

024 

AGPN40 KWNM 310232

MIMPAC



MARINE WEATHER DISCUSSION FOR N PACIFIC OCEAN

NWS OCEAN PREDICTION CENTER WASHINGTON DC

732 PM PDT SAT JUL 30 2016



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

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



1747Z ASCAT WIND RETRIEVALS INDC GALE FRC WINDS OFF THE NRN

CAL/SRN ORE COAST...AND IN THE NE WAS OFSHR WATERS...AS A PAIR OF

LOW PRES TROUGHS INTERACT WITH HIGH PRES W OF THE AREA. CRNT SFC

RPRTS INDC THE SAME...AND THE 18Z GFS WINDS ARE INIT OK WHEN

COMPARED WITH THE DATA. THE GFS INDC THE WINDS WL DROP BL GALE FRC

IN THE NE WAS WTRS TNGT...AND BY MON MORNING IN THE NRN CAL WTRS

AS THE INLND TROFS WKN. THE PREV FCST KEPT GALES CONSISTENT WITH

THE 12Z GFS...WHICH AGREES FAIRLY WELL WITH THE 12Z

ECMWF/UKMET/GEM/NAM...SO PLANNING IN MAINTAINING PREV SHORT TERM

WARNINGS IN THE UPDATE PKG.



THE 12Z/18Z MDLS INDC ANOTHER ROUND OF GALES OFF THE NRN CAL

COAST...AS A WK COLD SURGE MOVES DN THE COAST AND LOWERS STATIC

STABILITY...AS HIGH PRES BUILDS IN FM THE W. THE 12Z

ECMWF/UKMET/GEM ALL AGREE WELL WITH THE GFS ON THE OVERALL

PTTN...AND ALL INDC GALE OR NR GALE FRC WINDS OFF THE NRN CAL

COAST TUE NGT INTO THU NGT...AS STG HIGH PRES PERSISTS W OF THE

OFSHR WTRS. CONFDC IS CRNTLY MDT TO HIGH WITH THE GALES AS A

RESULT OF THE GUD MDL AGRMT...SO PLANNING ON BOOSTING WINDS

SLIGHTLY OFF THE NRN CAL WTRS...TO INCRS COVERAGE OF GALES IN ZONE

PZZ820. OTRW...NOT PLANNING ON MAKING ANY SIG CHANGES FOR THE

REMAINDER OF THE UPDATE PKG.



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

PREVIOUS DISCUSSION...



THE SAT IMG SHOWS THIN CLOUDDS TO CLEAR SKIES OVER THE NRN WATERS

WHILE FAILRY CLOUDY OVER THE SRN WATERS AND NO OBS OF LIGHTNING

STRIKES IN THE PAST FEW HOURS. AT 18Z HIGH PRES 1033 MB STILL W OF

THE REGION WITH RIDGES INTO THE NRN AND SRN WATERS WHILE INLAND

TROF ALSO STRETCHES NW NEAR THE CA COAST FROM A LOW PRES OVER SRN

CA/AZ. ANOTHER INLAND TROF STILL EXTENDS SW FROM LOW PRES OVER

CANADA JUST N OF WA STATE. THE PRES GRDIENT NEAR THE TROFS IS

FAIRLY TIGHT AND WINDS IN BOTH AREAS ARE IN THE GALE FORCE RANGE.



THE GLOBAL MODELS HAVE CONTINUED TO INTITIALIZE GENERALLY WELL

WITH THE SYNOPTIC PRES FIELDS BUT SOME DIFFERENCES STILL EXIST THE

WIND SPEED AND THAT IS AMPLIFIED OVER THE NRN AND CENTRAL AREAS

WITH HIGHER WINDS. CMC STILL HAS THE HIGHEST WINDS TO 45 KT WHILE

THE ECMWF REMAINS THE WEAKEST WITH WINDS ONLY TO 30 KT. GFS HAS

CONTINUED WITH WINDS TO 40 KT WHILE THE UKMETHR HAS WINDS TO 35

KT. COMPARING THE OBSERVED WIND SPEED WITH MODEL WINDS THE UKMETHR

STILL HAS 25 KT WINDS IN SOME ZONES THAT HAVE OBSERVATION REPORTS

OF 30 KT AND SAME APPLIES TO THE ECMWFHR. AS SUCH THE GFS HAS

CONTINUED TO INITIALIZE BETTER THAN MOST OF THE GLOBAL MODELS

SINCE THE CMC IS MUCH HIGHER THAT THE OBS AND SO WILL STAY USE GFS

FOR THIS PACKAGE. IN THE SHORT TERM THE HIGH PRES WILL CONTINUE TO

REMAIN TO THE W OF THE REGION AND THE INLAND TROFS WILL PERSIST.

THE HIGH WILL SLIGHTLY WEAKEN AND THAT WILL RELAX THE PRES

GRADIENT OVER THE WATERS ALLOWING WINDS TO DIMINISH TO BELOW GALE

FORCE. THE HIGH WILL THEN SLOWLY START TO MOVE E OWRD THE WATERS

AND THO WEAK...THE ISOBARS OVER THE ERN PARTS AND THE NRN WATERS

WILL PACK AGAIN AND TIGHTEN THE PRES GRADIENT THAT WILL PROLONG

THE GALE WARNINGS IN THE EXTENDED PERIOD.



.SEAS...THE HIGHEST SEAS ARE STILL 13 FT OVER THE N AND 14 FT OVR

NRN CA WATERS. THE SEAS RANGE BETWEEN 4 AND 6 FT OVER THE FAR

S-ERN WATERS. THE NWW3 MULTI GRID WAVE MODEL HAS INITIALIZED VERY

WELL WITH THE OBSERVED SEAS PATTERN AND HAS BEEN QUITE CONSISTENT

IN THE PREVIOUS RUNS. THE ECMWFWAVE HAS ALSO INITIALIZED WELL AND

IS VERY CLOSE TO THE NWW3. BOTH WAVE MODELS ARE IN GOOD AGREEMENT

OVER THE SHORT TERM WITH JUST MINOR DIFFEERNCES IN THE EXTENDED

PERIOD WITHIN A FOOT. SEAS WILL REMAIN RELATIVELY LARGE OVER THE

CENTRAL AND NRN WATERS AND WILL PEAK AT 16 FT THIS WEEKEND THEN

SUBSIDE EARLY NEXT WEEK.





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







.WARNINGS...PRELIMINARY.



.PZ5 WASHINGTON/OREGON WATERS...

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

     GALE TONIGHT.

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

     GALE TONIGHT INTO SUN. 



.PZ6 CALIFORNIA WATERS...

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

     GALE TONIGHT INTO SUN NIGHT. 

     GALE POSSIBLE TUE NIGHT INTO THU. 



$$



.FORECASTER KELLS/MUSONDA. OCEAN PREDICTION CENTER.

