Avalanche Advisory
Advisory: Logan Area Mountains Issued by Paige Pagnucco for Wednesday - January 18, 2017 - 5:33am
bottom line

The avalanche danger is LOW. Though natural and human triggered avalanches are unlikely, avalanches are still possible in isolated areas. Pay particular attention to daytime warming and its destabilizing effect on steep, southerly facing slopes. Avoid cornices, as they could break back further than expected, slopes with fresh wind drifts, and steep, rocky slopes with thin overall snow cover.




current conditions

The Tony Grove Snotel at 8400' reports 26 degrees F with 89 inches of total snow containing 163% of average SWE (Snow Water Equivalent). It's 25 degrees F at the CSI Logan Peak weather station at 9700', and winds are blowing 15-20 mph out of the southwest. Everyone is apparently finding good snow stability, with no word of recently triggered avalanches. Feathery surface hoar is widespread at all elevations and on shaded aspects in particular, the snow surface has weakened significantly. Good news - The surface hoar combined with small faceted crystals makes for "loud", fast, and excellent powder riding conditions. Bad news - If this layer gets buried intact beneath a slab, it has the potential to become a very dangerous weak layer.

Surface hoar is widespread in the Logan Zone.
recent activity

No new avalanches have been reported since last week's widespread, natural avalanche cycle.

List of notable activity from last week:

  • A natural avalanche hit Hwy 89 in the Beaver Canyon section of Logan Canyon just after noon Wednesday, closing the road until Thursday morning.
  • A dirt-filled natural avalanche in Zanavoo Gully in lower Logan Canyon ran about 2800' early Thursday morning, stopping 100 vertical feet above the Logan River Trail.
  • Natural avalanche activity in the Wellsville Range was extensive, and HUGE fresh natural avalanches can be seen from across Cache Valley.
  • Observers reported large, natural avalanches from the recent cycle on the east face of Mt. Magog, Cornice Ridge, Providence Peak, Hell's Kitchen, Tab Hollow, Steam Mill, Wood Camp, and Thurston Hollow in the Mount Naomi Wilderness.

Large, natural avalanches from last week in the Wellsville Range above Mendon.
Avalanche Problem 1
type aspect/elevation characteristics
LIKELIHOOD
LIKELY
UNLIKELY
SIZE
LARGE
SMALL
TREND
INCREASING DANGER
SAME
DECREASING DANGER
over the next 24 hours
description

Persistent slab avalanches, failing on buried weak layers, are unlikely but possible. Large, natural avalanches stepping into old snow were common during last week's storm. Weak layers of faceted snow exist above and below rain-crusts at mid and lower elevations. The snow is weakest in rocky terrain where it's thin or shallow. These types of avalanches are low probability - high consequence, meaning you're unlikely to trigger one, but if you get caught, you could get seriously injured. Sticking to slopes less than 30 degrees is a great way to avoid this problem altogether.

Avalanche Problem 2
type aspect/elevation characteristics
LIKELIHOOD
LIKELY
UNLIKELY
SIZE
LARGE
SMALL
TREND
INCREASING DANGER
SAME
DECREASING DANGER
over the next 24 hours
description
  • Large cornices developed on the exposed ridges during the recent storm and many are still sensitive to human weight. Cornices can break further back than expected and might trigger avalanches on drifted slopes below.
  • Winds ahead of the upcoming change in weather could create wind drifts today in upper elevation terrain. Avoid steep slopes with freshly wind- drifted snow.
Avalanche Problem 3
type aspect/elevation characteristics
LIKELIHOOD
LIKELY
UNLIKELY
SIZE
LARGE
SMALL
TREND
INCREASING DANGER
SAME
DECREASING DANGER
over the next 24 hours
description

The danger of wet avalanche activity will start out low this morning but could rise to moderate on southeast, south, southwest, and west facing steep slopes at mid and upper elevations as temperatures are expected to be toasty today in the mountains. Winds blowing from the southwest will usher in warm air with high's expected to reach the mid 30's at 8500'. If you notice the snow getting moist, it's time to move off of and out from under steep slopes and into more shaded terrain. Rollerballs, point releases and wet sluffing are all good indicators of increasing instability. Avoid sunny slopes in the heat of the day.

weather

One more day of beautiful, sunny high pressure before the weather becomes unsettled again starting tonight.

Today: Mostly sunny, with a high near 33. West wind 14 to 16 mph.
Tonight: A 20 percent chance of snow. Mostly cloudy, with a low around 20. Southwest wind 10 to 14 mph.
Thursday: Snow. High near 30. Southwest wind around 16 mph. Chance of precipitation is 90%. New snow accumulation of 1 to 3 inches possible.
Thursday Night: Snow, mainly before 11pm. Low around 19. West southwest wind around 11 mph. Chance of precipitation is 90%.
New snow accumulation of 2 to 4 inches possible.
Friday: A 50 percent chance of snow. Cloudy, with a high near 29. Southwest wind around 7 mph. New snow accumulation of less than one inch possible.

general announcements

Any time is a great time to practice companion rescue techniques with your partners. Companion Rescue Practice Video

The National Avalanche Center just released their Avalanche Problems Explained video... Not all avalanches are made the same. As a result, travel and decisions in avalanche terrain are influenced by the kind of avalanche you expect to encounter. Watch HERE

Discount lift tickets for Beaver Mountain, Snowbasin, Powder Mountain, and the Central Wasatch resorts are donated by the resorts to benefit the Utah Avalanche Center. Details and order information here.

Your information can save lives. If you see anything we should know please help us out by submitting snow and avalanche observations. You can call us at 801-524-5304, email by clicking HERE, or include @utavy in your Instagram. In the Logan Area you can reach me at 435-757-7578

We will update this advisory regularly on Monday, Wednesday, Friday, and Saturday mornings by about 7:30.

This advisory is from the U.S.D.A. Forest Service, which is solely responsible for its content. This advisory describes general avalanche conditions and local variations always exist.