Avalanche advisory: where to go, what to avoid
WINTER SPORTS -- Idaho Panhandle Avalanche Center technicians found great riding and sliding conditions in the mountains during their Thursday survey, but they also found areas to avoid, according to the report posted this morning.
The snow was lighter on top and firmer down toward the crust buried about 4 feet deep. Slopes in sheltered areas showed some weak layers that have not bonded in the upper 1-2 feet but they are moderately stable.
Steeper exposed windloaded slopes, N-E-SE, will be the areas to avoid today where slabs will be firmer and under some stress. Watch the weather Saturday night into Sunday for snowfall amounts, increasing winds, and warming temperatures.
Read on for the complete advisory issued today for the Selkirks and Lookout Pass regions.
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AVALANCHE ADVISORY |
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U.S. FOREST SERVICE |
FORECASTER: Davis |
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IDAHO PANHANDLE AVALANCHE CENTER |
EFFECTIVE DATE: 01/27/2012 |
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DATE ISSUED: 01/27/2012 0730 |
OUTLOOK: 01/27-29/2012 |
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This report does not apply to local ski areas within the forecast region and the hazard rating will remain valid through midnight January 27th, 2012. Special thanks to Idaho Parks and recreation for sponsoring this Avalanche advisory. |
Pit data coming in from all over yesterday. Thanks to Silver and Schweitzer patrol, and Jon dodge on the west side of the Selkirks. A lot of new snow this week so expect areas of unstable slabs. Snowmobile Avy class tonight, 7PM, Forest Service, Sandpoint. |
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WEATHER |
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TODAY: Cold in the mountains this morning, low to mid teens. All ski areas reporting about 8 inches of new snow in the last three days, but due to wind will feel like more. Partly sunny, temps in the 20s, light W wind. TONIGHT: Mostly cloudy with continued cold in the teens, and SW winds 9-11mph. SATURDAY: The outlook for Saturday and Sunday precipitation to increase along with westerly winds. Saturday will be mostly cloudy with temperatures in the 20s and moderate winds out of the W, Silver Valley S becoming N. Saturday night a chance of snow exists with rising temperatures and increasing SW winds. Sunday continued chance of snowfall, rising temperatures, and SW winds picking up with gusts in the 22mph range. The avalanche danger will increase Sunday with new snow, wind, and rising temps. |
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Selkirks and Cabinet mountains: Winds were howling and the snow swirling all day during our tour of Roman Nose Lakes. The new snow was slabbing up with a couple different weak layers at 6 inches and 1 foot deep on a N and E aspect. Shears were easy to moderate but did not break with energy. Near Phoebe’s Tip Eric found a similar pack. These layers will be weaker on wind-loaded slopes (NE-SE) being buried deeper with a firmer slab over the top. Wind-loaded areas will be deep and slabs over weak layers firm and able to propagate a fracture easier. Weak layers need time to settle. Overall, layers seem to be more stable in the trees and off exposed terrain. Warming with new snow loads Sunday may increase avalanche hazard. Avalanche danger is rated CONSIDERABLE on wind-loaded aspects steeper than 35 degrees above 5,000 feet. The avalanche danger is MODERATE on non wind-loaded slopes steeper than 35 degrees. St. Regis Basin and Silver valley: Observations from the area are showing that strong westerly winds have loaded lee aspects so you should avoid steep terrain below ridgelines. Down south on Twin Saddle Ed found surface hoar buried one foot deep and got moderate shears. At Silver Mountain, patrol got moderate shears about 1 foot deep in unbonded new snow. At Lookout Pass, Carole and Dan found easy shears in the new snow about 1 foot deep. The recurring them here is that the new snow has not fully bonded due to changes in density and areas of wind-loading will be more unstable under greater load and stress. The avalanche danger is rated CONSIDERABLE on wind-loaded aspects steeper than 35 degrees above 5,000 feet. The avalanche danger is MODERATE on non wind-loaded slopes steeper than 35 degrees. Earlier this week across our forecast region natural avalanches were observed. This was Tuesday evening due to a quick warming trend. If you see these signs be suspect about stability on similar and adjacent slopes. Temperatures have been dropping since then and weak layers may persist. Weak layers may be stressed just enough to be ready to go with just a little persuasion. Don’t be the persuader. These areas likely exist on steeper, exposed, wind-loaded aspects. We may get some settlement of the pack today and tomorrow, but avalanche hazard could increase with new snow, winds, and warming by Sunday. |
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The next avalanche advisory will be issued February 3rd. Have a safe and pleasant weekend!!!! |
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Contact: Kevin Davis (208) 265-6686, Ed Odegaard (208) 245-6209, or John Olson (208) 265-6635 This message is available by calling (208) 765-7323 or toll-free at 1-866-489-8664. E-mail address: kevingdavis@fs.fed.us, eodegaard@fs.fed.us, jrolson@fs.fed.us, ebmorgan@fs.fed.us |
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