You are here
Avalanche Advisory for 2017-04-06 06:42:55
- EXPIRED ON April 7, 2017 @ 6:42 amPublished on April 6, 2017 @ 6:42 am
- Issued by Aaron Beverly - Mount Shasta Avalanche Center
Avalanche Problem 1: Wind Slab
Likelihood ?CertainVery LikelyLikelyPossible
Size ?HistoricVery LargeLarge
With 8 inches of new snow overnight, and at 2-4 expected today, combined with moderate to strong south and southwest winds, wind slabs could become an issue as the day progresses. The old snow interface will provide a firm bed surface on which a wind slab could slide. Look for these on the lee slopes, near and above treeline. Slabs may exist on northwest, north, northeast, and east slopes near treeline. Above treeline, look for slabs on all aspects. Isolated slabs may exist below treeline near terrain exposed to the wind.
Mountain winds can be variable, so always pay attention to where the wind is blowing snow. Avoid wind loaded slopes greater than 30 degrees.
Looks like today could be a good ski day afterall.
Both Sand Flat and the Old Ski Bowl are reporting 7-8 inches of new snow since 11 PM last night. These amounts are significantly more than what was predicted. Moderate to strong winds are likely to start transporting this snow near and above treeline increasing wind slab hazards through out the day. Wind slabs may grow to 8-12 inches in thickness or more. Monitor conditions as you travel. Look for shooting cracks in the snow as an indicator of this problem.
Late tonight more snow is on the way which will add more weight to the snowpack and will continue to increase avalanche hazard.
If our weather stations are to be believed, we have received much more snow than predicted.
The Old Ski Bowl (7600') is reporting 8 inches of new snow since 11 PM last night. Winds have been southwest, south southwest, and south ranging from 11 - 13 mph. Temperatures have been at or below the freezing level and decreasing from the start of this precipitation event.
Sand Flat (6750') is reporting 7 inches of new snow. Castle Lake 6 inches.
Current Conditions at Bunny Flat (6950')
|0600 temperature:||30 deg. F.|
|Maximum temperature in the last 24 hours.||46 deg. F.|
|Average wind direction during the last 24 hours.||Southwest|
|Average wind speed during the last 24 hours.||11 mph|
|Maximum wind gust in the last 24 hours.||35 mph|
|New snowfall in the last 24 hours.||7 inches|
|Total snow depth.||107 inches|
A winter storm watch will be in effect from late tonight through friday morning.
Snow levels are expected to be 4500 feet today and 3900 feet tomorrow. The effects of a weak cold front could produce up 4 inches of snow today. Late tonight a warm front will pass through bringing with it significant precipitation and winds. Expect strong to gale force southerly winds near and above treeline. This system could drop over 3 inches of water by Saturday and over two feet of snow.
In Mt Shasta City at 0500, we have a current temperature of 34 F
On Mt Shasta (South Side) in the last 24 hours...
Sand Flat - 6,750 ft. The current temperature is 30 degrees F. Temperatures have ranged from 30 F to 46 F. Snow on the ground totals 107 inches with 7 inches of snow and 1 inch of settlement.
Old Ski Bowl - 7,600ft. The current temperature is 25 degrees F. Temperatures have ranged from 34 F to 48 F. Snow on the ground totals 182 inches with 8 inches of new snow and 1.5 inches of settlement.
Grey Butte - 8,000 feet. The current temperature is 26 degrees F. Temperatures have ranged from 26 F to 43 F. Winds have averaged 11 mph with gusts to 35 mph, blowing south, south southwest, and southwest.
Mt Eddy Range (West side of Interstate-5)...
Castle Lake - 5,800 feet. The current temperature is 31 degrees F. Temperatures have ranged from 31 F to 49 F. Snow on the ground totals 93 inches with about 6 inches of new and 2 inches of settlement.
Mt Eddy - 6,500 feet, the current temperature 30 degrees F. Temperatures have ranged from 30 F to 43 F. Snow on the ground measures 83 inches with a trace of new snow and about 2 inches of settlement. Winds have been variable averaging 2 mph with gusts up to 18 mph.
THIS SEASON PRECIPITATION for MT SHASTA CITY: Since October 1st (the wet season), we have received 49.60 inches of water, normal is 36.04 inches, putting us at 138% of normal. For the month of April, we have received 0.14 inches of water, normal is .58 inches, which is 24% of normal. And finally for the year of 2017, we received 28.44 inches of water, normal is 20.83 inches, putting us at 137% 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.
Two Day Mountain Weather Forecast
|For 7000 ft. to 9000 ft.|
|Weather||Snow likely before 11am, then a chance of snow showers after 11am. Cloudy. Windy. Chance of precipitation is 70%.||Snow. The snow could be heavy at times. Low around 28. Windy. Chance of precipitation is 100%.||Snow before 11am, then snow showers after 11am. Windy. Chance of precipitation is 100%.|
|Temperatures||39 deg. F.||28 deg. F.||34 deg. F.|
|Wind speed||15-25 mph, with gusts up to 60||20-30 mph||20-30|
|Expected snowfall||2-4 in.||9-18 in.||3-6 in.|
|For 9000 ft. to 11000 ft.|
|Weather||Snow likely before 11am, then a chance of snow showers after 11am. Cloudy. Windy. Chance of precipitation is 70%.||Snow. The snow could be heavy at times. Windy. Chance of precipitation is 100%.||Snow before 11am, then snow showers after 11am. The snow could be heavy at times. Windy. Chance of precipitation is 100%.|
|Temperatures||23 deg. F.||12 deg. F.||16 deg. F.|
|Wind speed||54 mph||62 mph||55 mph|
|Expected snowfall||2-4 in.||9-18 in.||3-6 in.|