130 PM PST TUE FEB 5 2008 WEATHER SYNOPSIS FOR TUESDAY AND WEDNESDAY The renewed active pattern over the northeast Pacific will cause a very stormy period in the Olympics and Cascades this week. Strong west flow aloft is carrying a strong front over the Northwest Tuesday midday. This should be accompanied by increasing strong crest level winds and increasing moderate to heavy snow Tuesday with a minor rise in the low snow levels. Strong west crest level flow and a cool unstable air mass should slam into the Cascades and cause heavy orographic snow showers Tuesday afternoon and night. West flow aloft over the Northwest should slightly decrease Wednesday morning, while weak surface high pressure slightly rebuilds over the area. This should cause a decrease in orographic snow showers. But convergence may prolong snow showers near Stevens and Snoqualmie passes. A very stormy period should be seen in the Olympics and Cascades Wednesday night and Thursday. Renewed very strong west flow aloft is indicated to carry the next very strong front to the Olympics and Cascades Wednesday night. This should cause increasing very strong crest level winds and increasing very heavy snow Wednesday night with another minor rise in the low snow levels. WEATHER FORECAST FOR TUESDAY AND WEDNESDAY OLYMPICS- Tuesday midday through night: Heavy snow showers heaviest west Olympics. Wednesday morning: Light to moderate snow showers. Wednesday afternoon and night: Increasing heavy snow. * WASHINGTON CASCADES NEAR AND WEST OF THE CREST- * CASCADE PASSES, INCLUDING STEVENS, SNOQUALMIE AND WHITE PASSES- Tuesday midday: Increasing moderate to heavy snow. Tuesday afternoon and night: Heavy orographic snow showers. Wednesday morning: Light to moderate snow showers possibly heaviest near Stevens and Snoqualmie. Wednesday afternoon and night: Increasing heavy snow. * EAST SLOPES WASHINGTON CASCADES- Tuesday midday: Increasing moderate snow. Tuesday afternoon and night: Moderate snow showers heaviest higher elevations. Wednesday morning: Light snow showers heaviest higher elevations and possibly near Stevens and Snoqualmie. Wednesday afternoon and night: Increasing moderate snow. * MT HOOD AREA- Tuesday midday: Increasing moderate snow. Tuesday afternoon and night: Heavy snow showers. Wednesday morning: Light to moderate snow showers. Wednesday afternoon and night: Increasing heavy snow. SNOW LEVELS-CASCADE MTNS 1500 ft N, 2500 ft C, 3500 ft S Tue midday except surface Cascade passes and east slopes Lowering Tue aft and eve 500 ft N, 1500 ft S Wed Rising Wed night 1000 ft N, 2500 ft C, 4000 ft S Thu morn SNOW LEVELS-OLYMPIC MTNS 3000 ft Tue midday Lowering Tue aft and eve 1000 ft Wed morn 1500 ft Wed aft 2500 ft Thu morn 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 WED THU * HURRICANE RIDGE 1 1-1.5 * MT BAKER 1.5 1.5 * WASHINGTON PASS 1 1 * STEVENS PASS 1.5 1 * SNOQUALMIE PASS 1.5-2 1-1.5 * MISSION RIDGE .25-.5 .25-.5 * CRYSTAL MTN .5-.75 .75 * PARADISE 1-1.5 1.5 * WHITE PASS 1 1-1.5 * MT HOOD 1 1.5-2 WINDS IN MILES PER HOUR (MPH) * CASCADE PASS LEVEL WINDS Light variable Tue midday W 15-25 Tue aft to Wed morn W 0-10 Wed aft and eve * FREE WINDS AT 5000 FT SW 35-45 Tue aft W 30-40 Tue night W 20-30 Wed WSW 30-40 Wed eve WSW 50-70 Wed night * FREE WINDS AT 9000 FT WSW 45-65 Tue aft W 40-50 Tue night W 30-40 Wed W 40-60 Wed eve W 70-90 Wed night EXTENDED WEATHER SYNOPSIS FOR THURSDAY THROUGH SATURDAY The very strong west flow aloft should carry the next front across the Olympics and Cascades Thursday early morning. This flow is indicated to only slowly decrease on Thursday. Another cool unstable air mass should slam into the Cascades on Thursday. This should cause heavy orographic snow showers in the Olympics and Cascades. A short wave ridge should move over the Northwest on Friday. Lingering strong west-northwest flow and moisture should slowly decrease on Friday but also with a moderate rise in snow levels. Increasing southwest flow should be seen again over the Northwest on Saturday as another front approaches and crosses the area. This should bring increasing precipitation and a rise in snow levels to the Olympics and Cascades. EXTENDED FORECAST FOR THURSDAY THROUGH SATURDAY Thursday: Heavy orographic snow showers slowly decreasing. Friday: Moderate orographic snow showers in the morning becoming light in the afternoon and evening. Saturday: Light snow in the morning becoming moderate to heavy in the afternoon and evening. * SNOW LEVELS Lowering to about 1000 ft N, 2000 ft S Thu Rising to about 1000 ft N, 4000 ft S Fri 3-4000 ft N, 5-6000 ft S Sat