-- RAINIER FORECAST -------------------------------------------------- http://www.wrh.noaa.gov/cgi-bin/getproduct.pl?SEASEARECSEA 1015 AM PST SAT DEC 13 2003 .SYNOPSIS...SHOWERS WILL GRADUALLY TAPER OFF THROUGH SATURDAY NIGHT AS A FRONT MOVES EAST OF THE AREA. A TROUGH OF LOW PRESSURE ASSOCIATED WITH A DEEP...BUT WEAKENING...STORM SYSTEM MOVING TOWARD NORTHERN VANCOUVER ISLAND WILL PASS THROUGH THE AREA SUNDAY BRINGING HEAVY SNOW ACCUMULATIONS TO THE CASCADES SUNDAY AFTERNOON AND SUNDAY NIGHT. A SLOW-MOVING PACIFIC FRONT WILL BRING MORE PRECIPITATION TO THE AREA TUESDAY AND WEDNESDAY. THE UNSETTLED WEATHER PATTERN WILL CONTINUE THROUGH NEXT WEEKEND. .SUNDAY...SNOW INCREASING IN THE AFTERNOON. WINDY. SNOW ACCUMULATION OF 4 TO 8 INCHES...MAINLY IN THE AFTERNOON. SNOW LEVEL 2500 FEET. temperature and wind: LONGMIRE / PARADISE / CAMP MUIR / SUMMIT ELEV 2700 5420 10188 14411 SUNDAY 40 / SW10 28 / W35 8 / W40 -6 / W50 -- AVALANCHE FORECAST ------------------------------------------------ http://www.seawfo.noaa.gov/products/SABWA 230 PM PST Saturday 13 December 2003 WASHINGTON CASCADES NEAR AND WEST OF THE CREST... ...AVALANCHE WARNING... Avalanche danger increasing and becoming high above 3000 feet and considerable below Saturday especially Cascade passes. Avalanche danger decreasing and becoming considerable above 4000 feet and moderate below Sunday. -- SNOWPACK ANALYSIS ------------------------------------------------- http://www.seawfo.noaa.gov/products/SABSEA 230 PM PST Saturday 13 December 2003 SNOWPACK ANALYSIS... Periodic light snowfall and cool temperatures was generally seen during the early and middle part of last week. This lower density snow accumulated on higher density snow or a crust produced during a period of heavier precipitation and warmer temperatures the first week of December. Older snow layers should have stabilized to some extent during that period. However the weather pattern and the avalanche potential began to significantly change on Thursday night. About 4-13 inches of new snow was reported on Friday morning in the Cascades near and west of the crest. Another 3-9 inches was reported on Saturday morning. This snow has fallen with moderate to strong south to southwest winds along the ridge tops, mostly east winds in the Cascade passes, and an overall warming trend. This is generally likely to be causing a greater potential for slab layers on steeper lee slopes. Lower density snow from early in the week could contribute to this potential. We have reports from most of the ski areas near and west of the crest in the Washington Cascades of fairly extensive easily triggered 4-10 inch soft slab layers on Friday including at Mt Baker, Stevens, Snoqualmie and Crystal. Some natural 10 inch slab avalanches on 35 degree north aspects were also reported by the Mt Baker ski patrol on Friday morning. The best chance for further developing new slab layers should be on north to east aspects at higher elevations and on more westerly aspects in the Cascade passes but slab layers may be possible on other aspects as well. Along the Cascade east slopes the Mission Ridge ski patrol on Friday reported that easily triggered 8 inch slab layers were found at higher elevations near ridges. Also it seems likely that the potential high avalanche danger is more restricted to higher elevations at Mt Hood since rain is reported to 5-6000 feet on Saturday morning and the snow pack there at lower elevations may have already somewhat consolidated and partly stabilized. Saturday... A strong front is expected to slowly cross the Olympics and Cascades on Saturday with the heaviest rain or snow in the south Cascades and Mt Hood area. This should be accompanied by southwest winds along the ridge tops, warmer temperatures, another change from east to west winds in the Cascade passes, and moderate to heavy rain or snow especially in the south Cascades and Mt Hood area. The increasing density snowfall or possible rain depending on location should cause slab layers to develop or be further loaded Saturday on lee slopes. This should continue to be north to east slopes at higher elevations but on more varied aspects in the Cascade passes. Back country travel on or near steep avalanche terrain is not recommended with natural or triggered avalanches becoming likely Saturday. Sunday... West winds along the ridge tops, snow showers and cooler temperatures are expected on Sunday, with yet another potential change from east to west winds in the Cascade passes. Snow showers should be heaviest Sunday afternoon in the north and central Cascades. This weather should begin allow previous recent slab layers to begin to partly stabilize but storm cycle slab layers should still be possible on steep lee slopes. This should be most likely to northeast to east aspects at higher elevations or on more varied aspects in the Cascade passes. It could be a good idea to hit the ski areas on Sunday and let new back country snow layers stabilize for a day or wait for the better weather expected Monday before making a back country trip. -- MOUNTAIN WEATHER FORECAST ----------------------------------------- http://www.seawfo.noaa.gov/products/SABNW 2 PM PST Saturday 13 December 2003 WEST SLOPES WASHINGTON CASCADES... Moderate to heavy rain or snow heaviest central and south Saturday afternoon. Moderate snow showers decreasing Saturday night. Mostly light snow showers Sunday morning. Increasing moderate to occasional heavy snow showers north and central and light to moderate snow showers south Sunday afternoon. Snow showers decreasing Sunday night and mostly ending early Monday. STEVENS...SNOQUALMIE...WHITE PASSES... Moderate to heavy snow Saturday afternoon with a possible change to rain Snoqualmie and White passes. Moderate snow showers all passes decreasing Saturday night. Generally light snow showers Sunday morning. Increasing moderate to occasional heavy snow showers Stevens and Snoqualmie and light to moderate snow showers White Pass Sunday afternoon. Snow showers decreasing Sunday night and mostly ending early Monday. EAST SLOPES WASHINGTON CASCADES.... Light to moderate rain or snow showers Saturday afternoon heaviest central and south and near the crest. Snow showers decreasing Saturday night. Generally light snow showers Sunday morning mainly near the crest. Increasing light to moderate snow showers Sunday afternoon heaviest north and central and near the crest. Snow showers decreasing Sunday night and mostly ending early Monday. SNOW LEVELS--CASCADE MTNS 2000 ft N 3000 ft S Sun and Sun night ----------------------------------------------------------------------