497 FXUS66 KPQR 041008 AFDPQR AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PORTLAND OR 208 AM PST WED NOV 4 2015 .SYNOPSIS...A WEAK RIDGE OF HIGH PRES WILL MOVE ACROSS THE PACIFIC NW TODAY BRINGING A SHORT PERIOD OF DRY WEATHER. THE NEXT WEATHERMAKER WILL BE A MOIST TROUGH OF LOW PRES ALOFT MOVING ACROSS THE REGION TONIGHT AND THU...BRINGING A GOOD CHANCE FOR RAIN TO THE REGION. A WEAK WARM FRONT WILL LIFT N INTO WA THU NIGHT AS HIGH PRESALOFT BUILDS IN FOR A DRY DAY FRI. ANOTHER SERIES OF FRONTS WILL BRING SOME RAIN TO THE PACIFIC NORTHWEST THIS WEEKEND. && .SHORT TERM...TEMPS EARLY THIS MORNING HAD ALREADY DROPPED INTO THE 30S AT MOST LOW ELEVATION LOCATIONS...AND WITH DEW POINTS IN THE LOW TO MID 30S SUGGESTS MANY AREAS WILL SEE THEIR FROST THIS MORNING. AREAS OF FOG WERE ALSO BEGINNING TO FORM IN SOME AREAS...AND WITH DEW POINT DEPRESSIONS SMALL WITH LIGHT WINDS EXPECT MANY VALLEY AREAS TO FILL IN WITH FOG DURING THE NEXT FEW HOURS. A RATHER FLAT POSITIVE TILT RIDGE WAS EVIDENT OFFSHORE THIS MORNING IN SATELLITE PICTURES. HIGH CLOUDS WERE BEGINNING TO SPILL IN OVER THE TOP OF THE RIDGE INTO WESTERN WA AND EXTREME NW OREGON EARLY THIS MORNING...AND WILL LIKELY SEE MORE HIGH CLOUDS SPREAD IN LATER TODAY AS THE RIDGE MOVES SE ACROSS THE REGION. MODELS REMAIN IN VERY GOOD AGREEMENT WITH THE SHORT WAVE EXPECTED TO MOVE SE ACROSS THE REGION LATE TONIGHT AND EARLY THU. MODEL TIME HEIGHT CROSS SECTIONS INDICATE DEEP MOISTURE TO MOVE ACROSS THE REGION WITH THIS WAVE. IN ADDITION TO MODEST LIFT PROVIDED BY THE SHORTWAVE...MODEL ISENTROPIC FIELDS ALSO INDICATE WEAK BUT DEEP MOIST ISENTROPIC LIFT BETWEEN 285 TO 300K ISENTROPES. WHILE NOT EXPECTED TO BE A HEAVY RAIN EVENT...MOISTURE AND LIFT APPEAR TO BE ENOUGH TO JUSTIFY GOING WITH FAIRLY HIGH POPS...LIKELY OR BETTER... FOR LATE TONIGHT AND EARLY THU. LOW LEVEL MOISTURE...BELOW 700 MB...IS SLOW TO CLEAR OUT LATER THU AND THU NIGHT. WEAK MOIST ISENTROPIC LIFT REMAINS BELOW THE 290K ISENTROPE THROUGH THU NIGHT...MAINLY ACROSS THE N PART OF THE FORECAST AREA IN AN AREA OF WEAK WARM AIR ADVECTION UNDER A BUILDING RIDGE ALOFT. AGAIN ANY PRECIPITATION LINGERING THROUGH THU NIGHT IS LIKELY TO BE ON THE LIGHT SIDE...BUT GIVEN THE LOW LEVEL LIFT AND MOISTURE WILL UP POPS A BIT MAINLY ACROSS THE N PART OF THE FORECAST AREA. ANOTHER TRANSITORY RIDGE ALOFT MOVING ACROSS THE REGION FRI SHOULD BRING A SHORT PERIOD OF DRY WEATHER BACK TO MOST AREAS...EXCEPT FOR A LINGERING SLIGHT CHANCE FOR LIGHT RAIN IN THE S WA CASCADES IN THE MORNING...AND A SLIGHT CHANCE FOR LIGHT RAIN REACHING THE S WA COAST FRI AFTERNOON AHEAD OF THE NEXT FRONTAL SYSTEM. .LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS. FRIDAY NIGHT THROUGH TUESDAY...PROGRESSIVE PATTERN CONTINUES THROUGH THE WEEKEND WITH RAIN MOVING BACK IN ON SATURDAY. THIS SYSTEM WILL NOT BRING AS MUCH RAIN AS WE SAW LAST WEEKEND...BUT MOST OF THE AREA COULD SEE A MODERATE AMOUNT OF RAIN. ANOTHER SHORTWAVE MOVES IN BEHIND THE FRONT SUNDAY WHICH WILL BRING DOWN SNOW LEVELS WITH MORE PRECIPITATION SUNDAY INTO MONDAY. THIS LOOKS LIKELY TO BRING MORE SNOW DOWN TO THE CASCADE PASSES AND MAYBE EVEN AS LOW AS HIGHER ELEVATIONS IN THE CASCADE FOOTHILLS. SHOWERY CONDITIONS THROUGH MONDAY...WITH TUESDAY LOOKING DRIER AT THIS TIME. -MCCOY && .AVIATION...VFR CONDITIONS EARLY THIS MORNING WILL GIVE WAY TO PLENTY OF LIFR CONDITIONS IN THE VALLEYS OF NORTHWEST OREGON AND SOUTHWEST WASHINGTON BETWEEN 11Z AND 17Z WEDNESDAY. IMPROVEMENT TO PREDOMINANTLY VFR CONDITIONS SHOULD OCCUR AROUND MIDDAY. A WEAKENING FRONTAL SYSTEM WILL BRING RAIN AND MVFR CIGS TO THE AREA AS WE APPROACH 12Z THURSDAY. KPDX AND APPROACHES...VFR CONDITIONS EARLY THIS MORNING SHOULD GIVE WAY TO LIFR/IFR CONDITIONS...PRIMARILY BETWEEN 12Z AND 16Z WEDNESDAY BEFORE CONDITIONS IMPROVE MIDDAY. A WEAK FRONTAL STORM SYSTEM WILL LIKELY BRING RAIN AND MVFR CONDITIONS TO THE AREA BETWEEN 06Z AND 12Z THURSDAY. /NEUMAN && .MARINE...EXPECT A FAIRLY BENIGN PERIOD OF WEATHER OVER THE WATERS FOR THE NEXT FEW DAYS AS WEAK HIGH PRESSURE LINGERS OVER THE NORTHEAST PACIFIC. A STRONGER FRONTAL STORM SYSTEM WILL THEN ARRIVE LATE IN THE WEEK AND LIKELY BRING SOLID SMALL CRAFT ADVISORY LEVEL WIND GUSTS OF 25 TO 30 KT TO THE WATERS LATE FRIDAY INTO EARLY SATURDAY. A WESTERLY SWELL BETWEEN 10 AND 15 FT WILL ALSO LIKELY PUSH INTO THE WATERS OVER THE WEEKEND AND PERSIST INTO EARLY NEXT WEEK. /NEUMAN && .PQR WATCHES/WARNINGS/ADVISORIES... OR...NONE. WA...NONE. PZ...NONE. && $$ INTERACT WITH US VIA SOCIAL MEDIA WWW.FACEBOOK.COM/NWSPORTLAND WWW.TWITTER.COM/NWSPORTLAND THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY REFERRED TO AS THE FORECAST AREA.