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Avalanche Advisory for 2016-03-31 06:25:58
- EXPIRED ON April 1, 2016 @ 6:25 amPublished on March 31, 2016 @ 6:25 am
- Issued by Nick Meyers - Shasta-Trinity National Forest
Bottom Line
This morning, LOW avalanche danger will prevail for all elevations and aspects. As daytime warming occurs, MODERATE danger is likely for loose-wet related instabilities on sunny slopes. Aspects east, southeast, south and southwest below 10,000 feet will host the best chance for human triggered loose-wet rollerballs, pinwheels and perhaps a larger point release loose wet slide. Calm winds and warm temperatures will persist through the week.
Avalanche Problem 1: Loose Wet
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Aspect/Elevation ?
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Likelihood ?CertainVery LikelyLikelyPossible
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Size ?HistoricVery LargeLargeSmall
Temperatures are several degrees warmer today and the wind is calm. This will allow for better warming of sun exposed slopes. We did not see much loose-wet activity yesterday. The chance for loose-wet activity today is better due to warmer temperatures, however with a good overnight re-freeze, chances of a larger loose-wet slide are slim. During the mid afternoon hours, if you start to see roller balls and pinwheels, this is a freebie from mother nature... an early warning sign of unstable snow and indicator that, especially if the warming continues and/or there are sunny hours left in the day, that larger loose-wet avalanches are possible. Those early warning signs are your cue to move onto shadier slopes or come back another day. Early signs of loose-wet instability can seem like not a big deal, perhaps even fun to play in the roller balls... Watch a giant loose wet slide snake its way down Avalanche Gulch, crossing climbers gully and piling up in a gully bottom (terrain trap) and you might have a different opinion! Shasta hosts long, consistently pitched slopes allowing for a lot of snow to become entrained as a loose wet avalanche builds size and momentum. Take these types of avalanches seriously and heed the warning signs. Loose wet slides are difficult to predict. Pay attention to early warning signs and best to play it safe.
Forecast Discussion
It doesn't get much more clear, bright and sunny as yesterday! A downright gorgeous blue sky dominated the forecast area hosting good corn skiing, sun tans and flip flops in the parking lot at Bunny Flat. Ready for another round? You'll get it today with high temperatures expected to be 4 to 6 degrees warmer than yesterday. Planning a candle light ceremony? Today and tomorrow will be perfect as mountain winds are incredibly light and variable and will continue as such for the next 48 hours. All in all, there is not much to report in the way of weather for the remainder of the work week expect for... perfect weather! Friday we may see a few clouds start to filter in over the region. Saturday a weak system passes and Sunday a stronger systems pushes in bringing light precipitation. While neither of these storms looks impressive, some clouds are likely with scattered showers. The extended outlook following the weekend... the NWS pro's are calling for very warm temperatures, perhaps record setting. Has Spring sprung? Next week it just might.
CLIMBERS & SKIERS:
We are on the edge of climbing season for Mount Shasta. As April and May roll around, this is when we typically get the most climber and skier traffic, AND it is when we get most of our accidents. Conditions right now are fantastic, but with that comes risk. The mountain is completely covered in snow and rime ice. While the rockfall potential is low, other hazards exist.
In no particular order...
First, weather... Late Winter and Spring can offer the full gammut of weather conditions - winter blizzards, howling wind, freezing cold to beautiful sunny days with flip flops and brews in the parking lot. You need to bring the appropriate attire to accomodate all these weather conditions.
Avalanche danger can also rise and fall quickly with passing storms resulting in wind slabs on top of firm, melt/freeze snow and also loose wet related instabilities on those warm days. An avalanche beacon, shovel and probe are essential.
As for the climbing, the snow surface conditions are currently very smooth and very firm. If you slip and fall, you WILL take a long slide for life if you do not immediately self-arrest. A helmet, ice axe and crampons essential! (A hiker slipped and fell on Spring Hill a few days ago, sliding into a tree, breaking a leg/hip... yes, the snow is smooth and firm!)
Lastly, exposed rocks are currently plastered in rime ice. This rime ice will break off and tumble downhill onto climbers and skiers on warm days, sometimes taking rock with it. The rime ice chunks can be just as hard as rock and cause serious inury.
Thus, full winter mountaineering conditions exist and a climb of Mt Shasta should not be taken lightly. Our goal is not scare tactics here, but to provide accurate, up to date and factual information so you can plan and prepare for a safe adventure on Mt Shasta, returning home in one piece. For your best chances at a safe climb, be sure you have the proper equipment (ice axe, crampons, helmet, avalanche transceiver, shovel, and probe) and know how to use all of it. Check the weather. Make sound decisions. Keep your group together. Know how to self-arrest. Please call us if you have further questions. 530-926-4511
Avalanche Gulch Overview, photo taken on 3.30.16 - Meyers
THIS SEASON PRECIPITATION for MT SHASTA CITY: Since October 1st (the wet season), we have received 36.73 inches of water, normal is 35.33 inches, putting us at 103% of normal. For the month of March we've received 11.21 inches of water, normal is 5.83 inches, putting us at 192% of normal, and finally... for the year of 2016 we've received 27.24 inches of water, normal is 20.12 inches, putting us at 135% of normal.
Recent Observations
Temperatures have been slowly climbing over the week. Yesterday, temperatures reported from local weather stations reached highs in the 40's to low 50's. Overnight, good radiational cooling and sub-freezing low's will give the snowpack a good re-freeze. Today however, high temps will climb higher and be several degrees warmer than yesterday, easily reaching the low 50s. Very few loose-wet instabilities were observed yesterday despite the warm temperatures. As mentioned, the chance for loose-wet activity today is better due to warmer temperatures, however with a good past overnight re-freeze, chances of a larger loose-wet slide are slim. Lower elevation avalanche terrain that experienced less of a freeze will have the best chance of showing signs of loose-wet instability. All said, problamatic large loose-wet slides do not seem likely today.
Firm snow conditions in the morning with some softening on sun exposed slopes in the afternoon can be found at lower and mid elevations (below approximately 10,000 feet). Upper elevations and shadier aspects hold smooth, scoured snow with scabs of sastrugi and wind effected, packed powder. Where corn snow is present, riding conditions have been fantastic.
Enjoy the backcountry as the melt/freeze cycle begins! Be sure to stay on your game this Spring... larger loose-wet slides happen every year on Shasta and can become large enough to cause serious harm. Along with this, falling rime ice and rocks necessitate the need for a helmet. Last, a slide for life on firm, smooth snow in the AM hours is possible....thus an ice axe and self arrest skills are absolutely required. These are some hazards not typically associated with winter conditions. Take note, be prepared, have fun!
From the west side of the forecast area, a local snowmobile rider came across this older debris pile. It looks like a section of cornice broke and subsequently triggered an avalanche. 3.30.16 - K. Riccomini
A nice view of Mt Shasta from the west side of the forecast area on 3.30.16 - Photo: K Riccomini
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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 34 F, the same temperature as yesterday at this time. Skies are clear with calm wind.
On Mt Shasta (South Side) in the last 24 hours...
Old Ski Bowl - 7,600 feet, the current temperature is 33 degrees F. Snow on the ground totals 151 inches with no new snow and 1 inch of settlement. Temperatures have ranged from 24 F to 45 F.
Gray Butte - 8,000 feet, the current temperature is 35 degrees F. Temperatures have ranged from 25 F to 42 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 29 F to 51 F. Snow on the ground totals 71 inches with no new snow and 2 inches settlement.
Mt Eddy - 6,500 feet, the current temperature is 31 degrees F. Temperatures have ranged from 23 F to 45 F. Snow on the ground measures 83 inches with no new snow and two inches settlement. Winds have been southerly in nature with an average of 2-4 mph, and a maximum gust of 9 mph, SE.
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: | 30 |
| Max. temperature in the last 24 hours: | 48 |
| 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: | 96 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, with a high near 54. North wind around 5 mph. | Mostly clear, with a low around 35. North northwest wind 5 to 10 mph becoming northeast after midnight. | Sunny, with a high near 58. Light and variable wind becoming south around 5 mph. |
| Temperature (°F) | 54 | 35 | 58 |
| Wind (mi/hr) | North 5-10 mph | North/Northwest, becoming northeast after midnight 5-10 mph | Light and variable, 0-5 mph 0-5 mph |
| Precipitation SWE / Snowfall (in) | / 0 | / 0 | / 0 |
| For 9000 ft to 11000 ft | |||
| Thursday | Thursday Night | Friday | |
| Weather | Sunny, with a high near 32. A north northeast wind 5 to 10 mph | Mostly clear, with a low around 32. East northeast wind 5-10 mph with gusts to 15-20 mph | Sunny, with a high near 32. North northeast wind 5 to 10 mph becoming calm in the morning. |
| Temperature (°F) | 32 | 32 | 32 |
| Wind (mi/hr) | North/Northeast 5-10 mph | East/Northeast 0 | North/Northeast 5-10 mph, becoming calm |
| Precipitation SWE / Snowfall (in) | / 0 | / 0 | / 0 |
