Marine Interpretation Message
Issued by NWS

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AGPN40 KWNM 061517
MIMPAC

MARINE WEATHER DISCUSSION FOR N PACIFIC OCEAN
NWS OCEAN PREDICTION CENTER WASHINGTON DC
817 AM PDT WED MAY 6 2015

.FORECAST DISCUSSION: MAJOR FEATURES/WINDS/SEAS/SIGNIFICANT
.WEATHER FOR THE NORTH PACIFIC N OF 30N AND E OF 150W.


CONDS HAVE CHANGED LITTLE OVER THE LATE NIGHT AND EARLY MORNING
HOURS. STRONG HIGH PRES REMAINS CENTERED NEAR 36N 143W. MODELS
SHOW AREA OF MINIMAL GALE FORCE WINDS OFF THE CNTRL CA COAST THIS
MRNG...MAINLY BTWN PT ARENA AND PT PINOS. A SHIP NR 40N 125W WAS
REPORTING NW WINDS AT 40 KT AT 12Z. A QC CHECK OF THE SHIPS WIND
HISTORY SHOWS IT TO HAVE A REPORTING BIAS OF 8 KT HIGH. ANOTHER
SHIP NR 37N 124W WAS REPORTING NW WINDS 37 KT WITH A HIGH BIAS OF
6 KT...BUT BLV THIS REPORT RELIABLE FOR GALE CONDS. ELSEWHERE...
LIGHT TO MOD N TO NW WINDS PERSIST OVER THE OR...WASH AND SRN CA
WATERS. SEAS ARE CLOSE TO THE WAVEWATCH...EXCEPT OFF THE CNTLR
CALIFORNIA COAST WHERE SEAS ARE 2 TO 3 FT HIGHER THAN THE MODEL.
WILL USE THE ECMWF WAM MODEL AS ITS SEAS FCST TO CLOSER TO THE
MOST RECENT OBSRVNS.

-----------------------------------------------------------------
PREVIOUS DISCUSSION...

ASCAT PASS FROM 06Z SHOWS SWATH OF 25-30 KT ALONG THE CENTRAL CA
CST...DATA IS MISSING ALONG THE IMMEDIATE CST WHERE GALES ARE
LIKELY OCCURING. ALTIMETER PASS FROM 03Z OVR PZ5 WATERS AND FAR
NW CA WATERS INDICATE SEAS GENERALLY 6-9 FT. OBS ALONG THE CENTRAL
CA CST AT 07Z ARE RPT SEAS TO 15 FT. THE STABLE SUMMERTIME PATTERN
WILL CONTINUE OVER THE NEXT SEVERAL DAYS AS THE THERMAL TROF OVER
INTERIOR CA PERSISTS...ALONG WITH STRONG HIGH PRES W OF THE
WATERS. THE RESULTING GRADIENT WILL PRODUCE GALE CONDITIONS ALONG
THE NRN CS CST. EXPECT MAX WINDS NR 40 KT DURING TIME OF MAX
HEATING. SEAS EXPECTED NR 16-17 FT IN COASTAL AND NR OFFSHORE
WATERS ALONG NRN CA CST. THE OVERALL FCST PATTERN HAS NOT CHANGED
OVR THE PAST SEVERAL DAYS. THE STRONGEST WINDS WILL OCCUR ALONG
NRN AND CENTRAL CA CST. THE GRADIENT WILL SLACKEN A BIT AFTER DAY
3 AS A WEAK COLD FRONT APPROACHES THE WATERS...WEAKENING THE
GRADIENT. ALL OF THE 00Z GLOBAL MODELS ARE IN VERY GOOD AGREEMENT
THROUGH THE FCST PERIOD...JUST DIFFERING WITH THE STRENGTH OF THE
BL WINDS. THE 30M GFS WILL BE THE MODEL OF CHOICE TO POP THE WIND
GRIDS WITH...IT IS SLIGHTLY STRONGER THAN THE OTHER MODELS AND HAS
BETTER HANDLE OF THE AREA OF GALE CONDITIONS,

SEAS...BOTH THE ENP AND ECMWF WAVE GUID ARE REASONABLE APPROX OF
WAVE HGTS...ALTHOUGH THE ECMWF WAVE GUID IS SLIGHTLY HIGHER IN
AREAS OF GALES...AND WILL BY MY MODEL OF CHOICE FOR THE NEXT
COUPLE OF DAYS....THEN I WILL TRANSITION BACK TO THE ENP.

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


.WARNINGS...PRELIMINARY.

.PZ5 WASHINGTON/OREGON WATERS...
     NONE.

.PZ6 CALIFORNIA WATERS...
.PZZ820...INNER WATERS FROM POINT ST. GEORGE TO POINT ARENA...
     GALE TODAY INTO THU NIGHT.
.PZZ825...INNER WATERS FROM POINT ARENA TO PIGEON POINT...
     GALE TODAY INTO THU NIGHT.
.PZZ830...INNER WATERS FROM PIGEON POINT TO POINT PIEDRAS BLANCAS...
     GALE TONIGHT INTO THU.

$$

.FORECASTER PROSISE/SHAW. OCEAN PREDICTION CENTER.



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