Marine Interpretation Message
Issued by NWS

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000
AGNT40 KWNM 010143
MIMATN

MARINE WEATHER DISCUSSION FOR N ATLANTIC OCEAN
NWS OCEAN PREDICTION CENTER WASHINGTON DC
843 PM EST SAT FEB 28 2015

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


STRONG HIGH PRES WAS CENTERED ALONG THE COAST OF MARYLAND THIS
EVENING AND CONTS TO SLOWLY MOVE E. LIGHT WINDS PREVAIL OVER MOST
OF THE WRN ATLCNTIC...EXCEPT SW OF HATTERAS CANYO WHERE NE WINDS
INCRS TO NEAR GALE FRC. AT 00Z...WINDS WERE NE AT 25 G 31 KT AT
41013...FRYING PAN SHOALS AND ALSO AT 41008 GREY`S REEF FTHR S AND
NE 27G33KT INBETWEEN THE TWO AT BUOY 41004. A SCATTEROMETER AT 18Z
SHOWED WINDS CLOSE TO GFS 30M WINDS. AM ON THE FENCE CONSERNING
GALES OVER THE GULF STREAM. WINDS SHOULD BE GRADU DMNSHNG
TNGT...BUT HV REMAINED NEARY STEADY OVR THE STHRN WATERS FOPR THE
PAST FEW HOURS. FOR NOW...WL LIKELY LEAVE THEM IN... WITH WINDS
AND SEAS TRENDING DOWN SLIGHTLY TNGHT. OTW...WILL MAKE ONLY MINOR
CHANGES TO THE FCST.

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

AS STRONG HIGH PRES SLOWLY BUILDS E TWDS THE NRN MID ATLC COAST
THE NELY GRADIENT TO ITS S CONTS TO SLOWLY STRENGTHEN PRETTY MUCH
AS PREVLY EXPECTED. WITH BUOYS 41004 AND 41013 AT 12Z BOTH RPRTG
050/25 G 31 KT AT 12Z...BELIEVE MARGINAL GALES ARE PRESENT IN THE
GULF STREAM TO THEIR IMMED E OVER ZONE ANZ835. MAX SEAS OVER THE
SRN NT2 WTRS ARE IN THE 8-11 FT RANGE WHICH ARE RUNNING ON AVG 1-3
FT HIGHER THAN FCST BY THE 06Z WAVEWATCH III AND 00Z ECMWF
WAM...SO WL CONT TO ADJUST UP THE FCST SEAS ACRS THESE WTRS OVER
THE IMMED SHORT TERM.

OVER THE SHORT TERM...WITH AN EARLIER 1534Z HI RESOLUTION ASCAT-A
PASS RETURNING SOLID 30 KT WINDS AND WITH BUOYS 41008/41004/41013
ALL RECENTLY GUSTING TO GALE FORCE BELIEVE THAT NELY GALES ARE
PRESENT ESPECLY IN THE GULF STREAM OVER THE SW PORTION OF ZONE
ANZ835. PER THE NEW 12Z NAM/GFS/GEM 30M BL WINDS WL START THE
TONITE FCST PERIOD WITH MARGINAL GALES OVER THESE WTRS. THEN AS
ALL OF THE 12Z MDLS FCST THE STRONG SFC HIGH THAT IS SPRTG THIS
GRADIENT TO MOV OFSHR TONITE INVOF 40N AND THEN SINK SEWD SUN WHL
GRADLY WKNG WL CONT TO FCST WINDS ACRS THE SRN NT2 WTRS TO GRADLY
DMNSH LATER TONITE INTO SUN SMLR TO THE PREV FCST. THEREFORE TO
BETTER ACCOUNT FOR THIS GRADIENT WL POPULATE OUR FCST WINDS GRIDS
WITH THE REPRESENTATIVE 12Z GFS 30M BL WINDS FOR TONITE THRU SUN.
THEN LATE SUN NITE AND MON THE 12Z GFS REMAINS CONSISTENT VS ITS
PREV RESPECTIVE RUNS IN FCSTG A STRONG COLD FRONT TO PUSH SE ACRS
THE WTRS WITH AN ASCD ATTENDANT SFC LOW INTENSIFYING NE OF THE NT1
WTRS MON/MON NITE. PER A CONSENSUS OF THE 12Z MDLS STIL HV HI FCST
CONFIDENCE IN PREFRONTAL SWLY ASCD GALES DVLPG ACRS THE WARMER
OUTER CNTRL/NERN NT2 WTRS SUN NITE/EARLY MON...FLWD THEN BY
POSTFRONTAL WNWLY GALES DVLPG THRUT THE NT1 AND NRN/CNTRL NT2 WTRS
MON INTO MON NITE. SINCE OVERALL THEY ARE SPRTD BY THE OTHER 12Z
MDLS AND THE 12Z GEFS MEAN...PLAN ON POPULATING WITH THE WEAKER
12Z GFS 10M BL WINDS SUN NITE (TO BETTER ACCOUNT FOR THE SLY WARM
AIR ADVECTION)...FLWD BY THE STRONGER 12Z GFS 30M BL WINDS MON/MON
NITE (TO BETTER ACCOUNT FOR THE STRONG COLD AIR ADVECTION AND
IMPRESSIVE NEGATIVE STATIC STABILIES FCSTD). SO THE END RESULT OF
THESE WINDS WL RESULT IN ONLY MINOR SHORT TERM CHNGS TO THE PREV
OFSHR FCSTS.

IN THE LONG RANGE...THE 12Z MDLS ALL FCST A STRONG HIGH PRES
RIDGE TO BUILD OFSHR TUE WITH DMNSHG CONDS DVLPG THRUT. WL CONT
TO POPULATE WITH THE 12Z GFS 30M BL WINDS INTO TUE WHICH WELL
ACCOUNTS FOR THIS DMNSHG TREND. THEN THE 12Z GFS RMNS CONSISTENT
VS ITS PREV RESPECTIVE RUNS IN FCSTG A STRONGER ATTENDANT SFC LOW
TO TRACK NE ACRS THE ERN GREAT LAKES TUE NITE AND PASS N THEN NE
OF THE WTRS WED. AS A RESULT THE 12Z GFS FCSTS A STRONGER SLY
GRADIENT THAN THE 12Z UKMET/GEM TO DVLP THRUT THE WTRS TUE NITE AS
A WARM FRONT LIFTS NEWD...THEN FCSTS A MR PROGRESSIVE COLD FRONT
MOVG OFSHR WED INTO THU NITE. BUT NOW THE NEW 12Z ECMWF HAS COME
INTO MUCH BETTER AGRMT WITH THE 12Z GFS SOLUTION ON TUE NITE THRU
WED NITE. THEREFORE WL POPULATE WITH A 50/50 BLEND OF THE 12Z GFS
10M AND 12Z ECMWF BL WINDS FRO TUE NITE THRU WED NITE. THEN PER
THE 12Z GEFS MEAN BLV THE 12Z GFS BCMS A LTL TOO SLOW WITH ITS
COLD FROPA THU/THU NITE. THEREFORE SINCE THEIR FCST GRADIENTS ARE
SMLR WL THEN TRANSITION TO A 50/50 BLEND OF THE 12Z ECMWF AND 12Z
GFS 30M BL WINDS THU/THU NITE...WITH THE GFS WINDS TIME SHIFTED
6HRS FASTER.

.SEAS...WL FAVOR THE SLIGHTLY HIGHER 12Z ECMWF WAM FCST SEAS
TONITE AND HENCE WL POPULATE OUR FCST WAVE GRIDS ACRDGLY FOR
TONITE. THEN SINCE THE OVERALL DIFFS BWTN THE TWO MDLS REMAIN REL
SMALL...WL POPULATE WITH A 50/50 BLEND OF THE TWO MDLS SUN THRU
THU NITE.

.EXTRATROPICAL STORM SURGE GUIDANCE...IN THE STRONG NELY GRADIENT
ACRS THE SRN NT2 WTRS...SMLR TO THEIR PREV RESPECTIVE RUNS THE
12Z ESTOFS CONTS TO FCST A MR SIG SURGE THAN THE 12Z ETSS TONITE
ALONG THE S CAROLINA AND GEORGIA COASTS WHICH CONTS TO LOOK RSNBL.
AS THIS GRADIENT WKNS SUN INTO MON THE DIFFS BTWN THE MDLS THEN
BCMS NEGLIGIBLE. FURTHER N ON MON/MON NITE IN THE STRONG WNWLY
GRADIENT THE 12Z ESTOFS IS FCSTG A MR SIG NEGATIVE SURGE TO DVLP
ALONG THE COASTS FM THE DELMARVA NWD THAN THE 12Z ETSS. A
COMPROMISE BTWN THE TWO MDLS WL LKLY VERIFY BEST THEN.


.WARNINGS...PRELIMINARY.

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

.NT2 MID ATLC WATERS...
.ANZ820...HUDSON CANYON TO BALTIMORE CANYON...
     GALE MON.
     GALE POSSIBLE TUE NIGHT INTO WED.
.ANZ915...HUDSON CANYON TO THE GREAT SOUTH CHANNEL...
     GALE MON.
     GALE POSSIBLE MON NIGHT.
     GALE POSSIBLE TUE NIGHT INTO WED.
.ANZ920...BALTIMORE CANYON TO THE GREAT SOUTH CHANNEL...
     GALE SUN NIGHT INTO MON.
     GALE POSSIBLE TUE NIGHT INTO WED.
.ANZ905...THE GREAT SOUTH CHANNEL TO THE HAGUE LINE...
     GALE MON.
     GALE POSSIBLE MON NIGHT.
     GALE POSSIBLE TUE NIGHT INTO WED.
.ANZ910...EAST OF THE GREAT SOUTH CHANNEL AND SOUTH OF 39N...
     GALE SUN NIGHT INTO MON.
     GALE POSSIBLE MON NIGHT.
     GALE POSSIBLE WED.
.ANZ825...INNER WATERS FROM BALTIMORE CANYON TO CAPE CHARLES LIGHT...
     GALE POSSIBLE WED.
.ANZ828...INNER WATERS FROM CAPE CHARLES LIGHT TO CURRITUCK BEACH LIGHT...
     GALE POSSIBLE TUE NIGHT INTO WED.
     GALE POSSIBLE THU INTO THU NIGHT.
.ANZ925...OUTER WATERS FROM BALTIMORE CANYON TO HATTERAS CANYON...
     GALE SUN NIGHT INTO MON.
     GALE POSSIBLE TUE NIGHT INTO WED.
     GALE POSSIBLE THU INTO THU NIGHT.
.ANZ830...INNER WATERS FROM CURRITUCK BEACH LIGHT TO CAPE HATTERAS...
     GALE POSSIBLE TUE NIGHT.
     GALE POSSIBLE THU INTO THU NIGHT.
.ANZ833...INNER WATERS FROM CAPE HATTERAS TO CAPE FEAR...
     GALE POSSIBLE THU INTO THU NIGHT.
.ANZ930...OUTER WATERS FROM HATTERAS CANYON TO CAPE FEAR...
     GALE POSSIBLE THU INTO THU NIGHT.
.ANZ835...INNER WATERS FROM CAPE FEAR TO 31N...
     GALE TONIGHT.
     GALE POSSIBLE THU NIGHT.
.ANZ935...OUTER WATERS FROM CAPE FEAR TO 31N...
     GALE POSSIBLE THU NIGHT.

$$

.FORECASTER PROSISE/VUKITS. OCEAN PREDICTION CENTER.



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