145 PM PST WED MAR 5 2008 WEATHER SYNOPSIS FOR WEDNESDAY AND THURSDAY Mild temperatures, light winds and plenty of late winter sunshine abound in the mountains of the Pacific Northwest Wednesday afternoon! This due to the strong upper level ridge of high pressure centered off the Washington and Oregon coasts. The ridge should provide fair weather for the next few days as it slowly moves eastward towards the coast. The ridge should be centered over western Washington and Oregon Thursday morning and move east of the area Thursday night. Freezing levels should rise Wednesday and peak over the region Thursday with very light winds and sunny days and clear nights through Thursday. Once the upper ridge moves east of the area late Thursday a weak upper trough is expected to dissipate as it approaches the coast Thursday night. This should only cause a few high clouds to spread across the area Thursday night. WEATHER FORECAST FOR WEDNESDAY AND THURSDAY * OLYMPICS- Wednesday aft and eve: Mostly sunny with warming and light winds. Wednesday night: Fair and mild. Thursday: Mostly sunny and mild. Thursday night: Mostly fair with variable high clouds. * WASHINGTON CASCADES NEAR AND WEST OF THE CREST- * CASCADE PASSES, INCLUDING STEVENS, SNOQUALMIE AND WHITE PASSES- Wednesday aft and eve: Mostly sunny with warming and light winds. Wednesday night: Fair and mild. Thursday: Mostly sunny and mild. Thursday night: Mostly fair with variable high clouds. * EAST SLOPES WASHINGTON CASCADES- Wednesday aft and eve: Mostly sunny with warming and light winds. Wednesday night: Fair and mild. Thursday: Mostly sunny and mild. Thursday night: Mostly fair with variable high clouds. * MT HOOD AREA- Wednesday aft and eve: Mostly sunny with warming and light winds. Wednesday night: Fair and mild. Thursday: Mostly sunny and mild. Thursday night: Mostly fair with variable high clouds. FREEZING LEVELS-CASCADE MTNS 7000 ft N, 8500 ft S Wednesday aft 8000 ft N, 9000 ft S Wednesday night 8000 ft N, 9000 ft S Thursday morn 7500 ft N, 9500 ft S Thursday aft and night FREEZING LEVELS-OLYMPIC MTNS 8000 ft Wednesday aft 8500 ft Wednesday night 8500 ft Thursday morn 7500 ft Thursday aft and 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 0 0 * MT BAKER 0 0 * WASHINGTON PASS 0 0 * STEVENS PASS 0 0 * SNOQUALMIE PASS 0 0 * MISSION RIDGE 0 0 * CRYSTAL MTN 0 0 * PARADISE 0 0 * WHITE PASS 0 0 * MT HOOD 0 0 WINDS IN MILES PER HOUR (MPH) * CASCADE PASS LEVEL WINDS E 5-15 Wed aft thru Thu morn Var 0-10 Thu aft W 0-10 Thu night * FREE WINDS AT 5000 FT E-SE 5-15 Wed aft and night S-SE 0-10 Thu morn S-SW 5-15 Thu aft and night * FREE WINDS AT 9000 FT N-NE 5-15 Wed aft N-NW 5-15 Wed night W 5-15 Thu W 10-20 Thu aft W-SW 15-25 Thu night EXTENDED WEATHER SYNOPSIS FOR FRIDAY THROUGH SUNDAY A weakening upper trough is expected to approach the offshore waters Friday. This should allow for gradually increasing southwest flow aloft during the day Friday as well as increasing mid and high level clouds. A weak to moderate frontal passage is expected late Friday night. This should cause a period of moderate precipitation and increased winds Friday night at lowering freezing levels. A brief period of westerly flow through Saturday morning should maintain generally light snow showers at low freezing levels through mid morning Saturday. High pressure ridging is expected to rebuild offshore during the day Saturday. This should allow for gradual clearing with showers ending midday Saturday. Light winds and clearing weather is expected later Saturday into early Sunday with rising freezing levels. The next upstream weather disturbance is expected to weaken as it encounters a splitting westerly flow over the eastern north Pacific Sunday. This should send most of the energy northward. Some light precipitation associated with the warm front may reach the Olympics Sunday with a little light precipitation possibly reaching the Cascades later Sunday however model runs have varied a great deal for the Sunday period. A weakening trend in the models indicates that what ever energy reaches the area Sunday it should be weak. EXTENDED FORECAST FOR FRIDAY THROUGH SUNDAY Friday: Increasing clouds with light rain or snow developing late Friday in the Olympics and Friday evening in the Cascades. Friday night and early Saturday: Light to moderate rain or snow changing to showers early Saturday. Saturday: Light to moderate snow showers early, decreasing to light snow showers midday or ending. Saturday night: Partial clearing. Sunday: Partly to mostly cloudy with a chance of light rain or snow mainly Olympics. * FREEZING LEVELS Fri morn: 6-7000 ft N, 8-9000 ft S * SNOW LEVELS Fri aft and night: 3-4000 ft N, 4-5000 ft S Sat: 1-2000 ft N, 15-2500 ft S Sun: 4-5000 ft N, 6-7000 ft S