Jan 25, 2008 @ 7:00 am

January 25 Avalanche Advisory

Weekend Avalanche Advisory
Posted January 25th at 0700

Hello! This is Steve Karkanen at the West Central Montana Avalanche Center with the weekend avalanche advisory for January 25th-27th, 2008. The avalanche danger rating expires at midnight January 25th. This report is based on field observations and data collected on Thursday and describes conditions seen at that time. This advisory is the sole responsibility of the Forest Service and does not apply to operating ski areas.

Weather and Snowpack Analysis

Last weekend brought another foot of snow to most locations then temperatures plummeted into the negative numbers. This cold blast was short lived as mountain temperatures have moderated the past couple of days. Temperatures this morning are much warmer at the higher elevations due to the inversion with most SNOTEL sites showing temperatures around 15 degrees. 8000′ winds at Point Six are 20mph from the W-SW. The cold clear conditions this week are giving us abundant surface hoar formation in many areas.

Observers report mostly stable and challenging skiing conditions. The wind hammered all the high elevation locations and no aspect was spared. Some locations have thin wind slabs that will need to be treated with caution but overall conditions are significantly more stable than what we’ve been seeing this season. The surface hoar seen on our tours is spread around on multiple aspects but the wind has blown it off the more open exposed terrain. This will be the next weakness to be concerned with once this is buried. Observers in the Southern Bitterroot reported small wind slabs failing on hard old snow surfaces on North aspects along with some shooting cracks in localized areas.

Today’s Avalanche Danger

Above 5000′ in all advisory area locations, the avalanche danger is MODERATE. Natural avalanches are unlikely. Human triggered avalanches are possible. Below 5000′ the avalanche danger is LOW. Natural avalanches are very unlikely and human triggered avalanches are unlikely. Low avalanche danger does not mean there is no avalanche danger.

Weather Forecast and Avalanche Outlook

A weak weather disturbance will bring increased cloud cover and light snow showers to the area Friday. A more active upper level pattern will bring a chance of heavier snowfall for the higher terrain Saturday night into Sunday. Winds aloft will increase bringing gusty winds to the mountain peaks. A winter storm watch has been issued for the Northern Clearwater Mountains for Saturday afternoon into Sunday. Moderate to heavy snowfall could impact the area as low pressure passes through the area.

Expect snowpack stability conditions to worsen during periods of heavy snowfall and high wind. We now have abundant surface hoar in widespread areas of West Central Montana. This is not a problem today but once it’s buried, it has a nasty reputation for setting up the perfect conditions for an avalanche cycle.

We’ve been getting awesome reports from many different areas recently. These reports really do help us piece together an advisory that covers a large area. If you want to send us an observation or report an avalanche, contact us by sending an email to [email protected].

The next avalanche advisory will be posted on February 1, 2008.


This information is the sole responsibility of the Forest Service and does not apply to operating ski areas. The avalanche danger rating expires at midnight tonight but the information can help you make a more informed decision regarding travel in avalanche terrain for the next few days.

Our advisory area includes National Forest System lands in the Bitterroot Mountains from Lost Trail Pass north to Granite Pass, the Rattlesnake Mountains north of Missoula and the Southern Swan and Mission Mountains near Seeley Lake, MT. Avalanche information for the Lookout Pass/St. Regis Basin area is available from the Idaho Panhandle Avalanche Center.