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Avalanche Advisory for 2016-12-07 07:01:51
- EXPIRED ON December 8, 2016 @ 7:01 amPublished on December 7, 2016 @ 7:01 am
- Issued by Nick Meyers - Shasta-Trinity National Forest
Bottom Line
TODAY... LOW avalanche danger and normal caution advised. Be cautious of firm, icy and smooth snow surface conditons above treeline.
An incoming storm this afternoon will bring a couple inches of new snow with gradually increasing southwest/west wind. Newly formed wind slabs on our firm, icy, old-snow surface is likely. This is expected to increase the avalanche hazard. Always check the forecast before heading into the backcountry!
Shallow buried objects still exist in some locations within the forecast area.
Avalanche Problem 1: Normal Caution
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Likelihood ?CertainVery LikelyLikelyPossible
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Normal caution will preside for one more day before things change. Most of today will be a transition from clear skies this morning to incoming clouds this afternoon. Expect snow this evening. For today's daylight hours, backcountry users will not encounter anything different than we've seen over the week. The avalanche danger will change as the incoming system gives us (we hope!) several inches of new snow tonight and tomorrow. Wind out of the southwest will gradually increase with the storm. Pair up a firm bed surface, a few inches of new, cold snow and strong winds...a few red flags for avalanche danger in my mind.
Recent cold and clear nights may also have created areas of surface hoar formation that, if not destroyed by sun and/or wind today, would be a great weak layer for new snow and wind slabs to form over. Thursday and Friday, backcountry users should be ready to make keen snowpack observations upon heading into avalanche terrain. A few inches of new snow may not be a big deal, but thicker winds slabs that may form on leeward slopes will be a concern. Think about ridgelines and the upper portions of bowls, narrow couloirs and rock outcrops as ideal starting zones for new wind slabs. Take out your probe or use your pole to determine how thick those new wind slabs are. Hollow sounding, firm wind slabs are not uncommon on Shasta and while seemingly stable, they can "pop" without warning and send you on a crash course down the mountain. Again, this problem is not expected until late tonight and tomorrow, but just a fair warning!
Forecast Discussion
Dust on crust was about all the was received out the recent storms that grazed the forecast area this week. For the keen powder slayer, a few soft and fluffy turns can be sliced and diced on select northerly and/or shaded slopes near treeline, but beware as one soft turn can be followed by a breakable, firm and funky one! All forms of skiing skills necessary shall we say. Today is going to remain cold, though we will see a warm front move into the area with increasing clouds and precipitation to begin late this afternoon. Temperatures will not rise much until tomorrow.
Southern Siskiyou County is off to a great start for the 2016/17 Winter. We've already had several decent storms and even a few good sized avalanches. The NWS Climate Prediction Center continues to show Northern California to host below normal temperatures and above normal precipitation for the next month. Yahoo!
Snow totals on Mt Shasta range from 2-4 feet below and near treeline. One will find about 4-6 feet at upper elevations. West of I-5 in the Castle/Mt Eddy regions, snow totals are less but still in the 1-2 foot range. East of Mt Shasta in the Ash Creek Butte area, an average of 3-4 feet is on the ground. The most usable areas for backcountry recreation is still limited to Mt Shasta itself. Predominantly cooler temperatures and a lot of wind has kept things variable and firm. Be cautious of smooth, firm and slick snow on steep slopes above treeline. An ice axe, crampons and a helmet are absolutely necessary during conditions as such.
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LOCAL AREA ROAD, NORDIC, AND SNOWMOBILE PARK STATUS:
The Sand Flat cross country ski trails are in good shape still 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 CLOSED for the time being but will be opening soon! The trails are covered in snow and they are working on getting things going this month. 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
No new observations within the forecast area. Temperatures are the coldest we've seen yet this season with Sand Flat (Bunny Flat area) coming in at 6 degrees F this morning. Mt Eddy is in second place at 7 degrees, followed by Gray Butte and Old Ski Bowl recording 10 and 11 degrees F, respectively. Castle is the warmest at 15 degrees F. Conditions remain much the same as they have over the week. Cold temperatures have locked up the snowpack into a firm, solid mass. Icy surface conditions have been observed above treeline on Mt Shasta and Ash Creek Butte. Firm, wind pack powder and scoured, hard snow is widespread also above treeline. What loose snow that is remaining on our bomber snowpack has collected in some isolated pockets but does not pose a threat to backcountry riders. Breakable crust is also prevalent on slopes near and below treeline, especially on aspects exposed to the direct rays of the sun. Indeed, some shallow buried objects also exist still, so be cautious. We've got a lot of great skiing and winter ahead of us!
Have you seen our new, BIG BLUE buttons on our website? Yep, thats them, just up and to your left! You can use those and absolutely should. No more email, no more text, no more messing around! So cool. Please submit your observations by clicking either 'snowpack' or 'avalanche' observation and follow the template. Just a photo? Great! Snowpit profile? Awesome! Video, notes, weather...you name it, there is a place for it. It's simple, easy and fun and extremely useful for us and other users. We also have a drop down menu within the obs template that allows you to submit observations from "out of the forecast area". Heading to Crater Lake or Mt Lassen? Submit some obs! This will help us create the BEST possible avalanche advisory AND provide a great place for peeps to go for checking backcountry conditions. Saddle up!
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Weather and Current Conditions
Weather Summary
A westerly moving warm front sits off the coast of California this morning and will make its way toward land today. By mid-afternoon, we should start to see some clouds with light precip and by this evening precipitation is likely. Immediate affects of the warm air will not be seen right away as cold air remaining in the area will be overrun and trapped by the warm front. About .36 inches of water is expect for Wednesday night, followed by another .30 inches of water on Thursday. Freezing rain is a possibility however snow is most probable for our area. Snow levels will be down to at least city level, if not lower. Tomorrow, temperatures will increase and drive freezing levels to around 4,500 feet. Mt Shasta sits decently placed in the path of this small system, so we should do a little better than the dust on crust we received from the last storm this week. We are going see a gradual crescendo of southwesterly wind near and above treeline, increasing throughout the day and peaking tomorrow.
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In Mt Shasta City at 0500, we have a current temperature of 17 F, seven degrees cooler than yesterday. Skies area clear and stars are showing!
On Mt Shasta (South Side) in the last 24 hours...
Old Ski Bowl - 7,600 feet, the current temperature is 11 degrees F. Snow on the ground totals 41 inches with with no new snow and one inch settlement. Temperatures have ranged from 8F to 19F.
Gray Butte - 8,000 feet, the current temperature is 10 degrees F. Temperatures have ranged from 9 F to 20 F. Winds have been blowing 25-35 mph with gusts to 49 mph out of the NW up until 1600 yesterday when the wind diminished, averaging 5-10 mph, variable in direction, with one 28mph gust out of the east.
Mt Eddy Range (West side of Interstate-5)...
Castle Lake - 5,600 feet, the current temperature is 15 degrees F. Temperatures have ranged from 15 F to 27 F. Snow on the ground totals 15 inches with no new snow and little settlement.
Mt Eddy - 6,500 feet, the current temperature is 7 degrees F. Temperatures have ranged from 7 F to 20 F. Snow on the ground measures 18 inches with no new snow and little settlement. A light breeze, 2-3 mph out of the south/southeast has been blowing up there with a gust to 10 mph. At 2300, winds switched to west/southwest, 2-4 mph.
THIS SEASON PRECIPITATION for MT SHASTA CITY: Since October 1st (the wet season), we have received 16.48 inches of water, normal is 8.73 inches, putting us at 188% of normal. For the month of December we received 0.01 inches of water, normal is 1.37 inches, putting us at a fraction of 1% of normal, and finally... for the year of 2016 we've received 49.38 inches of water, normal is 36.73 inches, putting us at 134% 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.
| 0600 temperature: | 6 |
| Max. temperature in the last 24 hours: | 23 |
| Average wind direction during the last 24 hours: | Northwest |
| Average wind speed during the last 24 hours: | 0-5 mi/hr |
| Maximum wind gust in the last 24 hours: | 10-15 mi/hr |
| New snowfall in the last 24 hours: | 0 inches |
| Total snow depth: | 24 inches |
Two Day Mountain Weather Forecast
Produced in partnership with the Medford NWS
| For 7000 ft to 9000 ft | |||
|---|---|---|---|
|
Wednesday (4 a.m. to 10 p.m.) |
Wednesday Night (10 p.m. to 4 a.m.) |
Thursday (4 a.m. to 10 p.m.) |
|
| Weather | Snow, mainly after 4pm. | Snow. Windy. | Snow before 1pm, then rain and snow. Breezy. |
| Temperature (°F) | 28 | 22 | 33 |
| Wind (mi/hr) | East 0-5 mph | South 10-20 mph | South 10-20 mph |
| Precipitation SWE / Snowfall (in) | / 1-3 | / 4-8 | / 1-3 |
| For 9000 ft to 11000 ft | |||
| Wednesday | Wednesday Night | Thursday | |
| Weather | Snow, mainly after 4pm. Windy. | Snow. Windy. | Snow. Windy. |
| Temperature (°F) | 19 | 23 | 24 |
| Wind (mi/hr) | North, becoming southwest 5-10 mph this morning, then increasing 10-20 mph this afternoon | West/Southwest 1-3 | Southwest 35-45 mph, gusts 50+ mph |
| Precipitation SWE / Snowfall (in) | / 1-3 | / 4-8 | / 3-5 |
