

979 

AGPN40 KWNM 262107

MIMPAC



MARINE WEATHER DISCUSSION FOR N PACIFIC OCEAN

NWS OCEAN PREDICTION CENTER WASHINGTON DC

207 PM PDT TUE JUL 26 2016



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

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



UNFORTUNATELY THE MOST RECENT ASCAT AND RAPID SCAT PASSES MISSED

THE AREA ALONG THE NRN CA CST WHERE THE GALES ARE FCST. THE

OVERALL PATTERN ACROSS THE EPAC HASNT CHANGED MUCH OVER THE PAST

FEW DAYS WITH A LARGE RIDGE ANCHORED W OF THE OFFSHORE WATERS

WHILE A TROF PERSISTS ALONG THE CALIFORNIA CST. DURING THE NEXT 7

DAYS THIS OVERALL BLOCKY PATTERN WILL PERSIST...WHILE THE TROF

ALONG THE CA CST INTENSIFIES AND EXPANDS N SLIGHTLY INTO SW

OREGON. THE RESULTING PRESSURE GRADIENT WILL STRENGTHEN AND

PRODUCE A STEADY PERIOD OF GALES ACROSS THE INNER OFFSHORE WATERS

ALONG THE NRN CA CST...AND BRIEFLY BRING GALES TO THE INNER WATERS

OF THE FAR SW OREGON CST. FURTHER N...THE N TO NW FLOW WILL ALSO

CONTINUE ACROSS THE WA/OR WATERS. THE BIGGEST DECISION DURING THE

WEEK WILL BE WHETHER OR NOT TO ISSUE GALES FOR FRI NIGHT INTO SAT

OVER THE FAR NE PTN OF THE WASHINGTON WATERS. THE GFS HAS BEEN

VERY CONSISTANT THE LAST COUPLE OF DAYS IN FCSTING THE POSS OF

GALES OVER THAT REGION...WHILE THE OTHER GLOBAL MODELS ALSO HINT

AT GALES. WE HAVE BEEN HOLDING OFF ON ISSUING GALES UNTIL THE

EVENT GETS CLOSER. AFTER COORDINATION WITH THE MEDIUM RANGE FCSTER

IT WAS DECIDED TO MAINTAIN MAX WINDS OF 30 KT ACROSS THE

WASHINGTON WATERS FOR LATER IN THE WEEK. IF THE NEXT CYCLE OR TWO

GALES MAY NEED TO BE ISSUED FOR THE FAR NE WA WATERS. WILL POP THE

WIND GRIDS USING A 50/50 BLEND OF THE 10M AND 30M WINDS...WITH

SOME MINOR EDITS TO KEEP GALES OUT OF THE OUTER WATERS...AND TO

KEEP GALES FROM THE WASHINGTON WATERS AS WELL.



SEAS...BOTH THE ENP AND WAM ARE IN REALLY GOOD AGREEMENT

THROUGHOUT THE FCST PERIIOD...AND INITIALIZED FAIRLY WELL. WILL

POPULATE THE WAVE GRIDS USING THE ENP THROGHOUT THE FCST PERIOD.



ATTM I DONT PLAN ON MAKING ANY CHANGES TO THE GRIDS OR ASSOCIATED

TEXT FCST. THE LATEST ASCAT PASS INDICATES THAT CONDITIONS ARE

VERY NEAR GALE FORCE ALONG THE NRN CA CST. 



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

PREVIOUS DISCUSSION...



UPPER LEVEL HIGH PRES WILL DOMINATE THE REGION THROUGH FRI...AND

THEN SLOWLY BE REPLACED BY AN UPPER LEVEL TROF DEVELOPING OVER

WESTERN CANADA AND THE ERN N PACIFIC OCEAN SATURDAY INTO SUNDAY

AS THE PERSISTENT WEATHER PATTERN OVER THE REGION FINALLY BEGINS

TO CHANGE.



SHORT TERM...A 0600Z ASCAT PASS INDICATED 30 KT WINDS OVR NE CALIF

OFF WTRS WITH THE PASS UNFORTUNATELY MISSING MOST OF THE COASTAL

WTRS. THE 06Z PRELIM OPC SFC ANALYSIS INDICATED 1029 MB HIGH PRES

CENTERED NR 40N137W...WITH SEVERAL LOW PRES AREAS LOCATED FROM SW

CANADA S TO CENTRAL CALIF. MULTIPLE FRONTAL BOUNDARIES TO THE W

AND NW OF THE HIGH PRES AREA WERE WEAKENING EARLY THIS MORNING AS

THE PUSH E INTO THE STRONG HIGH PRES RIDGE. THE 00Z GLOBAL MODELS

REMAIN IN VERY GOOD AGREEMENT ACROSS THE AREA FOR THE NEXT FEW

DAYS. A STRONG PRESSURE GRADIENT BETWEEN THE HIGH TO THE W OF THE

WTRS AND LOWER PRESSURES NR THE COAST AND INLAND WILL DOMINATE

CONDITIONS RIGHT THROUGH THU. WE WILL USE A BLEND OF THE 00Z GFS

10M AND 30M WINDS WHICH HAS BEEN USED IN THE PREV FEW OPC FCSTS

FOR THE EARLY AM PACKAGE...AND MAKE A FEW MINOR MANUAL ADJUSTMENTS

TO MAINTAIN THE PREV HEADLINES. OVERALL...NO MAJOR CHANGES FROM

THE PREV FCST APPEARS NEEDED FOR THE EARLY AM PACKAGE.



LONG TERM...A WEAK COLD FRONT WILL APPROACH PZ5 WTRS FROM THE NW

THU...THEN PASS SE OVR THESE WTRS THU NITE...WITH THE FRONT THEN

LKLY DISSIPATING AS IT MOVES FURTHER S FRI AND FRI NITE. THE HIGH

TO THE W OF THE WTRS WILL RETREAT SLOWLY W AND STRENGTH SOME THU

INTO SAT NITE. SFC PRESSURES WILL REMAIN RELATIVELY LOW OVR THE

WRN STATES THU INTO SAT NITE. AS A RESULT...THE PRES GRAD WILL

REMAIN RATHER STRONG ESPEC OVR NRN CALIF AND SRN OREG OFF WTRS

DURING THE LONG TERM PORTION OF THE FCST. THE 00Z GLBL MDLS REMAIN

IN GOOD AGREEMENT OVR THE WTRS THRU SAT NITE. WE WILL CONT TO

POPULATE THE FCST WITH THE 00Z GFS 10M-30M BLEND. THIS WILL RESULT

IN NO MAJOR CHANGES FROM THE PREV FEW FCSTS FOR THE EARLY AM OPC

PACKAGE.



FCST CONFDC AND TROPICAL WX...FCST CONFDC WILL REMAIN NR TO ABV

AVEARGE OVR THE WTRS THRU SAT NITE AS THE 00Z MDLS REMAIN IN GOOD

AGREEMENT OVR THE WTRS THRU THE PERIOD. T.S. FRANK AND HURCN

GEORGETTE REMAIN WELL S AND SW OF THE WTRS EARLY THIS MORNING.

BOTH ARE FCST TO TRACK TOWARD THE W-NW AND WEAKEN OVR THE NEXT

FEW DAYS...WITH NO SIGNIFICANT IMPACT ON THE OFF WTRS EXPECTED.

FOR ADTL DETAILS PLS REFER TO THE LATEST NHC ADVISORIES.



SEAS...BOTH THE 00Z ENP WV WATCH III AND ECMWF WAM MDLS REMAIN IN

GOOD AGREEMENT THROUGHOUT THE PERIOD. SEA HEIGHTS RANGE FROM NR 12

FT OVR AND NR THE GALE WNG AREA TO 5 FT OR SO OVR SE SOCAL AND NW

WASH WTRS PER THE LATEST OBS OVR THE REGION. WE WILL CONT TO RELY

ON THE 00Z ENP WW3 MDL GUID FOR THE EARLY AM PACKAGE...WITH NO

MAJOR CHANGES FROM THE PREV FEW OPC FCSTS.



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







.WARNINGS...PRELIMINARY.



.PZ5 WASHINGTON/OREGON WATERS...

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

     GALE POSSIBLE FRI NIGHT INTO SAT. 

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

     GALE POSSIBLE THU NIGHT INTO SAT NIGHT. 



.PZ6 CALIFORNIA WATERS...

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

     GALE TONIGHT INTO THU. 

     GALE POSSIBLE THU NIGHT INTO SUN. 

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

     GALE POSSIBLE FRI NIGHT INTO SAT. 

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

     GALE POSSIBLE SAT.



$$



.FORECASTER SHAW. OCEAN PREDICTION CENTER.

