

637 

AGPN40 KWNM 280807

MIMPAC



MARINE WEATHER DISCUSSION FOR N PACIFIC OCEAN

NWS OCEAN PREDICTION CENTER WASHINGTON DC

107 AM PDT THU JUL 28 2016



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

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



THE FOCUS OF THE NEXT FORECAST REMAINS ON THE INTERACTION BETWEEN

THE HEAT LOW/TROF OVER THE INTERIOR IN CENTRAL CAL AND STRONG HIGH

PRES W OF THE NRN CAL WTRS. THE STRONGEST PART OF THE PRES GRAD IS

TO THE W OF PT ST GEORGE...AND CRNT SFC RPRTS INDC UP TO 30

KT...THO NONE INVOF THE STGST GRAD. ALSO...ASCAT FM 0430Z LARGELY

MISSED THE STGST PART OF THE GRAD...THO DID CATCH PART OF IT OFF

THE SW OREGON COAST AND INDC GALES. THE EARLIER ASCAT FM 18Z YDA

WENT RIGHT OVER THE STGST WINDS...AND HAD A LRG AREA OF GALES IN

THE COASTAL WATERS AND A LARGE AREA OF 30 KT EXTENDING INTO OFSHR

WTRS. IN ADDITION...WIND RETRIEVALS FM A 1830 UTC ALTIMETER PASS 

ALSO INDC 30 KT...WITH SEAS ABV 14 FT...SEVL FT HIGHER THAN THE

WAVE GUID. HOWEVER...THE THERMAL TROF IS NEARING ITS WEAKEST STAGE

OF THE DAY WITH THE DIURNAL MINIMUM...SO NOT EXPECTING ANYTHING

STGR FM EARLIER. THE 00Z GFS 10M WINDS ARE INIT A LTL LOW WHEN

COMPARED WITH THE CRNT DATA...AND THE 30M WINDS SEEMS A LTL

OVERDONE...SO PLANNING ON STAYING WITH PREV BLEND OF 10M/30M WINDS

TO START OFF WITH...AS IT SEEMS TO BEST REFLECT CRNT CONDITIONS.

ALSO...THE 00Z GFS INDC THE CRNT PTN WL CONT OVR PZ6 INTO

SUN...MAINTAINING GALES JUST OFF THE NRN CAL COAST UP TO THAT

TIME. THE 00Z ECMWF/UKMET/GEM/NAM ALL AGREE FAIRLY WELL WITH THE

GFS ON THE OVERALL PTTN...AND ALL INDC GALE OR NEAR GALE FORCE

WINDS INTO SUN BEFORE HIGH PRES DRIFTS TO THE W AND CAUSES THE

GRAD TO WEAKEN. THE PREV FCST HAD GALES CONSISTENT WITH THE

GFS IN THE INNER NRN CAL AND SRN OREGON WATERS...AND CONFDC IS

FAIRLY HIGH WITH THEM DUE TO THE GOOD MDL AGRMT AND RUN TO RUN

CONSISTENCY...SO PLANNING ON MAINTAINING PREV WRNG IN NE PZ6/SE

PZ5 IN NEXT PKG.



ALSO...THE LTST GOES IR IMGRY INDC A STG LOW PRES SYS IS CRNTLY

CENTERED OVER THE GULF OF ALASKA....WITH A FRONTAL BNDRY

EXTENDING TO THE S THEN SW FROM THE LOW CENTER. THE IMGRY ALSO

INDC A WK FRNTL WAVE CRNTLY NR 47N146W...MOVG TO THE E TWD NRN

PZ5 WATERS. THE 00Z MDLS AGREE FAIRLY WELL ON MOVING THE WK WAVE

INTO NRN PZ5 LATE TNGT INTO FRI...AND THEN DSIPT THE FRONT.

HOWEVER...THE 00Z GFS/NAM/ECMWF ALL INDC THE WK CD SURGE WL ACT

TO LOWER STATIC STABILITY OVR PZ5...MAKING IT EASIER FOR STGR

WINDS ALOFT TO MIX DN. THE GFS/ECMWF ALS0 INDC WINDS IN THE 45 TO

50 KT RANGE OVR THE NE WAS WTRS BY LATE FRI INTO SAT...SO THE

POTENTIAL FOR GALES TO MIX DN IS THERE. IN ADDITION...THE MDLS

INDC A SECOND SFC TROF WL DEVELOP ALONG THE COAST OF WAS AND

EXTEND OVER VANCOUVER ISLAND...INTERACT WITH THE AFOREMENTIONED

HIGH W OF THE AREA...AND INCREASE THE PRES GRAD OVER ZONE PZZ800. 

AS A RESULT...CONFDC IS HIGH WITH GALES OVER PZZ800 FRI NIGHT

INTO SAT NIGHT...SO PLANNING ON KEEPING PREV WARNING IN NEXT PKG.



OTRW...THE 00Z GFS HAS BEEN CONSISTENT WITH THE OVERALL PTTN OVER

THE PAST FEW DAYS...AND INDC ANOTHER WK CD FNT WL MOV INTO NRN PZ5

MON. THE 00Z ECMWF/GEM ARE SLIGHTLY SLOWER THAN THE GFS...WHICH IS

DECENT AGRMT WITH THE 00Z ON THE TMG OF THE FRONT. HOWEVER...THE

ECWMF HAS BEEN A BIT INCONSISTENT WITH THE TMG...AND WAS MUCH

SLOWER WITH THE 12Z RUN FROM YDA. THE TREND TWD THE MORE

CONSISTENT GFS SOLN INCREASES CONFDC WITH THE GFS...SO PLANNING ON

FAVORING IT THRUT THE REMAINDER OF THE FCST PD.



.SEAS...THE JASON-2 ALTIMETER PASS FROM 1828Z INDICATES THAT BOTH

THE NWW3 AND ECMWF WAM GUIDANCE WERE RUNNING UP TO 3 FT LOW

WITHIN THE STRONG NLY FLOW OFF NRN CA...BUT THERE NO CRNT REPORTS

INVOF OF THE NRN CAL GALES. ATTM STILL PLANNING ON ADJUSTING SEAS

HIGHER OFF NRN CAL...AS WAVE MODELS HAVE BEEN STRUGGLING TO KEEP

UP. HOWEVER...THE 00Z WAVE MODELS ARE INIT OK OVER THE REMAINDER

OF THE E PAC WHEN COMPARED WITH THE AVAIALBLE DATA. THE 00Z

WAVEWATCH-III AND ECWMF WAM AGREE FAIRLY WELL OVER THE FCST

PERIOD...SO ATTM PLANNING ON USING A BLEND OF THE TWO...FAVORING

THE 00Z NWW3 MORE HEAVILY AS IT BEST REFLECTS THE PREFERRED GFS

WINDS.



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



.WARNINGS...PRELIMINARY.



.PZ5 WASHINGTON/OREGON WATERS...

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

     GALE FRI INTO FRI NIGHT. 

     GALE POSSIBLE SAT INTO SAT NIGHT. 

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

     GALE TONIGHT INTO FRI NIGHT. 

     GALE POSSIBLE SAT INTO SUN. 



.PZ6 CALIFORNIA WATERS...

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

     GALE EARLY TODAY INTO FRI NIGHT. 

     GALE POSSIBLE SAT INTO SUN NIGHT. 



$$



.FORECASTER KELLS. OCEAN PREDICTION CENTER.

