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Avalanche Advisory for 2016-04-07 06:42:18
- EXPIRED ON April 9, 2016 @ 6:42 amPublished on April 7, 2016 @ 6:42 am
- Issued by Nick Meyers - Shasta-Trinity National Forest
Bottom Line
Today represents the best chance of loose wet instability for the week. Poor overnight re-freeze and warming temperatures have reached their zenith. LOW avalanche danger this morning will rise to MODERATE with pockets of CONSIDERABLE this afternoon for loose wet avalanches on S-SE-S-SW facing slopes steeper than 35 degrees. Roller balls and loose, heavy, wet snow on sunny aspects is the best clue indicating larger loose wet slides are possible.
Avalanche Problem 1: Loose Wet
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If we see any loose wet activity this week, today would likely be the day. Steadily rising temperatures, poor overnight re-freeze and daytime highs in the 50's and 60's is a recipe for loose wet slides. An early sign of instability will be roller balls, pinwheels and small point release slides. If you find yourself witnessing those early warning signs AND you're on a sunny aspect, sweating your you know what off and sinking deeply into wet, heavy, mushy snow... that is your cue to head back to the barn or move onto a shadier aspect for the remainder of the day. Mother Nature often provides these free clues to us to indicate snow instability. Heed those clues as larger loose wet slides are possible.
Typically, south and southeast facing slopes are the most common aspects to see loose wet slides occur on Mt Shasta. That said, east and southwest aspects in other parts of the forecast area could see loose wet activity. Open, sunny slopes that are protected from the wind and are 35 degrees or steeper will host the best chance of loose wet slides today.
Loose wet slides generally are not the big "killers" in the backcountry, but that does not mean they should be taken lightly. They could easily entrain enough snow to be a hazard to back country travelers. The snow is wet and heavy and can easily knock you off of your feet and take you over a cliff, strain you through trees or push you into a terrain trap where enough snow may gather to fully bury you. Remember, it's best to avoid these slopes all together if signs of instability present themselves. If you must travel on suspect slopes during the warm afternoon hours, be cautious with your route finding. Ski one at a time to and from safe zones, and space out when crossing suspect slopes.
It's beginning to be that time of year when the mountain can become quite crowded with other climbers/skiers within your sphere of influence. So, not only should you be concerned about triggering a loose wet slide that you or your group is involved in, you need to pay attention to where other groups are located. Are you above or below another group? Could you trigger a slide on top of somebody or is another skier going to trigger something on top of you? We are talking situational awareness here. Keep yours on high.
Forecast Discussion
Another day of near record high temperatures today, however a change to a more moist pattern will occur this weekend. Cooler temperatures will still be above normal for now as a upper level trough moves into Southern California. This will bring increasing clouds to Northern California. Light showers could be seen as early as late tonight in SW Siskiyou County. By Friday, clouds will move into the area and showers likely to develop over the Cascades and Siskiyous by late Friday afternoon. Were looking at about a quarter inch of precipitation over a 24 hours period beginning tomorrow morning. Winds do not look extreme and should remain light to moderate above treeline. Snow levels are high, very high, in the 9 to 10,000 foot range. The weekend and next week will continue with an active weather pattern.
THIS SEASON PRECIPITATION for MT SHASTA CITY: Since October 1st (the wet season), we have received 36.76 inches of water, normal is 36.16 inches, putting us at 101% of normal. For the month of April we've received 0.03 inches of water, normal is 0.70 inches, putting us at 4% of normal, and finally... for the year of 2016 we've received 27.27 inches of water, normal is 20.95 inches, putting us at 130% of normal.
Recent Observations
We've had no new observations come in over the past two days. A steady rise in daytime high and overnight low temperatures gives reason to believe that loose wet slides have a good chance of human trigger today. Last night, low temps at the Old Ski Bowl and Gray Butte weather stations both were 47 degrees with high's in the low to mid 50's. Yesterday, Castle Lake hit a high of 68F. Mt Shasta City hit 81F degrees. Snow conditions continue to remain variable. Good where it's smooth and not that good where the wind has worked its erosional ways.
Climbing Conditions: Current climbing conditions are good to great. Steadily increasing temperatures this week with overnight lows above freezing will not allow a solid snow re-freeze at night. This could mean post-holing at lower elevations. At higher elevations (11,000 feet and above), however, snow will refreeze better and be firm in the morning hours making crampons (and ice axe) necessary equipment.
Below are some things to think about when planning your trip this Spring:
- Avalanche Danger & Weather: You may encounter a variety of snow conditions during the spring time. Late season storms can bring fresh snow and high winds to the mountains. Avalanche danger can quickly spike due to new wind and storm slabs on top of icy, firm melt/freeze snow. Further, warm and sometimes downright hot days can create loose wet avalanches. Low danger in the cool morning hours may rise rapidly to higher danger during the afternoon hours on sunny aspects. These are two different avalanche problems associated with different weather patterns with both being possible during the same week, or even the same day. A beacon, shovel and probe continue to be essential, even during Spring time. Always check the avalanche advisory before starting your climb, and call the ranger station for the latest in weather and conditions. Spring time weather patterns can bring it all. The point is... you need to bring the appropriate attire to accommodate all weather conditions. Snow, rain, sun, wind... you can count on all of it on Shasta at some point during Spring time. Further, Mt Shasta can often host a cloud cap creating poor visibility conditions. DO NO climb into a white-out. It is very easy to wander off the WRONG side of Mt Shasta when on the upper mountain, >12,500 feet. This can create a long day and perhaps night for climber, party members, rescue resources and family. Play it safe.
- Firm and smooth snow (slide for life conditions): Snow conditions on Mount Shasta are great right now. That being said, the snow in the morning hours is very firm and very smooth. These types of conditions have caused serious injury in the past to those who slip, trip, or fall and fail to self-arrest as they slide. You MUST know how to self-arrest with an ice axe. This is one of your best defenses for a safe trip on Mt Shasta. Practice this and other climbing skills on small, short slopes in soft snow. If you fall, you must immediately self-arrest or you will take a long, sliding, tumbling fall resulting in serious injury or death. Along with your solid ice axe skills, know how to walk/climb with crampons on. It is easy to catch the front points of the crampon on the cuff of your pant leg resulting in a fall if you are not careful with each step.
- Rime Ice: What is rime ice? Rime ice forms on rocks, towers, etc. as super cooled water droplets freeze upon contact with a solid object. The ice grows into the wind taking on a cauliflower like appearance. The exposed rocks on Mt Shasta at higher elevations are currently plastered in rime ice. This hazard will diminish as the ice flakes off on warm days, but until then... HEADS UP! You absolutely should wear a helmet if climbing. As the days warm, chances increase of getting hit by falling ice until all of it falls off.
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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 season. http://www.mtshastanordic.org
The Pilgrim Creek & Deer Mountain Snowmobile Parks are open, however snow is dwindling fast at these locations. One had to drive down the 19 road (Military Pass) a mile or so to get to consistent snow before unloading just a few days ago. 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.
Weather and Current Conditions
Weather Summary
Good Morning! In Mt Shasta City at 0500, we have a current temperature of 47 F. Skies are clear with light wind out of the northeast.
On Mt Shasta (South Side) in the last 24 hours...
Old Ski Bowl - 7,600 feet, the current temperature is 47 degrees F. Snow on the ground totals 138 inches with no new snow and 4 inches of settlement. Temperatures have ranged from 45 F to 52 F.
Gray Butte - 8,000 feet, the current temperature is 50 degrees F. Temperatures have ranged from 47 F to 54 F. Wind speeds are not available for Gray Butte at this time. The anemometer was taken down due to the need for repairs. Thank you for your understanding.
Mt Eddy Range (West side of Interstate-5)...
Castle Lake - 5,600 feet, the current temperature is 51 degrees F. Temperatures have ranged from 45 F to 68 F. Snow on the ground totals 60 inches with no new snow and 4 inches of settlement.
Mt Eddy - 6,500 feet, the current temperature is 43 degrees F. Temperatures have ranged from 43 F to 62 F. Snow on the ground measures 72 inches with no new snow and 3 inches of settlement. Winds have been west/southwest in nature with an average of 3 mph, and a maximum gust of 11 mph out of the south.
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: | 48 |
| Max. temperature in the last 24 hours: | 64 |
| Average wind direction during the last 24 hours: | N/A |
| Average wind speed during the last 24 hours: | N/A mi/hr |
| Maximum wind gust in the last 24 hours: | N/A mi/hr |
| New snowfall in the last 24 hours: | 0 inches |
| Total snow depth: | 82 inches |
Two Day Mountain Weather Forecast
Produced in partnership with the Medford NWS
| For 7000 ft to 9000 ft | |||
|---|---|---|---|
|
Thursday (4 a.m. to 10 p.m.) |
Thursday Night (10 p.m. to 4 a.m.) |
Friday (4 a.m. to 10 p.m.) |
|
| Weather | Sunny | Mostly cloudy | A 40 percent chance of showers. Mostly cloudy |
| Temperature (°F) | 65 | 42 | 55 |
| Wind (mi/hr) | East/Southeast 10-15 mph | South/Southwest 5-10 mph | Southwest 5-10 mph |
| Precipitation SWE / Snowfall (in) | / 0 | / 0 | / 0 |
| For 9000 ft to 11000 ft | |||
| Thursday | Thursday Night | Friday | |
| Weather | Sunny, windy | Mostly cloudy, breezy | A 40 percent chance of snow showers. Mostly cloudy, with a temperature falling to around 33 by 4pm. Windy. |
| Temperature (°F) | 40 | 34 | 33 |
| Wind (mi/hr) | Southeast 10-20 mph with gusts higher | East/Southeast 0 | East 10-20 mph with gusts higher |
| Precipitation SWE / Snowfall (in) | / 0 | / 0 | / 1-2 |
