THIS AVALANCHE FORECAST EXPIRED ON March 1, 2020 @ 6:45 am
Avalanche Forecast published on February 29, 2020 @ 6:45 am
Issued by Brandon Schwartz - Tahoe National Forest

Some loose wet avalanche problems may exist today near and below treeline with MODERATE avalanche danger. Following the onset of snowfall this evening, wind slab, storm slab, and/or loose dry avalanche problems are expected to form with MODERATE to CONSIDERABLE avalanche danger expected during the overnight hours at all elevations on slopes with preexisting snow cover.

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

Cloud cover thinned enough last night that at least a weak snow surface refreeze from radiational cooling is expected to have occurred overnight on open slopes despite above freezing air temperatures at low to mid elevations. Snow surface refreeze under forest canopy may not have occurred in some areas. The strongest refreeze is expected to have occurred above 8,000'. Maximum daytime air temperatures will be a bit colder today than what has occurred over the past few days, but still above freezing. Some snow surface melt is expected to occur today on mid to lower elevation slopes with direct sun exposure and protection from the strong SW winds. A loose wet avalanche problem is possible in these specific areas near and below treeline on E-SE-S-SW-W aspects, especially where overnight refreeze was poor. Wind exposed slopes, especially above 8,000' to 8,500' will likely remain frozen all day due to convective cooling of the snow surface. Exercise caution on or below any steep slopes that have wet surface snow and marginal to poor supportability.

Forecast discussion

The avalanche problems will change dramatically tonight as new snow accumulates. Expect discussion of wind slab, storm slab, and/or loose dry avalanche problems in tomorrow's avalanche forecast.

recent observations
Submit Observations

* SE-S-SW aspects hold the most consolidated and well established melt-freeze snowpack conditions.

* NW-N-NE aspects remain highly variable, ranging from firm to soft with surface conditions ranging from ice to surface facets.

Weather and CURRENT CONDITIONS
weather summary

Thicker than forecast cloud cover from yesterday has moved out of the region overnight with partly cloudy skies this morning. Strong SW ridgetop winds have mixed out air temperature inversions, but overnight lows have remained above freezing at low to mid elevations and also at some upper elevation sites. Some sunshine will occur today before cloud cover increases late day ahead of an approaching cold front. Following frontal passage, a 2 to 6 hour period of snowfall is expected to deposit 5 to 10 inches along the Sierra Crest. This weather system will move north to south through the forecast area with snowfall expected to start near I-80 as early as 5-7 pm with peak intensity around 8 pm to midnight. For areas south of Highway 50, peak intensity will be a bit later, sometime between 3 am and 10 am Sunday. As this weather system departs the region, a 100 to 125 mph ridgetop NE wind event is forecast for Sunday evening into Monday.

CONDITIONS ALONG THE SIERRA CREST BETWEEN 8200 FT. AND 9200 FT. IN THE LAST 24 HOURS
Weather Station Map
Weather Station Table
6am temperature: 27 to 33 deg. F.
Max. temperature: 39 to 47 deg. F.
Average ridgetop wind direction: SW
Average ridgetop wind speed: 35 mph
Maximum ridgetop wind gust: 70 mph
New snowfall: 0 inches
Total snow depth: 35 to 46 inches
Two-Day Mountain Weather Forecast Produced in partnership with the Reno NWS
For 7000 ft. to 8000 ft.
Saturday Saturday Night Sunday
Weather: Partly cloudy, then sunny, then mostly cloudy. Chance of precipitation is 0%. Mostly cloudy. Chance of showers. Snow levels below 7000 feet. Chance of precipitation is 90%. Cloudy. Snow showers likely in the morning, then snow showers in the afternoon. Snow levels below 7000 feet. Chance of precipitation is 70%.
Temperatures: 41 to 46. deg. F. 17 to 22. deg. F. 21 to 26. deg. F.
Mid Slope Winds: Southwest 15 to 30 mph with gusts to 50 mph. Southwest 15 to 30 mph with gusts to 60 mph decreasing to 15 to 20 mph with gusts to 45 mph after midnight. North 15 to 20 mph. Gusts up to 25 mph increasing to 40 mph in the afternoon.
Expected snowfall: No accumulation. | SWE = none. 70% probability of 1 to 3 inches. 30% probability of 3 to 6 inches. | SWE = 0.15-0.25 inch. 70% probability of 1 to 3 inches. 30% probability up to 2 inches. | SWE = 0.15-0.25 inch.
For 8000 ft. to 9000 ft.
Saturday Saturday Night Sunday
Weather: Partly cloudy, then sunny, then mostly cloudy. Chance of precipitation is 0%. Mostly cloudy. Chance of showers. Snow levels below 7000 feet. Chance of precipitation is 95%. Cloudy. Snow showers likely in the morning, then snow showers in the afternoon. Snow levels below 7000 feet. Chance of precipitation is 70%.
Temperatures: 36 to 42. deg. F. 13 to 18. deg. F. 15 to 21. deg. F.
Ridge Top Winds: Southwest 30 to 50 mph with gusts to 80 mph. Southwest 30 to 45 mph with gusts to 85 mph decreasing to 20 to 30 mph with gusts to 60 mph after midnight. Northwest 15 to 20 mph with gusts to 35 mph shifting to the northeast 15 to 30 mph with gusts to 55 mph in the afternoon.
Expected snowfall: No accumulation. | SWE = none. 70% probability of 1 to 3 inches. 30% probability of 3 to 6 inches. | SWE = up to 0.30 inch. 80% probability of 1 to 3 inches. 20% probability up to 2 inches. | SWE = up to 0.30 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