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Avalanche Advisory for 2017-03-11 04:19:48

  • EXPIRED ON March 12, 2017 @ 5:19 am
    Published on March 11, 2017 @ 4:19 am
  • Issued by Aaron Beverly - Mount Shasta Avalanche Center

Prolonged above-freezing temperatures over the last two days means loose-wet avalanches are possible today. Avalanche danger is MODERATE below, at, and above treeline. Elevations above 10,000 feet that have been subjected to cooler temperatures are less likely to see this problem. Long, steep slopes provide the potential for loose wet avalanches to gain significant size and entrain enough snow to bury a person. Remember warming temperatures can also loosen up the rime on rocks causing ice to plummet from above.

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.

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

Forecast Hotline: (530) 926-9613

Avalanche Problem 1: Loose Wet

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Warm weather continues without a hard freeze overnight. Rapid warming is a red flag for avalanches and can lead to loose wet slides. Several were observed yesterday on eastern aspects exposed to the sun. Expect more today. These will primarily be a concern below 10,000' where the snowpack is subjected to warmer temperatures. But be vigilant where ever you are. Accidents happen when we become complacent in the backcountry. 

A loose wet slide is a release of unconsolidated snow or slush. It starts at a point and entrains snow as it moves down hill. A terrain trap underneath could increase the chances of being buried in one of these. If you are sinking up to your boot tops in soft snow and are seeing a lot of roller-balls, you might be in or near terrain capable of producing a loose wet avalanche.

Forecast Discussion

Put on your t-shirt and slather on the sun-block as warm partly sunny to sunny weather will continue over the next few days. Warming weather usually means an increased likelihood of loose wet avalanches particularly below 10,000'  but it can also loosen up the rime ice stuck to rocks causing it to fall. Ice falling from Red Banks turns the area above Helen Lake into a bowling alley. Remember, you are the pins and a low score is a winning score! Wear a helmet and avoid areas where falling ice is evident.

Settling snow and thawing temperatures will likely lead to firm smooth climbing conditions above Helen. Bring your ice axe and crampons and know how to use them. Falling and not self-arresting could lead to a long fast slide, injury, or death.

Spring skiing conditions should continue to improve as surface snow melts and compacts. Tomorrow will be a glorious sunny day and may be the day to get out to work on the tan while getting in some turns.



 

Recent Observations

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Yesterday was warm and sunny with highs in the mid-40's at higher elevations. Temperatures just touched 32 degrees for a moment during the night at Sand Flat. Snow has not quite transitioned to corn and remains soft with boot penetration up to knee deep. Firmer conditions exist above 9000'.  Rime ice is plastered on exposed rocks. A couple of loose wet slides were seen on easterly aspects. 2-3 inches of settlement occurred over the last 24 hours. See posted observation for more details.

 

 

 

 

 

Weather and Current Conditions

Weather Summary

Spring-like weather will continue through until Tuesday when temperatures are expected to return back down to normal. Don't get lured into thinking you can go plant your tomatoes. We are still well below normal precipitation for the month of March (15% of normal) and climate models suggest above normal precipitation and normal temperatures for the next month. Enjoy the break, work on your tan, and then put your boots back on and get ready for some more winter weather towards the end of the week.

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In Mt Shasta City at 0500, we have a current temperature of 35 F.

On Mt Shasta (South Side) in the last 24 hours...

Sand Flat - 6750 ft, the current temperture is 34 degrees F.  Temperatures have ranged from 32 F to 45 F.  Snow on the ground totals 112 inches with no new snow and 3.5 inches of settlement.

Old Ski Bowl - 7,600ft. the current temperature is 40 degrees F.  Temperatures have ranged from 33 F to 47 F.  Snow on the ground totals 187 inches with no new snow and 3 inches of settlement.

Gray Butte - 8,000 feet, the current temperature is 40 degrees F. Temperatures have ranged from 34 F to 46 F.  Winds have ranged from NW, W, E, and SW and have averaged 12 mph with gusts to 42.

Mt Eddy Range (West side of Interstate-5)... 

Castle Lake - 5,800 feet, the current temperature is 41 degrees F. Temperatures have ranged from 40 F to 50 F. Snow on the ground totals 110 inches with no new snow and 2 inches of settlement.

Mt Eddy - 6,500 feet, the current temperature is 38 degrees F. Temperatures have ranged from 34 F to 46 F. Snow on the ground measures 103 inches with no new snow and 2 inches of settlement. Winds have been variable, averaging 2 mph with gusts to 9 mph.

THIS SEASON PRECIPITATION for MT SHASTA CITY: Since October 1st (the wet season), we have received 43.67 inches of water, normal is 31.92 inches, putting us at 137% of normal.  For the month of March, we have received .36 inches of water, normal is 2.42 inches, which is 15% of normal. And finally for the year of 2017, we received 22.51 inches of water, normal is 16.71 inches, putting us at 135% of normal.

Always check the weather before you attempt to climb Mt Shasta. Further, monitor the weather as you climb. Becoming caught on the mountain in any type of weather can compromise life and limb. Be prepared.

CURRENT CONDITIONS at Bunny Flat (6950 ft)
Weather Station Map
Weather Station Table
0600 temperature: 34
Max. temperature in the last 24 hours: 47
Average wind direction during the last 24 hours: Northwest turning to SW
Average wind speed during the last 24 hours: 12 mi/hr
Maximum wind gust in the last 24 hours: 42 mi/hr
New snowfall in the last 24 hours: 0 inches
Total snow depth: 115 inches

Two Day Mountain Weather Forecast

Produced in partnership with the Medford NWS

For 7000 ft to 9000 ft
  Saturday
(4 a.m. to 10 p.m.) 		Saturday Night
(10 p.m. to 4 a.m.) 		Sunday
(4 a.m. to 10 p.m.)
Weather Partly sunny Partly cloudy Sunny
Temperature (°F) 50 37 54
Wind (mi/hr) West 8-12 mph West then North 3-15 mph East 5-6 mph
Precipitation SWE / Snowfall (in) / 0 / 0 / 0
For 9000 ft to 11000 ft
  Saturday Saturday Night Sunday
Weather Mostly cloudy this morning then becoming partly cloudy. Partly cloudy Partly cloudy in the morning then clearing.
Temperature (°F) 32 36 37
Wind (mi/hr) West Southwest 30-35 mph West Northwest 0 West 10-12 mph
Precipitation SWE / Snowfall (in) / 0 / 0 / 0

Disclaimer

This advisory does not apply to Ski Areas or Highways and is for the Mt. Shasta, Castle Lake and Mt. Eddy backcountry. Use this information for guidance only. You may find different conditions in the backcountry and should travel accordingly. This advisory expires on midnight of the date it was posted unless otherwise noted.