THIS AVALANCHE FORECAST EXPIRED ON April 20, 2019 @ 6:59 am
Avalanche Forecast published on April 19, 2019 @ 6:59 am
Issued by Andy Anderson - Tahoe National Forest - Sierra Avalanche Center

A short period of LOW avalanche danger will exist while the snow remains supportable early this morning. The danger will quickly increase to MODERATE as loose wet avalanche problems become possible due to warm temperatures, strong sunshine, and a weak overnight refreeze. 

2. Moderate

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

2. Moderate

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

2. Moderate

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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
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    Certain
    Very Likely
    Likely
    Possible
    Unlikely
  • Size ?
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    Very Large
    Large
    Small

Some areas may not have experienced much of a refreeze last night. In those areas that did, the refreeze should have been weak. Rapid warming and strong sunshine today will melt through this thin refreeze quickly leaving deep loose wet snow on most slopes. Loose wet avalanches will become possible on steep slopes as soon as the surface crust melts. Some of these could entrain enough snow to have consequences for backcountry travelers.

If there is a window for supportable melt/freeze conditions today, it will be short. Rollerballs, pinwheels, and boot-top deep wet snow can herald deteriorating recreation conditions as well as larger loose wet avalanche activity. Once the snow starts becoming unsupportable, it is time to call it a day or move to low angle slopes.

recent observations

* Yesterday observations from Mt. Judah and Rose Knob showed a weak refreeze at all elevations. By 10 am many slopes had already become unsupportable and held shin to knee deep wet snow.

* Ski cuts on Judah triggered small roller balls on steep slopes.

* Widespread loose wet avalanche activity has occurred since Monday.

Weather and CURRENT CONDITIONS
weather summary

Along ridges and at the upper elevations most sensors reported overnight lows in the 40's. Most lower elevations sensors reported temps in the mid to upper 30's. Only a handful showed temperatures falling to or below freezing in some lower elevations valleys. Expect another day with daytime highs above 7000 ft in the upper 50's and low 60's with lower elevations temperatures climbing even higher. Some cloud cover may start to move into the area today as the high pressure slides to the east and low pressure approaches the area. By tomorrow this low pressure should bring slight cooler temperatures, increased winds and clouds, and a chance for some precipitation. With snow levels forecasted to remain above 9000 ft, most of this would fall as rain. 

Weather observations from along the Sierra Crest between 8200 ft. and 8800 ft.
0600 temperature: 36 to 47 deg. F.
Max. temperature in the last 24 hours: 52 to 60 deg. F.
Average wind direction during the last 24 hours: E to SW
Average wind speed during the last 24 hours: 10 to 15 mph
Maximum wind gust in the last 24 hours: 39 mph
New snowfall in the last 24 hours: 0 inches
Total snow depth: 99 to 150 inches
Two-Day Mountain Weather Forecast Produced in partnership with the Reno NWS
For 7000 ft. to 8000 ft.
Friday Friday Night Saturday
Weather: Mostly sunny to partly cloudy. Snow levels 9500 feet. Chance of precipitation is 0%. Partly cloudy. Snow levels 9500 feet. Chance of precipitation is 0%. Mostly cloudy. Chance of showers in the afternoon. Snow levels 9000 feet. Chance of precipitation is 35%.
Temperatures: 56 to 62 deg. F. 35 to 40 deg. F. 40 to 47 deg. F.
Mid Slope Winds: Light winds becoming southwest 10 to 15 mph in the afternoon. Gusts up to 30 mph in the afternoon. Southwest 10 to 20 mph with gusts to 35 mph. Southwest 15 to 25 mph. Gusts up to 45 mph.
Expected snowfall: No accumulation. | SWE = none. No accumulation. | SWE = none. No accumulation. | SWE = less than 0.10 inch.
For 8000 ft. to 9000 ft.
Friday Friday Night Saturday
Weather: Mostly sunny to partly cloudy. Snow levels 9500 feet. Chance of precipitation is 0%. Partly cloudy. Snow levels 9500 feet. Chance of precipitation is 0%. Mostly cloudy. Chance of showers in the afternoon. Snow levels 9000 feet. Chance of precipitation is 35%.
Temperatures: 51 to 56 deg. F. 32 to 37 deg. F. 34 to 40 deg. F.
Ridge Top Winds: Southwest 10 to 15 mph with gusts to 30 mph. Southwest 15 to 30 mph. Gusts up to 40 mph increasing to 50 mph after midnight. Southwest 20 to 35 mph with gusts to 60 mph.
Expected snowfall: No accumulation. | SWE = none. No accumulation. | SWE = none. 80% probability up to 1 inch. 20% probability of 1 to 2 inches. | SWE = less than 0.10 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