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Avalanche Advisory for 2017-02-14 07:00:14

  • EXPIRED ON February 15, 2017 @ 7:00 am
    Published on February 14, 2017 @ 7:00 am
  • Issued by Andrew Kiefer - Mt Shasta Avalanche Center

The avalanche danger is LOW and normal caution is advised.  The potential exists for falling rime ice in the alpine and isolated wet-loose instabilities with incoming solar radiation throughout the day.  A series of storms will begin to affect the advisory area tomorrow, bringing strong southerly winds and a mix of rain snow.  Expect increasing avalanche danger throughout the week.     
 

Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.

Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.

Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.

Avalanche Problem 1: Normal Caution

  • Character ?
  • Aspect/Elevation ?
  • Likelihood ?
    Certain
    Very Likely
    Likely
    Possible
    Unlikely
  • Size ?
    Historic
    Very Large
    Large
    Small

Low danger and normal caution mean that there is a low likelihood of an avalanche occurring with the current conditions, but do not mean the backcountry is free of hazard.  The duration and intensity of solar radiation input will dictate potential instabilities today. Watch for falling rime ice in the alpine as it warms up throughout the day.  The potential for roller balls and isolated wet loose instabilities also exists, but likely will not be large enough to pose concerns for backcountry travelers.

Forecast Discussion

Very good snowpack stability exists throughout the advisory area, and both natural and human triggered avalanches are unlikely today.  Despite this, there is never a 100% guarantee of safety in the backcountry. Basic avalanche rescue skills are essential, and backcountry travelers should always carry a beacon, shovel and probe.  Watch for isolated instabilities and choose terrain appropriately. Make sure to have a plan before heading out and to exercise smart travel techniques to further reduce your risk.  The incoming weather tomorrow and Thursday is expected to change conditions quickly, and avalanche danger will be on the rise.

Recent Observations

Almost all remote weather stations throughout the advisory area have reported above freezing temperatures for the past 24 hours.  A temperature inversion remains in place with Mt. Shasta City dropping below freezing overnight.  Highs at the 8000ft level reached the upper 40’s F yesterday.  Easterly winds have remained light over the past 48 hours.

No avalanche activity has occurred in over a week.  A ride up to 9500ft in the Old Ski Bowl yesterday revealed evidence of 2 several-day-old cornice fall triggered wind slabs on the east and north aspects of Green Butte.  No evidence of blowing snow or presence of a reactive wind slab problem was observed.  High-level clouds remained in place for the majority of the day and significantly limited solar radiation input.  No evidence of wet loose instabilities were observed.  Relatively uniform and smooth snow surfaces were found above 8400ft.  One to three centimeters of moist snow rests atop a very firm and consolidated snowpack up to 9500ft.  A few surfaces were glazed over by a thin ice lens.  The majority of surfaces encountered were melted, but very supportable underneath, creating corn-like riding conditions.   

Weather and Current Conditions

Weather Summary

Today will be the last of the dry weather, as the high-pressure ridge currently in place slides to the east late this evening.  Skies will be mostly clear throughout the day, with high temperatures in the low 50’s at the 6000ft level.  High-level clouds moving in late this afternoon will be the first sign of the wetter weather to come.  A robust frontal system will push through northern California Wednesday night and Thursday.  This system will bring gusty southerly winds.  Over 2 inches of water will fall as a mix of rain and snow by Saturday, with freezing levels ranging between 5000-9000ft.  Wet and unsettled weather is expected to continue into next week.

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In Mt Shasta City at 0500, we have a current temperature of 28 F with partly cloudy skies skies.

On Mt Shasta (South Side) in the last 24 hours...

Old Ski Bowl - 7,600ft. the current temperture is 37 degrees F.  Temperatures have ranged from 32 F to 50 F.  Snow on the ground totals 157 inches with no new snow and 2 inches of settlement.

Grey Butte - 8,000 feet, the current temperature is 43 degrees F. Temperatures have ranged from 40 F to 46 F.  Winds have averaged 10-20 mph with gusts to 28 mph, blowing primarily out of the east.

Mt Eddy Range (West side of Interstate-5)... 

Castle Lake - 5,800 feet, the current temperature is 39 degrees F. Temperatures have ranged from 38 F to 45 F. Snow on the ground totals 84 inches with no new snow and little settlement.

Mt Eddy - 6,500 feet, the current temperature is 34 degrees F. Temperatures have ranged from 32 F to 48 F. Snow on the ground measures 80 inches with no new snow and 1 inch of settlement. Winds have averaged 1-4 mph with gusts to 6 mph, blowing west/southwest.

THIS SEASON PRECIPITATION for MT SHASTA CITY: Since October 1st (the wet season), we have received 39.04 inches of water, normal is 25.41 inches, putting us at 154% of normal.  For the month of February, we have received 6.78 inches of water, normal is 3.14, which is 216% of normal. And finally for the year of 2017, we received 17.88 inches of water, normal is 10.20 inches, putting us at 175% of normal.

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.

CURRENT CONDITIONS at Bunny Flat (6950 ft)
0600 temperature: 32
Max. temperature in the last 24 hours: 48
Average wind direction during the last 24 hours: East
Average wind speed during the last 24 hours: 5-10 mi/hr
Maximum wind gust in the last 24 hours: 15 mi/hr
New snowfall in the last 24 hours: 0 inches
Total snow depth: 93 inches

Two Day Mountain Weather Forecast

Produced in partnership with the Medford NWS

For 7000 ft to 9000 ft
  Tuesday
(4 a.m. to 10 p.m.)
Tuesday Night
(10 p.m. to 4 a.m.)
Wednesday
(4 a.m. to 10 p.m.)
Weather Mostly sunny Partly cloudy, then 30% chance of rain. Breezy. Rain likely, then rain/snow mix.
Temperature (°F) 50 31 41
Wind (mi/hr) Southeast 7-10 mph South/Southeast 15-17 mph South/Southeast 22 - 28 mph
Precipitation SWE / Snowfall (in) / 0 / 0 / 0-.5
For 9000 ft to 11000 ft
  Tuesday Tuesday Night Wednesday
Weather Mostly sunny and breezy Windy. Partly cloudy then 30% chance of snow after 4am. Windy. Snow, mainly after 10am
Temperature (°F) 34 33 33
Wind (mi/hr) South 15-20 mph, increasing to 24-29 mph in the afternoon Southwest 0 Southwest 41-51 mph, increasing to 60-7 mph in the afternoon
Precipitation SWE / Snowfall (in) / 0 / 0-.5 / 1-3

Disclaimer

This advisory does not apply to Ski Areas or Highways and is for the Mt. Shasta, Castle Lake and Mt. Eddy backcountry. Use this information for guidance only. You may find different conditions in the backcountry and should travel accordingly. This advisory expires on midnight of the date it was posted unless otherwise noted.