Avalanche Advisory
Advisory: Logan Area Mountains Issued by Toby Weed for Sunday - December 11, 2016 - 6:57am
bottom line

Significant accumulations of heavy new snow, consistent and strong westerly winds, and widespread areas with preexisting weak snow, created very dangerous conditions and a HIGH avalanche danger at upper elevations. Avoid travel in backcountry avalanche terrain, and stay clear of and out from under steep slopes and obvious or historic avalanche paths.

  • Very shallow early season snow cover exists in the backcountry, and hitting rocks is still a serious concern.
  • You don't want to take a ride even in a small avalanche, as you could easily be injured with the shallow snow hardly covering up the rocks and dead-fall in avalanche runout zones.
avalanche warning

THE FOREST SERVICE UTAH AVALANCHE CENTER IN SALT LAKE CITY HAS EXTENDED THE BACKCOUNTRY AVALANCHE WARNING.

* TIMING...IN EFFECT THROUGH 600 AM MONDAY.

* AFFECTED AREA...THE NORTHERN WASATCH MOUNTAINS EAST OF OGDEN AND LOGAN...AND THE BEAR RIVER RANGE.

* AVALANCHE DANGER...THE AVALANCHE DANGER REMAINS HIGH AT THE UPPER AND MID ELEVATIONS...AND WILL REMAIN ELEVATED THROUGH EARLY MONDAY MORNING.

* REASON/IMPACTS...DENSE HEAVY SNOW COMBINED WITH STRONG WINDS HAVE CREATED WIDESPREAD AREAS OF UNSTABLE SNOW AT THE MID AND UPPER ELEVATIONS. BOTH HUMAN TRIGGERED AND NATURAL AVALANCHES ARE CERTAIN. STAY OFF OF AND OUT FROM UNDER SLOPES STEEPER THE 30 DEGREES.

BACKCOUNTRY TRAVELERS SHOULD CONSULT WWW.UTAHAVALANCHECENTER.ORG OR CALL 1-888-999-4019 FOR MORE DETAILED INFORMATION. THIS WARNING DOES NOT APPLY TO SKI AREAS WHERE AVALANCHE HAZARD REDUCTION MEASURES ARE PERFORMED.
special announcement

Thanks to you our annual Pray for Snow party was obviously a big success, and it worked. The SNOW IS HERE!
current conditions

The storm has created very dangerous conditions and a HIGH avalanche danger on many slopes in the backcountry. Natural avalanches are still possible and triggered avalanches remain likely on many upper and mid-elevation slopes steeper than about 30 degrees...

Observers yesterday reported about 20" of heavy new snow above 8000', and the Tony Grove Snotel reports lots of heavy snow containing 4.7 inches of water accumulation since Thursday and 2" of water in the past 24 hrs. I'm reading much cooler 20 degrees this morning at 8400'. It's 13 degrees at 9700' at the CSI Logan Peak weather station, and the wind sensor is rimed. The UDOT Hwy 89 Logan Summit Wx station reports 20 degrees and northwest winds averaging around 25 mph, and gusting in the upper 30s....

  • Remember, the Tony Grove Road is a busy shared use area, so you have to watch your speed around pedestrians and dogs. The road is not maintained for driving in the winter, so be prepared with shovel and winter survival gear if you attempt the drive.
  • Beaver Mountain welcomes up-hill hiking traffic this time of year as it helps to pack out the slopes, but you should consider it as "backcountry terrain" before they open the lifts to the public.
recent activity

Observers report a large natural avalanche, failing on weak snow near the ground on Chicken Hill in the Bunch Grass drainage.


A sizable natural avalanche on Chicken Hill (12-10-2016)
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

Natural and triggered persistent slab avalanches are likely at upper and mid elevations in the backcountry. Significant accumulations of heavy new snow, sustained west wind, and warmer temperatures created a HIGH danger of persistent slab avalanches. The prolonged storm overloaded preexisting shallow faceted snow, weakened rapidly last week by a large temperature gradient due to the very cold temperatures in the mountains.

Destructive deep slab avalanches, failing on weak snow near the ground are likely on upper elevation north facing slopes.
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

Dangerous wind slab avalanche conditions exist on drifted slopes in the backcountry. Expect the danger to remain throughout the day, with significant drifting from northwest winds likely to continue.

weather

The last weather disturbance from this weekends long duration storm will cross northern Utah and southwest Wyoming this morning. Drier conditions will cover much of the area through early Tuesday, followed by a return of a moist westerly flow aloft midweek.

Weather Forecast: Tony Grove Lake (41.897,-111.6535), Elevation: 8800'
Overnight: A 50 percent chance of snow showers. Cloudy, with a steady temperature around 17. Wind chill values as low as -1. Blustery, with a west northwest wind around 23 mph. Total nighttime snow accumulation of 1 to 3 inches possible.
Sunday: A 50 percent chance of snow showers, mainly before 11am. Mostly cloudy, with a temperature rising to near 21 by noon, then falling to around 8 during the remainder of the day. Wind chill values as low as -11. Blustery, with a west wind 17 to 23 mph. New snow accumulation of less than a half inch possible.
Sunday Night: A 30 percent chance of snow showers. Mostly cloudy, with a temperature rising to around 15 by 10pm. Wind chill values as low as -10. Breezy, with a west wind 20 to 24 mph, with gusts as high as 38 mph. New snow accumulation of less than a half inch possible.
Monday: A 20 percent chance of snow. Cloudy, with a high near 20. Wind chill values as low as -9. Breezy, with a west wind around 22 mph.
Monday Night: A 40 percent chance of snow. Cloudy, with a low around 7. West wind 17 to 21 mph. New snow accumulation of 1 to 2 inches possible.

general announcements

The early season is a great time to refresh yourself and practice companion rescue techniques with your partners.

Check out Avalanche Canada's "Rescue at Cherry Bowl" story HERE

Between now and Jan 15th: Donate to the Utah Avalanche Center by shopping at Whole Foods Market Utah! When you visit any Utah Whole Foods Market locations, bring your re-usable bags, Whole Foods will donate a dime per bag to the Utah Avalanche Center - if you say DONATE my bag credit.

Remember your information can save lives. If you see anything we should know about, please help us out by submitting snow and avalanche observations. You can also call us at 801-524-5304, email by clicking HERE, or include @utavy in your Instagram. In the Logan Area you can get ahold of your local avalanche forcaster, me (Toby Weed), at 435-757-7578

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.