Avalanche forecast

Avalanche forecast

Payette Avalanche Center
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Avalanche danger

Alpine
1 · Low
Treeline
1 · Low
Below
1 · Low
Out of date — this forecast expired 3 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

Overall, stable snowpack conditions exist. Small, wet loose avalanches will be possible again today on steep, south-facing slopes. The upper few inches of snow could become moist and unstable by mid-day. Pay attention to clues (such as pinwheels or rollerballs) that the snow is becoming moist before jumping on a steep south-facing slope this afternoon.

Today's avalanche forecast is sponsored by Outer Impact of Boise

Avalanche problems

  • Loose Wet

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–1.5

    Expect another day with the potential for strong solar radiation on slopes that face the sun. Wet loose avalanches will be possible on any south-facing slope. Snow will begin shedding off rocks, trees, and cliffs in steep terrain; as daytime heating increases and more of the upper snow becomes saturated, these wet loose slides could entrain more snow and run farther distances. Scattered cloud cover and breezy conditions may keep air temperatures cooler, especially on shaded aspects. Pay close attention to the sun (not air temperature) with wet loose avalanches. If the sun is directly shining on steep slopes, wet loose avalanches are possible.

    Watch for pinwheels or rollberballs coming down the slope. These are a sign that the snow surface is becoming moist and unstable. Clues such as these are indicators that wet loose avalanches are becoming more likely. Pay attention to the terrain above you if wet loose avalanches begin to increase. Wet loose slides may contain the upper several inches of surface snow, but small wet slides that run long distances can be consequential in steep terrain. Pay attention to clues that the snow is becoming moist before jumping on a steep south-facing slope.

Avalanche Discussion

On shaded aspects, surface snow is becoming weak and loose. Yesterday, on West Mountain we observed some "loud powder" (noisy, weak snow at the surface) on shaded aspects. Just as you'll find Wet Loose on solar aspects, you can expect to find Wet Loose's cousin (Dry Loose) on shaded aspects. These small sluffs will contain the upper several inches of surface snow and should remain small. Pay attention to terrain features above and below you, such as trees, rocks, cliffs, gullies, and depressions.

FEBRUARY CONDITIONS UPDATE

Late January, we saw a significant rain event where rain levels rose up over 8000'. On the heels of the rain event, we experienced 4 days of near record warming. All of this warm, wet weather saturated most of the existing snowpack making an already dense slab of snow even denser. As temperatures cooled, the saturated snow formed a very thick crust complex that was buried on 02/01. The first 8 days of February, the region experienced cool weather with consistent light snowfall. Stability and snow conditions improved significantly during the first 10 days of February. Five days of dry weather brought us to Valentine's Day. Before last week's storm, we noticed facets forming above and below the 02/01 crust complex. The mountains received 1-2' of snow last Wednesday-Friday. There was a brief natural avalanche cycled that ensued at the tail end of the storm. Three more days of dry weather with one 24-hour period with below average temperatures. Monday-Wednesday this week, the mountains picked up another 5-10" of snow with warmer than average temperatures. During the month of February, every avalanche problem listed in the forecast has been new snow related (loose snow, wind slab, storm slab). The weak snow adjacent to the 02/01 crust complex has been healing with recent warm weather. Today, we'll have another warm, sunny day with good stability. Sunday, will be a day of transition as a storm system approaches and winter returns for the week.

If you're out in the mountains over the weekend, let us know what you're seeing by submitting an observation. Every observation submission gets entered into the FPAC monthly raffle and you could win some great prizes courtesy of the FPAC. Tell us what you're seeing when you're out riding in the mountains. Observations (such as these recent ones) can greatly improve information for avalanche forecasts.