THIS AVALANCHE FORECAST EXPIRED ON March 3, 2019 @ 6:50 am
Avalanche Forecast published on March 2, 2019 @ 6:50 am
Issued by Steve Reynaud - Tahoe National Forest

Another Pacific storm will impact our forecast region today and into Sunday.  CONSIDERABLE avalanche danger will exist due to wind slab, storm slab, and loose wet avalanche problems at all elevations.  Natural and human triggered avalanches will be likely today.

3. Considerable

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Above Treeline
Dangerous avalanche conditions. Careful snowpack evaluation, cautious route-finding and conservative decision-making essential.

3. Considerable

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Near Treeline
Dangerous avalanche conditions. Careful snowpack evaluation, cautious route-finding and conservative decision-making essential.

3. Considerable

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Below Treeline
Dangerous avalanche conditions. Careful snowpack evaluation, cautious route-finding and conservative decision-making essential.
    Dangerous avalanche conditions. Careful snowpack evaluation, cautious route-finding and conservative decision-making essential.
Avalanche Problem 1: Wind Slab
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New snow along with moderate to strong S/SW winds will form new wind slabs on W-NW-N-NE-E-SE aspects in near and above treeline terrain.  Wind slabs and cornices will build throughout today and be reactive to natural and human triggering.  Warming temperatures with potential rain on snow this afternoon could further weaken these wind slabs

Look for blowing snow, cornice formation, and wind pillows.  Avoid steep wind loaded terrain and areas below large cornices.

Avalanche Problem 2: Storm Slab
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Storm slabs could form on all aspects in wind protected near and below treeline terrain.  Weaknesses could develop within the new storm snow or at the old snow/new snow interface.  With snow levels forecasted to rise throughout the day, upside down storm snow conditions could occur with heavier snow on top of less dense snow.  Where rain on new snow occurs, storm slab avalanches could take on wet slab characteristics.

Look for cracking or any indication of cohesion of the new storm snow.  Rain on new snow could cause widespread instabilities.  Match appropriate terrain for the current conditions.  

Avalanche Problem 3: Loose Wet
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Loose wet avalanches will become likely in areas that receive rapid warming with rain on snow.  As snow levels rise throughout the day, potentially up to 7500', loose wet avalanches could entrain most or all of the new storm snow.  Some of these loose wet avalanches could be large enough to injure or bury a backcountry user.  

recent observations

*  Blustery conditions reported yesterday with blowing snow and mostly cloudy conditions throughout the forecast region.  Limited to no warming of the snow surface observed.

*  Large cornices exist throughout the forecast region along ridges and peaks.

*  Evidence of wind slab instabilities were limited to minor cracking in wind loaded terrain.

Weather and CURRENT CONDITIONS
weather summary

A Pacific storm entered our region overnight and will bring snow and moderate to strong S/SW winds through Sunday.  8 to 12'' of snow is forecasted for areas above 8000' today.  Snow levels should be below 6000' to start and, as warmer air moves into the area, rise up to 6500-7500' during the afternoon .  Light to moderate precipitation will continue into Sunday morning.  A break will develop for the early part of next week with another potentially stronger and warmer storm for Tuesday/Wednesday.  This stormy pattern looks to continue for the foreseeable future. 

Weather observations from along the Sierra Crest between 8200 ft. and 8800 ft.
0600 temperature: 27 to 32 deg. F.
Max. temperature in the last 24 hours: 33 deg. F.
Average wind direction during the last 24 hours: SW to S
Average wind speed during the last 24 hours: 20 to 40 mph
Maximum wind gust in the last 24 hours: 89 mph
New snowfall in the last 24 hours: 2 to 4 inches
Total snow depth: 115 to 119 inches
Two-Day Mountain Weather Forecast Produced in partnership with the Reno NWS
For 7000 ft. to 8000 ft.
Saturday Saturday Night Sunday
Weather: Cloudy. Snow. Snow levels below 7000 feet. Chance of precipitation is 100%. Cloudy. Showers likely. Snow levels 7000 feet. Chance of precipitation is 70%. Cloudy. Snow showers likely. Snow levels below 7000 feet. Chance of precipitation is 60%.
Temperatures: 33 to 38. deg. F. 26 to 31. deg. F. 33 to 38. deg. F.
Mid Slope Winds: Light winds becoming southwest 15 to 20 mph with gusts to 60 mph in the afternoon. Southwest 15 to 25 mph with gusts to 60 mph. Southwest 15 to 20 mph with gusts to 45 mph.
Expected snowfall: 80% probability of 5 to 10 inches. 20% probability of 10 to 14 inches. | SWE = 0.50-0.75 inch. 60% probability 2 to 4 inches. 40% probability up to 2 inches. | SWE = 0.15-0.25 inch. 80% probability of 1 to 4 inches. 20% probability of 4 to 6 inches. | SWE = up to 0.25 inch.
For 8000 ft. to 9000 ft.
Saturday Saturday Night Sunday
Weather: Cloudy. Snow. Snow levels below 7000 feet. Chance of precipitation is 100%. Cloudy. Snow showers likely. Snow levels 7000 feet. Chance of precipitation is 70%. Cloudy. Snow showers likely. Snow levels below 7000 feet. Chance of precipitation is 60%.
Temperatures: 29 to 35. deg. F. 23 to 28. deg. F. 29 to 35. deg. F.
Ridge Top Winds: South 15 to 25 mph increasing to southwest 30 to 40 mph in the afternoon. Gusts up to 65 mph. Southwest 30 to 45 mph with gusts to 70 mph. Southwest 25 to 35 mph with gusts to 75 mph.
Expected snowfall: 80% probability of 8 to 12 inches. 20% probability of 12 to 18 inches. | SWE = 0.60-0.85 inch. 70% probability of 2 to 4 inches. 30% probability of 4 to 8 inches. | SWE = up to 0.30 inch. 80% probability of 1 to 4 inches. 20% probability of 4 to 8 inches. | SWE = up to 0.25 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