Marine Interpretation Message
Issued by NWS

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AGNT40 KWNM 260124
MIMATN

MARINE WEATHER DISCUSSION FOR N ATLANTIC OCEAN
NWS OCEAN PREDICTION CENTER WASHINGTON DC
824 PM EST THU DEC 25 2014

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

IN THE GLF OF ME THIS EVENING BUOY 44005 HAD W WINDS WHICH WERE SUSTAINED
WINDS NR 27 KT WITH GUST TO 33 KT. GFS 30M WINDS HAS WINDS TO 35
KT OVR THIS REGION THRU MOST OF TNGT AND SUBGALE LATER TNGT/EARLY
FRI. STG CD FNT HAS PASSED E OF THE OFFSHR WTRS AND CONTS EWD
OVNGT. HAV NOT SEEN ANY RECENT QUIKSCAT OR ASCAT DATA. GFS 30M WINDS
WERE TO 30 KT OVR THE NEW ENGLAND INTO THE ERN AREAS OF THE MID
ATLC AND SMLR TO BUOY OBS. HIGH PRES ACRS THE INLAND AREAS OF MID
ATLC AND SWD TOWARDS FL MOVS FURTHER EWD OVNGT AND FRI WITH WINDS
DMNSHG ACRS THE OFFSHR AREAS. THE BROAD AREA OF HIGH PRES MOVS
OFFSHR FRI NGT AND SAT. FOR THE UPDATED FCST FEW CHANGES ARE
NEEDED WITH GFS GUID FOLLOWED THRU THE FCST PD.

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

NEAR TERM...A 1620Z RAPIDSCAT PASS INDICATED MAIN FNTL BNDRY WITH
S TO SW GALES FM GEORGES BANK TO FAR E CENTRAL NT2 AREA FOLLOWED BY
A SECOND CDFNT TO W WITH A SECONDARY SURGE OF W TO NW WINDS UP TO
35 KT STRONGEST S OF BALT CNYN TO NEAR 36N. TO N BUOY 46005
SHOWING G 35 KT WITH RAPIDSCAT SHOWING ONE 35 KT. HENCE CURRENT
FCST APPRS ON TARGET. WILL LKLY CARRY GALES FOR 21Z IN GRIDS AND
REFLECTED IN WRNG SUMMARY BELOW. STLT INDICATED MAIN TSTM ACTVTY
WITH FIRST FNT AND WX SHOULD MOV OUT EARLY THIS EVENING. OVERALL...LITTLE
CHANGE WILL BE MADE FM THE MRNG PACKAGE AND LAST FEW OPC FCSTS.
WE WILL RELY ON THE 12Z GFS FOR THE NEW PACKAGE INTO MUCH OF UPCOMING
WKND AS IT HAS REMAINED FAIRLY CONSISTENT AND IS IN DECENT
AGREEMENT WITH THE NON-GFS MDL GUID. INITIALLY WE WILL USE 30M GFS
WNDS WHICH SEEM TO FIT WELL WITH THE LATEST OBS AND EARLIER
SCATTEROMETER DATA...AND ALSO FIT WELL WITH THE COLD AIR ADV AND
UNSTABLE WIND FIELD DVLPG BEHIND THE CURRENT CDFNTS LATE THIS AFTN INTO
SAT. HIGH PRES WILL EXPAND FROM THE SE STATES NE INTO THE NT2
WTRS DURING FRI. THE HIGH WILL PERSIST OVR THE NT2 OFF WTRS FRI
NGT...AND MOVE E OF THESE WTRS SAT INTO SAT NGT. AS THE COLD AIR
ADVECTION WEAKENS BY EARLY SAT WE WILL THEN TRANSITION TO 10M GFS
WNDS LATE SAT INTO SAT NGT...WITH LITTLE CHANGE FROM THE PREV FEW
OPC FCSTS AS CONDITIONS IMPROVE OVR MOST OF THE OFF WTRS.

LONG TERM...STARTING SUN NIGHT THE 12Z MDLS BEGIN TO DIVERGE IN
THEIR SOLUTIONS OVR THE REGION....DIFFERING IN TRACK AND STRENGTH
OF LOW PRES WAVES TRACKING OFF MID ATLC CST ENEWD. THE 12Z GFS
VERSUS ITS PREVIOUS RUN DVLPS A STRONGER INITIAL WAVE IN NRN WTRS
ALONG A COLDFNT DROPPING INTO NT2 WTRS SUN NIGHT AND FOR NOW
CONSIDER IT AN OUTLIER...WITH LTL ENSEMBLE SPRT. PREFER NON-NCEP
CONSENSUS DVLPG A WAVE INLAND OVR CAROLINAS BY EARLY MON AND MOVG
IT E ALGM A STALLED FNT. OVERALL TIMING IS SIMILAR WITH GEM A BIT
SLOWER AND GEM/UKMET TRACKING LOW ACRS NRN NT2 AREA MON AND MON
NIGHT. FOR NOW WILL GO WITH 12Z ECMWF FOR SUN NIGHT AND BYND
SPRTD BY 12Z GEFS AND 00C ECMWF ENSEMBLE MEANS. PER ECMWF...FNT
SETTLES SE OF AREA AFTER LOW PASSES EARLY TUE. BOOSTED ECMWF SFC
WNDS BY 10 PCT IN CAA AS LOW PASSES.

.SEAS...THE 12Z WNA WW3 MDL GUID APPEARS TO BE RUNNING UP TO 1-2
FT TOO LOW VERSUS OBS OVR CENTRAL AND NRN NT2 WTRS IN CAA AND
PREFER SLGTLY HIGHER 12Z ECMWF WAM THRU TONIGHT...THEN
TRANSITIONED TO 12Z WW3 FRI THRU SAT WITH HIGH PRES MOVG ACRS
WTRS. THEN WITH SOME MDL DIFFERENCES DVLPG USED 50/50 BLEND OF
MDLS SAT NIGHT AND SUN. THEN SUN NIGHT AND BYND SHFTD TO 12Z ECMWF
WAM PER MDL PREFERENCE ABOVE.

.EXTRATROPICAL STORM SURGE GUIDANCE...THE LATEST ESTOFS AND ETSS
MDLS CONT TO INDICATE A NEG SURGE UP TO 1.5 FT DVLPG FROM THE NRN
MID ATLC N TO THE GULF OF MAINE TONIGHT INTO FRI WITH ETSS VALUES
SLGTLY LOWER AND THE AREA IS MORE CONFINED TO THE NY BIGHT AND SRN
NEW ENGLAND WATERS. OVERALL...LITTLE DEVIATION FROM THE ESSG
APPEARS NEEDED INTO THE UPCOMING WKND WITH NO MAJOR SURGE EVENT
EXPECTED.


.WARNINGS...PRELIMINARY.

.NT1 NEW ENGLAND WATERS...
.ANZ800...GULF OF MAINE...
     GALE TONIGHT.

.NT2 MID ATLC WATERS...
     NONE.

$$

.FORECASTER ROWLAND/BANCROFT. OCEAN PREDICTION CENTER.



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