

058 

AGPN40 KWNM 301530

MIMPAC



MARINE WEATHER DISCUSSION FOR N PACIFIC OCEAN

NWS OCEAN PREDICTION CENTER WASHINGTON DC

830 AM PDT SAT JUL 30 2016



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

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



THE SAT IMG SHOW AT 12Z HIGH PRES 1033 MB W OF THE REGION HAS ITS

RIDGES INTO THE NRN AND SRN WATERS WHILE INLAND TROF STRETCHES NW

NR THE CA COAST FROM A LOW PRES OVER SRN CA/AZ. ANOTHER INLAND

TROF EXTENDS SW FROM LOW PRES OVER CANADA JUST N OF WA STATE. THE

PRES GRDIENT NR THE TROFS IS FAIRLY TIGHT AND WINDS IN BOTHER

AREAS ARE IN THE GALE FORCE RANGE. THE HIGHEST SEAS ARE 13 FT OVER

THE N AND 14 FT OVR NRN CA WATERS. SEA RANGE BETWEEN 4 AND 6 FT

OVER THE FAR S-ERN WATERS.

 

THE GLOBAL MODELS HAVE INTITIALIZED GENERALLY WELL WITH THE

SYNOPTIC PRES FIELDS BUT SOME DIFFERENCES ARE IN THE WIND SPEED

AND THAT IS VIVID OVER THE NRN AREAS WITH HIGHER WINDS. CMC HAS

THE HIGHEST WINDS TO 45 KT WHILE THE ECMWF IS THE WEAKEST WITH

WINDS ONLY TO 30 KT. GFS HAS WINDS TO 40 KT WHILE THE UKMETHR HAS

WINDS TO 35 KT. COMPARING THE OBSERVED WIND SPEED WITH MODEL WINDS

THE UKMETHR HAS 25 KT WINDS IN A ZONE THAT HAS OBSERVATION REPORTS

OF 30 KT AND THAT IS THE CASE WITH THE ECMWFHR TOO. AS SUCH THE

GFS HAS A BETTER INITIALIZATION SINCE THE CMC IS MUCH HIGHER THAT

THE OBS AND SO WILL STAY WITH GFS FOR THIS UPDATE. IN THE SHORT

TERM THE HIGH PRES WILL REMAIN TO THE W OF THE REGION AS INLAND

TOFS PERSIST. THE HIGH WILL WEAKEN IN THE ETENDED PERIOD AND THAT

WILL RELAX THE PRES GRADIENT OVER THE WATERS ALLOWING WINDS TO

DIMINISH TO BELOW GALE FORCE.



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

PREVIOUS DISCUSSION...



THE LATEST HIGH RES ASCAT-A AND RAPIDSCAT IMAGERY BETWEEN 0430Z

AND 07Z SHOW GALES OFF SRN OREGON AND NRN CA COAST EVEN EXTENDING

OUT INTO SE PORTION OF SRN OUTER OREGON ZONE AND NRN CA OUTER

WTRS...MOSTLY MRGL GALES IN THE ENHANCED GRADIENT BETWEEN THE

INLAND THERMAL TROF AND THE STRONG HIGH TO THE W NR 43N145W.

ANOTHER AREA OF STRONGER GALES APPEARS OVR NRNMOST TWO ZONES WITH

STRONGEST 45 KT IN N PORTION OF PZZ800. A LOW PRES TROF HAS FORMED

OVR VANCOUVER ISL IN RESPONSE TO UPR SHRTWV TROF PASSING TO THE N

FOLLOWED BY SHRTWV RIDGING TO THE W CAUSING HIGH PRES TO BUILD FM

THE W. RECEIVED TWO SHIP RPTS WITH 45 KT IN THAT AREA AT 06Z. FOR

THE NEW FCST GRIDS...POPULATED WINDS WITH STRONGER 00Z GFS 30M

WINDS TO MORE CLOSELY MATCH OBS WITH SOME MINOR EDITS AT START OF

FIRST PRD. WINDS ARE LIGHTER AT NW 10 TO 20 KT OVR SRN HALF OF CA

WTRS CLOSER TO THE INVERTED TROF OVR CA.



LATEST 00Z MDLS SPRT MAINTAINING NLY GALES INTO SAT NIGHT BOTH FM

DIURNAL EFFCTS AND RDG BLDG FM W WITH EXTENSION OF GALES INTO ADJ

OUTER ZONES AT LEAST FOR FIRST PRD. CONT TO HAVE HIGHEST CONFDC

IN GALES FOR INNER ZONES OFF CA AND SRN OREGON WITH THE GALES IN

NRNMOST TWO ZONES PRESENTLY NR THEIR MAX. AN UPR CLOSED LOW IS

FCST BY MDLS TO APCH NRN WTRS FM WNW SAT NIGHT INTO SUN NIGHT

WHICH WILL WKN THE OFSHR HIGH PRES RDG FIRST IN THE NRN WTRS SAT

NIGHT...ENDING THE GALES THERE...AND THEN THE CENTRAL PORTIONS

INCUDING OREGON AND NRN CA SUN AND SUN NIGHT. UPR AND SFC RDG

REBUILD EWD AFTER UPR LOW MOVS INLAND MON NIGHT INTO TUE. THIS WL

LKLY INCREASE GRADIENT ENUF TO REDVLP NLY GALES AT LEAST OVR NRN

CA INNER WTRS TUE NIGHT INTO WED NIGHT. AFTER FIRST PRD POPULATED

RMNDR OF WIND GRIDS WITH REPRESENTATIVE 00Z GFS WITH OTHER

GUIDANCE ESPCLY ECMWF IN GOOD AGRMT. USED OTRW A 50/50 BLEND OF

00Z GFS 10M AND 30M WINDS. THE GFS AND OTHER GLOBAL MDLS HAVE

CHANGED LTL FM EARLER RECENT RUNS...SO THERE IS LTLCHG IN WRNGS. 



.SEAS...POPULATED SEAS WITH THE MORE REPRESENTATIVE 00Z ECMWF WAM

WHICH IS INITIALIZED WITH HIGHER SEAS THAN 00Z ENP WW3...AND FACT

BOOSTED SEAS BY 10 PCT TO MORE CLOSELY MATCH THE OBS. USED 00Z

ECMWF THRU SUN AND THEN AFTER THAT USED A 50/50 BLEND OF THE 00Z

WAVE MDLS AS THE MDLS AFTER SUN ONLY SHOW MINOR DIFFERENCES OF A

FOOT OR SO.



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





.WARNINGS...PRELIMINARY.



.PZ5 WASHINGTON/OREGON WATERS...

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

     GALE TODAY INTO TONIGHT. 

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

     GALE TODAY.

.PZZ805...INNER WATERS FROM CAPE SHOALWATER TO CAPE LOOKOUT...

     GALE TODAY.

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

     GALE TODAY INTO SUN. 



.PZ6 CALIFORNIA WATERS...

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

     GALE TODAY INTO SUN NIGHT. 

     GALE POSSIBLE TUE NIGHT INTO WED NIGHT. 

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

     GALE TODAY INTO TONIGHT. 

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

     GALE POSSIBLE TUE NIGHT INTO WED. 



$$



.FORECASTER MUSONDA/BANCROFT. OCEAN PREDICTION CENTER.

