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Avalanche Advisory for 2016-12-30 06:58:00

  • EXPIRED ON December 31, 2016 @ 6:58 am
    Published on December 30, 2016 @ 6:58 am
  • Issued by Nick Meyers - Shasta-Trinity National Forest

For today, LOW avalanche danger exists for all aspects and elevations within the forecast area and normal caution is advised. 
Climbers, beware of firm and smooth snow surface conditions.  This is a serious concern for novice climbers. A slide for life will occur without immediate self arrest.
Exposed rocks on Mt Shasta are plastered in rime ice. This presents a significant hazard, especially as the day warms and the ice falls onto climbers below. Wear a helmet.

Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.

Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.

Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.

Avalanche Problem 1: Normal Caution

  • Character ?
  • Aspect/Elevation ?
  • Likelihood ?
    Certain
    Very Likely
    Likely
    Possible
    Unlikely
  • Size ?
    Historic
    Very Large
    Large
    Small

A couple days of warm temperatures and several inches of settlement in the snowpack has brought us back to normal caution for backcountry travel today. Cooling temperatures will keep any loose wet related activity to a minimum. Wind slabs have been unreactive to trigger.  Continue to use safe travel practices and be able to identify isolated features of concern.

No matter what time of year or what the avalanche danger is, remember: Don't go into the backcountry until you get the proper gear and training. Ski and ride one at a time in avalanche terrain. Limit the number exposed to a potential avalanche. Don't re-group in avalanche paths or in run out zones! Stay out of harm's way. Don't exposed others to risk. Pay attention to who is below you AND above you. Promote and teach good backcountry etiquette for others to follow... because others WILL follow! Lets help make it better for everyone.

 

Forecast Discussion

An inversion is in place again this morning and air stagnation will continue in the valley's. The incoming cold front will help mix things up later today. Yesterday brought calm winds, warm temps and sunny skies to the area. Variable conditions prevail in the backcountry and any signs of instability have been hard to come by. If you are going skiing, I hope you like smorgasboards. Scoured/firm, icy, wind board, soft, breakable... there should be something to satisfy all appetites. Any climbers out there? Very smooth and firm conditions exist on many of Shasta's climbing routes.  This is a serious issue to consider if you are a novice climber. A slip/fall and failure to self arrest quickly will result in a long slide for life. Solid self arrest skills are mandatory. A trace of new snow will impact the area late today followed by another stronger system for later this weekend. Very cold air will move in Saturday driving snow levels down to valley floors. Today should be sunny this morning with increasing clouds later and falling temperatures. Go grab life by the horns!

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LOCAL AREA ROAD, NORDIC, AND SNOWMOBILE PARK STATUS:

The Sand Flat cross country ski trails are in good shape and ready for your cross country skis and snow shoes.  These are backcountry routes marked with blue diamonds on trees.  Trails are not groomed.  Snow shoers, please blaze a parallel trail to cross country skiers staying out of the skin track.  These trails can be accessed via the Everett Memorial Highway.  Thank you, and enjoy!

The Mt. Shasta Nordic Center is OPEN for the season! Take advantage of this wonderful venue. Groomed trails accomodate both classic and skate skiing styles. Rentals available. Visit their website for more details.  http://www.mtshastanordic.org

The Pilgrim Creek & Deer Mountain Snowmobile Parks are open, however there is no snow at these locations currently. One must drive down the 19 road (Military Pass) for several miles to get to consistent snow before unloading. Private industry is logging out there so watch out for log trucks. Head to our "Education" tab on our website and find the snowmobile section for trail information, grooming status, and other sledder resources.

The Castle Lake Road is OPEN. The Everett Memorial Highway is OPEN. The Castle Lake and Everett Hwy are plowed year round to the trailheads. The roads are not always first priority, so your dawn patrol powder mission might be ceased if the plow has not made it up yet. Siskiyou County does a great job keeping the roads clear. Be respectful of the plow drivers if you encounter them. If you get to Bunny Flat before or during when the plow is there, please park on the uphill, LEFT side of the parking lot as you drive in. This is uphill and lookers right of the bathrooms. Thank You!

The Five Red Flags of Avalanche Danger any time of year include: 1) Recent/current avalanche activity 2) Whumphing sounds or shooting cracks 3) Recent/current heavy snowfall 4) Strong winds transporting snow 5) Rapid warming or rain on snow.

Recent Observations

Gorgeous weather yesterday hosted all that ventured into the backcountry. Temperatures reaching the low 50's were recorded from local mountain weather stations. A few roller balls were observed on below treeline, easterly aspects, but did not present danger to skiers or riders. Variable snow surface conditions dominate. Recent signs of avalanches are nill and snowpit tests indicate a stable snowpack. Cooling temperatures today will prevent any further loose wet avalanche activity. The wind slab problem is of little concern. Observations from high on the mountain were made yesterday, along Avalanche Gulch, Casaval Ridge, The Catwalk and The Trinity Chutes (see observation below). Firm and very smooth chalky, wind board was fairly widespread with exposed rocks plastered in thick rime ice. Rime ice can be a potential threat to any climbers or skiers and a helmet is advised. An early start is also a good idea to avoid falling rime ice. Our unreactive 12/23 persistent weak layer that has been found beneath the crust about 1 foot down in the snowpack was also noted in some areas above 10,000 feet. We suspect this layer is mending and would only be a concern if a large snow load was on order. No avalanches have failed on this layer, but it still is producing sudden planar fracture characteristics from small column tests. Large column tests have not been able to produce propagation. This layer of weaker (rounding faceted) snow will be monitored. Again, it would take signifcant loading of this layer to cause concern at this point.

Weather and Current Conditions

Weather Summary

A weak cold front gradually moves into the area this morning. Temperatures will cool throughout the day. Areas of light precipitation this afternoon and this evening will occur with minimal accumulation. Snow level will start at 6,500 feet and lower to town by this evening. Westerly winds will increase above treeline, but remain light to moderate below treeline. This storm is nothing to get to excited about, however a stronger and more notable storm along with a very cold air mass will impact the area Saturday night. Several inches of snow and very cold temperatures are forecasted. We will keep you posted on this! If your house and or pets are susceptible to these frigid temps, take warning! 

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In Mt Shasta City at 0500, we have a current temperature of 23 F.

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

Old Ski Bowl - 7,600 feet, the current temperature is 36 degrees F. Snow on the ground totals 72 inches with 1 inch of settlement.  Temperatures have ranged from 35 F to 51 F.

Grey Butte - 8,000 feet, the current temperature is 36 degrees F. Temperatures have ranged from 36 F to 48F.  Winds have averaged 12 mph with gusts to 28 mph, all out of the west/southwest.

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

Castle Lake - 5,600 feet, the current temperature is 42 degrees F. Temperatures have ranged from 39 F to 51 F. Snow on the ground totals 26 inches with little settlement.

Mt Eddy - 6,500 feet, the current temperature is 35 degrees F. Temperatures have ranged from 34 F to 52 F. Snow on the ground measures 30 inches with little settlment.  Winds have averaged 2-4 mph with gusts to 6 mph, west/southwest.

THIS SEASON PRECIPITATION for MT SHASTA CITY: Since October 1st (the wet season), we have received 21.11 inches of water, normal is 14.70 inches, putting us at 143% of normal.  For the month of December we received 4.64 inches of water, normal is 7.34 inches, putting us at 63% of normal, and finally... for the year of 2016 we've received 54.01 inches of water, normal is 42.70 inches, putting us at 126% 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)
0600 temperature: 28
Max. temperature in the last 24 hours: 44
Average wind direction during the last 24 hours: West/Southwest
Average wind speed during the last 24 hours: 5-10 mi/hr
Maximum wind gust in the last 24 hours: 10 mi/hr
New snowfall in the last 24 hours: 0 inches
Total snow depth: 41 inches

Two Day Mountain Weather Forecast

Produced in partnership with the Medford NWS

For 7000 ft to 9000 ft
  Friday
(4 a.m. to 10 p.m.)
Friday Night
(10 p.m. to 4 a.m.)
Saturday
(4 a.m. to 10 p.m.)
Weather Snow showers after 4pm. Temperature rising to near 37 by 8am, then falling to around 27 during the remainder of the day. Chance of precipitation is 80%. Snow showers, mainly before 10pm. Chance of precipitation is 80%. A 20 percent chance of snow showers before 10am. Mostly sunny.
Temperature (°F) 37, falling 14 33
Wind (mi/hr) West 10-15 mph Northeast 10-15 mph Northeast 5-10 mph
Precipitation SWE / Snowfall (in) / 0-.5 / 0-1 / 0
For 9000 ft to 11000 ft
  Friday Friday Night Saturday
Weather Snow showers after 4pm... Temperature falling... Windy. Chance of precipitation is 80%. Snow showers, mainly before 10pm... Windy, Chance of precipitation is 80%. A 20 percent chance of snow showers before 10am. Mostly sunny... Windy.
Temperature (°F) 30, falling 12 27
Wind (mi/hr) West 30-40 mph East 0-.5 East 10-15 mph
Precipitation SWE / Snowfall (in) / 0-.5 / 0-1 / 0

Disclaimer

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