Marine Interpretation Message
Issued by NWS

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000
AGNT40 KWNM 210649
MIMATN

MARINE WEATHER DISCUSSION FOR N ATLANTIC OCEAN
NWS OCEAN PREDICTION CENTER WASHINGTON DC
249 AM EDT SUN SEP 21 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...THE NEW 00Z MDLS SHARE SMLR TIMING FOR THE
SFC LOW NOW OFF THE N CAROLINA COAST RACING NE INTO THE SE NT1
WTRS BY THIS EVENING...THEN PASSING OFF TO THE NE LATER TONITE
WHILE PULLING A TRAILING COLD FRONT E OF THE OFSHR WTRS. THE 00Z
NAM/GFS/GEM AS SLIGHTLY FASTER WITH THEIR FCST TRACKS VS THE 00Z
GEFS MEAN/UKMET/ECMWF...BUT NOT SIGLY SO. A COMPROMISE 00Z
GFS/UKMET FCST TIMING LOOKS THE MOST RSNBL. IN RGRDS TO THE FCST
GRADIENTS ASCD WITH THIS SYSTEM ALL OF THE 00Z MDLS FCST GALE
FORCE BL WINDS (WITH THE USUALLY TOO STRONG 00Z NAM/GEM FCSTG SM
STORM FORCE BL WINDS) DVLPG IN THE SSWLY GRADIENT OVER THE IMMED
SE QUADRANT OF THE LOW AND INADVOF ITS COLD FRONT. AS A COMPROMISE
BTWN THE STRONGER 00Z NAM/GEM AND WEAKER 00Z UKMET/ECMWF SOLUTIONS
FOR THIS SSWLY GRADIENT...PLAN ON POPULATING OUR FCST WIND GRIDS
WITH THE 00Z GFS 10M BL WINDS TODAY INTO MON...FLWD THEN BY THE
00Z GFS 30M BL WINDS FOR THE POST FRONTAL GRADIENT LATE MON/MON
NITE. SO PER THESE WINDS WL CONT WITH THE PREVLY FCSTD GALE WRNGS
FOR TODAY INTO TONITE FOR THE OUTER NT2 WTRS AND THE SE MOST NT1
WTRS.

IN THE LONG RANGE...THE 00Z GLOBAL MDLS GNRLY AGREE THAT STRONG
HIGH PRES WL BUILD IN FM THE W AND NW TUE/TUE NITE...MOVE INTO
THE NT1 WTRS WED/WED NITE...THEN MAINTAIN A WKNG RIDGE ACRS THE
NT1 WTRS THU/THU NITE CAUSING A MOD STRONG ENELY GRADIENT TO DVLP
TO ITS S ACRS THE NT2 WTRS. ON WED INTO THU NITE TO SIGLY
DIFFERENCE DEGREES THE 00Z GLOBAL MDLS FCST AN INVERTED SFC TROF
TO DVLP INVOF THE SE COAST WITH THE 00Z GEM/UKMET FCSTG SFC LOWS
TO DVLP ON THE TROF. WL DISREGARD WHAT IS HOPEFULLY THE OVERLY
AGGRESSIVE 00Z GEM SOLUTION WHICH FCSTS GALE/STORM FORCE ASCD BL
WINDS TO DVLP NR ITS SFC LOW. FOR NOW TO BE MR IN LINE WITH THE
LATEST WPC MEDIUM RANGE GUIDANCE WL FAVOR THE MR SUPPRESSED 00Z
GFS/ECMWF SOLUTION FOR THIS GRADIENT...THO BLV THE 00Z ECMWF IS
FCSTG A SLIGHTLY TOO WEAK GRADIENT. THEREFORE PLAN ON CONTG TO
POPULATE OUR LONG RANGE GRIDS TUE THRU THU NITE WITH THE 00Z GFS
30M BL WINDS...WITH SM FURTHER EDITS MADE IN DEFERENCE TO THE 00Z
ECMWF BL WINDS...WHICH WL RESULT IN MAX WINDS UP TO 25 OR 30 KT
ACRS THE NT2 WTRS. SO NO MAJOR LONG RANGE CHNGS ARE ANTICIPATED TO
THE PREV OFSHR FCSTS.

.SEAS...PLAN ON USING A 80/20 BLEND OF THE 00Z WAVEWATCH III AND
00Z ECMWF WAM MAINLY TO TONE DOWN THE SEAS SLIGHTLY IN THE AREA
OF SHORT TERM GALES.

.EXTRATROPICAL STORM SURGE GUIDANCE...BY LATE TUE INTO WED AS THE
MOD STRONG NELY GRADIENT DVLPS...THE 00Z ESTOFS FCSTS A SMWHT MR
SIG POSITIVE SURGE DVLPG ALONG THE CAROLINA AND GEORGIA COASTS
THAN THE 00Z ETSS MDL WHICH LOOKS RSNBL.

.WARNINGS...PRELIMINARY.

.NT1 NEW ENGLAND WATERS...
.ANZ900...GEORGES BANK EAST OF 68W...
     GALE TONIGHT.

.NT2 MID ATLC WATERS...
.ANZ920...BALTIMORE CANYON TO THE GREAT SOUTH CHANNEL...
     GALE TODAY.
.ANZ905...THE GREAT SOUTH CHANNEL TO THE HAGUE LINE...
     GALE TODAY INTO TONIGHT.
.ANZ910...EAST OF THE GREAT SOUTH CHANNEL AND SOUTH OF 39N...
     GALE TODAY INTO TONIGHT.
.ANZ925...OUTER WATERS FROM BALTIMORE CANYON TO HATTERAS CANYON...
     GALE TODAY.
.ANZ930...OUTER WATERS FROM HATTERAS CANYON TO CAPE FEAR...
     GALE TODAY.

$$

.FORECASTER VUKITS. OCEAN PREDICTION CENTER.



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