

825 

AGPN40 KWNM 200301

MIMPAC



MARINE WEATHER DISCUSSION FOR N PACIFIC OCEAN

NWS OCEAN PREDICTION CENTER WASHINGTON DC

801 PM PDT FRI AUG 19 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. MOST RECENT ASCAT PASS SHOWS SWATH OF 20-30

KT WINDS STRETCHING SW FROM VANISL ACROSS THE WRN PTNS OF THE

WZA/OR WATERS. MAX SEAS NR 13 FT AS INDICATED BY CURRENT OBS AND

ALTIMETER PASS.



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

PREVIOUS DISCUSSION...



THE SAT IMG STILL INDC STRONG HIGH PRES TO THE W OF THE REGION.

ALL THE OBSERVATIONS INCLUDING THE ASCAT PASS AT 1823Z SHOW MAX

WINDS OVER THE NRN WATERS. THE LATEST NCEP MAP HAS HIGH PRES

CENTER 1034 MB THAT HAS SHIFTED W WHILE THE INLAND LOW PRES 1010

MB OVER CA STILL HAS ITS TROF EXTENDING NW. THE RETREATING HIGH

PRES TO THE W HAS HELPED TO FARTHER RELAX THE PRES GRADIENT OVER

THE REGION WHICH HAS RESULTED IN WINDS TO REMAIN BELOW GALE FORCE.

 

THE GLOBAL MODELS HAVE CONTINUED TO INITIALIZE FAIRLY WELL WITH

THE PRES FIELDS AND AGAIN JUST SMALL DIFFERENCES IN THE WIND SPEED

AND DIRECTION IN AREAS WITH MAX WINDS. CMC/GFS/NOGAPS/UKMETHR

MATCH SOME OF THE OBS BUT ARE 5 KT HIGHER THAN THE OBS IN SOME

AREAS WHILE JMA/ECMWFHR HAVE ALSO MATCHED THE OBS IN SOME AREAS

BUT LOWER BY 5 KT IN AREAS WITH HIGHER WIND SPEEDS. ALL THE MODELS

HAVE MATCHED THE PRES FIELDS WELL BUT DIFFERENCES INCREASE WITH

TIME AND MAINLY ON THE CENTRAL PRES VALUE FOR THE DOMINANT HIGH TO

THE W. IN THE SHORT TERM ALL THE MODELS AGREE ON STRENGTHENING THE

HIGH AS IT SHIFTS SW AND IN THE EXTENDED PERIOD THE HIGH WILL

START TO MOVE NE TWD THE NRN WATERS AS IT WEAKENS BUT WILL GAIN

MORE STRENGTH BY THE END OF FORECAST PERIOD. THE MODELS ARE IN IN

GOOD AGREEMENT WITH THE PRES FIELD PATTER BUT THE DIFFRENCES ARE

MAINLY ON THE CENTRAL PRES VALUE AND THE TIMING. OTHERWISE THESE

SMALL DIFFERENCES TO DOT ALTER THE SYNOP PATTERN ACROSS THE

FORECAST WATERS AND SO WILL STAY WITH GFS. IN THE SHORT TERM THE

HIGH PRES WILL REMAIN TO THE W OF THE REGION AND STILL MAINATIN

ITS RIDGE CAROS THE REGION WHILE THE INLAND TROF PERSITS OVER NEAR

THE CA AND OR COAST. THE PRES GRADIENT WILL REMAIN RELAXED THRU

MOST OF THE PERIOD AND WITH MOD TO HIGH CONFDC THAT SHOULD KEEP

THE WINDS BELOW GALE FORCE THRU THE FORECAST PERIOD.





.SEAS...THEY NOW PEAK AT 11 FT OVER THE WRN EDGE OF THE NRN

WATERS AND THEY RANGE BETWEEN 6 AND 10 FT ELSEWHERE. NWW3 WAVE

MODEL STILL FITS VERY WELL AND MATCHES THE PEAK VALUES WITH THE

OBSERVATIONS. NWW3 HAS ALSO BEEN QUITE STABLE IN THE PREVIOUS

RUNS AND HAS CONTINUED TO BE VERY CLOSE TO THE ECMWFWAVE. WILL

CONTINUE WITH NWW3 FOR THE SEAS.





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







.WARNINGS...PRELIMINARY.



.PZ5 WASHINGTON/OREGON WATERS...

     NONE.



.PZ6 CALIFORNIA WATERS...

     NONE.



$$



.FORECASTER SHAW/MUSONDA. OCEAN PREDICTION CENTER.

