

544 

AGPN40 KWNM 180320

MIMPAC



MARINE WEATHER DISCUSSION FOR N PACIFIC OCEAN

NWS OCEAN PREDICTION CENTER WASHINGTON DC

820 PM PDT WED AUG 17 2016



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

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



ATTM I DONT PLAN ON MAKING ANY CHANGES TO THE CURRENT GRIDS OR

ASSOCIATED TEXT FCST. THE ASCAT PASS FROM THIS AFTERNOON INICATES

GALES ALONG THE NRN CA CST...MAINLY OVER THE COASTAL WATERS

ALTHOUGH EXTENDING INTO THE INNER OFFSHORE ZONES AS WELL. FURTHER

N...30 KT WINDS ARE SHOWN EXTENDING INTO THE WA WATERS AT 19Z.



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

PREVIOUS DISCUSSION...



THE SAT IMG INDC A RIDGE TO THE W OF THE FORECAST WATERS. ALL THE

OBSERVATIONS INCLUDING THE ASCAT PASSES AT 1724Z AND 1902Z SHOW

MAX WINDS IN GALE FORCE RANGE OVER THE NRN CA AND FAR SRN OR

WATERS. AT 18Z THE NCEP MAP HAS HIGH PRES CENTERS 1033 MB NEAR

50N137W AND 43N140W WITH A RIDGE EXTENDING SE INTO THE SRN AND

ANOTHER INTO THE NRN WATERS. INLAND LOW PRES 1006 MB OVER CA WITH

TROFS EXTENDING NW AND SE. ANOTHER INLAND LOW PRES 1013 MB OVER

CENTRAL WA HAS ITS TROF EXTENDING NW PASSING JUST NE OF THE

WATERS. THE PRES GRADIENT IN THE VICINITY OF THE TROFS IS FAIRLY

TIGHT AND THE WINDS ARE IN GALE FORCE RANGE.



THE GLOBAL MODELS HAVE INITIALIZED WELL AND THEY CONTINUE TO BE IN

GOOD AGREEMENT ESPECIALLY IN THE SHORT TERM. THERE ARE SOME

DIFFERENCES IN THE CENTRAL PRES VALUE FOR THE INLAND LOW WHERE

EACH MODEL HAS A VALUE HIGHER THAN THE OBSERVATION BUT WITHIN 3

MB. OTHERWISE THE SYNOP PATTERN REMAINS VERY CLOSE TO THE

OBSERVATIONS. THE MODELS HAVE SOME DIFFRENCES IN THE EXTENDED

PERIOD MAINLY ON THE CENTRAL PRES VALUE FOR THE HIGH THAT WILL

PERSIST TO THE W AND DOMIATE THE WX OVER THE REGION. CMC IS THE

WEAKEST BY UP TO 5 MB AND HAS ITS CENTER CLOSER TO THE WATERS.

UKMETHR AND THE ECMWFHR ARE ONLY 1 MB LOWER THAN GFS. THE ECMWFHR

IS WEAKER THAN UKMET AND GFS ON THE WINDS THAT WILL BE ELEVATED

OVER THE NRN WATERS. THERE IS SOME ENERGY THAT WILL LINGER OVER

THE ERN PARTS AND SOME THAT WILL GLIDE OVER THE RIDGE TO THE N AND

SPREAD S. FOR THE GRIDS WILL GO WITH GFS OVER UKMETHR BECAUSE

DATA IS EVERY 6 HOURS COMPARED TO GFS EVERY 3 HOURS. IN THE SHORT

TERM HIGH PRES WILL PERSIST TO THE W OF THE REGION WHILE THE

INLAND TROF WIL ALSO PERSIT AND THAT WILL KEEP GALE FORCE WINDS

OVER THE CENRAL WATERS AND WINDS WILL ALSO BE ELAVATED OVER THE

NRN WATERS AND WITH LOW TO MOD CONFDC WILL ADD GALES TO THE FAR N

PORTION OF THE WA WATERS.



.SEAS...THE SEAS ARE ALSO LARGE OVER THE AREAS WITH HIGH WINDS AND

HAVE PEAKED AT 13 FT OVER THE CENTRAL WATERS AND 11 FT OVER THE NE

WA WATERS. OTHERWISE SEAS RANGE BETWEEN 6 AND 9 FT ELSEWHERE. THE

NWW3 MULTI GRID HAS CONTINUED TO FIT WELL WITH THE OBSERVED SEAS

PATTERN AND STILL CLOSE TO THE ECMWFWAVE MODEL. BOTH WAVE MODELS

ARE IN GOOD AGREEMENT IN THE SHORT TERM AND EVEN IN THE EXTENDED

PERIOD WITH JUST MINOR DIFFERENCES. THE SEAS WILL REMAIN LARGE

OVER THE CENTRAL WATERS IN THE SHORT TERM BUT WILL SUBSIDE IN THE

EXTENDED PERIOD. 



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





.WARNINGS...PRELIMINARY.



.PZ5 WASHINGTON/OREGON WATERS...

.PZZ800...INNER WATERS FROM CAPE FLATTERY TO CAPE SHOALWATER...

     GALE POSSIBLE SUN NIGHT.

.PZZ900...OUTER WATERS FROM CAPE FLATTERY TO CAPE SHOALWATER...

     GALE TONIGHT.

     GALE THU NIGHT.



.PZ6 CALIFORNIA WATERS...

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

     GALE TONIGHT.



$$



.FORECASTER SHAW/MUSONDA. OCEAN PREDICTION CENTER.

