Avalanche Advisory: Tuesday - Mar 5, 2019

THIS AVALANCHE ADVISORY EXPIRED ON March 6, 2019 @ 6:57 am
Avalanche Advisory published on March 5, 2019 @ 6:57 am
Issued by Steve Mace - ESAC

Avalanche Danger will rise to CONSIDERABLE today at mid and upper elevations while remaining MODERATE at lower elevations.  With 4-8" of new snow expected today coupled with strong south winds expect the Hazard to increase steadily throughout the day. Careful snowpack evaluation and cautious route finding are recommended.

3. Considerable

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Above Treeline
Dangerous avalanche conditions. Careful snowpack evaluation, cautious route-finding and conservative decision-making essential.

3. Considerable

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Near Treeline
Dangerous avalanche conditions. Careful snowpack evaluation, cautious route-finding and conservative decision-making essential.

2. Moderate

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Below Treeline
Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern.
    Dangerous avalanche conditions. Careful snowpack evaluation, cautious route-finding and conservative decision-making essential.
Avalanche Problem 1: Wind Slab
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Snow showers expected to intensify throughout the day today accompanied by moderate to strong south winds. Expect sensitive wind slab development in areas where terrain features encourage drifting such as the leeward sides of ridgelines and the sidewalls of gullies. Use surface clues such as blowing snow, drifting, new cornice growth, and uneven snow surface to identify and avoid wind-loaded areas.   While fresh slab development on northerly aspects at mid and upper elevations will be the primary concern today, strong winds can lead to unpredictable distribution. It may be possible to find isolated pockets of wind slab at lower elevations even in more sheltered locations.  

Avalanche Problem 2: Storm Slab
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With 4-8” of new snow expected during daylight hours today and an additional 5-9” tonight be on the lookout for storm slab development particularly later in the day.   Storm slabs will become more widespread and consequential as the new snow accumulates late this afternoon and tonight. Watch for signs of instability such as shooting cracks, wumphing or recent avalanche activity. 

 

advisory discussion

As our next stint of winter weather begins today be ready for conditions to change quickly. Avalanche danger will be relatively low this morning but expect it to rise as new snow adds up.  Pay attention to the weather and its effect on your local area and keep in mind that surface conditions are variable across the landscape. Recent observations suggest that the Valentines Day rain crust is still on or near the surface in many areas.  While storm snow from last Saturday seems largely to have bonded well to the crust this layer is worth keeping in mind as travel on this stout crust is still difficult and more importantly, it has proven to make for a good bed surface. 

recent observations
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3/4- Bishop Area, Mt Tom Snow Conditions

3/4- Mammoth Area, Wind effect and warming on Red Cone 

3/4- Big Pine Area, Birch Mtn, Variable Surface Conditions

3/4- Pine Creek, Mayfield Couloir Snow Conditions

3/3- Convict area, loose wet activity and strong winds

3-3- Mammoth Area, Midstorm avalanche activity in the lakes basin

3/3- Bishop Area, Recent avalanche activity in Bishop Creek.

Weather and CURRENT CONDITIONS
weather summary

 Expect cloudy skies moderate temperatures and increasing snow showers today. It’s possible that we will see 4-8” of new snow at upper elevations today. Expect temperatures to reach into the high 20’s today with moderate to strong south winds gusting around 75 MPH on ridge tops this afternoon.

Snow showers will continue to intensify tonight with 5-9” expected this evening. Strong southwest winds will remain through the night as temperatures drop into the low 20’s/ high teens.

Winter weather will continue throughout the week as the approaching atmospheric river continues to impact the area.  Models are more mixed as we move into the weekend but continued moisture remains likely into next week.

 

 

Two-Day Mountain Weather Forecast Produced in partnership with the Reno NWS
For 8,000 ft. to 10,000 ft.
Tuesday Tuesday Night Wednesday
Weather: Cloudy. Chance of snow in the morning, then snow in the afternoon. Snow levels below 7000 feet increasing to 7500 feet in the afternoon. Chance of precipitation is 85%. Cloudy. Snow. Snow levels 7000 feet. Chance of precipitation is 85%. Cloudy. Snow through the day. Slight chance of thunderstorms in the afternoon. Snow levels below 7000 feet. Chance of precipitation is 95%.
Temperatures: 31 to 37. deg. F. 24 to 30. deg. F. 30 to 38. deg. F.
Mid Slope Winds: South 15 to 20 mph with gusts to 70 mph. South 15 to 25 mph with gusts to 75 mph. South 15 to 30 mph with gusts to 75 mph.
Expected snowfall: 80% probability of 2 to 6 inches. 20% probability of 6 to 10 inches. | SWE = 0.25-0.50 inch. in. 80% probability of 3 to 9 inches. 20% probability of 10 to 14 inches. | SWE = 0.30-0.55 inch. in. 80% probability of 6 to 10 inches. 20% probability of 10 to 15 inches. | SWE = 0.50-0.75 inch. in.
Over 10,000 ft.
Tuesday Tuesday Night Wednesday
Weather: Cloudy. Chance of snow in the morning, then snow in the afternoon. Snow levels below 7000 feet increasing to 7500 feet in the afternoon. Chance of precipitation is 95%. Cloudy. Snow. Snow levels 7000 feet. Chance of precipitation is 95%. Cloudy. Snow. Snow levels 7000 feet. Chance of precipitation is 100%.
Temperatures: 24 to 30. deg. F. 18 to 23. deg. F. 22 to 28. deg. F.
Ridge Top Winds: South 25 to 40 mph increasing to 35 to 50 mph in the afternoon. Gusts up to 75 mph. Southwest 35 to 50 mph with gusts to 75 mph. Southwest 35 to 55 mph with gusts to 85 mph.
Expected snowfall: 80% probability of 4 to 8 inches. 20% probability of 8 to 12 inches. | SWE = 0.40-0.65 inch. in. 80% probability of 5 to 9 inches. 20% probability of 10 to 14 inches. | SWE = 0.40-0.65 inch. in. 80% probability of 6 to 12 inches. 20% probability of 12 to 16 inches. | SWE = 0.55-1.05 inches. in.
Disclaimer
This Avalanche Advisory is designed to generally describe avalanche conditions where local variations always occur. This product only applies to backcountry areas located outside established ski area boundaries. The information in this Avalanche Advisory is provided by the Eastern Sierra Avalanche Center, who is solely responsible for its content.

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