472 WWUS86 KPQR 311702 SABOR ORZ011-011700- ********************************************************** FOREST SERVICE NORTHWEST WEATHER AND AVALANCHE CENTER ISSUED THROUGH NATIONAL WEATHER SERVICE PORTLAND, OR ********************************************************** SUMMARY BACKCOUNTRY AVALANCHE FORECAST FOR THE MT HOOD AREA AND SOUTHERN WASHINGTON CASCADES These forecasts apply to back country avalanche terrain below 7000 feet. They do not apply to highways or operating ski areas. ********************************************************** 9 AM PST Monday 31 March 2003 ********************************************************** ZONE AVALANCHE FORECASTS..... SOUTH WASHINGTON CASCADES...MT HOOD AREA... Decreasing moderate avalanche danger below 7000 feet Monday and Tuesday. SNOWPACK SYNOPSIS.... The most recent significant heavy snow was seen last Tuesday and Wednesday. Temperatures stayed fairly cool on Thursday, then began to warm on Friday. Temperatures further greatly warmed in the Olympics and Cascades on Saturday and Sunday with freezing levels rising to near 10000 feet and temperatures in the 50s at many sites. This caused many natural and triggered wet snow avalanches of the recent snow on varied aspects. Rain to high elevations was seen Sunday night especially in the north Cascades from about Snoqualmie north. This may have prolonged the wet snow avalanche cycle especially in that area. Wet snow avalanches may have been less extensive and shallower along the Cascade east slopes were temperatures have been cooler and recent snowfall lighter. MONDAY... Light rain or snow showers mainly over the Olympics and near and west of the Cascade crest have rapidly decreased on Monday morning with greatly cooling temperatures. A refreezing snow pack, along with prior avalanches and settlement should lead to a rapid decrease the overall avalanche danger. Backcountry travelers should continue to use caution Monday, especially in the Olympics and near and west of the Cascade crest. Renewed light to moderate rain or snow showers should be seen Monday night with further cooling and lowering snow levels. This should continue to decrease the overall avalanche danger as prior wet snow continues to settle, refreeze and stabilize on most slopes. TUESDAY... Light snow showers are expected Tuesday morning. Increasing light to moderate snow showers with possible thunderstorms are expected Tuesday afternoon and evening. Showers should occur mainly over the west Olympics and near and west of the Cascade crest with low snow levels and cool temperatures. This should continue to refreeze and strengthen previous wet snow and further decrease the overall avalanche danger. Shallow new unstable layers in new snow may develop on a slopes. This should be mainly near and west of the Cascade crest where snowfall should be greatest by Wednesday morning. This should be limited however to steep slopes near ridges and mountain tops since new snowfall is not expected to be heavy. Backcountry travelers should remember to use normal precautions on Tuesday. ********************************************************** Backcountry travelers should be aware that elevation and geographic distinctions are approximate and 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 Mountain Weather Forecasts and mountain weather data are also available by visiting our Web site at www.nwac.noaa.gov. Ferber/Forest Service Northwest Weather and Avalanche Center