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Avalanche Advisory for 2016-04-11 06:38:19
- EXPIRED ON April 12, 2016 @ 6:38 amPublished on April 11, 2016 @ 6:38 am
- Issued by Nick Meyers - Shasta-Trinity National Forest
Bottom Line
Overall, LOW avalanche danger exists for all elevations and aspects. Normal caution advised.
Cooler temperatures and clouds will keep loose wet slides on the rack. New snow from this past weekend likely did not see enough accumulation to cause trouble for backcountry users.
Be cautious of falling rime ice off exposed rocks. Lightening activity on the mountain is also a serious hazard. Do not climb into a white out and/or ascend the mountain during electrical storms.
Avalanche Problem 1: Normal Caution
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Likelihood ?CertainVery LikelyLikelyPossible
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Continued poor overnight refreeze temps with night time lows remaining above freezing below 9,500-10,000 feet will keep the snow on the soft side this morning. That said, today's cloud cover and the potential for scattered thunder showers will limit loose wet instabilities. The other thing to consider is that precipitation associated with our most recent storm (Saturday) fell as snow above 10,000 feet and may have blown around developing new, small wind slab formations. The size, distribution and sensitivity to trigger of any wind slab formations are uncertain. If they do exist it could be on multiple aspects due to the variable wind directions. Poor visibility and more thunderstorm activity will likely prevent anyone from venturing up on to the upper portions of the mountain today. It is likely that not enough snow accumulated to cause serious concern. If any wind slabs did form, they will be small and not encountered until one ascends above 10,000 feet.
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.
A note on lightening:
Mt Shasta is essentially a 14,000 foot lightening rod. Climbing Mt Shasta or being on the mountain during any kind of electrical activity is a very poor idea... especially if on a ridge route or on the upper mountain. We've seen ice axes spark and buzz and had hair stand on end due to high electrical activity. It is downright scary and the message is clear: go down. Do not play with fire.
Forecast Discussion
Today were looking at mostly cloudy skies with a slight chance of rain showers this morning. Rain and thunderstorms are likely this afternoon and tonight with models trending wetter than previous runs for the next 24 hours. This is especially true for the west side. About a tenth to two tenths of an inch of water is expected with snow levels around 9,000 to 9,500 feet today / tonight. Winds look to be light to moderate at mid mountain levels, averaging 5-10 mph with gusts in the 10-20 mph range. Below treeline, winds will be light. This front will push across the Cascades this evening and through Tuesday morning. Tuesday into Wednesday, another weaker front will push through with rain showers most likely for areas west of here. Wednesday afternoon through Friday, we should see another round of precip and snow levels are going to dive to near 3,000 feet. This will come as a bit of a shock to those who have become accustomed to the last week of warm temps. At this point, precip amounts are in the 1-3 inch range which could mean 6-12 inches of new snow above 5,000 feet. At this point, future shifts in the weather will need to be monitored to dial in the precip rate and timing, and potential impacts. A quick shift back to spring-like conditions and high pressure should give a clear day or two in the mountains this next weekend.
THIS SEASON PRECIPITATION for MT SHASTA CITY: Since October 1st (the wet season), we have received 37.06 inches of water, normal is 36.58 inches, putting us at 101% of normal. For the month of April we've received 0.33 inches of water, normal is 1.12 inches, putting us at 29% of normal, and finally... for the year of 2016 we've received 25.57 inches of water, normal is 21.37 inches, putting us at 119% of normal.
Recent Observations
Temperatures are a degree or two cooler today. Some areas reached freezing last night, though most were in the mid 30's to 40 F. Yesterday brought partly to mostly cloudy skies with some rain and thunderstorms. Rain came in squalls and was heavy at times, albeit short lived. Lightening and thunder lingered well into the evening and local data shows upwards of 99 cloud to ground strikes occurring in the last 24 hours. Snow levels were 10,000 feet plus.
We saw some loose wet activity late last week, but with cooling temps and cloud cover, no new wet loose activity has been observed. A small dusting of new snow on the upper moountain occured most recently, but not enough snow fell to cause any serious impacts for backcountry travelers. Today will be the same: loose wet slides will stay on the rack and new snow insufficient for wind and/or storm slabs. The main hazard for today will be limited visibility for climbers on the upper mountain. Do not climb into a white out.
Overall, generally great skiing and climbing conditions have been happening. Warme days makes for soft snow for the lower half of the mountain. Post holing and sticky, wet snow will be found. Cooler days has the snow firm in the morning for climbers and skiers, softening by mid-day. Aspect and elevation play a key role in snow condition. Rime ice is still a problem for climbers. Wear a helmet. Wind sculpted sastrugi patches are healing up and smoothing out. A few inches of new snow this week will also hopeully help smooth things out further.
Sunset ski, Avalanche Gulch near treeline, April 8th. Photo: S Rathbun / Rider: S Loughlin
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 49 F, one degree cooler than yesterday at this time. Skies are overcast with calm wind.
On Mt Shasta (South Side) in the last 24 hours...
Old Ski Bowl - 7,600 feet, the current temperature is 38 degrees F. Snow on the ground totals 129 inches with no new snow and 2 inches of settlement. Temperatures have ranged from 35 F to 50 F.
Gray Butte - 8,000 feet, the current temperature is 40 degrees F. Temperatures have ranged from 35 F to 49 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 39 degrees F. Temperatures have ranged from 39 F to 55 F. Snow on the ground totals 51 inches with no new snow and 2 inches of settlement.
Mt Eddy - 6,500 feet, the current temperature is 36 degrees F. Temperatures have ranged from 35 F to 50 F. Snow on the ground measures 62 inches with no new snow and 1 inch of settlement. Winds have been southerly in nature with an average of 2-3 mph, and a maximum gust of 8 mph.
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: | 32 |
| Max. temperature in the last 24 hours: | 50 |
| 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: | 74 inches |
Two Day Mountain Weather Forecast
Produced in partnership with the Medford NWS
| For 7000 ft to 9000 ft | |||
|---|---|---|---|
|
Monday (4 a.m. to 10 p.m.) |
Monday Night (10 p.m. to 4 a.m.) |
Tuesday (4 a.m. to 10 p.m.) |
|
| Weather | A chance of showers, with thunderstorms also possible after 2pm. Mostly cloudy. Chance of precipitation is 40%. | A chance of showers and thunderstorms. Mostly cloudy. Chance of precipitation is 50%. | A 50 percent chance of showers. Mostly cloudy. |
| Temperature (°F) | 51 | 37 | 45 |
| Wind (mi/hr) | South/Southwest 5-10 mph | South/Southwest 5-10 mph | Southwest 10-15 mph |
| Precipitation SWE / Snowfall (in) | / 0 | / 0 | / 0 |
| For 9000 ft to 11000 ft | |||
| Monday | Monday Night | Tuesday | |
| Weather | A 50 percent chance of snow showers, mainly after 11am. Some thunder is also possible. Mostly cloudy, with a high near 29. East wind 13 to 21 mph becoming south in the afternoon. Winds could gust as high as 31 mph. New snow accumulation of less than one inch possible. | Snow showers likely, mainly before 11pm. Some thunder is also possible. Mostly cloudy, with a low around 22. Windy, with a southwest wind 24 to 30 mph, with gusts as high as 44 mph. Chance of precipitation is 60%. New snow accumulation of 2 to 4 inches possible. | Snow showers likely, mainly before 11am. Mostly cloudy, with a high near 22. Windy, with a west wind 35 to 40 mph decreasing to 24 to 29 mph in the morning. Winds could gust as high as 60 mph. Chance of precipitation is 60%. New snow accumulation of 1 to 3 inches possible. |
| Temperature (°F) | 29 | 22 | 22 |
| Wind (mi/hr) | East 10-20 mph | Southwest 0-1 | West 30-35 mph decreasing to 20-25 mph in the morning |
| Precipitation SWE / Snowfall (in) | / 0-1 | / 2-4 | / 1-3 |
