around 5,500'-6,000' this morning. High-intensity snowfall is expected today. Continued light to moderate snowfall rates are expected tonight and tomorrow morning before snowfall intensity increases again Sunday afternoon. Ridgetop winds remain out of the S to SSW and are increasing in speed this morning. Strong ridgetop winds are expected to continue. For the latest info on this storm cycle, see NWS Reno.

Weather observations from along the Sierra Crest between 8200 ft. and 8800 ft.
0600 temperature: 29 to 34 deg. F.
Max. temperature in the last 24 hours: 30 to 39 deg. F.
Average wind direction during the last 24 hours: SSW
Average wind speed during the last 24 hours: 38 mph
Maximum wind gust in the last 24 hours: 79 mph
New snowfall in the last 24 hours: 3 to 8 inches
Total snow depth: 63 to 84 inches
Two-Day Mountain Weather Forecast Produced in partnership with the Reno NWS
For 7000 ft. to 8000 ft.
Saturday Saturday Night Sunday
Weather: Heavy snow. Snow levels below 7000 feet. Chance of precipitation is 100%. Cloudy. Snow. Snow levels below 7000 feet. Chance of precipitation is 80%. Cloudy. Snow. Snow levels below 7000 feet. Chance of precipitation is 85%.
Temperatures: 32 to 37 deg. F. 22 to 27 deg. F. 30 to 35 deg. F.
Mid Slope Winds: South 10 to 15 mph. Gusts up to 40 mph decreasing to 30 mph in the afternoon. South 15 to 25 mph with gusts to 40 mph. Southwest 15 to 30 mph. Gusts up to 40 mph increasing to 55 mph in the afternoon.
Expected snowfall: 80% probability of 11 to 19 inches. 20% probability of 7 to 11 inches. | SWE = up to 1.40 inches. 80% probability of 4 to 8 inches. 20% probability of 8 to 12 inches. | SWE = 0.25-0.50 inch. 70% probability of 4 to 10 inches. 30% probability of 10 to 14 inches. | SWE = 0.35-0.55 inch.
For 8000 ft. to 9000 ft.
Saturday Saturday Night Sunday
Weather: Heavy 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 85%.
Temperatures: 30 to 35 deg. F. 19 to 24 deg. F. 26 to 32 deg. F.
Ridge Top Winds: South 20 to 35 mph with gusts to 80 mph. South 20 to 35 mph with gusts to 80 mph. Southwest 30 to 45 mph with gusts to 80 mph.
Expected snowfall: 80% probability of 14 to 22 inches. 20% probability of 11 to 17 inches. | SWE = 1.00-1.50 inches. 80% probability of 5 to 9 inches. 20% probability of 6 to 12 inches. | SWE = 0.30-0.55 inch. 70% probability of 4 to 10 inches. 30% probability of 10 to 15 inches. | SWE = 0.40-0.65 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