Advisory: Logan Area Mountains | Issued by Toby Weed for April 12, 2013 - 6:50am |
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Above 8,500 ft.
7,000-8,500 ft.
5,000-7,000 ft.
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bottom line Heightened avalanche conditions exist and there is a MODERATE (or level 2) danger in the backcountry. You could trigger wind slab avalanches on steep slopes with recent deposits of heavy wind drifted snow, and natural cornice falls are possible. Rapidly rising temperatures and strong solar warming will create heightened and potentially dangerous avalanche conditions in steep terrain, with wet or heat related soft slabs and entraining loose snow avalanches involving Tuesday's storm snow possible on steep slopes with lots of recent accumulation. Evaluate the snow and terrain carefully, avoid steep drifted terrain and steep slopes with warming or saturated fresh snow.
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special announcement UDOT avalanche forecaster Craig Patterson died in an avalanche near Kessler Peak in Big Cottonwood Canyon in the Salt Lake Area Mountains late yesterday. Our deepest sympathy goes out to his family and friends. |
current conditions The Tony Grove Snotel reports 26 degrees and 58 inches of total snow, containing 64% of average water for the date. The station recorded a couple feet of accumulation and 3.2 inches of snow-water equivalent in the last week, (since last Friday morning.) The CSI Logan Peak weather station at 9700' reports 23 degrees and northwest winds averaging a bit over 20 mph this morning. Tuesday's very windy storm consisted of a strong and somewhat unusual northeasterly (wrap around and up-slope) flow. An extraordinary amount of new snow fell Monday night and Tuesday on the eastern side of the Bear River Range, while strong northeast winds battered the high peaks and the west side of the range. The UDOT Hwy 89 Logan Summit weather station reported 25 inches of new snow, while the Campbell Scientific weather station was blasted by northeast winds with 55 mph average wind speeds and 80 mph gusts. This resulted in widely varied snow conditions, with widespread wind damage and extensive drifting. There is much less fresh snow on the west side of the Bear River Range, but more wind damage. Solar warming was the issue yesterday, and rapid warming from the the high angled sun affected the fresh snow, moistening the surface which will have refrozen into crusts of varying thickness overnight. Video Observation, 4-9-2013, Swan Flats Area
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recent activity Bruce Tremper and Drew Hardesty of the Utah Avalanche Center are on their way up to the site of yesterday's tragic avalanche accident in Big Cottonwood Canyon in the Salt Lake Area Mountains this morning, and will submit a report on this Website as soon as they can. No significant new avalanches were reported recently in the Logan Area, but I certainly wouldn't be surprised to hear of or observe evidence of some from this week, and only a few people have been out in the backcountry in the last few days..... Here's a link to our updated Avalanche List.
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type | aspect/elevation | characteristics |
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Above 8,500 ft.
7,000-8,500 ft.
5,000-7,000 ft.
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description
Triggered wind slab avalanches in the 1 to 3-foot-deep range remain possible in drifted upper elevation terrain, and rapid warming could make these more sensitive to triggering. Watch for and avoid stiffer snow and fresh drifts on the lee of major ridges and in and around terrain features like sub-ridges, rock bands, and gullies. In isolated places, the wind drifts could have overloaded pockets of shallow weak snow in rocky upper elevation terrain, resulting in potential for a deeper slide. Recently built-up and greatly enlarged cornices are also a concern, as they may still be somewhat sensitive today, might break further back than you expect, and could trigger significant slab avalanches on slopes below. Warmth and strong sun today will cause these guys to sag and buckle, and some may naturally calve off during the midday heat. |
type | aspect/elevation | characteristics |
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Above 8,500 ft.
7,000-8,500 ft.
5,000-7,000 ft.
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description
Solar warming will cause this week's fresher snow to become saturated and more likely to avalanche. Crusts from overnight cooling will quickly soften in the high angled sun, which is getting onto all slopes around midday these days. Natural soft slab avalanches are possible in steep terrain as the snow surface becomes saturated and triggers roll off rock bands or tree limbs onto steep slopes today. Triggered moist sluffs or point release type avalanches could entrain significant snow in descent and pile up deeply below steep slopes. Be sure nobody is below or above you, and watch for potential terrain traps.... |
weather A weak high pressure system will control the weather today, and it'll be very sunny in the mountains with 9000' high temperatures around 40 degrees and calm winds becoming light and westerly in the afternoon. It'll be partly cloudy tonight with mountain low temperatures hovering around freezing and increasing southwest winds. Snow showers are likely tomorrow after around noon, we'll see fairly strong west-southwest winds, temperatures are expected to be in the upper thirties, and 1 to 3 inches of accumulation is forecast. Snow showers should continue through Saturday night and into Sunday, but not much in the way of accumulation is expected and temperatures will stay cool, with highs below freezing Sunday and Monday. Check out the Logan Mountain Weather page...
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general annoucements For a printer friendly version of this advisory click HERE Remember your information from the backcountry can save lives. If you see or trigger an avalanche, or see anything else we should know about, please send us your snow and avalanche observations. You can also call us at 801-524-5304 or email by clicking HERE. In the Logan Area you can contact Toby Weed directly at 435-757-7578. I will update this advisory on Monday, Wednesday, Friday, and Saturday mornings by around 7:30... This advisory is produced by the U.S.D.A. Forest Service, which is solely responsible for its content. It describes only general avalanche conditions and local variations always exist. |