200 PM PST WED FEB 6 2008 WEATHER SYNOPSIS FOR WEDNESDAY AND THURSDAY The active pattern over the northeast Pacific carried a strong front across the Northwest on Tuesday afternoon. This was followed by west crest level flow and orographic snow Tuesday night. Sites at Hurricane and near and west of the crest in the Cascades report about 13-20 inches of snowfall for the 24 hours ending Wednesday morning. A relative break between systems was seen Wednesday morning with decreasing snow showers at most locations. Increasing very strong west flow aloft will carry another very strong front and deep moisture across the Northwest Wednesday night. The front should cross the Olympics around midnight and the Cascades during the early morning hours. The front should be accompanied by very strong crest level winds, heavy snow, and another minor rise in snow levels. Strong west northwest flow should carry a cooler slightly unstable air mass across the Northwest much of Thursday and Thursday night. This should cause a strong period of orographic snow showers in the Olympics and Cascades. Convergence effects may enhance snow showers in the central Cascades by Thursday night. WEATHER FORECAST FOR WEDNESDAY AND THURSDAY * OLYMPICS- Wednesday afternoon: Increasing light to moderate snow. Wednesday night: Stormy with increasing heavy snow. Thursday: Windy with moderate to heavy snow showers heaviest west Olympics. Thursday night: Moderate snow showers heaviest west Olympics. * WASHINGTON CASCADES NEAR AND WEST OF THE CREST- * CASCADE PASSES, INCLUDING STEVENS, SNOQUALMIE AND WHITE PASSES- Wednesday afternoon: Increasing light to moderate snow. Wednesday night: Stormy with increasing heavy snow. Thursday: Windy with moderate to heavy snow showers. Thursday night: Moderate snow showers. * EAST SLOPES WASHINGTON CASCADES- Wednesday afternoon: Increasing light to moderate snow. Wednesday night: Stormy with increasing moderate snow. Thursday: Windy with moderate snow showers especially higher elevations. Thursday night: Moderate snow showers especially higher elevations. * MT HOOD AREA- Wednesday afternoon: Increasing light to moderate snow. Wednesday night: Stormy with increasing heavy snow. Thursday: Windy with moderate to heavy snow showers. Thursday night: Moderate snow showers. SNOW LEVELS-CASCADE MTNS 1000 ft N, 1500 ft S Wed aft 2000 ft N, 2500 ft C, 4000 ft S Wed night 1500 ft N, 2000 ft S Thu 1000 ft N, 2000 ft S Thu night SNOW LEVELS-OLYMPIC MTNS 1500 ft Wed aft 4000 ft Wed night 2000 ft Thu and Thu night Cascade Snow/Freezing Levels refer to the northern Washington Cascades (N) through Mt Hood area (S). Central Washington Cascade snow levels (typically near Snoqualmie Pass) are normally midway between indicated N and S levels. Note that surface snow/freezing levels are common near the passes during easterly pass flow and may result in multiple snow/freezing levels. 24 HOUR FORECAST OF PRECIPITATION IN INCHES OF WATER EQUIVALENT ENDING AT 4AM THU FRI * HURRICANE RIDGE 1 1 * MT BAKER 1-1.5 1-1.5 * WASHINGTON PASS 1 1 * STEVENS PASS 1 1-1.5 * SNOQUALMIE PASS 1 1-1.5 * MISSION RIDGE .25-.5 .25-.5 * CRYSTAL MTN .5-.75 .5-.75 * PARADISE 1-1.5 1-1.5 * WHITE PASS 1 1 * MT HOOD 1-1.5 1-1.5 WINDS IN MILES PER HOUR (MPH) * CASCADE PASS LEVEL WINDS W 5-15 Wed aft W 10-20 Wed eve W 15-25 Wed night to Thu night * FREE WINDS AT 5000 FT W 20-30 Wed aft WSW 50-70 Wed night W 40-50 Thu W 35-45 Thu night * FREE WINDS AT 9000 FT W 30-40 Wed aft W 70-90 Wed night W 50-70 Thu W 40-60 Thu night EXTENDED WEATHER SYNOPSIS FOR FRIDAY THROUGH SUNDAY A short wave ridge is indicated to move over the Northwest on Friday. A strong northwest flow aloft and moisture Friday should decrease by Friday night. This should cause decreasing orographic snow showers by Friday night. Increasing west flow should carry the next front to the Northwest Saturday afternoon and night. This should cause increasing precipitation with a bit of rise in snow levels. West flow should continue to carry a slightly unstable cooler air mass across the Northwest on Sunday. EXTENDED FORECAST FOR FRIDAY THROUGH SUNDAY Friday: Moderate orographic snow showers in the morning becoming light in the afternoon and evening. Saturday morning: Cloudy mainly near and west of the crest. Saturday afternoon and night: Increasing moderate to heavy rain or snow. Sunday: Moderate orographic snow showers. Sunday night: Light orographic snow showers. * SNOW LEVELS 5-1500 ft N, 2-4000 ft S Fri 3-4000 ft N, 4-6000 ft S Sat except generally near the surface passes and east slopes 1-2000 ft N, 3-4000 ft S Sun