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Avalanche Advisory for 2017-03-24 06:37:53
- EXPIRED ON March 25, 2017 @ 6:37 amPublished on March 24, 2017 @ 6:37 am
- Issued by Nick Meyers - Shasta-Trinity National Forest
Avalanche Problem 1: Wind Slab
Likelihood ?CertainVery LikelyLikelyPossible
Size ?HistoricVery LargeLarge
The wind slab avalanche problem near and primarily above treeline will be today's concern. New and existing wind slabs are fair game for human trigger. Several inches of new snow and windy southwesterlies will load leeward N-NE-E aspects. Existing wind loaded S-SE aspects may host thicker wind slabs and be suspect as well. Touchy conditions can be expected today, especially this morning, and a human triggered wind slab is likely along exposed ridgelines and bowls where evidence of wind loading is observed. Play it safe!
We've had .36 inches of precipitation (SWE) fall overnight, starting at 2000 hours. This has translated to about 3-5 inches of new snow. Temperatures are about 5 degrees warmer this morning. Winds blew 5-10 mph on average with gusts to 15-20 mph out of the west/northwest up until the onset of the storm, switching to south/southwest at the same time, about 1900 to 2000 hours.
East/Southeast aspects above treeline have experienced both natural and rider triggered wind slabs over the past several days including one snowmobile triggered wind slab yesterday. These slides were small to medium sized avalanches. Some loose snow surface sluffing was easily initiated below ski and snowmobile tracks as well.
Weather and Current Conditions
A Winter Weather Advisory remains in place, issued by the NWS Medford, until 2 PM PDT this afternoon... expect snow this morning, heavy at times. This afternoon, precipitation will taper off and showery conditions will bring us into the evening. Up to an additional .5 inches of water is forecasted, but I don't think we will see that much. Snow levels will hover around 3,900 feet today, 4,600 feet tonight and tomorrow. Today will be windy out of the south, tapering off later this afternoon. Overall, while we may see short periods of clearing and perhaps a peeking sun tomorrow, the weekend appears to be mostly cloudy with addtional precipitation on Sunday.
In Mt Shasta City at 0500, we have a current temperature of 33 F.
On Mt Shasta (South Side) in the last 24 hours...
Sand Flat - 6,750 ft, the current temperture is 26 degrees F. Temperatures have ranged from 17 F to 37 F. Snow on the ground totals 110 inches with 2-4 inches of new snow and little settlement.
Old Ski Bowl - 7,600ft. the current temperature is 23 degrees F. Temperatures have ranged from 15 F to 35 F. Snow on the ground totals 190 inches with 4-6 inches of new snow and little settlement.
Gray Butte - 8,000 feet, the current temperature is 22 degrees F. Temperatures have ranged from 19 F to 32 F. Winds have averaged 5-10 mph with gusts to 15-20 mph, blowing from the WNW up until 1900 hours, then switching to S/SW.
Mt Eddy Range (West side of Interstate-5)...
Castle Lake - 5,800 feet, the current temperature is 26 degrees F. Temperatures have ranged from 24 F to 41 F. Snow on the ground totals 97 inches with 2-4 inches of new snow and little settlement.
Mt Eddy - 6,500 feet, the current temperature is 24 degrees F. Temperatures have ranged from 16 F to 35 F. Snow on the ground measures 92 inches with 1-2 inches of new snow and little settlement. Winds have been southerly averaging 2-3 mph with gusts up to 12 mph.
THIS SEASON PRECIPITATION for MT SHASTA CITY: Since October 1st (the wet season), we have received 47.63 inches of water, normal is 34.36 inches, putting us at 138% of normal. For the month of March, we have received 4.32 inches of water, normal is 4.86 inches, which is 88% of normal. And finally for the year of 2017, we received 26.47 inches of water, normal is 19.15 inches, putting us at 138% 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:||37|
|Average wind direction during the last 24 hours:||W/NW --> S/SW|
|Average wind speed during the last 24 hours:||5-10 mi/hr|
|Maximum wind gust in the last 24 hours:||15-20 mi/hr|
|New snowfall in the last 24 hours:||2-4 inches|
|Total snow depth:||110 inches|
Two Day Mountain Weather Forecast
Produced in partnership with the Medford NWS
|For 7000 ft to 9000 ft|
|Weather||Snow before 11am, then snow showers after 11am. The snow could be heavy at times. Breezy. Chance of precipitation is 100%.||Snow showers, mainly before 11pm. Chance of precipitation is 80%.||A 20 percent chance of snow showers. Partly sunny.|
|Wind Speed (mi/hr)||15-20 mph||5-10 mph||5 mph|
|Expected Snowfall (in)||4-6||1-3||0|
|For 9000 ft to 11000 ft|
|Weather||Snow before 11am, then snow showers after 11am. The snow could be heavy at times. Windy. Wind chill values as low as -7. Chance of precipitation is 100%.||Snow showers, mainly before 11pm. Low around 13. Windy. Wind chill values as low as -10. Chance of precipitation is 80%.||A 20 percent chance of snow showers. Partly sunny. Windy. Wind chill values as low as -9.|
|Wind Speed (mi/hr)||40-45 mph||20-25 mph||15-20 mph|
|Expected Snowfall (in)||4-6||1-3||0|