Marine Interpretation Message
Issued by NWS

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AGPN40 KWNM 020312
MIMPAC

MARINE WEATHER DISCUSSION FOR N PACIFIC OCEAN
NWS OCEAN PREDICTION CENTER WASHINGTON DC
812 PM PDT SUN MAY 1 2016

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

WINDS WERE LGT AT 15 KT OR LESS ACRS THE NRN OFFSHR WTRS THIS
EVENING WITH A WK CD FNT W OF THE WA/OR AND NRN CA WTRS. THE CD
FNT MOVS SLOWLY E ACRS THE WA/OR WTRS MON INTO MON NGT. ACRS CA
A COASTAL TROF DRIFTS OFFSHR TNGT WITH WINDS AT 15 KT OR LESS.
THERE IS LTL CHANGE IN THE SYNOPTIC PATTERN OVR THE SHORT TERM
WITH AN INCRS IN A NLY SURGE BY EARLY TUE NGT INTO WED AS THE CD
FNT MOVS SE OVR THE CNTRL CA WTRS AND HIGH PRES BLDS IN FM THE W.
MDLS LOOK SMLR WITH TRENDS AND HAV WINDS TO 25 KT TUE NGT AND TO
30 KT BY LATE WED AND WED NGT OVR THE ERN AREAS OF THE NRN CA WTRS.
FOR THE UPDATE NO CHANGES WL BE MADE FOR NOW AND WL AWAIT 00Z MDL
GUID BEFORE ANY CHANGES ARE MADE LATER TNGT.


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

12Z GLOBAL MODELS IN GOOD AGREEMENT THROUGH MOST OF THE
PERIOD...WITH SOME SLIGHT DIFFERENCES NOTED WITH POTENTIAL LOW
DEVELOPMENT ALONG A FRONT TO AFFECT THE AREA TUE AND TUE NIGHT.
WILL POPULATE WIND GRIDS WITH 10M WINDS FROM THE 12Z GFS THROUGH
THE FORECAST PERIOD.

LOW PRES TROUGH ALONG THE COAST CONTINUING TO WEAKEN. TROUGH
EXPECTED TO MOVE OFFSHORE TONIGHT...WITH WEAK LOW DEVELOPMENT
EXPECTED OFF NRN CALIF/SRN OR. LOW EXPECTED TO MOVE N OFF THE
WASH/OR COAST TONIGHT INTO MON.

COLD FRONT MOVES MOVES SE INTO NRN PZ6 WATERS MON AND MON
NIGHT...THEN CONTINUES SE INTO THE CENTRAL PZ6 WATERS TUE AND TUE
NIGHT. MODELS SHOWING LOW PRES DEVELOPMENT ALONG THE FRONT W OF
THE CENTRAL WATERS MON NIGHT INTO TUE. UKMET HAS SHIFTED LOW
FURTHER N AND IS NOW IN LINE WITH THE GFS...WHILE THE ECMWF KEEPS
LOW FURTHER S AND W. WILL LEAN TOWARDS THE GFS SOLUTION. MOST OF
THE WIND ENHANCEMENT WILL BE IN THE NW QUAD OF THE LOW AND BEHIND
THE COLD FRONT. LOW WILL SLOWLY WEAKEN AS IT MOVES E WITH THE COLD
FRONT TUE AND TUE NIGHT...BECOMING ABSORBED INTO THE FRONT WED. DO
NOT ANTICIPATE ANY GALES WITH THIS LOW IN THE OFFSHORE
WATERS...BUT COULD HAVE A FEW GALES W OF THE AREA TUE. FRONT
CONTINUES SE THROUGH THE CENTRAL WATERS WED INTO WED NIGHT...AND
INTO THE SRN WATERS WED NIGHT INTO THU.

MEANWHILE...HIGH PRES RIDGE WILL BUILD NW BEHIND THE FRONT TUE AND
TUE NIGHT...AND SLOWLY STRENGTHEN WED IN TO FRI NIGHT. ALONG THE
COAST...LOW PRES TROUGH DEVELOPS WED INTO WED NIGHT...AND PERSISTS
THROUGH THE REMAINDER OF THE FORECAST PERIOD. MODELS SHOWING
GREATEST POTENTIAL FOR GALES IS FRI NIGHT...AND HAVE INSERTED
GALES INTO THE FORECAST. IT WILL BE A CLOSE CALL AS TO WHETHER
GALES DEVELOP THU NIGHT...BUT MODELS TRENDING TOWARDS WINDS BEING
JUST BELOW GALE FORCE DURING THIS TIME PERIOD...AT LEAST IN THE
OFFSHORE WATERS...AND WILL KEEP WINDS TO 30 KT IN THIS PACKAGE.
RIDGE BEGINS TO WEAKEN FRI NIGHT...ALLOWING FOR WINDS TO DIMINISH
BELOW GALE FORCE.


.SEAS...ENP VERSION OF WWIII WITHIN A FT OR TWO OF CURRENT OBS.
WILL POPULATE WAVE GRIDS FROM 12Z ENP THROUGH THE FORECAST PERIOD.


.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 POSSIBLE FRI INTO FRI NIGHT.

$$

.FORECASTER ROWLAND/ACHORN. OCEAN PREDICTION CENTER.


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