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Avalanche Advisory for 2016-02-27 06:51:27
- EXPIRED ON February 28, 2016 @ 6:51 amPublished on February 27, 2016 @ 6:51 am
- Issued by Jon Dove - Shasta-Trinity National Forest
Bottom Line
Overall, the avalanche danger is LOW for all elevations and aspects. Precipitation that fell yesterday was less than forecast. Winds increased, blowing strong to moderate above treeline. Any wind slabs that may have formed will be found on NW-N-NE-E-SE aspects above 8,000 feet, and will be small in size. Some clouds and cool temperatures today will make the developement of loose wet snow instabilities unlikely.
Normal caution is advised today.
Avalanche Problem 1: Normal Caution
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Character ?
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Aspect/Elevation ?
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Likelihood ?CertainVery LikelyLikelyPossible
Unlikely -
Size ?HistoricVery LargeLargeSmall
Overall LOW avalanche danger exists across the forecast area. You need to remember that risk is ALWAYS present in mountain travel. Even with LOW danger, avalanches can still happen in isolated places.
Some current considerations:
- Newly formed wind slabs may be encountered on the upper mountain. Yesterday's storm brought only 2-3 inches of new snow at elevations above 8,000 feet with moderate to strong west/southwest winds. If ascending above treeline small winds slabs may be encountered on N-NE-E-SE aspects with possible cross loading on NW aspects. The consequences are low, burial is unlikely, but if on a steep slope with a long fetch enough snow may be entrained that may take you over a cliff or into rocks.
- Loose wet instability hazard is always low in the morning but can become moderate to considerable in the warm afternoon hours, especially after poor overnight re-freeze. Today, some clouds and cooler temperatures will help to keep snow in place. We haven't seen any major loose wet snow activity yet this year, however roller balls and pin wheels are a good sign that the snow is loosing strength and larger slides are possible. Mt Shasta has slopes with long fetch and this allows loose wet slides to gain a good bit of momentum and snow. Combine one of these slides with a terrain trap like a gully or depression, and enough snow may gather to bury a person. These larger loose wet slides will become more of a problem as we move into Spring.
- Cornices, some very large, have been observed in the area backcountry. While none have been able to trigger, the old elevator drop is always certain to get your heart pumping and can send you for a ride...not magic mountain style. Simply, stay back on terra firma by noting rocks or trees protruding from the landscape.
Forecast Discussion
The cold front that passed through late yesterday evening brought rain to the area, and snow to elevations of 8,000 feet and above. 0.25 inches of water was recorded at the Old Ski Bowl weather station which was 0.2 inches less than what was expected. Skies have mostly cleared out, and temperatures have dropped considerably overnight. The next front will begin to move over our area late tonight into Sunday morning bringing more wind, and less precipitation than yesterday's system. Despite calls for some precipitation, models show water amounts of zero through Monday. For today, expect some clouds with any precipitation being very light. Monday's weather will be fairly uneventful with a moderate to strong storm system arriving on Tuesday, which looks to be much wetter and windy. We are transitioning into a more wet weather pattern during the next week.
THIS SEASON PRECIPITATION for MT SHASTA CITY: Since October 1st (the wet season), we have received 25.52 inches of water, normal is 28.96 inches, putting us at 88% of normal. For the month of February we've received 3.03 inches of water, normal is 6.69 inches, putting us at 45% of normal, and finally... for the year of 2016 we've received 16.03 inches of water, normal is 13.75 inches, putting us at 116% of normal .
Recent Observations
Yesterday's storm lost some steam and brought a modest 0.25 inches of water to the Mt. Shasta area. The day started with warm temperatures, but cooled in mid to late afternoon just as precipitation began to fall. Heavy, wet snow fell at elevations of around 8,000 feet, but did not accumulate enough to register at the Old Ski Bowl weather station. 2-3 inches of snow likely fell at higher elevations, but moderate to strong west/southwest winds will have transported that snow around or simply blown it away. Any wind slab formations will be on N-NE-E-SE aspects with some cross loading possible on NW aspects, above 8,000 feet in elevation, and will be small in size. Therefore, the avalanche danger has not changed since yesterday. For today, some clouds and cooler temperatures will limit the development of any loose wet snow instabilities making them an unlikely hazard. No observations were made or reported from the field. Avalanche instabilities have been hard to find over the past several days. Any danger remains Low, and will continue that way until we encounter the next significant storm system, which is not forecast until Tuesday of this coming week. A variety of snow surface conditions will be found, depending on your aspect and elevation. Overall, good skiing/riding conditions can be enjoyed throughout the forecast area on different types of snow surface conditions.
West side of the forecast area, Castle Crags area, 2.24.26 - Photo: C. Carr, Shasta Mountain Guides
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LOCAL AREA ROAD, NORDIC, AND SNOWMOBILE PARK STATUS:
The Sand Flat cross country ski trails are in good shape 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 open! These beautiful, groomed trails can be accessed via the Ski Park Highway. http://www.mtshastanordic.org
The Pilgrim Creek & Deer Mountain Snowmobile Parks are open! Trails have not been groomed in the past week and a half due to warm temperatures. 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 plowed to the lake. The Everett Memorial Highway is plowed to Bunny Flat.
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 33 F, eight degrees cooler than yesterday at this time, with clear skies and calm wind.
On Mt Shasta (South Side) in the last 24 hours...
Old Ski Bowl - 7,600 feet, the current temperature is 26 degrees F. Snow on the ground totals 118 inches with no new snow and little settlement. Temperatures have ranged from 24 F to 40 F.
Grey Butte - 8,000 feet, the current temperature is 23 degrees F. Temperatures have ranged from 22 F to 38 F. Winds have averaged 10-15 mph and southwesterly in nature with a max gust to 35 mph southwest. At 2100 last night the winds picked up out of the west/southwest then shifted to northwest averaging 20-25 mph with gusts to 49mph.
Mt Eddy Range (West side of Interstate-5)...
Castle Lake - 5,600 feet, the current temperature is 29 degrees. Temperatures have ranged from 29 F to 47 F. Snow on the ground totals 66 inches with no new snow and 1 inch of settlement.
Mt Eddy - 6,500 feet, the current temperature is 25 degrees F. Temperatures have ranged from 25 F to 44 F. Snow on the ground measures 77 inches with no new snow and 1 inch of settlement. Winds have averaged 2 mph, southerly in direction with a max gust of 12 mph, south/southwest.
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: | 28 |
| Max. temperature in the last 24 hours: | 46 |
| Average wind direction during the last 24 hours: | Variable |
| Average wind speed during the last 24 hours: | 15-20 mi/hr |
| Maximum wind gust in the last 24 hours: | 49 (Grey Butte) mi/hr |
| New snowfall in the last 24 hours: | 0 inches |
| Total snow depth: | 84 inches |
Two Day Mountain Weather Forecast
Produced in partnership with the Medford NWS
| For 7000 ft to 9000 ft | |||
|---|---|---|---|
|
Saturday (4 a.m. to 10 p.m.) |
Saturday Night (10 p.m. to 4 a.m.) |
Sunday (4 a.m. to 10 p.m.) |
|
| Weather | Partly sunny. A 20% chance of snow showers before 10 am. | Mostly cloudy with a 30% chance of snow after 4 am. | Mostly cloudy. A chance of snow before 10 am, then rain likely, possibly mixed with snow. Chance of precip. 60% |
| Temperature (°F) | 36 | 34 | 42 |
| Wind (mi/hr) | South 5-10 mph | South 5-10 mph | South shifting to West in the afternoon 5-10 mph |
| Precipitation SWE / Snowfall (in) | / 0 | / 0 | / 0 |
| For 9000 ft to 11000 ft | |||
| Saturday | Saturday Night | Sunday | |
| Weather | Partly sunny. A 20% chance of snow showers before 10 am. Windy with wind chill values as low as -3 | Mostly cloudy. A 30% chance of snow after 4 am. Windy | Mostly cloudy with snow likely, mainly after 10 am. Windy. Chance of precipitation 60% |
| Temperature (°F) | 24 | 24 | 26 |
| Wind (mi/hr) | West/southwest 20-25 mph | West/southwest 0 | West 40-45 mph |
| Precipitation SWE / Snowfall (in) | / 0 | / 0-.5 | / 0-1 |
