WSUS86 KSEW 302011 SABSEA BACKCOUNTRY AVALANCHE FORECAST FOR THE OLYMPICS WASHINGTON CASCADES AND MT HOOD AREA NORTHWEST WEATHER AND AVALANCHE CENTER SEATTLE WASHINGTON 130 PM PDT WED SEP 30 2009 NWAC Program administered by: USDA-Forest Service with cooperative funding and support from: Washington State Department of Transportation National Weather Service National Park Service Washington State Parks and Recreation Commission Pacific Northwest Ski Area Association Friends of the Avalanche Center and other private organizations. This forecast applies to back country avalanche terrain below 7000 feet and does not apply to highways or operating ski areas. WAZ513-518-519-019-042-501-502-ORZ011-012000- && FALL AVALANCHE STATEMENT As the winter season rapidly approaches, the Northwest Weather and Avalanche Center is preparing once again to provide daily avalanche forecasts for the Olympics and Cascades. These forecasts will become available in late November or December when sufficient snow has accumulated at moderate and lower elevations to create a potential avalanche danger. These forecasts to not apply to developed ski areas or highways. For your information a few general notes regarding fall avalanches follow . . . During the fall the atmosphere experiences significant cooling at higher latitudes. As this cold northern air is mixed progressively southward by fall storms, pronounced changes in the air temperatures over the Northwest are a characteristic result. These large temperature variations can result in rapid decreases in the snowpack stability in areas with sufficient snow to slide. Wet cool weather depositing substantial snowfall at the higher elevations followed by rapid warming still common in the fall can quickly produce greatly increased avalanche danger. In the fall this problem is usually confined to permanent snow fields on the volcanic peaks, as vegetation and other anchoring prevalent at lower elevations generally prevents slides of a shallow snow cover. Back-country travelers should make terrain, weather and snowpack stability evaluations as they travel over snow covered terrain. Remember that seemingly insignificant slides may be dangerous. Almost half of all avalanche fatalities occur in slides traveling less than 300 feet. Have a safe and enjoyable fall and winter! If you have any comments or suggestions regarding our avalanche forecasting program, please direct them to: Northwest Weather and Avalanche Center 7600 Sandpoint Way NE Seattle, WA 98115 You may email comments to: nwac.sew@noaa.gov && Backcountry travelers should be aware that elevation and geographic distinctions are approximate and that a transition zone between dangers exists. Remember there are avalanche safe areas in the mountains during all levels of avalanche danger. Contact local authorities in your area of interest for further information. NWAC weather data and forecasts are also available by calling 206-526-6677 for Washington, 503-808-2400 for the Mt Hood area, or by visiting our Web site at www.nwac.us. Also note that field snowpack information is often available on the FOAC website at www.avalanchenw.org, and weather and avalanche glossaries for commonly used terms in the forecasts can be found on the NWAC education page. Ferber/Northwest Weather and Avalanche Center $$