

675 

AGPN40 KWNM 250249

MIMPAC



MARINE WEATHER DISCUSSION FOR N PACIFIC OCEAN 

NWS OCEAN PREDICTION CENTER WASHINGTON DC

750 PM PDT WED 24 AUG 2016 



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

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



THE 18Z/24 GFS AND 18Z/24 AND 00Z/25 NAM WERE VERY CONSISTENT 

WITH THEIR RESPECTIVE PREVIOUS RUNS. OVERALL MODELS ARE IN WELL 

ABOVE AVERAGE AGREEMENT ACROSS THE E PACIFIC FOR THE NEXT 

SEVERAL DAYS. THE PREVIOUS OPC WIND AND WAVE HEIGHT GRIDS LOOK 

REASONABLE THROUGH THE FORECAST PERIOD AND WILL NOT BE MAKING 

ANY SIGNIFICANT ADJUSTMENTS TO THEM IN THIS EVENINGS UPDATES. 

BOTH THE 18Z WAVEWATCH III WAS WELL INITIALIZED WITH E PACIFIC 

WAVE HEIGHTS THIS EVENING. THE 12Z ECMWF WAM APPEARS A COUPLE FT 

TOO HIGH ACROSS OUTER PZ5 WATERS. 



--------------------------------------------------------------

...PREVIOUS DISCUSSION... 



THE 18Z SFC ANALYSIS INDICATED HIGH PRES CENTERED NEAR 51N138W 

WITH RIDGE EXTENDING NE INTO WESTERN BRITISH COLUMBOA...AND S 

ALONG 140W. COASTAL TROUGH EXTENDED N ALONG THE ENTIRE W COAST 

TO N OF VANCOUVER ISLAND. AN ASCAT PASS FROM 1733Z WITH DATA 

LIMITED TO CENTRAL/S CA WATERS INDICATED A SMALL AREA OF 25 KT W 

OF CHANNEL ISLANDS...OTHERWISE WINDS WERE 20 KT OR LESS. 



THE 12Z MODELS CONTINUE TO BE IN VERY GOOD AGREEMENT DURING MOST 

OF THE FCST PERIOD...WITH SOME DIFFERENCES SHOWING UP DURING THE 

DAY 5 PERIOD. FOR TONIGHT THROUGH SUN NIGHT...NO MAJOR CHANGES 

FROM PREVIOUS FCST ARE ANTICIPATED AS THE 12Z GFS IS SIMILAR TO 

THE 00Z RUN...WHICH WAS USED TO POPULATE WIND GRIDS ON PREVIOUS 

SHIFT. THE HIGH PRES MENTIONED ABOVE WILL MOVE SW THE NEXT FEW 

DAYS WHILE GRADUALLY WEAKENING...WHILE THE TROUGH ALONG THE 

COAST ALSO WEAKENS SAT INTO SUN. WITH THE TROUGH AXIS NEAR THE 

COAST OR SLIGHTLY OFFSHORE...EXPECT THE STRONGEST WINDS THE NEXT 

FEW DAYS OVER THE OUTER WATERS OF WA/OR/N CA WITH HIGHEST SPEEDS 

TOPPING OUT AROUND 25 KT FOR THE MOST PART. LOOKING AHEAD TO 

LATER SUN THROUGH MON NIGHT...THE MODELS ALL INDICATE A LOW 

FORMING OVER THE GULF OF AK THEN MOVING SE. SEVERAL WEAK COLD 

FRONTS WILL AFFECT THE WA/OR WATERS DURING THIS PERIOD...THOUGH 

WINDS WILL REMAIN WELL BELOW WARNING CRITIERIA. THERE ARE SOME 

DIFFERENCES ON THE TRACK AND INTENSITY OF THE LOW WITH THE UKMET 

BEING FURTHER S AND SLIGHTLY STRONGER...WITH THE ECMWF FURTHER N 

AND WEAKER. THE GFS ACTUALLY LOOKS LIKE A DECENT COMPROMISE 

HERE...AND IS NOT TOO DIFFERENT FROM THE GEM. WITH THIS IN 

MIND...PLAN ON POPULATING WIND GRIDS WITH 12Z GFS 10M WINDS 

THROUGHOUT. 



.SEAS...THE 18Z SEA STATE ANALYSIS INDICATED THAT OBSERVED SEAS 

CONTINUE TO MATCH UP WELL WITH THE MODEL FCST VALUES. PLAN ON 

USING THE MWW3 THROUGHOUT. 



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



.WARNINGS...PRELIMINARY. 



.PZ5 WASHINGTON/OREGON WATERS... 

     NONE. 



.PZ6 CALIFORNIA WATERS... 

     NONE. 



$$ 



.FORECASTER CLARK/KOSIER. OCEAN PREDICTION CENTER.

