

799 

AGNT40 KWNM 241929

MIMATN



MARINE WEATHER DISCUSSION FOR N ATLANTIC OCEAN

NWS OCEAN PREDICTION CENTER WASHINGTON DC

329 PM EDT WED AUG 24 2016



.FORECAST DISCUSSION: MAJOR FEATURES/WINDS/SEAS/SIGNIFICANT

.WEATHER FOR THE NORTH ATLANTIC OCEAN W OF 50W FROM 30N TO 50N.



THE LTST GOES VIS IMGRY INDC A WK FRNTL BNDRY JUST E OF THE SRN

OFSHR WTRS...AND HIGH PRES BUILDING OVER THE SRN OFSHR WATERS.

THE 14Z ASCAT PASS FM THIS MORNING STILL INDC 20 KT...MAINLY IN

SRN NT2. CRNT SFC RPRTS INDC ABT THE SAME...10 KT OR LESS OVER THE

N PORTION OF THE OFSHR WATERS UNDER THE HIGH PRES RIDGE. THE 12Z

GFS 10M WINDS ARE INIT OK WHEN COMPARED WITH THE DATA...AND INDC

THE WINDS WL RMN NRLY THE SAME AS THE FRONT E OF THE AREA SLOWLY

DRIFTS W TWD THE AREA AS THE HIGH SHIFTS E OF THE AREA. THE 12Z

GLBL AND RGNL MDLS AGREE WELL WITH THE GFS IN THE SHORT TERM ON 

THE MAIN SYNOP FEATURES...AND THE GFS HAS BEEN FAIRLY CONSISTENT

FOR THE PAST FEW DAYS. THE PREV FCST FLWD THE GFS IN THE SHORT

TERM...SO PLANNING ON USING THE 12Z RUN IN THE NEXT FCST.



LATE THU INTO FRI...THE 12Z GFS INDC ANTHR FRNTL BNDRY WL PASS

THRU THE NT1 WTRS...AND HAS BEEN CONSISTENT WITH THE TMG AND

INTNSTY OF THE FRONT AND WINDS. THE GFS ALSO AGREES WELL WITH THE

THE 12Z MDLS...ALTHO THE 12Z GEM CONT TO BE A PROGRESSIVE

OUTLIER...BUT HAS TRENDED A LTL SLOWER IN ITS 12Z RUN AND IS

CLOSER TO THE REST OF THE 12Z GUID. HOWEVER...THE 12Z GFS INDC 25

KT IN THE GULF OF MAINE...IN THE SW FLOW AHD OF THE CD FNT. CRNT

BUOY RPRTS INDC SSTS NR 70 DEG IN NT1...SO THE NORMALLY SUPPRESSED

MIXING IN SW FLOW MAY NOT BE AS SUPRESSED MUCH WITH THE STATIC

STABILITIES A LTL LOWER THAN USUAL. HOWEVER...THE MDL STABILITIES

STILL INDC THAT THE MXG WL BE LIMITED...AND WITH THE 12Z

ECMWF/UKMET INDCG 15 TO 20 KT MAX IN THE GULF OF MAINE IN THE SW

FLOW...PLANNING ON CAPPING WINDS AT 20 KT.



IN THE EXTENDED...THE 12Z ECMWF/GFS/GEM SOLNS ALL INDC HIGH PRES

BUILDS OVER THE OFSHR WATERS...AS A THIRD CDFNT MOVES INTO THE W

ATLC. THE GFS AND GEM ARE IN DECENT AGRMT WITH THE TMG...AND THE

ECMWF IS A LTL SLOWER. THE 12Z UKMET IS A SLOW OUTLIER...SO WL BE

DISREGARDING FOR THIS FEATURE. FOR THE WINDS...THE GFS KEEPS THEM

GENLY 15 KT OR LESS...WHICH SEEMS RSNBL...SO FAVORING THE GFS

ATTM. TO THE S OF THE OFSHR WTRS...THE 12Z MDLS INDC THAT A PAIR

OF TROPICAL SYSTEMS WL APRCH THE OFSHR WTRS...GASTON FROM THE SE

AND THE CRNT AREA OF DISTURBED WX ALONG A TRPCL WAVE NR PUERTO

RICO WL APRCH FM THE S. THE MDLS DISAGREE ON THE DVLPMT OF THE

TRPCL WAVE TO THE S...AND THE GFS BRINGS THE LOW UP THE COAST OF

FL TO JUST S OF THE NT2 WATERS BY THE END OF THE FCST PD. THE GFS

IS A BIT OF AN OUTLIER...AND INDC WINDS INCSRG TO 20 KT IN SRN

NT1. AS A RESULT...PLANNING ON CAPPING WINDS AT 15 KT IN SRN

NT2...BUT WL OTRW FAVOR THE GFS AS IT SUPPORTED BY THE OTHER 12Z

SOLNS ON ALL OTHER FEATURES.



SEAS...THE 12Z WAVEWATCH III AND ECMWF WAM BOTH INITIALIZED WELL

OVER THE OFSHR WTRS WHEN COMPARED WITH CRNT DATA AND THE RA1 SEA

STATE ANALYSIS...WHICH SHOW SEAS UP TO 6 FT CRNTLY IN THE OFSHR

WTRS. BOTH MDLS LOOK REASONABLE AND GENERALLY STAY WITHIN 1 OR 2

FEET OF EACH OTHER THRU MOST OF THE FCST PERIOD...SO WILL USE A

50/50 BLEND OF THE TWO SOLNS AS A COMPRIMISE SOLN. HOWEVER...WL

TONE DOWN SLIGHTLY IN SRN NT2 MON INTO MON NGT...AS THE

AFOREMENTIONED OVERDONE GFS WINDS IS REFLECTED IN THE WAVEWATCH.



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



.WARNINGS...PRELIMINARY.



.NT1 NEW ENGLAND WATERS...

     NONE.



.NT2 MID ATLC WATERS...

     NONE.



$$



.FORECASTER KELLS. OCEAN PREDICTION CENTER.

