GNFAC Avalanche Forecast for Sat Apr 4, 2020

Not the Current Forecast

Good Morning. This is Ian Hoyer with the Gallatin National Forest Avalanche Forecast on Saturday, April 4th at 7:00 a.m. Today’s forecast is sponsored by Klim Gear and Grizzly Outfitters.

Bridger Bowl is closed and advises against uphill travel which could place first responders at risk. Backcountry conditions exist. There is no avalanche control or ski patrol rescue. Please do not loiter or congregate in the parking lots.

Mountain Weather

Yesterday morning it snowed 2-3 inches near West Yellowstone and Cooke City, while the mountains around Big Sky and Bozeman stayed dry. This morning temperatures are in the teens and low 20s F. Winds are southwest and west at 10-25 mph with gusts of 30-45 mph. Clouds will break up this morning leaving us with mostly sunny skies. Winds today will be 10-25 mph out of the southwest. Temperatures will rise into the mid-30s F. A dusting of snow is possible overnight.

Snowpack and Avalanche Discussion

All Regions

Winds picked up yesterday, building fresh drifts that can be triggered by a skier or rider today. Skiers in the Bridger Range yesterday saw rapid wind loading near the ridge. Be skeptical of any recently wind-loaded slope and steer clear of fresh drifts. If you feel the snow surface stiffen and see cracks shoot out in front of you, you’ve found one of these drifts and should carefully retreat out of steep terrain.

Avalanches can also break on weak layers buried 2-3 feet deep. It’s worth digging down to look for these weak layers, as not every slope has them. Yesterday, Doug found good stability on a west facing slope in Beehive Basin with a number of ice crusts in the upper snowpack that were well bonded (video), but noted that other slopes have surface hoar or near surface facets instead. Skiers near Ross Pass yesterday got a big collapse on facets near an ice crust as they stepped out of their skis to dig a snowpit (details). They took that clear sign of instability as a clue to avoid steep terrain and chose an alternative, mellower, route back to the trailhead. Just to the south, a different group found buried surface hoar and got unstable test results. A collapse and unstable test results are evidence that the potential still exists to trigger avalanches on these layers. Careful analysis of these layers is needed before committing to steep terrain.

Temperatures are going to rise another 5 degrees warmer than yesterday. With sunny skies this afternoon, the snow surface will become wet, lose cohesion and become unstable. Watch for roller balls and pinwheels as clues that this process is starting. Plan to be off steep, sun exposed slopes by early afternoon to avoid triggering a wet snow avalanche.

The avalanche danger is rated MODERATE across our advisory area.

We are ending daily avalanche forecasts tomorrow Sunday, April 5th and will post general weather and avalanche bulletins every Monday and Friday through April. Continue to send us your observations. You can fill out an observation form, email us (mtavalanche@gmail.com), leave a VM at 406-587-6984, or Instagram (#gnfacobs).


Closures and Stay-at-home Order

A Stay at Home order is in effect for the State of Montana due to COVID-19. This order specifically discourages “outdoor recreation activities that pose enhanced risks of injury or could otherwise stress the ability of local first responders to address the COVID-19 emergency (e.g., backcountry skiing in a manner inconsistent with avalanche recommendations or in closed terrain)”.

Park County is requesting anyone who is not a permanent resident or provider of essential service to avoid travel to Cooke City/ Silvergate. This includes both single day and overnight visitors.

Hyalite Canyon is closed to vehicle traffic and will reopen on May 15th. This is the regular spring use closure.


Avalanche Education & Events

Give Big Gallatin Valley is April 30th - May 1st. The Friends of the Avalanche Center are participating again this year and we’d really appreciate your support!

If you like to plan ahead, you can put the PowderBlast on your calendar for next fall (Friday, October 23rd, 2020). This event is always a good time and is our biggest fundraiser of the year. Hope to see you there!

The Last Word

Yesterday, a snowmobiler was caught in an avalanche and killed in the Palisades area of SE Idaho (news report). This is less than 20 miles from where a backcountry skier was caught, buried, and killed in an avalanche on Taylor Mountain, near Teton Pass, in Wyoming on Wednesday (news report).


  <<    >>