THIS AVALANCHE FORECAST EXPIRED ON April 22, 2020 @ 6:49 am
Avalanche Forecast published on April 21, 2020 @ 6:49 am
Issued by Brandon Schwartz - Tahoe National Forest

Firm surface conditions early this morning will give way to snow surface melt and the possibility of loose wet snow avalanches at all elevations as the day progresses. MODERATE avalanche danger will exist today at all elevations once the surface crust melts away, exposing areas of deep wet snow.

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 decreased substantially after midnight last night allowing for radiational cooling of the snowpack. This combined with below freezing air temperatures at nearly all locations early this morning is expected to have lead to a strong overnight refreeze of the top several inches of the snowpack. Rapid snow surface melt fueled by the late April level of incoming solar radiation will melt away this surface crust today, exposing deep wet snow, and opening the door for loose wet snow avalanches as the day progresses. A loose wet avalanche problem is expected today on all aspects at all elevations. Avalanche size is expected at D1 to D2, depending on what the terrain is capable of producing.

Avoid travel in avalanche terrain on slopes where marginally supportable to unsupportable deep wet snow exists. Today's winds may create some cooling and slow melt rates this morning directly along the ridgetops, but not mid slope or below.

recent observations
Submit Observations

* Diurnal melt-freeze conditions exist on all aspects.

* Observations made yesterday on Silver Peak (Pole Creek area) showed snow surface melt occurring at the mid to lower elevations traveled despite substantial cloud cover. By 10 am, E aspects at 8,000' held 2 inches of surface wet snow over a weakening but still supportable melt freeze crust. About 3 feet of residual, non-refrozen wet snow existed below the surface crust.

* Signs of layer consolidation from recent melt and rain have been observed in the top few feet of the snowpack on all aspects, minimizing the concerns for additional wet slab avalanches.

Weather and CURRENT CONDITIONS
weather summary

Sunny skies are expected this morning before some afternoon cumulus buildups occur later today. Daytime heating and residual moisture may lead to some isolated showers along the Sierra Crest this afternoon with a very slight chance for thunderstorms in the approximately 3 pm to 6 pm timeframe. NE ridgetop winds this morning at light to moderate speeds are expected to shift to the NW this afternoon. A warming trend starts today and will last into this weekend. There is a decent chance that air temperature inversion conditions will set up tonight. Going forward this week, expect above normal maximum daytime air temperatures and decreased cloud cover as high pressure builds over the region.

CONDITIONS ALONG THE SIERRA CREST BETWEEN 8200 FT. AND 9200 FT. IN THE LAST 24 HOURS
Weather Station Map
Weather Station Table
6am temperature: 28 to 33 deg. F.
Max. temperature: 34 to 45 deg. F.
Average ridgetop wind direction: SW shifting to NE
Average ridgetop wind speed: SW 19 mph | NE 15 mph
Maximum ridgetop wind gust: SW 37 mph | NE 23 mph
New snowfall: 0 to trace inches
Total snow depth: 53 to 75 inches
Two-Day Mountain Weather Forecast Produced in partnership with the Reno NWS
For 7000 ft. to 8000 ft.
Tuesday Tuesday Night Wednesday
Weather: Sunny skies becoming partly cloudy. Isolated showers in the afternoon. Snow levels 7000 feet increasing to 8500 feet in the afternoon. Chance of precipitation is 15%. Partly cloudy then becoming clear. Snow levels 9000 feet. Chance of precipitation is 5%. Sunny then becoming partly cloudy. Snow levels 9000 feet. Chance of precipitation is 0%.
Temperatures: 49 to 55. deg. F. 30 to 36. deg. F. 53 to 59. deg. F.
Mid Slope Winds: Light winds becoming northwest around 10 mph with gusts to 20 mph in the afternoon. Light winds. Light winds becoming west around 15 mph with gusts to 30 mph in the afternoon.
Expected snowfall: No accumulation. | SWE = trace amounts. No accumulation. | SWE = none. No accumulation. | SWE = none.
For 8000 ft. to 9000 ft.
Tuesday Tuesday Night Wednesday
Weather: Sunny skies becoming partly cloudy. Isolated showers in the afternoon. Snow levels 7000 feet increasing to 8500 feet in the afternoon. Chance of precipitation is 15%. Partly cloudy then becoming clear. Snow levels 9000 feet. Chance of precipitation is 5%. Sunny then becoming partly cloudy. Snow levels 9000 feet. Chance of precipitation is 0%.
Temperatures: 41 to 49. deg. F. 31 to 36. deg. F. 46 to 54. deg. F.
Ridge Top Winds: Northeast 10 to 20 mph becoming north to northwest in the afternoon. Gusts to 30 mph in the afternoon. Northwest around 15 mph with gusts to 30 mph. West 15 to 25 mph. Gusts up to 30 mph increasing to 40 mph in the afternoon.
Expected snowfall: No accumulation. | SWE = trace amounts. 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