

377 

AGPN40 KWNM 012052

MIMPAC



MARINE WEATHER DISCUSSION FOR N PACIFIC OCEAN 

NWS OCEAN PREDICTION CENTER WASHINGTON DC

150 PM PDT MON 1 AUG 2016 



.FORECAST DISCUSSION: MAJOR FEATURES/WINDS/SEAS/SIGNIFICANT 

.WEATHER FOR THE NORTH PACIFIC N OF 30N AND E OF 150W. 



AT 18Z A WEAK SURFACE LOW WAS LOCATED JUST OFF VANCOUVER ISLAND 

WITH A COLD FRONT EXTENDING S AND SW FROM LOW ACROSS THE PZ5 

WATERS. LATEST MODELS ARE IN GOOD AGREEMENT THAT THE COLD FRONT 

SHOULD DIMINISH AS IT MOVES THROUGH THE NRN PZ6 WATERS 

TONIGHT... WITH THE ASSOCIATED MID/UPPER LEVEL LOW MOVING 

ONSHORE ACROSS WA  EARLY TUE. AN 18Z METOP-A ASCAT OVERPASS 

INDICATED HIGHEST WINDS TO 30 KT ACROSS COASTAL ZONES FROM CAPE 

BLANCO TO PT ST GEORGE. THERE WERE ALSO SOME 30 KT RETURNS ABOUT 

60 TO 80 NM WSW OF CAPE MENDOCINO. THE 12Z GFS WINDS LOOK WELL 

INITIALIZED ACROSS THE COASTAL ZONES BUT MAY BE 5 KT OR SO 

ACROSS INNER ANZ820 WATERS.  



THE 12Z MODELS ARE IN GOOD AGREEMENT THAT HIGH PRES CENTERED 

NEAR 45N148W AT 18Z WILL DRIFT E WHILE STRENGTHENING OVER THE 

NEXT 24 TO 36 HOURS AND THEN PERSIST INTO THE WEEKEND. OVER THE 

PAST FEW RUNS THE MODELS HAVE GENERALLY TRENDED WEAKER WITH THE 

N WINDS FROM CAPE BLANCO TO PT ARENA THIS WEEK. THE 12Z GFS NO 

LONGER SHOWS ANY GALE FORCE WINDS EXTENDING BEYOND 60 NM INTO 

OFFSHORE WATERS. FOR CONTINUITY HAVE DECIDED NOT TO DROP THE 

GALES BUT DID ADJUST THE PREVIOS BLEND OF THE GFS 10M AND FIRST 

SIGMA LAYER WINDS WITH HIGHER CONTRIBUTION FROM THE LOWER 10M 

WINDS. ONLY HAVE MODERATE CONFIDENCE WITH THESE GALES BUT WILL 

AWAIT SUBSEQUENT MODEL RUNS BEFORE DROPPING THEM ENTIRELY. 



THE 12Z WAVEWATCH III AND 12Z ECMWF WAM ARE WELL INTIALIZED WITH 

WAVE HEIGHTS ACROSS THE E PACIFIC THIS AFTERNOON. OPC WAVE 

HEIGHT GRIDS ARE LARGELY BASED ON THE 12Z WW3. HOWEVER GRIDS 

WERE ADJUSTED UPWARD BY ABOUT 10 PERCENT ACROSS AREAS WITH WINDS 

GREATER THAN 25 KT AND/OR SEAS GREATER THAN 9 FT OFF NRN 

CALIFORNIA TUE THROUGH FRI. 



.EXTRATROPICAL STORM SURGE GUIDANCE...N/A. 



.WARNINGS...PRELIMINARY. 



.PZ5 WASHINGTON/OREGON WATERS...

     NONE.



.PZ6 CALIFORNIA WATERS...

.PZZ820...INNER WATERS FROM POINT ST. GEORGE TO POINT ARENA...

     GALE WED.

     GALE POSSIBLE WED NIGHT.

     GALE POSSIBLE THU NIGHT.



$$ 



.FORECASTER CLARK. OCEAN PREDICTION CENTER.

