Marine Interpretation Message
Issued by NWS

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232
AGPN40 KWNM 280342
MIMPAC

MARINE WEATHER DISCUSSION FOR N PACIFIC OCEAN
NWS OCEAN PREDICTION CENTER WASHINGTON DC
842 PM PDT FRI MAY 27 2016

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

THE SAT IMG SHOWS SOME CLOUDS APPROACHING THE NRN WATERS. MOST OF
THE CENTRAL AND SOUTHERN WATERS HAVE FEW CLOUDS AND THERE IS NO
LIGHTNING ASSOCIATED WITH THEM OVER THE FORECAST REGION. THE RADAR
HAS NO SIGN OF TSTMS OVER THE REGION AND THE SREF MODEL HAS LESS
THAT 5 PERCENT CHANCE OF SEV TSTMS OVER THE WATERS. AT 00Z HIGH
PRESSURE 1030 MB NEAR 37N140W HAS ITS RIDGE EXTENDING E INTO MOST
OF THE REGION. AN INLAND LOW PRESSURE 1005 MB OVER SRN CA HAS ITS
TROF STRETCHING NW ACROSS CA STATE AND THAT HAS COMBINED WITH THE
HIGH PRES TO FORCE A TIGHT PRESSURE GRADIENT OVER THE ERN PARTS OF
THE CENTRAL WATERS WHERE THE WINDS ARE IN THE GALE FORCE RANGE.
LOW PRES 1018 MB ABOUT 240 NM NW OF THE WA WATERS HAS A WARM FRONT
EXTENDING SE THAT IS JUST W OF THE WA WATERS. THE SEAS ARE EQUALLY
LOW IN MOST AREAS LESS THAN 6 FT BUT THEY PEAK AT 13 FT OVER THE
ERN PARTS OF THE CENTRAL WATERS. THE NWW3 MULTI GRID WAVE MODEL
FITS VERY WELL WITH THE OBSERVED SEAS PATTERN AND IS VERY CLOSE TO
THE ECMWFWAVE MODEL.

AN UPPER LEVEL RIDGE IS APPARENT ALONG 140W WHILE AN UPPER LEVEL
RIDGE WITH SOME SIG ENERGY IS NOW INLAND JUST E OF THE WATERS. THE
UPPERLEVRL RIDGE WILL SHIFT E AND BE OVER THE ENTIRE REGION FROR A
WHILE AND THAT WILL FORCE THE PRES GRADIENT OVR THE ERN PARTS TO
RELAX AND ALLOW WINDS TO DIMINISH TO BELOW GALE FORCE BY SAT
AFTERNOON. THE GLOBAL MODELS HAVE INITIALIZED WELL AND THEY ARE IN
DECENT AGREEMENT IN THE SHORT TERM ON RELAXING THE PRES GRADIENT
OVER THE CENTARL WATERS. EVERN IN THE EXTENDED PERIOD THE MODELS
AGREE WELL ON KEEPING THE HIGH PRES OVER THE REGION. SO WILL
CONTINUE WITH GFS.

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

12Z MODEL AGREEMENT REMAINS GOOD FOR THE EARLIER PERIODS OF THE
FORECAST...HOWEVER THEY BEGIN TO HAVE SOME DIFFERENCES TUE. ECMWF
AND UKMET SEEM TO HAVE SOMEWHAT BETTER AGREEMENT WITH A LOW
PRESSURE TO THE W OF THE FORECAST WATERS SO WILL POPULATE WITH THE
ECMWF TUE THROUGH THE END OF THE FORECAST PERIOD.

EARLIER IN THE FORECAST...LIMITED THE EXTENT OF THE GALES EXPECTED
TONIGHT THROUGH SAT. MODEL SUPPORT SEEMS TO HAVE WANED A BIT AND
THE OBSERVATIONS DO NOT SUGGEST AS LARGE OF AN EXTENT AS EXPECTED
IN PREVIOUS FORECASTS. 30M GFS IS THE MODEL OF CHOICE THROUGH
SATURDAY BUT THEN SWITCHED TO THE 10M GFS THROUGH TUE TO KEEP
GALES OUT OF THE FORECAST WATERS.

.SEAS...USED THE ENP WAVES THROUGHOUT BUT DID MAKE SOME CHANGES TO
ADJUST WAVES...PARTICULARLY IN SOME OF THE SOUTHERN ZONES IN THE
LATER PERIODS.


.EXTRATROPICAL STORM SURGE GUIDANCE...N/A



.WARNINGS...PRELIMINARY.

.PZ5 WASHINGTON/OREGON WATERS...
     NONE.

.PZ6 CALIFORNIA WATERS...
.PZZ825...INNER WATERS FROM POINT ARENA TO PIGEON POINT...
     GALE TONIGHT.

$$

.FORECASTER MUSONDA/SOMMERVILLE. OCEAN PREDICTION CENTER.



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