You are here
Avalanche Advisory for 2015-01-24 06:15:51
- EXPIRED ON January 25, 2015 @ 6:15 amPublished on January 24, 2015 @ 6:15 am
- Issued by Nick Meyers - Shasta-Trinity National Forest
Avalanche Problem 1: Wet Slab
Likelihood ?CertainVery LikelyLikelyPossible
Size ?HistoricVery LargeLarge
In the last 24 hours at the Old Ski Bowl weather station (7,600 feet), we saw temperatures rise to 50 F degrees at 2100 last night. Since 0900 yesterday morning, temperatures have not dropped below 40 F degrees.
Wet/loose snow instabilities will host our avalanche problem for this weekend. Rising night and daytime temperatures and freezing levels over 11,000 feet could create wet/loose snow instabilities in the form of roller balls, pinwheels, point releases and/or small surface sluffs.
Slopes steeper than 35 degrees and E-SE-S facing up to 11,000 feet will be the most likely areas to encounter wet/loose instabilities
While most of the time these types of slides are of little consequence, they always have the chance to build as they entrain more snow as they move down a slope and potentially sweep a rider off their feet and into undesireable locations like trees, over a cliff or into a terrain trap.
Conditions can be affected by sun, rain and warm tempertures. Timing before the onset of significant sun/warmth is key.
Inversions and Juneuary conditions dominate as high pressure moves overhead today. In the last 24 hours at the Old Ski Bowl weather station (7,600 feet), we saw temperatures rise to 50 F degrees at 2100 last night. Since 0900 yesterday morning, temperatures have not dropped below 40 F degrees. Sunshine and increasing temperatures over the week have graced us with a melt/freeze cycle producing great corn snow at many elevations. Naturally - aspect, time of day and elevation are dictating the corn quality. Mt Shasta is one of the few areas in the state that has reasonable snow coverage and the sliding and riding conditions as of yesterday were... amazing. As much as we would like to keep this a secret, well - I already blew it. Temperatures continue to warm into Sunday and good, no...amazing corn conditions will push higher in elevation. Time it right on warm, sunny aspects and you will not be dissapointed.
The weak layer within wind slabs from last weekend has healed and not of concern at this point. Said weak layer was destroyed by rain and sun settlement within the snowpack. Observations made during the week personally and by local folk resulted in no instabilities. Avalanche Gulch, Giddy-Giddy Gulch, 50/50 Flat, and Shastarama have all reported smooth snow and good corn skiing/snowmobiling. Climbers headed onto the upper mountain will find smooth and firm snow surface conditions presenting the possibility for "slide for life" incidents... probably goes without saying, but bring your crampons, helmet, and ice axe. Rock and ice fall were observed and heard yesterday off Sargents ridge. No instabilities have been observed or recorded on the upper mountain.
To summarize, concerns for skiing and climbing on Shasta this weekend will be: 1) Wet/loose snow instabilities in the form of roller balls, pinwheels, small point releases and surface sluffs on sun warmed slopes steeper than 35 degrees, low to mid mountain levels. These instabilities will likely be small in size and of little consequence, but as always, use caution on steeper slopes in extreme terrain where even a small slide could sweep one off their feet into undesireable locations 2) Rime and water ice melting/flaking off exposed rocks and falling onto one below 3) Smooth and firm upper mountain conditions posing the threat for a slide for life should one slip and fall.
Below, top to bottom: Skier on Green Butte Ridge from past week, Avalanche Gulch in background - Photo: Shane Rathbun / Wind and Lake Helen from this past week - Photo: S Rathbun / Looking up at Shastarama, Old Ski Bowl, Mt Shasta, approx. 9,700 feet, 1.22.15 - Photo: Jon Dove / Looking out into Old Ski Bowl, 9,300 feet, 1.22.15 - Photo: J Dove
DON'T FORGET! THE SHASTA ASCENSION RANDONEE RACE IS TODAY AND THE LOCATION HAS BEEN CHANGED TO THE BUNNY FLAT TRAILHEAD DUE TO LACK OF SNOW AT THE SKI PARK. Registration is from 0700-0930 and the race begins at 1000. FOLLOWING the race is the 13th Annual SNOW BALL PARTY at the Mt Shasta City Park. This is the MSAC's biggest fundraiser of the year...come out and have an amazing time and help support everything you love about this advisory and website! Details under "Events" tab on this website. See you soon!
Report your observations to the MSAC! A photo, a few words... send them in! (firstname.lastname@example.org or 530-926-9614)
Castle Lake area has a shallow snowpack. Be careful of shallow buried objects. Skiing has been reported as poor to non-existent.
Sand Flat Winter Trails: OPEN
Pilgrim Creek Snowmobile Park: OPEN, however due to lack of low elevation snow, one must drive up the road several miles before enough snow is encountered. One CANNOT DRIVE over Military Pass.
Terrain: Remember most of the terrain that we like to play on is greater than 30 degrees. Avalanches are possible on anything steeper than 30 degrees. Avoid cornices, rock bands, terrain traps and runout zones of avalanche paths.
Weather: Most of our areas avalanche danger will occur 24-48 hours after a storm. We still can see persistent weak layers from time to time and we always will be sure to let you know about that! Heed the basic signs: Wind (significant snow transport and depositions), Temperature (rain/snow/rain/snow, which in turn weakens the snowpack), and Precipitation (Snow or rain add weight and stress to the current snowpack).
Snowpack: If snow accumulates, give the snowpack a chance to adjust to the new snow load before you play on or near steep slopes (greater than 30 degrees). Most direct action avalanches occur within 24-48 hours of recent snowfall. Watch for obvious signs of snowpack instability such as recent natural avalanche activity, collapsing of the snowpack (often associated with a “whumphing” sound), and shooting cracks. If you see these signs of instability, limit your recreation to lower angle slopes.
Human Factor: Don’t forget to carry and know how to use avalanche rescue gear. You should NOT be skiing or climbing potential avalanche slopes without having beacons, shovels, and probes. Only one person in a group should be exposed to potential avalanche danger at a time. Remember, climbing, skiing, and riding down the edge of slopes is safer than being in the center. Just because another person is on a slope doesn’t mean that it is safe. Be an individual! Make your own decisions. Heed the signs of instability: rapid warming, “whumphing” noises, shooting cracks, snowing an inch an hour or more, rain, roller balls, wind loading, recent avalanche activity.
The Five Red Flags of Avalanche Danger any time of year include: 1) Recent/current avalanche activity 2) Whumpfing 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
In Mt Shasta City this morning at 0500, inversions are showing with a current temperature of 33 degrees witw clear skies.
WEATHER STATION INFORMATION (0500hrs):
On Mt Shasta (South Side) in the last 24 hours...
Old Ski Bowl - 7,600 feet, the current temperature is 40 F. Snow on the ground totals 68 inches with no settlement and no new snow. Temperatures have ranged from 36 F to 50 F.
Gray Butte - 8,000 feet, winds have averaged 7 mph and variable in direction, with a max gust to 28 mph from the north. The current temperature is 42 F and temps have ranged from 37 F to 47 F in the last 24 hours.
Castle Lake and Mt Eddy (West side of Interstate-5)...
Castle Lake - 5,600 feet, the current temperature is 44 F. Temps have ranged from 37 F to 46 F in the last 24 hours. The Castle Lake area has up to 1.5 feet of snow on the ground and no new snow over the past week.
Mt Eddy - 6,500 feet, the current temperature is 44 F. Temps have ranged from 32 F to 48 F in the last 24 hours. Current snow depth is 20 inches with no new snow over the past week and no settlement. Winds have averaged 2 mph and SW in direction, with gusts to 10 mph from the SW.
WEATHER SYNOPSIS: Inversions are in place and will continue through the weekend for the area and a warm front is making its way onto land this morning. We will see high temperatures rise even further, by one or two degrees by Sunday. National Weather Service claims we could see near record high temps. Really not a whole lot to mention concerning the weather today and this weekend is going to provide some lovely weather out there. As the high moves overhead, we will sit in the "donut hole" and thus winds will be light and variable in direction for most elevations on the mountain. Flow aloft and on the upper mountain remains northerly. Climbers on the upper mountain may experience higher winds once the 12,500 mark is reached. Northerly wind, 20-30 mph can be expected today on the upper mountain. Otherwise, get your eye shades and sunscreen out and prepare to harvest some corn!
THIS SEASON: Since October 1st (the wet season) , we have received 20.00 inches of water, normal is 20.57 inches, putting us at 97% of normal. For January/2015, we've received 0.48 inches of water, normal is 5.36, putting us at 8% of normal.
Looking back into 2014, Mt Shasta finished off with 34.36 inches of water with normal being 43.21 inches, leaving us at 79% of normal for the year. For the month of December, Mt Shasta finished at 163% of normal, receiving 12.83 inches of water, normal is 7.85 inches.
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.
|Max. temperature in the last 24 hours:||50|
|Average wind direction during the last 24 hours:||Variable|
|Average wind speed during the last 24 hours:||7 mi/hr|
|Maximum wind gust in the last 24 hours:||28 mi/hr|
|New snowfall in the last 24 hours:||0 inches|
|Total snow depth:||68 inches|
Two Day Mountain Weather Forecast
Produced in partnership with the Medford NWS
|For 7000 ft to 9000 ft|
(4 a.m. to 10 p.m.)
(10 p.m. to 4 a.m.)
(4 a.m. to 10 p.m.)
|Wind (mi/hr)||East/Northeast Ligh, 5-10 mph||East Light, 5-10 mph||East/Southeast Light, 5-10 mph|
|Precipitation SWE / Snowfall (in)||/ 0||/ 0||/ 0|
|For 9000 ft to 11000 ft|
|Wind (mi/hr)||North/Northeast Light, 5-15mph||North/Northeast 0||South/Southeast Light, 5-10 mph|
|Precipitation SWE / Snowfall (in)||/ 0||/ 0||/ 0|