FXUS66 KPQR 161008
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
210 AM PST WED DEC 16 2009

.SYNOPSIS...A MOIST SW FLOW ALOFT WILL CONTINUE INTO THE WEEKEND. A 
SERIES OF SHORT WAVES WILL KEEP SOME THREAT OF RAIN IN EACH 
DAY...WHILE FRONTAL SYSTEMS THU AND OVER THE WEEKEND WILL BRING MORE 
ORGAZINED THREATS FOR PRECIPITATION.
&&

.SHORT TERM...A WEAK COLD FRONT THAT PUSHED IN THIS EVENING HAS 
MOVED INTO THE CASCADES...AS A SHORTWAVE SEEN IN WATER VAPOR 
PICTURES OVER WESTERN OREGON CONTINUES TO PUSH THE FRONT E. 
SATELLITE SHOWS A BREAK IN ORGANIZED SYSTEMS COMING UP THIS 
MORNING...BEFORE ANOTHER SHORT WAVE AND WEAK FRONT MOVES THROUGH 
THIS AFTERNOON. THIS SYSTEM LOOKS RATHER ANEMIC IN SATELLITE 
PICTURES AS IT MOVES E ACROSS 130W. LOW LEVEL MOISTURE WITH A SW LOW 
RADAR ECHOES OF LIGHT SHOWERS OVER THE COAST RANGE SUGGEST THAT THE 
LEVEL SW ONSHORE FLOW WILL KEEP SOME THREAT OF SHOWERS IN THIS 
MORNING...BEFORE THE AFTERNOON SYSTEM IMPROVES CHANCES FOR 
PRECIPITATION. 

SURFACE TEMPS IN THE UPPER HOOD RIVER VALLEY REMAIN AT OR NEAR 
FREEZING EARLY THIS MORNING...SUGGESTING A THERMAL PROFILE CONDUCIVE 
TO A CONTINUED THREAT FOR FREEZING RAIN. AS ANY WIDESPREAD RAINFALL 
SHOULD BE WINDING DOWN IN THE NEXT COUPLE HOURS AND PRECIPITATION 
THREAT BECOMES MORE OROGRAPHICALLY DRIVEN...SHOULD SEE ANY THREAT OF 
FREEZING TYPE PRECIPITATION BECOME GREATLY REDUCED.

A MORE ORGANIZED SYSTEM MOVES IN FRI...AS A DEEP SURFACE LOW AS A 
DEEP SURFACE LOW LIFTS NE TOWARDS NORTHERN BC. MODELS INDICATE FLOW 
TURNS SOUTHERLY AHEAD OF THIS SYSTEM WITH A WARM FRONT LIFTING UP 
LATE THU. BEST ISENTROPIC LIFT OVER THE WARM FRONT THOUGH APPEARS TO 
BE FURTHER TO THE NW...SO BEST POPS WILL NOT ARRIVE UNTIL THE COLD 
FRONT MOVES THROUGH THU NIGHT. PRECIPITABLE WATER SATELLITE IMAGES 
SHOW THIS SYSTEM PICKING UP A LITTLE SUBTROPICAL MOISTURE AHEAD OF 
IT NEARING 150W.

POPS LOOK LIKE THEY DROP OFF THU NIGHT AND FRI AS A WEAK RIDGE MOVES 
ACROSS.

.LONG TERM....WET WEATHER PERSISTS THROUGH THE EXTENDED PERIOD. AN 
UPPER LEVEL TROUGH PUSHES A RIDGE EASTWARD...ALLOWING PRECIP TO 
ENVELOP THE CWA BY LATE FRI. MODELS DISAGREE ON THE TIMING AND 
IMPACTED AREAS OF A BRIEF BREAK SOMETIME SAT. GFS SHOWS MUCH OF THE 
CWA UNDER A WEAK RIDGE SAT AFTERNOON...ECMWF SHOWS SOUTHERN OREGON 
ENJOYING THIS BREAK INSTEAD. ANOTHER STRONG UPPER LOW SPINS OFF THE 
COAST EARLY SUN...MAKING LANDFALL AROUND MON. SEVERAL SYSTEMS FOLLOW 
BY EARLY NEXT WEEK. THESE SYSTEMS ARE LADEN WITH MOISTURE...AND AT 
TIMES MAY BRING HEAVY RAINFALL AND WINDY CONDITIONS TO THE PAC NW. 
SNOW LEVELS SHOULD RISE TO NEAR 8000 FT THROUGH THE WEEKEND...BUT 
STEADILY FALL ONCE AGAIN BY NEXT WEEK. LRAMIREZ
&&

.AVIATION...REGION LIES BETWEEN SYSTEMS THIS AM. MVFR TO IFR 
CONDITIONS WILL CONT ON THE COAST THIS AM...TRENDING TO MORE MVFR BY 
18Z. INLAND SEEING SOME IMPROVEMENT...AS VFR NOW BEGINNING TO 
DOMINATE...ALTHOUGH WILL CONTINUE TO SEE POCKETS OF MVFR CIGS 
ESPECIALLY IN AND AROUND KPDX THROUGH 18Z. SYSTEM ARRIVING THIS 
AFTERNOON APPEARS TO BE MORE SHOWERY IN NATURE...WHICH SHOULD 
CONTRIBUTE TO A MIX OF MVFR AND VFR CIGS...WHERE THE MVFR LIKELY TO 
BE ASSOCIATED WITH THE SHOWERS. WILL HAVE TO WATCH FOR POTENTIAL OF 
FOG AND LOW CLOUDS LATER TONIGHT AS AIR MASS STABILIZES AND WINDS 
TREND LIGHTER. 

.KPDX AND APPROACHES...MIX OF MVFR AND VFR THIS AM...WITH THE WORST 
BETWEEN NOW AND 15Z. AFTERWARDS...TRENDING TO MORE VFR. 
HOWEVER...WILL SEE OCCASIONAL MVFR AS SHOWERS BEGIN TO PUSH INTO THE 
OPS AREA AFTER 18Z.
&&

.MARINE...NEXT SYSTEM NOW APPROACHNING...BUT MAIN ENERGY WILL REMAIN 
TO OUR N. STILL...WINDS WILL INCREASE A BIT BY MID MORNING. THOUGH 
WILL HAVE SMALL CRAFT ADVISORY WINDS...BUT WOULD NOT BE SURPRISED TO 
SEE A FEW GUSTS UP TO 30 TO 35 KT. OVERALL...NOT ENOUGH TO SUPPORT A 
GALE WARNING. OTHER ITEM OF NOTE IS THE INCREASING SWELL. BUOY 6... 
LOCATED ABOUT 650 NM WSW OF BROOKINGS...PEAKED AT 25 FT EARLIER 
TONIGHT. THIS SWELL WILL CONTINUE MOVING ALONG THE GREAT CIRCLE ARC 
AND SHOULD MOVE INTO OUR COASTAL WATERS LATER THIS AFTERNOON. WILL 
SEE W SWELL PEAK AROUND 20 FT TONIGHT. WILL ALSO ISSUE A HIGH SURF 
ADVISORY FOR THE COAST AS THESE SWELL ROLL INTO THE SURF ZONE 
STARTING THIS EVENING. SWELL WILL GRADUALLY SUBSIDE LATER THU AM.
&&

.PQR WATCHES/WARNINGS/ADVISORIES...

OR/WA...SMALL CRAFT ADVISORY FOR WIND ON THE COASTAL WATERS FROM 
           CAPE SHOALWATER TO FLORENCE THROUGH THIS EVENING.
        SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS ON THE COASTAL 
           WATERS FROM CAPE SHOALWATER TO FLORENCE THROUGH THU.
        SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA BAR CONDITIONS 
           THROUGH THU.
        HIGH SURF ADVISORY FOR THE SOUTH WASHINGTON AND THE NORTH
           AND CENTRAL OREGON COAST FOR TONIGHT THROUGH THU AM.
&&

$$

MORE WEATHER INFORMATION ONLINE AT...
HTTP://WEATHER.GOV/PORTLAND

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.