Marine Interpretation Message
Issued by NWS

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000
AGNT40 KWNM 180110
MIMATN

MARINE WEATHER DISCUSSION FOR N ATLANTIC OCEAN
NWS OCEAN PREDICTION CENTER WASHINGTON DC
910 PM EDT THU APR 17 2014

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


STNRY FRONT  EXTENDS NE TO SW FM NEAR 40N60W TO 31N73W.
EXTENDSING ABOUT 300 NM NW OF THIS FRONT IN AN AREA OF NE WINDS 20
TO 30 KT AS THE GRADIENT BTWN WK WAVE ALONG THE FRONT NR 37N64W
AND STRONG 1044 MB HIGH CNTRD OVR NEW BRUSNWICK...WITH A SFC RDG
EXTENDING SW FM THE HIGH CNTR DWN TO THE SE CONUS. HIGH RES ASCAT
PASS FM 15Z TODAY SHOWED A SMALL AREA OF NE GALES JUST E OF THE
OFFSHR WATERS NEAR 36-7N AND 69W. CONSIDERED ADDED GALE WARNINGS
TO THE OFFSHR WATERS N OF BALT CNYN NEAR THE GF STREAM...BUT THE
GRADIENT IS EASING AS THE HIGH MVS E AND WEAKENS. SEAS AT 00Z ARE
CLOSE TO THE WAVE MODEL NEARSHORE...BUT ARE 10 TO 20 PCT HIGHER
THAN THE WAVE MODEL IN THE MODERATE NE FLOW FTHR OFFSHR SHORE.
WILL MAKE MINOR ADJSTMNTS IN FCST FOR THE UPDATE.


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

THE 18Z SFC ANALYSIS INDICATED A STATIONARY FRONT JUST TO THE E OF
THE FAR SE NT2 WATERS. ASACT PASS FROM AROUND 14Z STILL INDICATED
A SMALL AREA OF NE GALES JUST TO THE S OF THE BALT CANYON TO HAGUE
WATERS...WITH SOLID AREA OF 20 TO 30 KT WINDS OVER REMAINDER OF
THE NT1 WATERS AND THE ERN PORTIONS OF THE NT2 WATERS...WITH 15 TO
25 KT OER THE GULF OF MAINE.

THE 12Z MODELS CONTINUE TO BE IN VERY GOOD AGREEMENT DURING THE
SHORT TERM PERIOD TONIGHT THROUGH ABOUT 00Z SAT. THEREAFTER...THE
MODEL AGREEMENT GOES DOWNHILL...WITH THE GFS BEING THE MAIN
OUTLIER. FOR TONIGHT THROUGH FRI...THE MODELS ARE SIMILAR
INDICATING THE FRONT DRIFTING SLOWLY W AS SEVERAL LOW PRES AREAS
MOVE NE ALONG THE FRONT. FOR 00Z SAT AND BEYOND...THE 12Z
ECMWF/UKMET/CMC ARE ALL VERY SIMILAR WITH THE PRES
PATTERN...THOUGH THEY DO DIFFER SOMEWHAT ON THE SPEED OF LOW FCST
TO MOVE ACROSS N FLORIDA...THEN E PASSING NEAR OR JUST S OF THE
SRN NT2 WATERS. THE GFS HAS CONTINUED TO TREND TOWARD THE MORE
CONSISTENT ECMWF/UKMET/CMC THE PAST FEW RUNS...BUT STILL PREFER
THE 12Z ECMWF AS ITS PRES PATTERN MORE RESEMBLES UKMET/CMC. WITH
THIS IN MIND...WILL POPULATE GRIDS USING THE 12Z GFS THROUGH 00Z
SAT...THEN WILL TRANSISTION TO THE 12Z ECMWF FOR REMAINDER OF THE
PERIOD. WILL USE THE 30M GFS WINDS AS THEY ARE MORE REPRESENTATIVE
OF ACTUAL CONDITIONS. THE ECMWF HAS BACKED OFF ON THE EXTENT OF
GALES OVER THE NT2 WATERS...NOW KEEPING THEM CONFINED TO THE CAPE
FEAR WATERS SUN INTO SUN NIGHT.

.SEAS...THE 18Z SEA STATE ANALYSIS INDICATED THAT THE MWW3
CONTINUES TO HAVE A GOOD HANDLE ON SEAS...WITH OBSERVED SEAS
WITHIN A FT OF THE GUIDANCE. WILL THEN TRANSITION TO THE ECMWF WAM
VALUES FOR THE REMAINDER OF THE PERIOD SINCE WILL BE USING THE
ECMWF WINDS.

.EXTRATROPICAL STORM SURGE GUIDANCE...12Z ETSS AND ESTOFS DVLP
SML POS SURGES GENLY 1 FT OR LESS...WITH ESTOFS SLGTLY
HIGHER...AND MORE EXPANSIVE IN CVRG NWD FOR TONIGHT THRU FRI BUT
IN LATER PRDS WHERE GFS IS NOT PREFERRED ETSS/ESTOFS MAY BE LESS
RELIABLE.



.WARNINGS...PRELIMINARY. ANY CHANGES WILL BE COORDINATED THROUGH
AWIPS 12 PLANET CHAT OR BY TELEPHONE:

.NT1 NEW ENGLAND WATERS...
     NONE.

.NT2 MID ATLC WATERS...
.ANZ835...INNER WATERS FROM CAPE FEAR TO 31N...
     GALE POSSIBLE SUN INTO SUN NIGHT.

$$

.FORECASTER PROSISE/KOSIER. OCEAN PREDICTION CENTER.



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