130 PM PST TUE FEB 26 2008 WEATHER SYNOPSIS FOR TUESDAY AND WEDNESDAY A weak upper trough and moisture slowly shifted to the east of the Cascades on Monday morning. This caused showers mainly over the south Cascades to end on Monday. An upper ridge, decreased flow aloft, and a drier air mass presently over the US west coast should shift slowly east on Tuesday. This should cause fair weather in the Olympics and Cascades with a bit of a rise in freezing levels. Increasing crest level flow and increasing clouds should be seen Tuesday night, mainly in the Olympics and north Cascades, as a weak front approaches Tuesday night. An upper trough and the weak front should move over the west coast ridge and mainly to BC on Wednesday. The front should brush mainly the Olympics and north Cascades as it passes late Wednesday morning. This should cause further slightly increased crest level flow and slightly increasing precipitation on Wednesday morning mainly in the Olympics and north Cascades. Light showers should spread to areas near and west of the crest following the front Wednesday afternoon. Light showers near and west of the crest should end with decreasing clouds Wednesday night. WEATHER FORECAST FOR TUESDAY AND WEDNESDAY OLYMPICS- Tuesday: Partly sunny with high clouds. Tuesday evening: Increasing clouds. Tuesday night: Light rain or snow developing. Wednesday morning: Increasing light to moderate rain or snow. Wednesday afternoon: Light rain or snow showers. Wednesday night: Light rain or snow showers ending with partial clearing. * WASHINGTON CASCADES NEAR AND WEST OF THE CREST- * CASCADE PASSES, INCLUDING STEVENS, SNOQUALMIE AND WHITE PASSES- Tuesday: Partly sunny with high clouds, local low clouds east approaches to the passes mainly in the morning. Tuesday evening: Increasing clouds mainly north. Tuesday night: Further increasing clouds with light rain or snow north. Wednesday morning: Increasing light to moderate rain or snow north, light rain or snow central, and chance or rain or snow south. Wednesday afternoon: Light rain or snow showers. Wednesday night: Light rain or snow showers ending with partial clearing. * EAST SLOPES WASHINGTON CASCADES- Tuesday: Partly or mostly sunny, areas low clouds lower elevations. Tuesday evening: Increasing high clouds mainly north. Tuesday night: Further increasing clouds especially north. Wednesday morning: Increasing light rain or snow north and central, and chance or rain or snow south. Wednesday afternoon: Light rain or snow showers higher elevations. Wednesday night: Light rain or snow showers higher elevations ending with partial clearing. * MT HOOD AREA- Tuesday: Partly sunny with some high clouds. Tuesday night: Increasing high clouds. Wednesday: Further increasing clouds and chance of light rain or snow. Wednesday afternoon: Light rain or snow showers. Wednesday night: Light rain or snow showers ending with partial clearing. FREEZING LEVELS-CASCADE MTNS 4000 ft N, 5000 ft C, 7000 ft S Tue 5000 ft N, 6000 ft C, 8000 ft S Tue eve SNOW LEVELS 5000 ft N, 6000 ft C, 7000 ft S Wed 4000 ft N, 5000 ft C, 6000 ft S Wed eve FREEZING LEVELS-OLYMPIC MTNS 5000 ft Tue 6000 ft Tue eve SNOW LEVELS 6000 ft Wed 5000 ft Wed eve 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 .25 .25-.5 * MT BAKER .25 .5 * WASHINGTON PASS LT .10 .25 * STEVENS PASS LT .10 .25 * SNOQUALMIE PASS LT .10 .25-.5 * MISSION RIDGE 0 LT .25 * CRYSTAL MTN 0 LT .25 * PARADISE 0 .25 * WHITE PASS 0 LT .25 * MT HOOD 0 LT .25 WINDS IN MILES PER HOUR (MPH) * CASCADE PASS LEVEL WINDS E 5-10 Tue to Wed morn W 10-15 Wed aft and eve * FREE WINDS AT 5000 FT SW 10-20 Tue aft and eve SW 20-30 Wed morn strongest Olympics and north part SW 15-25 Wed aft and eve strongest Olympics and north part * FREE WINDS AT 9000 FT SW 30-40 Tue aft and eve W 40-50 Wed morn strongest Olympics and north part W 30-40 Wed aft and eve strongest Olympics and north part EXTENDED WEATHER SYNOPSIS FOR THURSDAY THROUGH SATURDAY The ridge should slightly rebuild and shift east over the Northwest on Thursday. This should cause fair weather and a rise in freezing levels. Flow and weather over the northeast Pacific Ocean continue to be indicated to get temporarily active on Friday and Saturday. Stronger flow aloft should carry a front across the Northwest on Friday. This should cause increasing moderate to heavy precipitation especially near and west of the crest with falling snow levels. Another secondary front is indicated Saturday. This should cause moderate renewed snow mainly near and west of crest with further lowering snow levels. EXTENDED FORECAST FOR THURSDAY THROUGH SATURDAY Thursday: Partly to mostly sunny. Thursday night: Increasing clouds. Friday: Increasing moderate to heavy rain or snow especially near and west of the crest with lowering snow levels. Saturday: Renewed moderate snow mainly near and west of the crest with further lowering snow levels. * FREEZING LEVELS Rising to 4-5000 ft N, 7-8000 ft S Thu SNOW LEVELS Lowering to 3-4000 ft N, 4-5000 ft S Fri Further lowering to 15-2500 ft N, 2-3000 ft S Sat