THIS AVALANCHE FORECAST EXPIRED ON April 7, 2019 @ 6:59 am
Avalanche Forecast published on April 6, 2019 @ 6:59 am
Issued by Andy Anderson - Tahoe National Forest - Sierra Avalanche Center

MODERATE avalanche danger will exist at all elevations today as daytime warming and potential rain on snow allow loose wet avalanches to become possible. Small wind slab problems may also exist on some exposed slopes in near and above treeline terrain. 

2. Moderate

?

Above Treeline
Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern.

2. Moderate

?

Near Treeline
Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern.

2. Moderate

?

Below Treeline
Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern.
    Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern.
Avalanche Problem 1: Loose Wet
  • Type ?
  • Aspect/Elevation ?
  • Likelihood ?
    Certain
    Very Likely
    Likely
    Possible
    Unlikely
  • Size ?
    Historic
    Very Large
    Large
    Small

Warm daytime temperatures, new snow, and potential rain showers will allow loose wet avalanches to become possible again today. The potential for this problem could be more widespread across aspects and reach higher in elevation. In areas where enough warming occurs to melt through the thin crust under the new snow, these avalanches would entrain the few inches of new snow as well as some of the wet snow below.

Signs foreshadowing larger loose wet avalanches an include wet, sticky surface snow, roller balls, and pinwheels. These signs also herald deteriorating riding conditions. As soon as you notice them, it is time to look for aspects/elevations where colder more frozen conditions still exist.

Avalanche Problem 2: Wind Slab
  • Type ?
  • Aspect/Elevation ?
  • Likelihood ?
    Certain
    Very Likely
    Likely
    Possible
    Unlikely
  • Size ?
    Historic
    Very Large
    Large
    Small

Strong SW winds have drifted snow onto the leeward aspects. The wind slabs that have formed on these aspects should remain small and not extend very far away from the ridgelines due to the meager amounts of new snow. Most of these wind slabs would be unlikely to cause significant problems for backcountry travelers. However, some of them could be large enough to be problematic especially in areas with terrain traps or where getting knocked off balance would have serious consequences.

recent observations

* Yesterday on Mt. Tallac small wind slabs up to 10 inches deep had formed along exposed ridgelines by noon. These did not break in response to ski cut and tests did not show signs of instability even though they rested on a layer of less dense snow on top of a crust. They also did not extend very far down slope.

* In sheltered areas 1 to 2 inches of new snow had accumulated on top of a crust above 7800 ft. with a dusting of new snow on the crust below 7800 ft. The crust was breakable at low elevations and supportable at higher elevations.

Weather and CURRENT CONDITIONS
weather summary

Snow levels hovered between 6000 and 6500 ft for much of yesterday. By last evening snow showers started to taper off. Some lingering showers may continue today and could produce rain or snow as snow levels climb to around 7500 ft or higher. Accumulations should remain light. Warm air moving into the region should bring temperatures into the mid to upper 40's at mid elevations and upper 30's to low 40's at higher elevations. The forecast calls for a sunny spring day tomorrow with decreased winds, dramatically warmer temperatures, and some sunshine. 

Weather observations from along the Sierra Crest between 8200 ft. and 8800 ft.
0600 temperature: 25 to 30 deg. F.
Max. temperature in the last 24 hours: 29 to 36 deg. F.
Average wind direction during the last 24 hours: SW
Average wind speed during the last 24 hours: 28 to 38 mph
Maximum wind gust in the last 24 hours: 95 mph
New snowfall in the last 24 hours: 1 to 3 inches
Total snow depth: 113 to 161 inches
Two-Day Mountain Weather Forecast Produced in partnership with the Reno NWS
For 7000 ft. to 8000 ft.
Saturday Saturday Night Sunday
Weather: Mostly cloudy. A chance of showers. Snow levels below 7000 feet increasing to 7500 feet in the afternoon. Chance of precipitation is 40%. Mostly cloudy. Snow levels 8000 feet. Chance of precipitation is 5%. Mostly sunny. Snow levels 7500 feet increasing to 8500 feet in the afternoon. Chance of precipitation is 0%.
Temperatures: 41 to 47 deg. F. 28 to 33 deg. F. 50 to 56 deg. F.
Mid Slope Winds: Southwest 10 to 20 mph with gusts to 40 mph. Southwest 10 to 20 mph with gusts to 35 mph. Southwest 15 to 25 mph. Gusts up to 45 mph.
Expected snowfall: 40% probability up to 1 inch. 60% probability no accumulation. | SWE = less than 0.10 inch. No accumulation. | SWE = none. No accumulation. | SWE = none.
For 8000 ft. to 9000 ft.
Saturday Saturday Night Sunday
Weather: Mostly cloudy. A chance of snow showers. Snow levels below 7000 feet increasing to 7500 feet in the afternoon. Chance of precipitation is 50%. Mostly cloudy. Snow levels 8000 feet. Chance of precipitation is 5%. Mostly sunny. Snow levels 7500 feet increasing to 8500 feet in the afternoon. Chance of precipitation is 0%.
Temperatures: 34 to 40 deg. F. 25 to 30 deg. F. 41 to 47 deg. F.
Ridge Top Winds: Southwest 25 to 45 mph with gusts to 70 mph. Southwest 15 to 30 mph with gusts to 50 mph. Southwest 20 to 35 mph with gusts to 65 mph.
Expected snowfall: 40% probability up to 1 inch. 60% probability no accumulation. | SWE = less than 0.10 inch. No accumulation. | SWE = none. No accumulation. | SWE = none.
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