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000
AGNT40 KWNM 230543
MIMATN

MARINE WEATHER DISCUSSION FOR N ATLANTIC OCEAN
NWS OCEAN PREDICTION CENTER WASHINGTON DC
140 AM EDT THU 23 MAY 2013

.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 NEW 00Z MDLS (AND OLD 12Z ECMWF) SHARE
SMLR TIMING FOR A COLD FRONT FCST TO SLOWLY APRCH FROM THE NW
TODAY...MOVE OFSHR LATE TONITE...THEN DRIFT SLOWLY E ACRS THE
OFSHR WTRS FRI INTO SAT. IN THE MEANTIME THE MDLS HV COME INTO
BETTER AGRMT IN REGARDS TO THE FCST TRACK AND STRENGTH OF AN
ASCD FRONTAL LOW DRIFTING OFF THE NRN MID ATLC COAST
FRI...DRIFTING SLOWLY NE ACRS THE NT1 WTRS SAT/SAT NITE...THEN
PASSING N OF THE WTRS SUN INTO MON. IN THE GRADLY STRENGTHENING
SSWLY GRADIENT INADVOF THE COLD FRONT...PER A CONSENSUS OF THE
00Z MDLS...WL CONT TO FCST SLY GALES DVLPG LATE TONITE ACRS THE
BALT CNYN TO THE HAGUE LINE AND ERN BALT CNYN TO HAT CNYN WTRS.
FURTHER N INADVOF THE FRONT ACRS THE NRN WTRS (N OF THE GULF
STREAM) BELIEVE THE GALE FORCE BL WINDS FCST THERE BY THE LATEST
MDLS WL NOT BE ABLE TO COMPLETELY MIX DOWN TO THE SFC DUE TO THE
WARM AIR ADVECTION OVER THE COLD WTRS CREATING STRONG LOW LEVEL
INVERSIONS. THEREFORE WL CONT TO FCST SUBGALE FORCE WINDS ACRS
THE NRN WTRS. SO OVERALL DO NOT PLAN ON MAKING ANY MAJOR SHORT
TERM CHNGS IN THE NEXT OFSHR FCST PACKAGE.

IN THE LONG RANGE...OVERALL PLAN ON FAVORING THE 00Z GFS FCST
TIMING AND TRACK FOR THE FRONTAL LOW SAT INTO MON...WHICH IS IN
LINE WITH THE LATEST WPC MEDIUM RANGE GUIDANCE. BY LATE SUN INTO
MON THO THE 00Z GEFS INDICATES THAT THE 00Z GFS FCST TRACK BCMS
TOO FAR E...BUT NOT SIGLY SO. SMLR TO ITS PREV RESPECTIVE
RUNS... THE 00Z GFS CONTS TO FCST SM GALE FORCE BL WINDS DVLPG W
OF ITS FCST SFC LOW SAT/SAT NITE ACRS THE NRN WTRS. BUT FOR NOW
(UNLESS THE 00Z ECMWF COMES IN LATER SIGLY STRONGER THAN ITS
PREV RUN) WITH THE OTHER GLOBAL MDLS FCSTG WEAKER GRADIENTS WL
KEEP THE ASCD FCST WINDS THEN W OF THE LOW SUBGALE. SO PLAN ON
MAKING MAINLY MINOR LONG RANGE CHNGS TO THE PREV OFSHR FCSTS.

SEAS...OTHER THAN INTITIALIZING ITS SEAS N OF THE GULF STREAM A
LTL TOO HIGH...OVER THE 00Z WAVEWATCH III FCST SEAS LOOK
REPRESENTATIVE OVER THE SHORT TERM. WL WAIT TO SEE THE 00Z
ECMWF...BUT IF IT REMAINS CONSISTENT WL LKLY BLEND THE 00Z
WAVEWATCH III FCST SEAS WITH THOSE FM THE ECMWF WAM IN THE LONG
RANGE...WHICH WAS DONE PREVLY.

EXTRATROPICAL STORM SURGE GUIDANCE...N/A.

.WARNINGS/FORECAST CONFIDENCE...PRELIMINARY. ANY CHANGES WILL BE
COORDINATED THROUGH AWIPS 12 PLANET CHAT OR BY TELEPHONE:

.NT1 NEW ENGLAND WATERS...
.GULF OF MAINE...NONE.
.GEORGES BANK...NONE.
.SOUTH OF NEW ENGLAND...NONE.

.NT2 MID ATLC WATERS...
.HUDSON CANYON TO BALTIMORE CANYON...NONE.
.BALTIMORE CANYON TO HAGUE LINE...GALE THU NITE INTO SAT...MOD
CONFDC.
.BALTIMORE CANYON TO HATTERAS CANYON...GALE THU NITE INTO
FRI...LOW TO MOD CONFDC.
.HATTERAS CANYON TO CAPE FEAR...NONE.
.CAPE FEAR TO 31N...NONE.
$$

.FORECASTER VUKITS. OCEAN PREDICTION CENTER.