GNFAC Avalanche Advisory for Fri Mar 7, 2014
Good Morning. This is Mark Staples with the Gallatin National Forest Avalanche Advisory issued on Friday, March 7 at 7:30 a.m. Grizzly Outfitters, in partnership with the Friends of the Avalanche Center, sponsors today’s advisory. This advisory does not apply to operating ski areas.
Yesterday the Bridger Range received 10 inches of heavy snow (15% density) and all other areas received 4-6 inches of similar snow. Low elevation areas received some rain. Temperatures this morning were in the 20s F. Ridge top winds yesterday were blowing 20-30 mph with some gusts of 50 mph. This morning winds had eased and were blowing westerly 10-15 mph gusting to 25 mph. Today temperatures should warm to near 30 F and by afternoon winds should ease a bit more. About 1 inch of new snow should fall today.
Yesterday the Fisher Creek SNOTEL site recorded 0.9 inches of snow water equivalent (SWE) that fell as 6 inches of dense snow. This snowfall continues an unbelievable period of nearly constant snowfall since late January (chart from Fisher Creek). With this constant
Gallatin Range Madison Range
Lionhead area near West Yellowstone
Yesterday’s precipitation totaled 1 inch of snow water equivalent (SWE) near West Yellowstone, 0.7 inches near Big Sky, 0.6 inches near Carrot Basin, and 0.4 inches south of Bozeman in Hyalite. In low elevation areas some of this precipitation fell as rain.
Yesterday in Hyalite Canyon on Mt. Blackmore my partner and I found the January facets buried almost 3 feet deep (ECTP 22). One problem is that many slopes produced avalanches in late December and early January. These slopes may have a weaker snowpack than slopes where we typically perform
- Yesterday’s precipitation was a rapid and heavy load especially near West Yellowstone. Whether it fell as snow, rain, or a mix of the two, it all counts as weight added to the snowpack. More weight means more stress on buried
- Avalanche activity continues to occur. This activity hasn’t been a widespread cycle of avalanches, but avalanches have occurred at least somewhere on most days.
Together, these facts tell us there’s a good chance of more avalanches today. Most
There are two ways to rate the avalanche danger (danger scale). One is based on the likelihood of
Yesterday the Bridger Range received 10 inches of snow with nearly 1.5 inches of SWE. This snow fell in a period of about 5 hours. This rapid, heavy load is a red flag by itself. An avalanche was spotted on Saddle Peak yesterday involving the new snow that ran from the summit past the cliffs. The Bridger Bowl Ski Patrol found that the new snow had bonded fairly quickly, and they did not
I will issue the next advisory tomorrow morning at 7:30 a.m. If you have any snowpack or avalanche observations drop us a line at firstname.lastname@example.org or call us at 587-6984.
It’s worth noting that
BACKCOUNTRY SKIERS AND RIDERS NEEDED FOR MSU SURVEY
This project aims to collect GPS location information and survey responses from backcountry skiers and riders to better understand what types of terrain decision we make. The focus is on backcountry skiers and riders of all abilities and experience. You need not be an expert backcountry skier to participate in this research. For more information and to sign up: www.montana.edu/snowscience/tracks