

025 

AGPN40 KWNM 131522

MIMPAC



MARINE WEATHER DISCUSSION FOR N PACIFIC OCEAN

NWS OCEAN PREDICTION CENTER WASHINGTON DC

822 AM PDT SAT AUG 13 2016



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

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



THE VIS AND IR SAT IMG INDC MOSTLY CLOUDY SKIES ACROSS THE

FORECAST WATERS. THE OBSERVATIONS AND EARLIER ASCAT PASS SHOW

HIGHER N WINDS OVER THE PZ5 WATERS. THE 12Z NCEP MAP HAS A BROAD

HIGH PRES ACROSS THE NRN PACIFIC WITH SEVERAL CENTERS. THE HIGH

HAS ITS RIDGE EXTENDING NE INTO THE NRN WATERS AND ANOTHER ONE SE

INTO THE SRN WATERS. INLAND TROUGH EXTENDS FROM SRN CA INTO SRN WA

WHILE LOW PRES 990 MB OVR THE ALEUTIAN ISLANDS HAS AN OCCLUDED

FRONT THAT STRETCHES NE AND E THEN A WARM FRONT THAT ENDS ABOUT

180 NM N OF THE REGION AND A COLD FRONT STRETCHES SW PASSING ABOUT

360 NM W OF THE PZ5 WATERS. THE PRES GRADIENT IS QUITE RELAXED AND

MAX WINDS ARE ONLY 25 KT. THE SEAS RANGE BETWEEN 6 AND 8 FT OVER

THERN WATERS AND THEY RANGE BETWEEN 4 AND 6 FT OVER THE SRN

WATERS. THE NWW3 MULTI GRID FITS VERY WELL WITH THE OBSERVED SEAS

PATTERN AND MATCHES THE PEAK VALUES TOO. EVEN THE ECMWFWAVE HAS

ALSO INITILAIZED WELL AND IS GOOD AGREEMENT WITH THE NWW3 AND BOTH

WAVE MODELS AHVE BEEN QUITE CONSSISTENT AND SO WILL JUST USE NWW3

FOR THE GRIDS.



AN UPPERLEVEL RIDGE WITH VERY LITTLE ENRGY IS OVER THE REGION.

THERE IS SOME ENRGY EMBEDDED IN AN UPPERLELVEL LOW OVER THE

ELEUTIAN ISLANDS THAT WILL BE PUSHED INTO THE GULF OF AK. JUST

BEHIND THE UPPERLEVEL RIDGE IS A TROUGH THAT HAS SOME ENERGY THAT

WILL GLIDE NE OVER THE HIGH AND MOVE INTO THE NRN WATERS THEN MOVE

SE AND BE JUST E OF THE CENTRAL WATERS AND THAT WILL HELP TO

MAINTAIN A STRONGER INLAND TROF.



THE GLOBAL MODELS HAVE INITIALIZED FAIRLY WELL WITH JUST MINOR

DIFFERENCES AND THEY ARE IN DECENT AGREEMENT ON THE FEW SYNOPTIC

FEATURES AFFECTING THE WEATHER ACROSS THE FORECAST WATERS. THE

ECMWFHR AND UKMETHR ARE BOTH WEAKER THAN THE MAX OBSERVED WINDS BY

5 KT WHILE THE CMC IS HIGHER BY 5 KT. THE GFS/NOGAPS AND JMA MATCH

THE MAX OBSERVED WINDS. THE GLOBAL MODELS HAVE BEEN CONSISTENT

WITH THE GALES IN THE EXTENDED PERIOD AND WITH THE EXPECTED ENERGY

TO REACH E OF THE CENTRAL WATERS WILL RETAIN THE GALE WARNINGS

WITH MOD TO HIGH CONFDC. IN THE SHORT TERM HIGH PRES WILL REAMIN

TO THE W OF THE WATERS AND WILL STILL MAINTAIN ITS RIDGES OVER THE

WATERS WHILE THE INLAND TROF WILL ALSO PERSIST AND EVEN

STRENGTHEN. GALE WARNINGS ARE ON TRACK TO SPREAD INTO THE WATERS

MON NIGHT ONWARDS.



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PREVIOUS DISCUSSION...



THERE WAS AN ASCAT PASS AT 05Z WHICH COVERED MUCH OF THE OFFSHR

ESPECIALLY THE WA/OR WTRS WHERE MDL GUID HAS THE STGST WINDS. THE

STGST WINDS WERE TO 20 KT WHICH MATCHES WELL WITH A SHIP OBS OVR

THE NRN WA WTRS WITH 20 KT AND ALSO MATCHES WELL WITH BUOY DATA ON

THE ERN AND WRN AREAS OF THE SWATH. GFS 10M WINDS ARE IN CLOSE

AGRMT WITH THE SATEL DERIVED WINDS.



FOR TDA THE HIGH PRES RDG TO THE W AND SW OF THE NRN OFFSHR WTRS

WL BECOM SLGTLY WKR TDA INTO TNGT...THEN BECOM STGR AS A RDG

BUILDS BACK E OVR THE WTRS SUN THRU WED NGT. GFS HAS THE COASTAL

TROF SHUD REDEVLPG OVR THE NRN CA WTRS SUN EARLIER THAN THE

UKMET/ECMWF WHICH ARE IN CLOSER AGRMT BY LATER MON WITH

INTENSIFICATION OCCURRING THRU WED NGT. OVR THE OFFSHR WTRS XPCT

WINDS TO INCRS TO GALE FORCE BY MON AFTN OVR THE ERN AREAS OF THE

NRN CA OFFSHR WTRS. THE GFS BECOMS STGST WITH THE AREA OF HIGH

PRES TO THE W OF THE NRN WTRS BY WED AND NGT WITH OTHER MDL GUID

IN SMLR AGRMT. THE STGST WINDS DVLP BY TUE NGT AND CONT THRU WED

NGT WITH STGST WINDS OVR THE ERN AREAS OF THE NRN CA. IN ADDITION OVR

THE ERN AREAS OF THE NRN WA WTRS WINDS INCRS TO GALE FORCE AS THE

HIGH PRES STRENGTHENS AND COASTAL TROF INTENSIFIES. WL HAV WINDS

TO 35 KT DURING THE PK PDS.



SEAS...COMPARISON OF THE MULTIGRID WWIII AND ECMWF WAM THRU THE

FCST PD SHOWS CLOSE AGRMT THRU TUE NGT WITH THE WWIII FURTHER S

WITH MAX SEAS ALG THE CNTRL CA WTRS BY LATE WED AND WED NGT. PLAN

TO USE A 50/50 BLEND OF THE WWIII/ECMWF WAM THRU THE FCST PD WITH

MINOR MODIFICATIONS MAINLY TO THE LATER FCST PDS. 





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







.WARNINGS...PRELIMINARY.



.PZ5 WASHINGTON/OREGON WATERS...

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

     GALE POSSIBLE WED INTO WED NIGHT. 

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

     GALE POSSIBLE WED INTO WED NIGHT. 

.PZZ815...INNER WATERS FROM FLORENCE OR TO POINT ST. GEORGE...

     GALE POSSIBLE TUE NIGHT INTO WED NIGHT. 



.PZ6 CALIFORNIA WATERS...

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

     GALE POSSIBLE MON NIGHT INTO WED NIGHT. 

.PZZ920...OUTER WATERS FROM POINT ST. GEORGE TO POINT ARENA...

     GALE POSSIBLE TUE NIGHT INTO WED NIGHT. 

.PZZ825...INNER WATERS FROM POINT ARENA TO PIGEON POINT...

     GALE POSSIBLE WED INTO WED NIGHT. 

.PZZ925...OUTER WATERS FROM POINT ARENA TO PIGEON POINT...

     GALE POSSIBLE WED INTO WED NIGHT. 



$$



.FORECASTER MUSONDA/ROWLAND. OCEAN PREDICTION CENTER.

