Logan Avalanche Advisory

Forecaster: Toby Weed

BOTTOM LINE

Danger by aspect and elevation on slopes approaching 35° or steeper.
(click HERE for tomorrow's danger rating)


Danger Rose Tutorial

Warm and windy conditions over the weekend helped to maintain a level 2 or Moderate danger in the backcountry around Logan, and heightened avalanche conditions exist in drifted areas and on steep slopes with saturated snow. You could trigger wind slab avalanches, mainly at upper elevations and in exposed, lee terrain. Although still fairly unlikely, more dangerous hard slab avalanches running on buried persistent weak layers are possible in isolated places with significant deposits of recently drifted snow and on some warmth-softened slopes. Solar warming and warm mountain temperatures will cause a possibility of wet avalanches on steep slopes with saturated snow. Continue to practice safe travel protocols and evaluate the snow and terrain carefully, especially on recently drifted or sun softened slopes...

CURRENT CONDITIONS

Strong southwest winds and warm mountain temperatures over the weekend wrecked the friendly shallow powder conditions in many areas, leaving sheltered shady slopes the desired option. I did find a little spring-like supportable "corn" snow in sunny terrain yesterday, but warm air temperatures and solar heating are softening the snow, even exposed once rock solid January ice-crusts. At least rime melted off the wind sensor at the CSI weather station at 9700' on Logan Peak, and the station is recording 25 mph west winds and a balmy 29 degrees at 6:00 this morning. The Tony Grove Snotel reports a very marginal overnight refreeze and a toasty 34 degrees this morning... Apparently, we picked up a couple inches of snow last night, with 2/10ths of an inch of water, and there's 88 inches of total snow on the ground at 8400'.

RECENT ACTIVITY

We received a second-hand report of a close call in the Western Uinta Mountains yesterday, with two partial and a full burial.... Apparently, everything turned out alright, all machines were recovered, and no injuries were reported... Locally; a snowmobiler went for a nice ride when a large cornice broke out under him up on Cornice Ridge yesterday. He was wearing a helmet-cam and caught some heart-pumping footage of the event. HERE

Check our backcountry avalanche list.... HERE

THREAT #1
WHERE PROBABILITY SIZE TREND
      Over the next 24 hours.

An observer reports triggering an audible collapse or whumpf yesterday under wind-jacked snow in Franklin Basin, another was noted by a couple members of my party near the summit of Big Baldy on Friday. Collapsing indicates the presence of unstable buried weak layers.

Some of the stiff wind slabs that built earlier in the week and over the weekend are resting on weak sugary snow and/or feathery surface hoar above a solid ice-crust from mid-January rain. Watch for and avoid recent wind drifts on steep slopes off the lee sides of ridges and sub-ridges, under cliff bands, around rock outcroppings, along gully walls, or in scoops or depressions. Wind slab avalanches are possible on drifted slopes steeper than about 35 degrees... Dangerous and destructive hard slab avalanches involving old snow, running on January weak layers below the ice-crust, and in the 1 to 3 foot-deep range are unlikely but still possible on isolated slopes with significant recent wind loading and existing buried weak layers. Other than the presence of recently drifted snow, there may be no prior warning signs, but remember that collapsing is a major red flag. You might trigger a persistent slab avalanche remotely or from a distance, and hopefully not from below....

THREAT #2
WHERE PROBABILITY SIZE TREND
      Over the next 24 hours.

Ridgetop cornices could break further back and be larger than expected, and falling cornice chunks might trigger wind slab avalanches on slopes below.

THREAT #3
WHERE PROBABILITY SIZE TREND
      Over the next 10 hours.

With mountain temperatures climbing well above freezing again today, many sunny slopes may be adversely affected by the higher angled February sun, but shady slopes may also become damp today, and wet avalanches are possible on any steep slope where the snow becomes damp or saturated.

MOUNTAIN WEATHER

We'll see a good deal of sunshine and continued southwest wind in the mountains today, with a high pressure firmly in place over the area. Mountain temperatures will warm up a bit today with a high of about 42 degrees forecast for 8000', and continuing moderate southwest winds. South and southwest winds will intensify tomorrow and will be even stronger on Wednesday, with gusts of around 45 mph likely and thunder storms possible. Expect a storm Wednesday night with 6-10 inches forecast.....

GENERAL ANNOUNCEMENTS

You can view a photo summary of last year's avalanche activity in the Logan Area HERE

Join the friends of the Utah Avalanche Center in Logan on facebook. Click HERE

I will update this advisory in the mornings on Mondays, Wednesdays, Fridays, and Saturdays, and on other days if backcountry avalanche conditions warrant...

You have the opportunity to participate in the creation of our own community avalanche advisory by submitting avalanche and snow observations. You can also call us at 801-524-5304 or Toby at 435-757-7578, or email by clicking HERE

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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 occur.

This information does not apply to developed ski areas or highways where avalanche control is normally done.  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 occur.

This advisory provided by the USDA Forest Service, in partnership with:

The Friends of the Utah Avalanche Center, Utah Division of State Parks and Recreation, Utah Division of Emergency Management, Salt Lake County, Salt Lake Unified Fire Authority and the friends of the La Sal Avalanche Center. See our Sponsors Page for a complete list.