Advisory: Logan Area Mountains | utahavalanchecenter.org

Avalanche Advisory

Advisory: Logan Area Mountains	Issued by Toby Weed for Monday - November 25, 2013 - 7:20am

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Heightened avalanche conditions exist and there is a MODERATE (or level 2) danger on drifted slopes at upper elevations in the backcountry. You could trigger dangerous hard persistent slab avalanches on steep slopes and in unusual or unexpected locations. Evaluate the snow and terrain carefully, and you should continue to avoid steep and especially drifted north facing slopes at upper elevations.

current conditions

The Logan Peak weather station at 9700' reports 26 degrees and northwest wind currently averaging 23 mph, with a 35 mph gust earlier this morning. Tony Grove Snotel at 8400' reports 34 degrees, and 18 inches of total snow containing 4.3 inches of water equivalent, 90% of average water content for the date. You'll find nice soft snow on a shallow supportable base in sheltered terrain and a moonscape of sastrugi, rock hard drifts of varying depths, and slopes stripped bare of snow. Very shallow, early season snow conditions exist. The Tony Grove Road is not maintained for wheeled travel in the winter, and the road is currently somewhat treacherous. 4-wheel-drive vehicles and chains are recommended. It's important to check your avalanche rescue equipment, change to fresh batteries in your beacon, and test it's range. Refresh yourself and your partners with easy companion rescue scenarios, and continue practicing in the early season.

Check out Paige's video observation from 11-22-2013 in the Tony Grove Area.......HERE

recent activity

Observers reported a couple small natural wind slab avalanches and loose sluffs in steep terrain in the Tony Grove Lake Area last week, and I could see evidence of a hard slab avalanche high in the Mount Wellsville wilderness under Box Elder Peak. Otherwise, no significant avalanches have yet been reported in the backcountry around Logan, but several parties in the past week reported triggering audible collapses and shooting cracks indicating unstable snow conditions on drifted upper elevation slopes.

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 Triggered persistent slab avalanches 1 to 2 feet deep, releasing on sugary or faceted old snow are possible in some areas today, especially on drifted smooth upper elevation slopes. The shallow old snow from the Halloween storms remained on upper elevation north facing slopes, and it has become very weak and faceted.. Sustained and very strong east wind scoured snow from exposed terrain and drifted it into lee slope avalanche stating zones and other terrain influenced deposition areas. East winds are somewhat unusual, as our prevailing winds are normally from the west, so we'll find hard wind slabs in some unusual or unexpected areas. You could trigger a persistent slab avalanche on a steep drifted slope today, especially in a terrain feature like a gully or scoop that has old faceted snow as a basal layer. Hard slabs also likely formed around sub-ridges, timber stringers, and cliffs or rock outcroppings. Persistent slab avalanches could be triggered remotely, from a distance, or worse from below. Keep in mind that with shallow early season snow cover and sharp rocks everywhere, a ride in even a small avalanche will be fairly dangerous. Reassess your route in the case of obvious signs of instability like fresh avalanche activity, cracking within the new snow, or audible collapsing.

type

aspect/elevation

characteristics

LIKELIHOOD

LIKELY

UNLIKELY

SIZE

LARGE

SMALL

TREND

INCREASING DANGER

SAME

DECREASING DANGER

over the next 24 hours

description

Triggered persistent slab avalanches 1 to 2 feet deep, releasing on sugary or faceted old snow are possible in some areas today, especially on drifted smooth upper elevation slopes. The shallow old snow from the Halloween storms remained on upper elevation north facing slopes, and it has become very weak and faceted.. Sustained and very strong east wind scoured snow from exposed terrain and drifted it into lee slope avalanche stating zones and other terrain influenced deposition areas. East winds are somewhat unusual, as our prevailing winds are normally from the west, so we'll find hard wind slabs in some unusual or unexpected areas.

You could trigger a persistent slab avalanche on a steep drifted slope today, especially in a terrain feature like a gully or scoop that has old faceted snow as a basal layer. Hard slabs also likely formed around sub-ridges, timber stringers, and cliffs or rock outcroppings. Persistent slab avalanches could be triggered remotely, from a distance, or worse from below. Keep in mind that with shallow early season snow cover and sharp rocks everywhere, a ride in even a small avalanche will be fairly dangerous. Reassess your route in the case of obvious signs of instability like fresh avalanche activity, cracking within the new snow, or audible collapsing.

weather

A high pressure system will control the weather pattern and fair weather in the mountains will continue through most of the week. The Models advertise a change and the development of a more productive pattern early next week.

Check out our one stop weather page........HERE

general announcements

Our annual "Pray for Snow" fundraiser/party is scheduled for the evening of December 5 at the Italian Place in downtown Logan, and you are invited, so save the date.

Sign up early for one of our life-saving avalanche classes.......HERE And refresh your avalanche knowledge, check out some of our tutorials........HERE

I'll start issuing regular backcountry advisories in December.

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