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.

Strong high pressure will continue to dominate the weather pattern for a few more days. Another round of sunny skies and warm air temperatures are forecast for today. A slight chance of thunderstorms exists for this afternoon. Maximum daytime air temperatures are expected to reach the upper 50s to low 70s at all elevations today. A strong air temperature inversion is in place this morning with air temperatures below 7,500' in the mid to upper 30s. Air temperatures above 7,500' are in the upper 40s to low 50s in nearly all locations. Ridgetop winds shifted from northeast to north overnight and remain light to moderate in speed. Winds are forecast to eventually shift to the southwest and become light by this afternoon.

Yesterday, observations made on Tamarack Peak and Mt. Houghton (Mount Rose area) revealed that radiational snowpack cooling had created a fair refreeze of surface snow overnight. This occurred despite an air temperature inversion with air temperatures above 7,000' in the upper 40s to 50s. Testpit data collected on Tamarack Peak at 9,880' on a NE aspect, 34 degrees slope in Hourglass Bowl indicated that free water formation had been limited to the upper 5 to 6 inches of the snowpack. On east and south aspects on both Tamarack Peak and Mt. Houghton, a well developed melt-freeze snowpack was observed all the way up to the Mt. Houghton summit at 10,480'. Ski cuts performed at 9,200' on steep E aspect convex terrain features at 11:30 am yielded wet snow sluffs on top of the still supportable melt-freeze crust. Wet snow on these aspects remained supportable up until around noon when the remnants of the overnight refreeze had almost completely melted. At this point, feet of wet snow existed at the snow surface in some areas.

Last night, a fair snow surface refreeze is expected to have occurred above 7,500' and a stronger refreeze is expected to have occurred below 7,500' due to the air temperature inversion and radiational cooling. Today, the combination of well above freezing air temperatures at the upper elevations this morning and rapid daytime warming will cause areas of instability to form by mid day. Most avalanche activity is expected to occur as human triggered wet loose snow avalanches on steep E-SE-S-SW-W aspects. Some smaller areas of wet surface snow instability are expected to form on steep NW-N-NE aspects, mainly below 9,500' in sun exposed areas. Natural avalanche activity is unlikely but not impossible today. Areas of cornice collapse could create larger wet loose snow avalanches. In areas where the snowpack sits on top of steep granite slabs, isolated wet slab avalanches are not impossible. At this time, wet slab avalanches remain unlikely on E-SE-S-SW-W aspects due to the already well established drainage of free water from the snowpack. With free water limited to the top 6 inches of the snowpack in most NW-N-NE aspect avalanche start zones, wet loose surface snow instability remains more likely than deeper wet slab instability at this time.

The bottom line:

Early this morning, avalanche danger is LOW for all elevations and aspects. Avalanche danger will rise to MODERATE on E-SE-S-SW-W aspects 37 degrees and steeper in response to daytime warming. Pockets of MODERATE danger will also form on NW-N-NE aspects, 37 degrees and steeper as warming occurs.

Brandon Schwartz - Avalanche Forecaster, Tahoe National Forest

Weather Observations from along the Sierra Crest between 8200 ft and 8800 ft:

0600 temperature:	51 deg. F.
Max. temperature in the last 24 hours:	58 deg. F.
Average wind direction during the last 24 hours:	Northeast
Average wind speed during the last 24 hours:	11 mph
Maximum wind gust in the last 24 hours:	26 mph
New snowfall in the last 24 hours:	O inches
Total snow depth:	128 inches

Two-Day Mountain Weather Forecast - Produced in partnership with the Reno NWS

For 7000-8000 ft:
	Tuesday:	Tuesday Night:	Wednesday:
Weather:	Sunny skies in the morning, becoming partly cloudy with a slight chance of thunderstorms in the afternoon.	Partly cloudy skies with a slight chance of thunderstorms in the evening, becoming clear after midnight.	Sunny skies in the morning, becoming partly cloudy with a slight chance of thunderstorms in the afternoon.
Temperatures:	64 to 70 deg. F.	42 to 48 deg. F.	57 to 64 deg. F.
Wind direction:	E shifting to SW	SW	SE
Wind speed:	Up to 10 mph.	Around 10 mph in the evening becoming light.	Light in the morning, increasing to 10 to 15 mph in the afternoon.
Expected snowfall:	O in.	O in.	O in.
For 8000-9000 ft:
	Tuesday:	Tuesday Night:	Wednesday:
Weather:	Sunny skies in the morning, becoming partly cloudy with a slight chance of thunderstorms in the afternoon.	Partly cloudy skies with a slight chance of thunderstorms in the evening, becoming clear after midnight.	Sunny skies in the morning, becoming partly cloudy with a slight chance of thunderstorms in the afternoon.
Temperatures:	57 to 63 deg. F.	38 to 45 deg. F.	55 to 61 deg. F.
Wind direction:	E shifting to SW	W	SW shifting to SE.
Wind speed:	10 to 15 mph.	Around 10 mph.	Around 10 mph with gusts to 25 mph in the afternoon.
Expected snowfall:	O in.	O in.	O in.