Marine Interpretation Message
Issued by NWS

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AGNT40 KWNM 010048
MIMATN

MARINE WEATHER DISCUSSION FOR N ATLANTIC OCEAN
NWS OCEAN PREDICTION CENTER WASHINGTON DC
848 PM EDT WED AUG 31 2016

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

NOTE: OPC IS PROVIDING NHC POST-TROPICAL FORECAST POINTS FOR
HURCN GASTON...T.S. HERMINE...AND T.D. 8 SO WL BE BRIEF.

T.D. 8 APPEARS TO BE NR 36.5N71.0W AT THE MOMENT. OVERALL THE
18Z GFS AND 12Z UKMET/ECMWF SHARE VERY SMLR TRACKS FOR THE SYSTEM
TO CONT NE ACRS THE NE NT2 WTRS THRU 01/18Z IN RSNBLY GOOD AGRMT
WITH THE LATEST NHC ADVSRY. THEREFORE DO NOT ANTICIPATE NHC MAKING
ANY DRAMATIC CHNGS IN THEIR NEXT FCST ADVSRY AND WL LKLY CONT TO
USE THE PREVLY POPULATED 12Z ECMWF BL WINDS...BOOSTED UP IN THE
IMMED VCNTY OF THE T.D.

OTHERWISE OVER THE SHORT TERM WOULD FAVOR A BLEND OF THE SMLR
18Z GFS/12Z ECMWF FOR A SECOND SFC LOW TO TRACK NE ACRS THE
SRN/CNTRL NT2 WTRS TONITE INTO THU NITE. IT LOOKS CLOSE AS TO
WHETHER THIS SYSTEM WL REACH GALE FORCE...BUT FOR NOW WITH THE 18Z
GFS 10M WINDS BEING SMLR...WL CONT WITH THE PREVLY USED 12Z ECMWF
BL WINDS AND WL HOLD OFF ON ANY WRNGS.

LATER IN THE FCST PERIOD THE FCST SHIFTS TO T.S. HERMINE. AS HAS
BEEN THE CASE SINCE YESTERDAYS RUNS...THE LATEST GLOBAL MDLS IN
GNRL AGREE THAT THE SYSTEM WL BCM CAPTURED BY A CLOSED UPR LOW SAT
INTO MON NITE...BUT DUE TO DIFFERENCES IN EXACTLY WHEN THIS WL
OCCUR CAUSES EACH MDL TO FCST A DIFFERENT FCST TRACK FOR THE T.S..
VS ITS PREV 12Z RUN...THE 18Z GFS NOW FCSTS A MR OFSHR TRACK SAT
INTO SUN...BEFORE BCMG MR SMLR SUN NITE INTO MON NITE. THE 18Z
GEFS MEAN INDICATES EARLY...FRI INTO SAT NITE...THAT THE 18Z GFS
TRACK MAY BE SLIGHTLY TOO FAST. THE 12Z ECENS MEAN INDICATES THAT
THE 00Z ECMWF TRACK MAY BE TOO FAR W ON SUN. THE 12Z UKMET LOOKS
LIKE AN ERN OUTLIER SOLUTION SAT THRU SUN...BEFORE IT THEN
CONVERGES TWDS THE SMLR 18Z GFS/12Z ECMWF SOLUTIONIS SUN NITE INTO
MON NITE. THEREFORE WITH SO MUCH MDL DISPARITY RMNG IN
PLACE...SUSPECT THAT NHC WL MAKE ONLY MINOR CHNGS THEIR PREV FCST
TRACK IN THE NEXT ADVSRY.


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

THE SAT IMG STILL SHOW A RIDGE ACROSS THE NRN WATERS. THE
OBSERVATIONS INLUDING ASCAT PASS STILL SHOW HIGH WINDS OVER THE
FAR SRN WATERS BUT THEY ARE SLWOLY PICKING UP OVER THE CENTRAL
WATERS TOO. WINDS RANGE BETWEEN 5 AND 15 KT OVER THE REST OF THE
REGION. AT 18Z THE NCEP MAP HAS A HIGH PRES RIDGE ACROSS THE NRN
WATERS WITH A STNRY FRONT ACROSS THE CENTRAL WATERS. TD EIGHT OVER
THE SRN WATERS NEAR 35.5N 73.1W IS MOVING NE AT 13 KT. FOR LATEST
INFORMATION ON TD EIGHT SEE THE NHC ADVISORY. TROPICAL STORM
HERMINE IS IN THE GULF OF MEXICO AND CONTINUE TO MONITOR IT
CLOSELY WITH LATEST INFORMATION BY THE NHC.

THE MODELS GFS/ECMWFHR/CMC/UKMETHR STILL HAVE A GENERALLY DECENT
INITIALIZATION WITH THE 18Z OBSERVATIONS AND CONTINUE TO AGREE
WELL IN THE EARLY STAGES OF TD EIGHT. THE DIFFERENCES ARE STILL
FAIRLY LARGE IN THE EXTENDED PERIOD ESPECIALLY WITH TROPICAL STORM
HERMINE. INITIALLY THE GFS AND ECMWF ARE VERY CLOSE BUT
DIFFERENCES BECOME NOTICEABLE AFTER 02/12Z AS GFS AND ECMWF BEGIN
TO DIVERGE AND THEY ALSO DIFFER IN WINDS SPEED WITH GFS BEING MORE
AGRESSIVE AT FIRST THEN A REVERSE OCCURS LATER IN THE PERIOD. WILL
AGAIN COMPROMISE MODEL WINDS TO FIT THE OFFICIAL TRACKS OF THE T.D
8 AND TS HERMINE. WILL START OFF WITH ECMWF AND THEN INCLUDE GFS
WITH ADJUSTMENTS WHERE NECESSARY.

.SEAS...THE SEAS ARE HIGHER OVER THE SRN WATERS AND ALSO IN THE
AREAS AROUND TD 8 WITH PEAKS TO 7 AND 11 FT RESPECTIVELY. THE NWW3
FITS WELL WITH THE OBSERVED SEAS PATTERN BUT IS STILL UNDERDONE
AROUND THE TD EIGHT AREA. THE ECMWFWAVE HAS ALSO INITIALIZED WELL
WITH THE SEAS PATTERN BUT IS ALSO UNDERDONE NEAR TD 8. WILL STAY
WITH NWW3 BUT WILL HAVE TO MAKE ADJUSTMENTS MOSTLY AROUND THE TD
8.


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



.WARNINGS...PRELIMINARY.

.NT1 NEW ENGLAND WATERS...
.ANZ810...SOUTH OF NEW ENGLAND...
     GALE POSSIBLE MON.
.ANZ815...SOUTH OF LONG ISLAND...
     GALE POSSIBLE SUN INTO MON.

.NT2 MID ATLC WATERS...
.ANZ820...HUDSON CANYON TO BALTIMORE CANYON...
     GALE POSSIBLE SAT NIGHT INTO MON.
.ANZ915...HUDSON CANYON TO THE GREAT SOUTH CHANNEL...
     GALE POSSIBLE SUN INTO MON.
.ANZ920...BALTIMORE CANYON TO THE GREAT SOUTH CHANNEL...
     GALE POSSIBLE SUN INTO MON.
.ANZ825...INNER WATERS FROM BALTIMORE CANYON TO CAPE CHARLES LIGHT...
     GALE POSSIBLE SAT INTO SUN NIGHT.
.ANZ828...INNER WATERS FROM CAPE CHARLES LIGHT TO CURRITUCK BEACH LIGHT...
     GALE POSSIBLE SAT INTO SAT NIGHT.
.ANZ925...OUTER WATERS FROM BALTIMORE CANYON TO HATTERAS CANYON...
     GALE POSSIBLE SUN INTO SUN NIGHT.
.ANZ830...INNER WATERS FROM CURRITUCK BEACH LIGHT TO CAPE HATTERAS...
     GALE POSSIBLE SAT INTO SAT NIGHT.
.ANZ835...INNER WATERS FROM CAPE FEAR TO 31N...
     TROPICAL STORM FRI.
     TROPICAL STORM POSSIBLE FRI NIGHT.

$$

.FORECASTER VUKITS/MUSONDA/MUSONDA. OCEAN PREDICTION CENTER.



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