Marine Interpretation Message
Issued by NWS

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
AGPN40 KWNM 291518
MIMPAC

MARINE WEATHER DISCUSSION FOR N PACIFIC OCEAN
NWS OCEAN PREDICTION CENTER WASHINGTON DC
818 AM PDT FRI JUL 29 2016

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

THE SAT IMG INDC FAIRLY CLOUDY SKIES ACROSS THE REGION BUT ALMOST
NO REPORTS OF LIGHTNING STRIKES. ALL THE OBSERVATIONS INDC HIGHER
WINDS OVER THE NRN CAL AND SRN OREG WATERS. AT 12Z INLAND TROF
EXTENDS NW FROM LOW PRES OVER SRN CAL INTO THE SRN OREG. HIGH PRES
1033 MB W OF THE WATERS NR 42N145W HAS ITS RIDGE OVER MOST OF THE
REGION. THE PRES GRADIENT IS TIGHT OVER THE NRN CAL AND SRN OREG
WATERS BUT QUITE SLACK ELSEWHERE. THE SEAS PEAK AT 12 FT OVER THE
CENTRAL REGION AND THEY RANGE BETWEEN 4 AND 7 OVER THE FAR SRN AND
NRN WATERS. THE NWW3 MULTI GRID WAVE MODEL FITS FAIRLY WELL WITH
THE OBSERVED SEAS PATTERN AND HAS BEEN VERY CONSSISTENT.

THE GLOBAL MODELS HAVE INITIALIZED VERY WELL AND THEY ARE IN
GENERALLY A GOOD AGREEMENT ON THE FEW SYNOP FEATURES THAT ARE
CONTROLLING THE WX OVER THE REGION. WILL UPDATE THE FORECAST
WITHOUT MAJOR CHNAGES TO THE PREVIOUS FORECAST AND WILL STAY WITH
JUST GFS. IN THE SHORT TERM HGH PRES WILL REMAIN TO THE W AS
INLAND TROF PERSITS OVER CAL. THE WINDS WILL REMAIN ELEVATED IN
THE SHORT TERM BUT WILL DIMINISH TO BELOW GALE FORCE IN THE
EXTENDED PERIOD.

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

OVER THE SHORT TERM...THE NEW 00Z MDLS REMAIN CONSISTENT AND IN
RSNBLY GOOD AGRMT THAT THE STRONG SFC HIGH PRES CENTER WITH A MAIN
CENTER NR 41N145W WL SLOWLY SHIFT WNW WITH LTLCHG IN STRENGTH THRU
SAT NITE WHILE A SFC TROF REMAINS IN PLACE INLAND CALIFORNIA. IN
THE NLY GRADIENT BTWN THESE TWO SYSTEMS...THE 00Z NAM/GFS/GEM
CONTINUE TO FCST GALE FORCE BL WINDS ACRS THE NRN MOST PZ6 AND SE
MOST PZ5 WTRS THRU SAT NITE...WHL THE USUALLY CONSERVATIVE 00Z
UKMET/ECMWF FCST SOLID 25-30 KT BL WINDS WITH OCCASIONAL PERIODS
OF MARGINAL GALE FORCE WINDS. 00Z NAM/GFS REMAIN CONSISTENT VS
THEIR PREV RESPECTIVE RUNS AND THE OTHER 00Z GLOBAL MDLS IN
MAINTAINING THE FCST STRENGTH OF THE NLY GRADIENT WITH MARGINAL
GALES OFF THE NRN PZ6 AND SRN PZ5 WTRS THRU SAT NITE AND INTO SUN.
FURTHER N THE 00Z GFS/ECMWF CONT THEIR PREV RESPECTIVE TRENDS OF
FCSTG AN UPR SHORT WAVE TROF TO PASS N OF THE PZ5 WTRS LATE TODAY
INTO SAT THAT WL CAUSE AN INLAND SFC TROF TO DVLP WHICH WL RESULT
IN THE NNWLY GRADIENT ACRS THE NERN PZ5 WTRS TO STRENGTHEN TO GALE
FORCE LATE FRI AND PERSIST INTO EARLY SAT NITE. ALSO THE 00Z
GFS/NAM/ECMWF ALL INDICATE A WK CD SURGE BEHIND AN ASCD CD FNTL
PASSAGE IN NRN WTRS WHICH WL ACT TO LOWER STATIC STABILITY OVR
PZ5 AREA...SO THE POTENTIAL FOR GALES TO MIX DOWN IS HIGH. AS WAS
DONE PREVIOUSLY...PLAN ON POPULATING OUR FCST WIND GRIDS WITH A
50/50 BLEND OF THE 00Z GFS 30M AND 10M BL WINDS FOR TODAY THRU SAT
NIGHT...AS THESE CONDS APPR TO MATCH THE LATEST HI RES ASCAT-B
PASS. THIS WL RESULT IN NO MAJOR CHNGS TO THE PREVLY FCSTD GALE
WRNGS.

IN THE LONG RANGE...THE 00Z GLOBAL MDLS....ESPCLY THE 00Z
GFS/ECMWF...ARE IN RSNBLY GOOD AGRMT AND SHARE SMLR FCST TIMING
FOR A CLOSED UPR LOW TO APRCH FM THE WNW SUN...THEN CROSS THE NRN
PZ5 WTRS SUN NITE/MON WHICH WL SPRT A DSIPTG COLD FRONT TO PUSH
INTO THE PZ5 WTRS LATE SUN INTO MON WHICH ALLOW THE NLY GRADIENT
TO GRADLY WEAKEN TO BELOW GALE FORCE FIRST ACRS THE PZ5 WTRS SAT
NITE AND THEN ACRS THE PZ6 WTRS LATE SUN AND SUN NITE. THEN TO
SLIGHTLY VARYING DEGREES ALL OF THE 12Z GLOBAL MDLS THEN FCST A
SFC HIGH TO STRENGTHEN W OF THE PZ5 WTRS LATE MON NITE INTO TUE
NITE WHICH WL AGAIN CAUSE THE NLY GRADIENT TO GRADLY RESTRENGTHEN
THRUT THE PZ5 AND NRN PZ6 WTRS...LKLY REACHING GALE FORCE AGAIN
ACRS THE NRN PZ6 WTRS LATE TUE OR TUE NITE. SO PLAN ON CONTG TO
POPULATE WITH A 50/50 BLEND OF THE STILL REPRESENTATIVE 00Z GFS
30M AND 10M BL WINDS FOR SUN THRU TUE NITE.

.SEAS...OVERALL THE 00Z WAVEWATCH III AND 00Z ECMWF WAM OFFER
SIMILAR SOLNS..ALTHO APPR 1-2 FT LOW WITH MAX SEAS AS WAS THE
CASE SINCE LATE YESTERDAY. WITH THIS IN MIND AND WITH THEIR ASCD
GFS/ECMWF SOLUTIONS BEING SMLR AND WITH THEIR FCST DIFFERENCES
GNRLY RMNG IN THE 1-2 FT RANGE...PLAN ON POPULATING OUR FCST WAVE
GRIDS WITH A 50/50 BLEND OF THE 12Z WAVEWATCH III AND 12Z ECMWF
WAM MDLS FOR TONITE THRU TUE NITE WITH CONDS BOOSTED 10 PCT IN
GALE AREAS.

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


.WARNINGS...PRELIMINARY.

.PZ5 WASHINGTON/OREGON WATERS...
.PZZ800...INNER WATERS FROM CAPE FLATTERY TO CAPE SHOALWATER...
     GALE TONIGHT INTO SAT NIGHT.
.PZZ815...INNER WATERS FROM FLORENCE OR TO POINT ST. GEORGE...
     GALE TODAY INTO SAT NIGHT.
     GALE POSSIBLE SUN.

.PZ6 CALIFORNIA WATERS...
.PZZ820...INNER WATERS FROM POINT ST. GEORGE TO POINT ARENA...
     GALE TODAY INTO SAT NIGHT.
     GALE POSSIBLE SUN INTO SUN NIGHT.
     GALE POSSIBLE TUE NIGHT.
.PZZ920...OUTER WATERS FROM POINT ST. GEORGE TO POINT ARENA...
     GALE TODAY.
     GALE SAT INTO SAT NIGHT.
     GALE POSSIBLE SUN.
.PZZ825...INNER WATERS FROM POINT ARENA TO PIGEON POINT...
     GALE POSSIBLE TUE NIGHT.

$$

.FORECASTER MUSONDA/BANCROFT. OCEAN PREDICTION CENTER.


USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.