130 PM PST SAT JAN 19 2008 WEATHER SYNOPSIS FOR FRIDAY AND SATURDAY A strong large upper level ridge remains over the northeast Pacific Ocean. A short wave and surface low pressure system will move southeast over Vancouver Island Saturday morning and southeast over Washington Saturday afternoon and night. West flow over the Olympics and Cascades Saturday morning should become more northerly Saturday night. This moderate system should cause light to moderate snow at sites near and west of the crest on Saturday initially in the Olympics and north Cascades Saturday morning spreading to the south Cascades Saturday afternoon with lower snow levels. An west to east oriented trough should move south over Washington Saturday night causing further cooling and decreasing snow showers. The ridge should strengthen over the northeast Pacific Ocean on Sunday while surface high pressure and a cool dry air mass moves to BC. This should cause a northeast flow aloft, a clearing trend and offshore surface winds to develop in the Olympics and Cascades with cool temperatures. WEATHER FORECAST FOR FRIDAY AND SATURDAY * OLYMPICS- Saturday afternoon: Light to moderate snow. Saturday night: Light snow showers. Sunday: Light snow showers ending with partial clearing. Sunday night: Clearing. * WASHINGTON CASCADES NEAR AND WEST OF THE CREST-CASCADE PASSES INCLUDING STEVENS, SNOQUALMIE, WHITE PASSES- Saturday afternoon: Light snow showers north and light to moderate snow central and south. Saturday evening: Light snow showers north and central, light to moderate snow south. Sunday: Light snow showers ending with partial clearing initially north. Sunday night: Clearing initially north. * EAST SLOPES WASHINGTON CASCADES- Saturday afternoon: Light snow north and south. Saturday evening: Light snow showers north and light snow south. Sunday: Light snow showers ending with partial clearing initially north. Sunday night: Clearing initially north. * MT HOOD AREA- Saturday afternoon and evening: Increasing light to moderate snow. Sunday: Light snow showers ending. Sunday night: Clearing. SNOW LEVELS-CASCADE MTNS 2000 ft N and C, 5000 ft S Sat morn 1000 ft N, 2000 ft S Sat aft and eve Near sea level N, 1000 ft S Sun Near sea level N and S Sun night SNOW LEVELS-OLYMPIC MTNS 3000 ft Sat morn 1500 ft Sat aft and eve 1000 ft Sun morn Near sea level Sun 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 SUN MON * HURRICANE RIDGE .25-.5 LT .25 * MT BAKER .25 LT .10 * WASHINGTON PASS .25 LT .10 * STEVENS PASS .25-.5 LT .25 * SNOQUALMIE PASS .25-.5 LT .25 * MISSION RIDGE LT .25 LT .25 * CRYSTAL MTN .25 LT .25 * PARADISE .25-.5 LT .25 * WHITE PASS .25-.5 LT .25 * MT HOOD .25-.5 LT .25 WINDS IN MILES PER HOUR (MPH) * CASCADE PASS LEVEL WINDS W 10-20 Sat W 5-15 Sat night Light variable Sun morn E 5-15 Sun aft and eve * FREE WINDS AT 5000 FT W 20-30 Sat morn WNW 10-30 Sat aft and eve strongest south NNW 10-20 Sun morn NE 15-25 Sun aft and eve strongest south * FREE WINDS AT 9000 FT W 30-40 Sat morn WNW 20-40 Sat aft and eve strongest south NNW 15-25 Sun morn NE 15-25 Sun aft and eve EXTENDED WEATHER SYNOPSIS FOR MONDAY THROUGH WEDNESDAY The strong large upper ridge over the northeast Pacific should be dominant Monday to Wednesday. This should cause a dry cool north flow aloft Monday through Wednesday. Surface high pressure and cool surface air mass should move to over the northwest US. Northeast crest level winds are indicated to be strong on Monday but much lighter on Tuesday and Wednesday. EXTENDED FORECAST FOR MONDAY THROUGH WEDNESDAY Monday: Sunny with locally strong northeast crest level winds. Monday night: Clear with locally strong northeast crest level winds. Tuesday and Wednesday: Mostly sunny days and mostly clear nights. * FREEZING LEVELS Near sea level N and S Mon and Tue 1-2000 ft Olympics, near sea level Cascades Wed