Marine Interpretation Message
Issued by NWS

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AGNT40 KWNM 151925
MIMATN

MARINE WEATHER DISCUSSION FOR N ATLANTIC OCEAN
NWS OCEAN PREDICTION CENTER WASHINGTON DC
325 PM EDT MON SEP 15 2014

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

IN THE SHORT TERM...WEAK 1017 MB LOW WAS NEAR 36N68W WITH COLD
FRONT EXTENDING SW FROM THE LOW TO THE GEORGIA COAST. AS WAS THE
CASE LAST NIGHT...THE NRLY FLOW IMMED BEHIND THE FRONT SHOWED UP
STRNGR THEN MODEL FCST ON THE 15Z HI RES SCATTEROMETER PASS.
HIGHEST WINDS...TO 25 KT WERE OBSRVD NR 33N 74.5W...QUITE PSSBLY
ASSD WITH CONVECTION OVR THE AREA. WINDS WL DMNH TNGT AS COLD
FRONT DRIFT SW`WRD.

MODELS IN GOOD AGREEMENT ON WEAK COLD FRONT QUIETLY SLIPPING
OFFSHORE TUE AFTN AND DRIFT SE ACROSS THE WATERS TUE NGT THRU WED
NGT...THEN BCM STNRY OVR THE SRN WATERS THU. FRONT WILL PROVIDE
THE BOUNDRY FOR WEAK AREAS OF LOW PRES TO SLIDE NE ALONG THE
FRONT. THE 12Z MODELS..IN GENERAL AGREE WELL ON LOW PRES MOVING
OFF THE SE COAST WED AND SLOWLY TRACKING ENE. THE DETAILS ON EXACT
LOC DIFFER...BUT MOST WINDS WILL BE LIGHT. THE GFS ENSMBL MEMBERS
REFLECTS THE UNCERTAINTIES ON THE LOW LOC WHILE MOVING ALONG THE
FRONT. THE MODELS THEN DIVERGE IN THIER FCST. BY 12Z THU...MODELS
AGREE ON LOW TRACKING 150 TO 250 NM SE OF GEORGES BANK. THE
GFS/ECMWF AGREE ON AREA OF MOD N TO NE WINDS JUST N OF TH
LOW...WHILLE THE UKMET DVLPS A DOUBLE LOW AND THE GEM DVLPS A
STRNG GALE CNTR.

LATE THU NIGHT INTO SAT...STRNG HIGH PRES BLDNG IN FM THE NW IS
THE MAIN FEATURE. BY 00Z SAT...GLOBAL MODELS AGREE ON STRNG HIGH
CNTRD OVR THE GULF OF MAINE. THE GRADIENT BTWN THIS HIGH AND SAME
FRONT...APPCHNG BERMUDA...WILL CREATE AN AREA OF MOD N TO NE
FLOW...FIRST OVR THE NRN WATERS THU NGT...PUSHING INTO THE SRN
WATERS FRI NGT. THE STRNGTH OF THESE NE WIN DFFCLT TO GAUGE THIS
FAR OUT. THE GFS INCRS THESE WINDS TO 30 KT...COUNTER TO THE GULF
STREAM AND THUS FAVORABLE TO FOR AREAS OF GALES. HOWEVER...THE
UKMET/ECMWF WINDS ARE ABOUT 5 KT LOWER AND PREFER THESE ATTM.
WILL BLEND THE GFS AND ECMWF WINDFS FOR THU THRU FRI NIGHT.
SAT...THE GFS IS AN OUTLIER ON HOLDING ONTO THE WRN EXTSN OF THE
RDG OVR THE NRN WATERS...AND HAS PRES ALONG THE FRONT NEAR THE
BAHAMAS LOWER THEN CONSENSUS AND KEEPS A MOD TO STRNG E GRADIENT S
OF BALT CNYN. PREFER THE ECMWF/UKMET HERE. THE FCST ENDS 12Z SUN...
WHERE THE GFS HAS DVLPS A LOW OFF THE SE COAST. THE UKMET/ECMWF
DVLP A COASTAL TROF. THE GEM BRINGS A GALE UP THE COAST SAT INTO
SUN AND IS TOSSED OUT AS A PSBL SOLTN. PREFER THE UKMET/ECMWF
FCST...BUT THEIR NE 5 TO 10 KT WINDS LOOKS TOO LOW AND WILL BE
INCRSD SOME.


.SEAS...THE MULTIGRID WAVEWATCH III MODEL INITILZD WELL THIS
MRNG. AN ALTIMITER PASS CROSSED JUST E OF THE CENTER OF HURCN
EDOUARD WITH A MEASURMENT OF 36 FT SEAS. THE WAVE MODEL WAS VERY
CLOSE TO THIS VALUE. WAVEWATCH GDNC LOOKS GOOD THRU THU...THEN
PREFER THE ECMWF WAM FOR THU NGT AND FRI AND ITS LOWER SEAS SAT.

THE WAVEWATCH BRINGS 13 TO 15 SEC SWELLS TO THE COAST TUESDAY. THE
WAVE MODELS USUALLY TOO FAST WITH THE INITIAL SWELLS AND ALSO
OVERDOES THE ASSD SWELL WAVE HEIGHTS. SINCE LOCAL WINDS WILL BE
LIGHT...THESE SWELLS WILL BE THE PRIMARY SEAS FOR TUE THRU WED
NIGHT AND WILL BE MENTIONED IN THE FST. ALSO...WILL TRIM BACK SEAS
BY 10 TO 15 PCT. ALTHOUGH...EARLY IN THE GALE...BUOY 41049 AT 27N
63W IS REPORTING SEAS WITH A PERIOD 3 SEC SHORTH AND 3 FT LOWER
THEN THE WAVE WATCH


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


.WARNINGS...PRELIMINARY.

.NT1 NEW ENGLAND WATERS...
     NONE.

.NT2 MID ATLC WATERS...
     NONE.

$$

.FORECASTER PROSISE. OCEAN PREDICTION CENTER.



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