Apr 11, 2008 @ 7:00 am

Late Season Information / Update

Good Morning! This is Dudley Improta with the West Central Montana Avalanche Center. We ended formal advisories last weekend. However, we have received some reports from the backcountry and we are due for a significant weather change this weekend; and this is not the spring snowpack we have been used to for a long while.

This update does not apply to operating ski areas. If you are climbing, skiing or riding at a closed-for-the-season ski area, you should treat it as the backcountry.

Weather Forecast:
Snow showers are possible through Friday morning with possible accumulation above 5000 feet. A high-pressure ridge is building to move in Friday evening, which is predicted to produce warming under mainly clear skies. Temperatures at 8000 feet could reach 57 to 67 degrees F. on Sunday. We have not seen temperatures at elevation like this for some time.

for the most recent weather information for West Central Montana.

Hazard Update
There are layers in the pack that are still failing cleanly, although with a lot of force. There are some big cornices out there on exposed leeward ridges, as well. This morning Snotel sites in the region are showing 2 to 3 inches of new snow along the Idaho border and 4 to 5 inches in the Rattlesnakes. Pay particular attention and use caution on all steep slopes during the heat of the day this weekend. The southerly aspects have some weaknesses in the upper snowpack and we have observed weak layers on northerly aspects as deep as three feet from the surface. There was a reported skier –triggered slab avalanche on a southerly aspect during the heat of the day on April 4 in the Rattlesnakes. Temperatures were recorded above 40 degrees F. on April 4. Temperatures are expected to be quite a bit higher than that this weekend.

This update expires at midnight Friday April 11, 2008.

Thanks for all the observations and support this year!


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.