000
AGNT40 KWNM 131838
MIMATN
MARINE WEATHER DISCUSSION
NWS OCEAN PREDICTION CENTER WASHINGTON DC
135 PM EST WED 13 FEB 2013
.FORECAST DISCUSSION: MAJOR FEATURES/WINDS/SEAS/SIGNIFICANT
.WEATHER FOR NORTH ATLANTIC OCEAN W OF 50W FROM 30N TO 50N.
OVER THE SHORT TERM...THE NEW 12Z MDLS SHARE SMLR FCST TRACKS
FOR A SLOWLY INTENSIFYING SFC LOW TRACKING ENE OFF THE MID ATLC
COAST ACRS THE NRN NT2 WTRS TONITE INTO EARLY THU. OVERALL PLAN
ON USING A BLENDED 12Z GFS/GEM/UKMET/ECMWF SOLUTION FOR THIS
SYSTEM (THE 12Z NAM LOOKS A LTL TOO STRONG). PER THIS BLENDED
SOLUTION...AS NOTED EARLIER IT STIL LOOKS CLOSE AS TO WHETHER
ANY ASCD GALES WL SPREAD N INTO THE SE MOST NT1 WTRS. BUT FOR
NOW MAINLY PER THE 12Z GFS/GEM...WL NOT MAKING ANY TIMING AND/OR
AREAL COVERAGE CHNGS TO THE PREVLY FCSTD ASCD GALE WRNGS AND WL
JUST MAKE SOME MINOR CHNGS TO THE ASCD FCST CONDS. THEN BY LATE
THU THRU FRI WL FAVOR A BLENDED 12Z GFS/UKMET/ECMWF SOLUTION OF
A WEAK SFC HIGH PRES RIDGE DRIFTING OFSHR CAUSING LITE CONDS
THRUT THE CSTL/OFSHR WTRS.
IN THE LONG RANGE...THE 12Z MDLS GNRLY AGREE THAT AN UPR L/W
TROF WL DIG INTO THE ERN CONUS FRI NITE/SAT AND THEN SWING OFSHR
SUN. AFTER THEY GNRLY AGREE THAT A COLD FRONT WL MOVE OFSHR
FRI/NITE EARLY SAT...DUE TO DIFFERENCES IN THEIR FCST AMPLITUDE
OF THIS UPR TROF...THE 12Z MDLS DIFFER ON THEIR FCST TRACKS AND
STRENGTHS OF AN ASCD ATTENDANT SFC LOW DVLPG ON THE FRONT E OF
THE OFSHR WTRS LATE SAT INTO MON. THE 12Z GEM/UKMET FCST THE
MOST AMPLIFIED SOLUTIONS WITH THE STRONGEST ASCD SFC LOW
CROSSING NOVA SCOTIA LATE SUN WITH STRONG GALE FORCE AND/OR
MARGINAL STORM FORCE BL WINDS FCST TO DVLP ACRS THE NT1 AND NE
NT2 WTRS. THE 12Z GFS/ECMWF INITIALLY (SAT NITE/SUN) FCST LESS
AMPLIFIED SOLUTIONS WITH SMWHT MR PROGRESSIVE AND WEAKER SFC
LOWS APRCHG NEWFOUNDLAND BY LATE SUN. WITH SO MUCH DISPARITY
BTWN THE MDLS RGRDG THE ATTENDANT SFC LOW(S?) FOR NOW WL INSTEAD
FOCUS MR ON THE STRONG ASCD POSTFRONTAL NWLY GRADIENT FCST BY
ALL OF THE 12Z GLOBAL MDLS TO DVLP ACRS THE OFSHR WTRS. SO FOR
THIS GRADIENT WL FAVOR A BLEND OF THE 12Z GFS/GEFS MEAN/ECMWF
AND PER THIS BLEND WL CONT TO FCST GALES TO DVLP ACRS THE SRN
NT2 WTRS LATE SAT...SHIFT NEWD INTO THE NT1 AND NRN NT2 WTRS BY
LATE SUN...THEN BCM SUBGALE THRUT LATE MON.
SEAS...OVER THE SHORT TERM THE 12Z WAVEWATCH III FCST SEAS LOOK
REPRESENTATIVE AND WL NOT BE DEVIATED FM SIGLY. IN THE LONG
RANGE...AS WAS DONE PREVLY...WL LKLY BLEND THE 12Z WAVEWATCH III
FCST SEAS WITH THOSE FROM THE ECMWF WAM MDL.
EXTRATROPICAL STORM SURGE MODEL...N/A.
.WARNINGS/FORECAST CONFIDENCE...PRELIMINARY. ANY CHANGES WILL BE
COORDINATED THROUGH WIPES 12 PLANET CHAT OR BY TELEPHONE:
.NT1 NEW ENGLAND WATERS
.GULF OF MAINE...GALE SUN INTO MON...LOW TO MDT CONFDC.
.GEORGES BANK...GALE TNGT INTO THU...LOW CONFDC. GALE SUN INTO
MON...LOW TO MDT CONFDC.
.S OF NEW ENGLAND...GALE TNGT INTO THU...LOW CONFDC. GALE SUN
INTO MON...LOW CONFDC.
.NT2 MID ATLC WATERS
.HUDSON CNYN TO BALT CNYN...GALE TNGT...LOW CONFDC. GALE
SUN...LOW CONFDC.
.BALT CNYN TO HAGUE LINE... GALE TNGT INTO THU...MDT TO HI
CONFDC. GALE SUN INTO MON...MDT CNFDC.
.BALT CNYN TO HATTERAS CNYN... GALE TNGT INTO THU...HIGH CONFDC.
GALE SUN INTO MON...MDT CNFDC.
.HATTERAS CNYN TO CAPE FEAR...GALE TNGT...MDT TO HIGH CONFDC.
GALE SAT INTO SUN...LOW TO MDT CNFDC.
.CAPE FEAR TO 31N...GALE TNGT...MDT TO HI CONFDC. GALE SAT INTO
SUN...LOW TO MDT CNFDC.
.FORECASTER VUKITS. OCEAN FORECAST BRANCH.