| Island Park / West Yellowstone--Snow and Avalanche Information |
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| About Us: The developer of this site has over 30 years of experience with avalanche forecasting and winter recreation management. He served as a Recreation Management Specialist with the U.S. Forest Service at locations such as Jackson, Wyoming, and the Wasatch Front of Utah, as well as here in the Island Park area. As a resident of Island Park, he shares a concern that winter users understand the danger they face in backcountry areas. Readers of this site should carefully consider information and concepts on this page before backcountry travel. Experience has taught that it is NOT really possible for most people to learn enough about weather and avalanches to do an adequate job of evaluating avalanche hazards in order to be able to avoid them. This is especially true if they attempt frequent exposure to steep ( >30 degrees), open slopes. Even with years of experience, avalanche control specialists at ski areas have lost their lives. The same slope area can slide more than once, and it isn't always the snow that kills or injures. We have seen chests compressed against tree trunks, so that breathing was impossible. We have seen victims bleed to death due to major arteries being slashed by limbs broken off by the victim sliding along the trunk of an alpine fir tree. We have also seen avalanche forecasters hit by slides while they were evaluating pockets of snow that had previously slid. Luckily they survived--although buried to the chest. Avalanche slopes don't always fail with the first skier or snomachine impact. We have seen entire tram-car loads of 60 skiers saved from a major slab avalanche at a ski area, because the forecaster had a hunch his computer had missed something. Sixty skiers had already skied the bowl, but the second car of the day was stopped from unloading, while the slope was shot and cleared of a 4-6' slab in a 100 acre bowl. These experiences shout in our ears--to stop and be extra cautious--and as we share these concerns and some further avalanche philosophy, we hope that you will listen and consider........................... |
| "+1 Rating Concept": (the new, proposed North American avalanche danger rating wording that will be used by the National Avalanche Center in 2010)--is almost a complete match with the following conservative concepts that we have been recommending for years. The new rating wording is more conservative than the old system wording. The following discussion refers to the old, national danger rating scale that is about to be replaced.) Many avalanche incidents involving backcountry visitors occur on days with a forecast rating of MODERATE hazard as described by the old, 5-level national rating scale. The old definition of a MODERATE forecast rating stated: "Natural avalanches unlikely; human triggered avalanches possible; unstable slabs possible on steep terrain; and use caution in steeper terrain on certain aspects" (compare this to the new wording). Since avalanche forecasts are GENERAL in their application to broad areas, it is likely that under the old MODERATE rated conditions, there will likely be pockets of more highly unstable snow on steep(>30 degrees), open slopes than those described by the old MODERATE rating. Since these pockets are generally not detectable by a limited number of snow-study pits, the backcountry visitor may be more highly at risk, than the old MODERATE rating would imply. As backcountry visitors continue to poke around (e.g.--hill climbing with a snowmachine) on steep slopes, they eventually locate the unstable pocket and thus trigger a larger area into an avalanche (see photo example). We have also observed this situation to occur (very infrequently) even in ski resorts where avalanche prone slopes are controlled or closed to prevent access. Therefore, the bottom line, and safest approach seems to be to limit exposure to the hazard on days with the old rating of MODERATE or higher. By applying the "+1 Rating" Concept-- a LOW hazard day would be treated as a MODERATE day, and a MODERATE day would be treated as a CONSIDERABLE hazard day. The Concept is applied by simply adding "1" level higher rating to the forecast rating for the day. The reason for this Concept is that pockets of instability will nearly always exist (see photo example), and forecasters always warn, for example-- that even LOW hazard does not mean "no hazard". So--on the old, MODERATE hazard forecast days, which would equate to a CONSIDERABLE hazard condition, it would be appropriate to reduce the exposure and risk by avoiding gullies and slopes >30 degrees. This is appropriate because "natural avalanches are possible and human triggered avalanches are probable" according to the CONSIDERABLE forecast rating level. This is a different approach than the old US Avalanche Danger Scale, which does not begin to suggest restricting travel in avalanche terrain under a MODERATE forecast. It simply says: "Use caution in steeper terrain". Thus, the "+1 Rating" Concept provides a safer guideline for use, since it suggests limiting travel. The "+1 Rating" concept would even be more appropriate on CONSIDERABLE forecast days, where the old US Avalanche Danger Scale simply says: "Be increasingly cautious in steeper terrain". If you treat the old CONSIDERABLE forecast as HIGH--then you will follow the old national definition that says: "Travel in avalanche terrain is not recommended". Since many avalanche injuries and fatalities occur on MODERATE days, why would anyone want to go into or near avalanche terrain and take multiple risks of exposure, when the hazard is in reality (due to unstable pockets) at CONSIDERABLE, or even higher????? |
| Avalanche Philosophy--"101": NOTE: check out the new, proposed North American avalanche danger rating wording that will be used this winter ('09--'10). The rating scale has been revised and is very much in line with the concepts we have been publishing on these pages for the last 5 years. Our concepts discussion which follows is related to the old hazard rating scale wording. The hazard evaluation discussion which follows (in white column--at the right), is presented to encourage visitors to take time to gain enough knowledge, experience and training to travel safely in or near avalanche terrain. |
| See the Fremont County Search and Rescue discussion of avalanche awareness for additonal information on how to avoid or survive avalanches. Fremont County S&R will be your BEST FRIEND if you are in need. Consider joining their cause by making a donation. |
| As shown in this photo, timbered areas are not always safe for travel--especially if there are steep, open slopes above, which could send a large deposition down into the trees. |
