Marine Interpretation Message
Issued by NWS

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375
AGNT40 KWNM 300700
MIMATN

MARINE WEATHER DISCUSSION FOR N ATLANTIC OCEAN
NWS OCEAN PREDICTION CENTER WASHINGTON DC
300 AM EDT SAT APR 30 2016

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

OVER THE SHORT TERM...THE LATEST ASCAT SCATTEROMETER PASSES HV
MISSED THE STRONGEST PORTION OF THE NELY GRADIENT TO THE NW OF
THE SFC LOW NOW JUST E OF THE CNTRL NT2 WTRS. BUT PER THEIR
EARLIER 25-30 KT RETRIEVALS JUST OUTSIDE THIS AREA AM CONFIDENT
THAT GALES ARE NOW PRESENT IN THE VCNTY OF THE GULF STREAM IN NT2
ZONES ANZ920 AND ANZ910. WITH THIS IN MIND WULD FAVOR THE SLIGHTLY
STRONGER 00Z NAM/GFS/GEM SOLUTIONS FOR THIS SFC LOW TODAY INTO
TONITE AS THE MDLS ALL FCST THE LOW TO MOV OFF TO THE E WITH THE
GRADIENT IN ITS WAKE WKNG. THEREFORE PLAN ON POPULATING OUR FCST
WIND GRIDS WITH THE REPRESENTATIVE 00Z GFS 30M BL WINDS FOR TODAY
AND TONITE.

THEN SUN/SUN NITE...THE 00Z MDLS IN GNRL AGREE THAT A WARM FRONT
WL LIFT NNE FROM THE CNTRL/NRN NT2 WTRS INTO THE SRN NT1 WTRS
WITH AN ASCD SFC LOW MOVG NE OFF THE NRN MID ATLC AND INTO THE SRN
NT1 WTRS SUN NITE. OVERALL WULD FAVOR THE SLIGHTLY LESS
PROGRESSIVE 00Z NAM/GFS/ECMWF SOLUTION FOR THIS FROPA VS THE 00Z
GEM/UKMET. THEREFORE WL TRANSITION TO POPULATING WITH THE MR
REPRESENTATIVE 00Z GFS 10M BL WINDS ON SUN/SUN NITE.

IN THE LONG RANGE...THE 00Z MDLS IN GNRL AGREE THAT THE FRONTAL
LOW WL TRACK NE ACRS THE NT1 WTRS MON AND THEN CONT NE TO NOVA
SCOTIA BY TUE MORNING. IN RGRDS TO THE FCST TRACK OF THIS
LOW...THE 00Z GEM/ECMWF ARE NOW ON THE NRN FRINGE OF THE MDL TRACK
ENVELOPE WHL THE 00Z NAM/GFS/UKMET HV CONVERGED TWDS VERY SMLR MR
SRN TRACKS. SINCE IT RMNS MR CONSISTENT AND ALSO HAS THE SPRT OF
THE 00Z GEFS MEAN...WL ACPT THE 00Z GFS FCST TRACK FOR THIS LOW.
IN RGRDS TO THE ASCD FCST GRADIENTS WITH THIS LOW...BELIEVE THE
00Z GFS LOOKS LIKE A RSNBL COMPROMISE BTWN THE STRONGER 00Z
NAM/GFS AND WEAKER 00Z UKMET/ECMWF SOLUTIONS. THEREFORE WL CONT TO
POPULATE WITH THE 00Z GFS 10M BL WINDS MON INTO MON NITE...WITH SM
ADDITIONAL FURTHER EDITS NR THE GULF STREAM ACRS THE OUTER NE NT2
WTRS TO MAINTAIN THE PREVLY FCSTD PSBL GALES.

THEN FURTHER OUT IN THE LONG RANGE...THE DISPARITY BTWN THE 00Z
GLOBAL MDLS BCMS SIGNIFICANT. VS ITS PREV 18Z RUN WHICH FCST A
DVLPG SFC LOW TO MOV NE OFF THE MID ATLC COAST TUE NITE AND THEN
TRACK NE ACRS THE NRN NT2 AND THEN SERN NT1 WTRS WED/WED
NITE...THE 00Z GFS HAS NOW COMPLETELY BACKED OFF AND FCSTS NO SFC
LOW AT ALL MOVG OFSHR EVEN THO IT FCSTS A SHARPER UPR TROF TO DIG
INTO THE ERN CONUS WED NITE. ON THE OTHER HAND THO LESS
PROGRESSIVE THAN ITS PREV 12Z RUN...THE 00Z GEM STIL FCSTS A SIG
DVLPG SFC LOW TO TRACK NNE OFF THE MID ATLC AND NEW ENGLD COASTS
WED/WED NITE. THE 00Z UKMET/ECMWF NOW ALSO FCST A SIGLY MR
AMPLIFIED UPR LVL PTRN TO DVLP WITH AN ASCD DVLPG SFC LOW MOVG OFF
THE SE COAST WED NITE WITH GALE FORCE ASCD BL WINDS DVLPG. SO FOR
NOW WITH VERY LOW FCST CONFIDENCE...WL TRANSITION TO POPULATING
WITH THE 00Z ECMWF BL WINDS ON LATE MON NITE THRU WED NITE. BUT
DUE TO THE CURRENT MDL DISPARITY...WL CAP THESE WINDS BELOW GALE
FORCE ON WED NITE TO HOLD OFF ON FCSTG ANY PSBL WRNGS FOR NOW.

SEAS...THE 00Z WAVEWATCH III HAS INITIALIZED SLIGHTLY BETTER THAN
THE 00Z ECMWF WAM. WITH THIS IN MIND AND SINCE THE 00Z GFS WL BE
FAVORED...WL POPULATE OUR FCST WAVE GRIDS WITH THE 00Z WAVEWATCH
III FOR TODAY INTO MON NITE. THEN SINCE THE 00Z ECMWF WL THEN BCM
THE FAVORED SOLUTION...WL TRANSITION TO THE 00Z ECMWF WAM FCST
SEAS LATER MON NITE THRU WED NITE.

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

.WARNINGS...PRELIMINARY.

.NT1 NEW ENGLAND WATERS...
     NONE.

.NT2 MID ATLC WATERS...
.ANZ920...BALTIMORE CANYON TO THE GREAT SOUTH CHANNEL...
     GALE EARLY TODAY INTO TODAY.
     GALE POSSIBLE MON.
.ANZ905...THE GREAT SOUTH CHANNEL TO THE HAGUE LINE...
     GALE POSSIBLE MON.
.ANZ910...EAST OF THE GREAT SOUTH CHANNEL AND SOUTH OF 39N...
     GALE TODAY.
     GALE POSSIBLE MON INTO MON NIGHT.

$$

.FORECASTER VUKITS. OCEAN PREDICTION CENTER.



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