002 AGPN40 KWNM 250222 MIMPAC MARINE WEATHER DISCUSSION FOR N PACIFIC OCEAN NWS OCEAN PREDICTION CENTER WASHINGTON DC 720 PM PDT MON 24 AUG 2009 .FORECAST DISCUSSION: MAJOR FEATURES/WINDS/SEAS/SIGNIFICANT .WEATHER FOR THE NORTH PACIFIC N OF 30N AND E OF 150W. BASED ON 18Z GFS/NAM SEE NO REASON TO MAKE ANY CHANGES TO THE HEADLINES ALREADY IN PLACE. OTHERWISE WILL TWEAK INITAL CONDITIONS IN THE FIRST PERIODS OF THE FORECAST...ESPECIALLY IN THE AREAS NEAR WEAKENING COLD FRONT THAT IS BASICALLY BISECTING THE PZ5 WATERS (WHICH SHOWS UP QUITE NICELY ON FADING VIS IMGRY). SEAS WILL BE BUMPED UP ESP IN THE NW WA WATERS AS NW SWELLS HAVE ALREADY BEGAN TO SPREAD INTO THE WATERS...AND NOTABLY BUOY 46036 ABT 110 NM TO THE W OF THE WA WATERS IS ALREADY UP TO 16 FT AS OF 00Z. ------------------------------------------------------- PREVIOUS DISCUSSION: A SERIES OF STRONG UPR LVL LOW PRES SYSTEMS WILL IMPACT CONDITIONS FROM THE EASTERN PAC OCEAN W OVER THE GULF OF AK DURING THE NEXT SEVERAL DAYS. ONE UPR LVL LOW CURRENLY OVR THE ERN GULF OF AK WILL LIFT N AND WEAKEN OVR THE NEXT 24-36 HRS. THE NEXT IN A LINE OF UPR LVL LOWS WILL THEN FORM OVR THE CENTRAL GULF OF AK WED...AND MOVE SLOWLY E AND SE INTO EARLY THU BEFORE IT ALSO WEAKENS AND LIFTS N. A THIRD UPR LVL LOW WILL THEN TRACK SE FROM THE BERING SEA EARLY THU...TO THE ERN GULF OF AK FRI... BEFORE IT TO TRACKS SLWLY N SAT AND WKNS. ALSO DURING THE NEXT FEW DAYS UPR LVL HIGH PRES WILL BUILD OVR THE WRN STATES. THE MORNING QSCAT INDICATES A STRONG SFC LOW PRES CENTER ABOUT 250 NM W OF THE QN CHARLOTTE ISLANDS WITH HI RES QSCAT INDICATING WINDS OF STORM FORCE TO THE W AND NW OF THE LOW PRES CENTER. OVR THE OFFSHORE WTRS QSCAT SHOWS MAX BL WINDS OF 30KT OCCURRING JUST AHEAD OF A COLD FRONT OVR NW WASH OFF WTRS WITH WINDS OF 25KT OR LESS ELSEWHERE OVR THE OFF WTRS. OVERALL...THE 12Z MDLS APPEAR TO BE IN PRETTY GOOD AGREEMENT OVR THE OFF WTRS OVR THE NEXT FEW DAYS. A COLD FRONT MOVG INTO FAR WRN PZ5 WTRS TDA WILL MOVE E AND SE TONITE INTO TUE AND WEAKEN. WE WILL REMOVE GALES FOR NW WASH OFF WTRS FOR THE LATE DAY FCST PACKAGE WITH ALL MDLS INDICATING THE STRONGER WINDS TO THE NW AND N OF THE OFF WTRS BY THAT TIME. SFC HIGH PRES WILL THEN OVERSPREAD PZ5 AND NOCAL WTRS TUE AS A LOW PRES TROF FORMS TO THE S ALONG THE SOCAL AND CENTRAL CAL COASTS. THE HIGH WILL WEAKEN AND MOVE TO CENTRAL CAL OFF WTRS WED AS THE NEXT FRONT APPROACHES FROM THE W. THE FRONT WILL CONT TO APPROACH THE WTRS THU AS THE ASSOC LOW PRES AREA LIFTS TO THE N OVR THE GULF OF AK. THE PRES GRAD AHEAD OF THE FRONT MAY BE JUST STRONG ENUF TO WARRANT MINIMAL GALES FOR FAR WRN PZ5 WTRS WED NITE OR THU. THIS IS ONLY A MINOR ADJUSTMENT FROM THE PREV OFF FCST...WITH GALES LIMITED TO FAR WRN PARTS OF WASH WTRS WED NITE AND FOR FAR WRN WASH AND OREG WTRS THU. THE FRONT WILL LKLY DSIPT AS IT CROSSES OVR THE REGION EARLY FRI...AND SFC HIGH PRES AGAIN REBUILDS OVR THE NOCAL AND PZ5 WTRS. TO THE S...THE COASTAL LOW PRES TROF IS EXPECTED TO STRENGTHEN BY FRI...AND STRENGTHEN EVEN MORE SAT AS IT ALSO EXPANDS N ALONG THE CAL COAST TO FAR SW OREG. THE 12Z ECMWF EVEN INDICATES MIN GALES W OF CP MENDICINO EARLY SAT. WE WILL KEEP MAX BL WINDS AT 30 KT FOR NOW...MAINLY FROM NE SOCAL N TO ERN NOCAL OFF WTRS...AND CONT TO MONITOR THIS REGION OVR THE NEXT DAY OR TWO. SFC HIGH PRES WILL LKLY CONTROL THE WX OVR PZ5 AND NW NOCAL WTRS FOR SAT WITH BL WINDS LESS THAN 20KT OVR THESE WTRS. MODEL CHOICE...12Z GFS THROUGH THU...THEN CLOSER TO THE 12Z ECMWF FOR FRI AND SAT. THIS IS IN GOOD AGREEMENT WITH THE LATEST HPC MED RANGE GUID AS WELL. ALSO OF NOTE...THE NATIONAL HURRICANE CENTER MAY BE ON THE VERGE OF UPGRADING A DISTURBANCE NR 16N116W SOMETIME LTR TDA OR TONITE. MODEL GUID TENDS TO TAKE THIS SYSTEM TO THE NW...PASSING SOME 250NM TO 350NM W OR SW OF THE SOCAL OFF WTRS OVR THE NEXT FEW DAYS. WE WILL CONT TO MONITOR THE LATEST INFORMATION FROM THE NHC...TO SEE HOW IT MIGHT IMPACT CONDITIONS OVR THE OFF WTRS. SEAS...FOR NOW...WE WILL REMAIN CLOSE TO THE 12Z WAVE WATCH III MDL GUID THRU MOST OF THE FCST PACKAGE. INITIALLY IT APPEARS TO BE RUNNING WITHIN A FT OR TWO OF THE 18Z OBS OVR THE OFF WTRS. .WARNINGS/FORECAST CONFIDENCE...WARNINGS ARE PRELIMINARY AND ARE SUBJECT TO CHANGE. ANY CHANGES WILL BE COORDINATED THROUGH AWIPS 12 PLANET CHAT OR BY TELEPHONE. .PZ5 WASHINGTON/OREGON WATERS... .CAPE FLATTERY TO CAPE LOOKOUT....GALE WED NITE INTO THU...LOW CONFDC...MAINLY FAR W PART. .CAPE LOOKOUT TO POINT ST GEORGE...GALE EARLY THU...LOW CONFDC... MAINLY FAR W PART. .PZ6 CALIFORNIA WATERS... .PT ST GEORGE TO PT ARENA...NONE. .PT ARENA TO PT CONCEPTION...NONE. .PT CONCEPTION TO GUADALUPE ISLAND...NONE. .FORECASTER COLLINS/MILLS. OCEAN FORECAST BRANCH.