Advisory: Logan Area Mountains | Issued by Toby Weed for March 8, 2013 - 6:35am |
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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, there's a MODERATE (or level 2) danger in the backcountry, and you could trigger wind slab avalanches and/or cornice falls in drifted terrain. Recently added weight from drifting snow and/or rain could reactivate dormant weak layers consisting of sugary faceted snow, and dangerous persistent slab avalanches are possible in outlying terrain with poor snow structure. Rain and daytime warmth will again soften the saturated lower elevation snow and increase the danger of wet avalanches. Evaluate the snow and terrain carefully, and continue to use safe backcountry travel protocols.
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current conditions The Tony Grove Snotel at 8400' reports 1 inch of new snow in the last 24 hours containing 2/10ths of an inch of water. It's 28 degrees, and with 64" of total snow, the station sits at 65% of average water for the date. The CSI Logan Peak weather station at 9700' reports 22 degrees and southeast winds averaging around 10 mph this morning after sustaining closer to 30 mph hourly average wind speeds for several hours overnight.. I found nice powder riding conditions yesterday in the Franklin Basin Area, with a few inches of fresh snow and close to a foot of accumulation since last weekend in sheltered upper elevation terrain.
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recent activity We observed numerous natural loose wet avalanches from last Sunday involving rain-saturated snow and gouging to the ground at lower elevations in Logan Canyon, Providence Canyon, and across the region. A skier easily intentionally triggered a couple nice fresh hard wind slabs with cornice drops in the Ogden Area Mountains Wednesday. The largest of these was reported to be 1 to 3 feet deep and up to around 250' wide. No new avalanches were reported or observed in the Logan Area this week.. 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
Drifting of the week's fresh snow from sustained southeast winds overnight and south winds Wednesday created heightened wind slab avalanche conditions, mainly at upper elevations, I found Wednesday's drifts to be fairly well bonded in Steep Hollow yesterday, but there are areas where wind slabs built up on weaker surface snow. More fresh snow is likely today and tonight and drifting will continue to develop and thicken wind slabs. You could trigger wind slabs and/or cornice falls in steep drifted upper and mid elevation elevation terrain today. Watch for and avoid stiffer wind deposited snow on the lee side of major ridges and in and around terrain features like sub-ridges, cliff bands, and steep walled gullies. Ridge top cornices might break further back than expected, and cornice falls could trigger more dangerous slab avalanches on steep slopes below.
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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
Isolated persistent slab avalanches up to around 2-and-a-half feet deep, failing on weak sugary faceted snow or basal layer depth hoar are possible in outlying areas with shallow and poor snow structure. The added weight from this week's drifted snow and/or rain also might be enough to activate buried dormant weak layers in some areas, and dangerous triggered avalanches are a possibility that I must continue to include in this discussion. Whumpfing is a significant red flag indicating potential persistent slab instability.
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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
Daytime warming and continued rain at lower elevations will continue heightened wet avalanche conditions today, and you could trigger wet avalanches if you venture on steep slopes with saturated surface snow. Wet slabs are possible in some areas with saturated snow and poor snow structure. |
weather Expect some snow, mild temperatures, and moderate southwest winds today, becoming light and variable in the afternoon. Expect high temperatures at 9000' of around 31 degrees and an inch or two of accumulation forecast. Mild and moist weather will continue into the weekend, with another couple inches of accumulation possible tonight and intensifying north winds. It'll be mostly cloudy and windy tomorrow, with temperatures hovering just under freezing and north winds, with wind speeds averaging in the mid twenties and gusting to near 40 mph. Clearing and sunny conditions are expected to redevelop around Sunday. Check out the Logan Mountain Weather page...
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general annoucements Go to http://www.backcountry.com/utah-avalanche-center to get tickets for Beaver Mountain. You won't save a ton of money, but all proceeds from sales of these tickets will benefit the Utah Avalanche Center, and It's super easy to do. 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. |