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Avalanche Advisory for 2017-04-01 06:43:52
- EXPIRED ON April 2, 2017 @ 6:43 amPublished on April 1, 2017 @ 6:43 am
- Issued by Andrew Kiefer - Mt Shasta Avalanche Center
Avalanche Problem 1: Normal Caution
Likelihood ?CertainVery LikelyLikelyPossible
Size ?HistoricVery LargeLarge
Avalanches are unlikely throughout the advisory area, and any avalanche event would likely be small. As temperatures increase throughout the day and the solar radiation intensifies, the greatest objective hazard will be falling rime ice in the alpine on Mount Shasta. In addition, the potential for isolated wet loose avalanche activity exists on sun exposed slopes steeper than 35 degrees. Watch for falling rime ice if you venture high on the mountain this weekend. Also, monitor the snow surface as it warms up throughout the day. Watch for pinwheels and roller balls, and avoid steep slopes where the snow surface has become wet and unconsolidated.
Warm spring weather is expected today, although challenging windy conditions will likely continue at upper elevations on Mount Shasta. The recent snow from Thursday, paired with strong northerly winds, created a shallow wind slab problem yesterday that was short lived. The extreme winds were much more effective in scouring snow surfaces than loading snow to form wind slabs, and no signs of a significant wind slab problem were observed during a tour in Avalanche Gulch yesterday.
With warm temperatures and sunny skies expected for the morning and early afternoon, loose wet avalanches could become a concern on steep sun exposed slopes. The winds will likely minimize the potential for loose wet activity, as will increasing cloud cover throughout the day. As conditions in the advisory area continue to transition from winter to spring, wet loose avalanche activity and falling rime ice should be expected. Anticipate these hazards and plan your day accordingly.
Northerly winds were the driving factor on Mount Shasta yesterday. From 7-11am, steady 30-40mph winds were observed in Avalanche Gulch between Horse Camp and Lake Helen. Estimated gusts ranged from 60-80mph, and uphill travel against the downslope winds was a loosing battle. By noon, the winds diminished significantly below 8000ft, but continued above.
Snow surfaces were variable. The recent snow from Thursday was cold and dry, but was significantly affected by the wind. Only protected gully features held wind deposits, while the wind scoured nearly all other snow surfaces at and above 7500ft. Skies were clear and sunny and temperatures were above freezing. Snow surfaces softened by the early afternoon up to 9000ft. The new snow became very sticky and heavy below treeline as the day progressed. Slick and scoured surfaces allowed for a brief window of corn-like skiing before becoming sloppy by the afternoon.
Weather and Current Conditions
A ridge of high pressure is in place, and will allow for mostly dry and clear weather through the weekend. Skies will be mostly sunny this morning with increasing cloud cover building this afternoon and overnight. No precipitation is expected. Strong northerly winds will continue above the 10000ft level on Mount Shasta, and high temperatures for the day will reach the mid 50’s F at the 6000ft level. Tomorrow looks to bring similar conditions with clear and sunny weather in the morning, and increasing clouds again in the afternoon.
In Mt Shasta City at 0500, we have a current temperature of 45 F
On Mt Shasta (South Side) in the last 24 hours...
Sand Flat - 6,750 ft, the current temperture is 30 degrees F. Temperatures have ranged from 17 F to 31 F. Snow on the ground totals 108 inches with a trace of new snow and 4 inches of settlement.
Old Ski Bowl - 7,600ft. This weather station is down. We apologize for the inconvenience.
Grey Butte - 8,000 feet, the current temperature is 40 degrees F. Temperatures have ranged from 15 F to 40 F. Winds have averaged 15-20mph mph with gusts to 42 mph, and have transitioned from northerly southeasterly in direction.
Mt Eddy Range (West side of Interstate-5)...
Castle Lake - 5,800 feet, the current temperature is 37 degrees F. Temperatures have ranged from 23 F to 46 F. Snow on the ground totals 98 inches with no new snow and 1 inch of settlement.
Mt Eddy - 6,500 feet, the current temperature is 42 degrees F. Temperatures have ranged from 21 F to 42 F. Snow on the ground measures 92 inches with no new snow and 1 inch of settlement. Winds have averaged 2-5 mph with gusts up to 14 mph, blowing SE and SW.
THIS SEASON PRECIPITATION for MT SHASTA CITY: Since October 1st (the wet season), we have received 49.46 inches of water, normal is 35.46 inches, putting us at 139% of normal. For the month of March, we have received 6.15 inches of water, normal is 5.96 inches, which is 103% of normal. And finally for the year of 2017, we received 28.30 inches of water, normal is 20.25 inches, putting us at 140% 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.
|Max. temperature in the last 24 hours:||31|
|Average wind direction during the last 24 hours:||southeast|
|Average wind speed during the last 24 hours:||15 mi/hr|
|Maximum wind gust in the last 24 hours:||40 mi/hr|
|New snowfall in the last 24 hours:||trace inches|
|Total snow depth:||108 inches|
Two Day Mountain Weather Forecast
Produced in partnership with the Medford NWS
|For 7000 ft to 9000 ft|
|Weather||Mostly Sunny||Partly Cloudy||Mostly sunny.|
|Wind Speed (mi/hr)||8-18 mph||8 mph||7 mph|
|Expected Snowfall (in)||0||0||0|
|For 9000 ft to 11000 ft|
|Weather||Mostly Sunny and Windy||Partly Cloudy and Windy||Mostly Sunny and Windy|
|Wind Speed (mi/hr)||23-42 mph, Gusting to 48 mph||26-31 mph, Gusting 47 mph||28-38 mph, Gusting 55|
|Expected Snowfall (in)||0||0||0|