Marine Interpretation Message
Issued by NWS

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AGNT40 KWNM 260643
MIMATN

MARINE WEATHER DISCUSSION FOR N ATLANTIC OCEAN
NWS OCEAN PREDICTION CENTER WASHINGTON DC
243 AM EDT SUN OCT 26 2014

.FORECAST DISCUSSION: MAJOR FEATURES/WINDS/SEAS/SIGNIFICANT
.WEATHER FOR THE NORTH ATLANTIC OCEAN W OF 50W FROM 30N TO 50N.

OVER THE SHORT TERM...SMLR TO THEIR PREV RESPECTIVE RUNS...THE
NEW 00Z MDLS SHARE VERY SMLR TIMING FOR THE COLD FRONT NOW JUST
MOVG OFSHR TO RACE SE ACRS THE NT1 AND NRN/CNTRL NT2 WTRS
TODAY...THEN PASS SE OF THE SRN NT2 WTRS TONITE. AT THE SAME TIME
THE MDLS ALL FCST AN ASCD STRENGTHENING TRIPLE POINT SFC LOW TO
FORM ON THE FRONT AND MOV TO THE VCNTY OF NOVA SCOTIA BY THIS
EVENING...THEN MOVE SLOWLY OFF TO THE NE TONITE INTO MON. THE
BIGGEST FCST CHALLENGE STIL REMAINS HOW STRONG WL THE WNWLY
GRADIENT BCM BEHIND THE FRONT AND THE DVLPG SFC LOW. VS ITS PREV
18Z RUN...THE 00Z GFS BY FCSTG A MR RPDLY DVLPG TRIPLE POINT SFC
LOW NOW FCSTS ITS POSTFRONTAL GRADIENT TO STRENGTHEN SLIGHTLY
FASTER WITH MARGINAL GALE FORCE 30M BL WINDS DVLPG BY LATE
TODAY/EARLY TONITE OVER A SLIGHTLY LARGER AREA ACRS THE SRN
NT1/NRN NT2 WTRS. THE 00Z 4KM NAM NOW FOR THE FIRST TIME ALSO
FCSTS MARGINAL GALE FORCE BL WINDS TO DVLP OVER AN AREA SMLR TO
THE 00Z GFS. WITH THE OTHER 00Z GLOBAL MDLS ALL FCSTG AT LEAST
SOLID 25-30 KT BL WINDS IN THEIR POSTFRONTAL GRADIENTS...NOW HV A
SMWHT HIGHER LEVEL OF FCST CONFIDENCE IN GALES DVLPG. THEREFORE
PLAN ON POPULATING OUR SHORT TERM WIND GRIDS THRU MON NITE WITH
THE 00Z GFS 30M BL WINDS WITH SM FURTHER EDITS THEN MADE IN
DEFERENCE TO THE 00Z UKMET/ECMWF (MAINLY TO KEEP WINDS SUBGALE
ACRS THE GULF OF MAINE ON MON). SO THE BIGGEST CHNG OVER THE SHORT
TERM WL BE TO MAKE SM MINOR TIMING AND AREAL COVERAGE CHNGS TO THE
PREVLY FCSTD GALE WRNGS.

IN THE LONG RANGE...THE 00Z GLOBAL MDLS GNRLY AGREE THAT THE ONLY
SIG FEATURE WL BE A WEAKER COLD FRONT MOVG OFSHR WED/WED
NITE...THEN BCMG QSTNRY SW-NE ACRS THE NT2 WTRS LATE THU/THU NITE.
ON THU NITE THE DISPARITY BTWN THE 00Z GLOBAL MDLS INCREASES IN
RGRDS TO WHERE AN ASCD FRONTAL WAVE WL DVLP. IN RGRDS TO THE FCST
TIMING OF THIS FROPA...THE 00Z GFS IS SLIGHTLY FASTER THAN THE
OTHER 00Z GLOBAL MDLS...BUT NOT SIGLY SO. IN RGRDS TO THE FCST
GRADIENTS ASCD WITH THIS FROPA...BLV A BLENDED 00Z GFS/UKMET/ECMWF
SOLUTION LOOKS BEST. THEREFORE SINCE ITS SOLUTION IS IN WITH THE
LATEST WPC MEDIUM RANGE GUIDANCE...PLAN ON POPULATING OUR LONG
RANGE GRIDS...TUE THRU THU NITE WITH THE 00Z GFS 10M BL
WINDS...TIME SHIFTED 3 HRS SLOWER FOR THE FROPA WED NITE INTO THU.
SO AS A RESULT ANTICIPATE MAKING ONLY MINIMAL LONG RANGE CHNGS IN
THE NEXT OFSHR FCST PACKAGE.

.SEAS...WITH THE DIFFERENCES BTWN THE TWO MDLS PRIMARILY RMNG IN
THE 1-2 FT RANGE...PLAN ON USING A 50/50 BLEND OF THE 00Z
WAVEWATCH III AND 00Z ECMWF WAM THRUT THE FCST PERIOD.

.EXTRATROPICAL STORM SURGE GUIDANCE...SMLR TO THEIR PREV RESPECTIVE
RUNS...THE 00Z ESTOFS FCSTS A SLIGHTLY MR SIG NEGATIVE SURGE TO
DVLP IN THE POSTFRONTAL WNWLY GRADIENT ALONG THE NRN MID ATLC TO
THE NEW ENGLD COASTS TODAY INTO MON THAN THE 00Z ETSS
FCSTS...WHICH DOES NOT LOOK UNREASONABLE.

.WARNINGS...PRELIMINARY.

.NT1 NEW ENGLAND WATERS...
.ANZ805...GEORGES BANK WEST OF 68W...
     GALE TONIGHT.
.ANZ810...SOUTH OF NEW ENGLAND...
     GALE TODAY INTO TONIGHT.
.ANZ815...SOUTH OF LONG ISLAND...
     GALE TODAY INTO TONIGHT.

.NT2 MID ATLC WATERS...
.ANZ915...HUDSON CANYON TO THE GREAT SOUTH CHANNEL...
     GALE TONIGHT.
.ANZ905...THE GREAT SOUTH CHANNEL TO THE HAGUE LINE...
     GALE TONIGHT.

$$

.FORECASTER VUKITS. OCEAN PREDICTION CENTER.



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