Marine Interpretation Message
Issued by NWS

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000
AGNT40 KWNM 290156
MIMATN

MARINE WEATHER DISCUSSION FOR N ATLANTIC OCEAN
NWS OCEAN PREDICTION CENTER WASHINGTON DC
856 PM EST WED JAN 28 2015

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

HIGH PRES WAS CNTRD OVR WRN PA THIS EVENING. THE AREA OF HIGH
PRES WL MOV OFFSHR LATER TNGT AND THU WHILE WEAKENING. THE STGST
WINDS THIS EVENING WERE OVR THE ERN AREAS OF THE MID ATLC. THERE
WAS A SHIP OBS INVOF 32N72W WITH NW WINDS TO 30 KT. THIS FITS WELL
WITH GFS 30M WINDS WHICH HAS WINDS TO 30 KT OVR THE WTRS FM 32N TO
36N BETWEEN 74W AND 71W. WINDS DMNSH OVR THIS AREA OVR THE NEXT
SVRL HR TO 25 KT OR LESS LATER TNGT AS HIGH PRES MOVS OFFSHR. BY
THU NGT INTO FRI MDLS SMLR WITH DVLPG LOW PRES MOVG E INTO THE NRN
NEW ENGLAND WTRS AND STRENGTHENING WITH A STG CD FNT MOVG E ACRS
THE WTRS. GALES DVLP BY LATE MORN OR EARLY AFTN FRI AND XPND INTO
THE NEW ENGLAND WTRS LATE FRI INTO SAT. MDLS ARE IN GOOD AGRMT
INTO SAT AND SAT NGT AND THEREFORE NO CHANGES WL BE MADE. BY LATE
SUN INTO MON MDLS ARE SHOWING LOW PRES DVLPG ALG THE MID ATLC
WTRS. CONFDC IS NOT HIGH CONSIDERING WHAT MDL GUID SHOWED LAST NGT
FOR LATER SUN NGT INTO MON. GFS HAD A STG LOW PRES MOVG EWD INTO
THE WTRS FM THE INLAND AREAS SUN NGT INTO MON...BUT NOW HAS DVLPG
LOW PRES MOVG E OVR THE MID ATLC WTRS. OTHER GUID ALSO SHOWED
DIFFS FM EARLIER GUID. THE UKMET/ECMWF ARE SMLR WITH 18Z GFS AND
IT WL INTERESTING TO SEE IF 00Z MDL GUID CONTS TO SUPPORT 12Z
GUID.

OVERALL LTL CHANGE WL BE MADE TO GRIDS FOR NOW...AND AWAIT 00Z MDL
GUID FOR CONSISTENCY FM THE 12Z AND 18Z GUID.

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


LOW PRES THAT BOUGHT STORM FORCE WINDS OVR THE NRN WATERS LAST NGT
IS QUIKCKLY WEAKENING. MOD N TO NW WNIDS EXPECTED TNGT AS LRG
HIGH PRES BUILD IN FM THE W. NEXT SYSTEM TO AFFECT THE WATERS IS
LOW PRES FCST TO MOV ACRS NEW ENGLAND FRI...THEN ACRS THE NRN
WATERS LATE FRI AND FRI NIGHT WITH ASSD COLD FRONT SWEEPING ACROSS
THE REGION. THE GFS/UKMET/00Z ECMWF ARE IN VERY GOOD AGREEMENT
WITH DETAIL DFFRNC IN THE EXACT LOC OF THE LOW CENTER. ALL THE
GLOBAL MODELS ARE IN GOOD AGREEMENT NO THE STRNGTH OF THE LOW AND
ARE ALL WITHIN JUST A FEW MBS.

HE MODELS ARE IN EXCELLENT AGRMNT WITH THE SPEED OF THE ASSD COLD FRONT
FCST TO SWEEP E ACROSS THE OFFSHORE WATERS BTWN 06Z FRI AND 00Z
SAT. DESPITE THE QUICK PERIOD OF STHRLY FLOW AHD OF THE FRONT...
THE LWR ATMOS WL REMAIN UNSTABLE AND EXPECT SCT AREAS OF PREFRNTL
WINDS REACHING GALE FRC FRI OVR THE WATERS S OF 40N FRI AFTN. BY
LATE FRI...GFS/UKMET/ECMWF/GEM AGREE ON NW WINDS INCRSNG TO GALE
FRC BY 21Z FRI N OF HATTERAS CANYON. THE MODELS BGN TO DFFR ON ONE
VS TWO LOW CNTRS LATE FRI NGT AND SAT...THOUGH EITHER WAY THE
RESULT IS THE SAME WITH W TO NW GALES PREVAILING. WL FCST W TO NW
WINDS 30 TO 40 KT SAT ALSO N OF HTTRS CNYN...WITH NW WINDS DMNSHG
TO BLO GALE FORCE SAT NIGHT OVR THE NRN OFFSHR WATERS AS ASSD LOW
PRES MVS OFF TO THE NE.

FOR THE EXTENDED PERIOD...THE MODELS DIFFER WITH INCRSNG DFFRNCS.
THE COASTAL LOW IN PRVS DAYS RUNS FOR SUN/MON IS NOW A WEAK WV
ALONGA FRONT OFF THE MID ATLC COAST SUN NIGHT. THE GEM BCSMS AN
OUTLIER ALOFT AND WILL NOT BE CONSIDERED. THE GFS...WITH NO
CONTINUITY MAKES THIS THIS INTO A GALE MON WHILE DEEPENING AND
MVNG E. THE ECMWF IS QUITE A BIT DFFRNT FM PRVS RUNS AND IS SMLR
TO THE GFS WITH THE LOW...AND DVLPS A GALE N OF BERMUDA MON. THE
UKMET FLLWS THE ECMWF BUT IS SLOWER AND STRNGR WITH THE LOW. THE
GFS ENSMBL MEMBERS GIVE LTTL SUPPORT TO THE OP GFS RUN...SO WL
COMPROMS AND USE A 70/30 ECMWF/GFS BLEND FOR THIS PERIOD.

.SEAS..AT 18Z...THE MULTIGRID WAVEWATCH III MODEL APPEARS TO HAVE
INITLD FAIRLY WELL...ALTHO IS A FT OR TWO TOO LOW OVR THE GULF OF
MAINE. PREFER THIS MODELS OVER THE ECMWF WAM...WHICH HAS SEAS TOO
HIGH. WL USE A 4/1 BLEND OF WW/WAM THROUGH THE FCST...THEN FOR SUN
ON...WL FLLW SMLR TO THE SFC WINDS AND USE A 50/50 BLEND..


.EXTRATROPICAL STORM SURGE GUIDANCE...THE 12Z ESTOFS FCST A
POSITIVE 1 TO 1.5 FT SURGE ALONG THE NRN NC AND SRN VA COAST
TNGT...AND DMNSHNG THU. THE STG NWLY GRAD FCST TO DVLP FRI INTO
SAT CONTS TO SHOW A NEGATIVE SURGE OF 1 TO 1.5 FT TO DVLP ALONG
THE MID ATLC COAST FRI NIGHT...AND SPEAR NWRD THRU THE WATERS
SAT...THEN DMNSH SAT NGT INTO SUN.



.WARNINGS...PRELIMINARY.

.NT1 NEW ENGLAND WATERS...
.ANZ800...GULF OF MAINE...
     GALE POSSIBLE FRI NIGHT INTO SAT NIGHT.
.ANZ805...GEORGES BANK WEST OF 68W...
     GALE POSSIBLE SAT INTO SAT NIGHT.
.ANZ900...GEORGES BANK EAST OF 68W...
     GALE POSSIBLE SAT INTO SAT NIGHT.
.ANZ810...SOUTH OF NEW ENGLAND...
     GALE POSSIBLE FRI NIGHT INTO SAT NIGHT.
.ANZ815...SOUTH OF LONG ISLAND...
     GALE FRI.
     GALE POSSIBLE FRI NIGHT INTO SAT NIGHT.

.NT2 MID ATLC WATERS...
.ANZ820...HUDSON CANYON TO BALTIMORE CANYON...
     GALE FRI.
     GALE POSSIBLE FRI NIGHT INTO SAT.
.ANZ915...HUDSON CANYON TO THE GREAT SOUTH CHANNEL...
     GALE FRI.
     GALE POSSIBLE FRI NIGHT INTO SAT NIGHT.
.ANZ920...BALTIMORE CANYON TO THE GREAT SOUTH CHANNEL...
     GALE FRI.
     GALE POSSIBLE FRI NIGHT INTO SAT NIGHT.
.ANZ905...THE GREAT SOUTH CHANNEL TO THE HAGUE LINE...
     GALE FRI.
     GALE POSSIBLE FRI NIGHT INTO SAT NIGHT.
.ANZ910...EAST OF THE GREAT SOUTH CHANNEL AND SOUTH OF 39N...
     GALE FRI.
     GALE POSSIBLE FRI NIGHT INTO SAT NIGHT.
.ANZ825...INNER WATERS FROM BALTIMORE CANYON TO CAPE CHARLES LIGHT...
     GALE FRI.
     GALE POSSIBLE FRI NIGHT INTO SAT.
.ANZ828...INNER WATERS FROM CAPE CHARLES LIGHT TO CURRITUCK BEACH LIGHT...
     GALE FRI.
     GALE POSSIBLE FRI NIGHT INTO SAT.
.ANZ925...OUTER WATERS FROM BALTIMORE CANYON TO HATTERAS CANYON...
     GALE FRI.
     GALE POSSIBLE FRI NIGHT INTO SAT.
.ANZ830...INNER WATERS FROM CURRITUCK BEACH LIGHT TO CAPE HATTERAS...
     GALE FRI.
     GALE POSSIBLE FRI NIGHT INTO SAT.
.ANZ833...INNER WATERS FROM CAPE HATTERAS TO CAPE FEAR...
     GALE FRI.
     GALE POSSIBLE FRI NIGHT.
.ANZ930...OUTER WATERS FROM HATTERAS CANYON TO CAPE FEAR...
     GALE FRI.
     GALE POSSIBLE FRI NIGHT INTO SAT.
.ANZ935...OUTER WATERS FROM CAPE FEAR TO 31N...
     GALE FRI.

$$

.FORECASTER ROWLAND/PROSISE. OCEAN PREDICTION CENTER.


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