McCall Avalanche Danger

[Hunter2008]

Friday, February 15, 2008 6:46:41 AM

A moderate avalanche hazard means that natural avalanches are unlikely, but human triggered avalanches are possible.
Good morning, this is Jim Fitzgerald from the Payette National Forest Avalanche Center with the avalanche advisory for Friday February 15, 2008. This advisory is brought to you with the help of Idaho Department of Parks and Recreation and the snowmobile license program. The avalanche danger today is estimated to be Moderate. Stable conditions exist out there with a few potential hiccups as a preview of spring time conditions will influence our area. This danger rating expires at midnight on Friday February 15, 2008. Look for our next Advisory Sunday evening February 17, 2008

 

[Hunter2008]

Friday, February 29, 2008 7:19:39 AM

A moderate avalanche hazard means that natural avalanches are unlikely, but human triggered avalanches are possible.
The Payette Avalanche Center with the Avalanche Advisory for Friday February 29, 2008. Today the Avalanche Hazard is estimated to be Moderate. Natural avalanches are unlikely and human triggered avalanches are possible. The possibility of wet slides and sluffs will increase later today as high temperatures are expected in the mid to upper forties. Look for our next forecast Monday March 3

 

[Hunter2008]

A moderate avalanche hazard means that natural avalanches are unlikely, but human triggered avalanches are possible.
Good morning, this is Jim Fitzgerald from the Payette National Forest Avalanche Center. The avalanche danger today is estimated to be Moderate. The place you are most likely to find instability are on steeper slopes (>35 degree) where the new snow has not bonded well to the old, especially in areas of wind deposition, which favored east to north-east aspects.

Yesterday about 5 inches of snow fell as we toured past Sargents Mountain over to Cordoza and North-North coming out at Brundage Reservoir. It was as if we had hit the refresh button on the computer: old dirty spring snow was replaced with fresh white stuff. Although it did not accumulate enough to cover all the old tracks it did soften the impact to acceptable levels. Even the southerly aspects were starting to ski in the afternoon. On the south the new snow was topping a solid sun crust, of about 5-10cm, that made you wish for sharper edges. Winds were out of the west-south west gusting up to the high teens. We found scattered wind pillows on east and north aspects near ridgelines, but they were not wide spread. The six inches of snow over night, with no winds, will tend to hide these pillows, keeping things interesting. In any case the snow that fell over night only increases the load by about 2 pounds per square foot; probably not enough to tip the scales by itself. On the shady aspects there still was an underlying temperature crust, but the 5 inches of new snow kept you above it. We had a compression test score of no failure on a 37 degree slope with a northerly aspect. We did get some sloughing of the upper 2 inches on steeper northerly aspects, but they were small in size.


No new avalanches have been reported, or were observed.

Good snow has returned to our area! Get a feel for how the new snow is bonding to the older layer by testing smaller, low consequences type slopes before you decide to jump into the bigger commitments. It probably is wise to let those stabilize for a day or so. Tree bombs had finally started to come off trees on the north this past week; they have become firmly affixed to the old snow representing a tip crossing potential.

 

[Hunter2008]

CONSIDERABLE​

Friday, March 28, 2008 7:54:16 AM

Natural avalanches possible. Human triggered avalanches probable. Natural avalanches possible. Human triggered avalanches probable.
Good Morning this is John Groom from the Payette Avalanche Center with the Avalanche Advisory for Friday March 28, 2008. Today the Avalanche Hazard is Considerable on 35 degree and steeper upper elevation slopes due to a weak bond between 6 to 8 inches of new snow and a widespread crust formed earlier this week. due to expected snowfall this hazard will increase over the next couple of days. Mid elevation sun sheltered slopes lacking an underlying crust offer a Moderate hazard. * This will be our last regularly scheduled forecast for the season. We will continue to forecast into mid April Weather and event dependant.*


Upper elevation slopes gained 6 to 8 inches of new snow this past Wednesday and Thursday with another 2 to 4 inches expected today and a possible 5 to 10 inches in the mountains tonight.. A weak bond exists between the new snow and a crust formed during clear sunny days earlier this week on most aspects of upper elevation slopes. Expect instability at this interface and use caution on slopes 35 degrees and steeper. Thursday we were able to initiate a large slide on the North East face of Beaverdam Peak near Lick Creek summit which is listed below in Avalanche activity. The avalanche hazard will only increase over the next couple of days as continued snowfall and moderate southerly winds continue to load our already stressed steep upper elevation slopes. If the idea of skiing on pins and needles in the steep peaks doesn’t sound good to you consider looking towards sun sheltered mid elevation slopes where a lack of underlying crust will mean a better bond between the new and older snowpack.

Thursday we were able to trigger a soft slab avalanche on the North East face of Beaverdam peak near Lick Creek Summit. The slab broke 12 to 6 inches deep by 75 yards wide and ran approximately 800 feet in length. The bed surface was the crust layer I mentioned earlier and the slab was new snow warmed over the course of the morning. This bed surface existed on all aspects of the peak. Numerous sluffs had occurred overnight, but this was the only slab witnessed throughout the day.

Great skiing and riding conditions exist and with more snow on the way it’s only going to get better. By this weekend we should be sitting on top of 10 to 12 inches of new powder over a firm base. It’s hard to believe we’re going into April as the mountains are still in mid winter condition.

At 7:30 in McCall its -3 degrees with calm winds and mostly clear skies. That will all change later today as more snow moves into our area with 2 to 4 inches expected today and possibly 5 to 10 inches in the mountains tonight. Winds today will increase to 20 mph out of the south with gusts up to 30mph later this afternoon. High temps today will be between 30 and 40 dropping into the teens later tonight. Expect chances of snow throughout the weekend with similar temperatures over the next couple of days

 

[Hunter2008]

Tuesday, May 06, 2008 9:13:13 AM

Natural avalanches very unlikely. Human triggered avalanches unlikely.
The Payette Avalanche Center has stopped issuing advisories for the season. We will resume forecasting in early December. Thanks to everyone who helped out this season, our partners and volunteers.