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Avalanche Advisory for 2018-03-28 05:19
- EXPIRED ON March 29, 2018 @ 5:19 amPublished on March 28, 2018 @ 5:19 am
- Issued by Aaron Beverly - Mount Shasta Avalanche Center
Avalanche Problem 1: Normal Caution
Likelihood ?CertainVery LikelyLikelyPossible
Size ?HistoricVery LargeLarge
Generally safe avalanche conditions exist in the backcountry. LOW avalanche danger does not mean NO avalanche danger:
- Wind continued to blow snow above treeline yesterday. Watch for small isolated wind slabs on SW-SE aspects where areas of drifting have occurred and firm layers of surface snow overlie softer layers.
- Warm weather and solar radiation may cause small loose wet avalanches on S/E facing slopes. To avoid, travel when the snow surface is colder and stronger. Plan your trips to avoid crossing on or under very steep sunlit slopes.
- Small cornices exist on easterly aspects. Increasing temperatures may weaken these causing them to fall. Avoid traveling on top or below them.
Melt-freeze cycles are beginning. Corn snow will soon follow. Overall snowpack stability is good and will increase throughout the week.
There is plenty of rime ice caked on crags and cliffs near ridgetops (Red Banks and Trinity Chutes). Warming temperatures and solar radiation may cause this ice to dislodge. If climbing near these areas, stay vigilant, wear a helmet, and be practiced in your skills of dodgeball.
Yesterday's high reached 53 degrees at the Old Ski Bowl. Gray Butte continues to report light variable winds, though strong N-NE winds were observed above treeline. Some wind transport of snow was seen towards S-SW aspects, though no wind loading or wind slabs were observed. Blowing snow was sublimating. Sastrugis predominate snow surfaces above treeline in the Old Ski Bowl. See picture below.
Roller balls were observed near and below treeline on steep sun exposed aspects.
Moist snow surfaces down at least 5 cm (2 in) were encountered up to 9500 ft on Mount Shasta.
Height of snow around Castle Lake is 25-65 cm (10-25 in). Middle Peak offers a usable snowpack to an optimistic skier. Travel over lake ice is not recommended.
Snow Surface Conditions 9500 ft, Old Ski Bowl
Weather and Current Conditions
Late spring-like conditions will continue through the weekend. Expect daily highs to be in the 50's and nightly lows to be near freezing at 7000 ft. Above treeline today, N winds will average 20-25 mi/hr.
The ridge of high pressure impacting Northern California should begin breaking up early Saturday setting things up for more precipitation next week.
24 Hour Weather Station Data @ 5:00 AM
|Weather Station||Temp (°F)||Wind (mi/hr)||Snow (in)||Comments|
|Cur||Min||Max||Avg||Avg||Max Gust||Dir||Depth||New||Water Equivalent||Settlement|
|Mt. Shasta City (3540 ft)||38||27||51||40.5||4|
|Sand Flat (6750 ft)||station down|
|Ski Bowl (7600 ft)||37||32.5||53||40||87||0||0||3|
|Gray Butte (8000 ft)||38.5||29.5||43||38||5||18||SW|
|Castle Lake (5870 ft)||station down|
|Mount Eddy (6509 ft)||36.5||33||48||41||2||10||SE||49||0||3|
|Ash Creek Bowl (7250 ft)||station down|
|Ash Creek Ridge (7895 ft)||station down|
Two Day Mountain Weather Forecast
Produced in partnership with the Medford NWS
|For 7000 ft to 9000 ft|
|Wind Speed (mi/hr)||5-10 mi/hr||5-10 mi/hr||5-10 mi/hr|
|Expected Snowfall (in)||0||0||0|
|For 9000 ft to 11000 ft|
|Wind Speed (mi/hr)||20-25 mi/hr||20-25 mi/hr||10-15 mi/hr|
|Expected Snowfall (in)||0||0||0|
Season Precipitation for Mount Shasta City
|Period||Measured (in)||Normal (in)||Percent of Normal (%)|
|From Oct 1, 2017 (the wet season)||15.95||34.93||46|
|Month to Date (since Oct 1, 2018)||5.06||5.43||93|
|Year to Date (since Jan 1, 2018)||10.12||19.72||51|