

263 

AGNT40 KWNM 011505

MIMATN



MARINE WEATHER DISCUSSION FOR N ATLANTIC OCEAN 

NWS OCEAN PREDICTION CENTER WASHINGTON DC

1100 AM EDT THU 1 SEP 2016 



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

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



THE HIGHER RESOLUTION HRRR/RAP/NAM ARE INITIALIZED HIGHER THAN 

GFS/ECMWF WITH THE WINDS ASSOCIATED WITH THE SURFACE LOW OFF THE 

CAROLINA COAST THIS MORNING INVOF 33.5N75.5W. BASED ON THESE 

HIGHER RESOLUTION MODELS...WILL BE ADDING MARGINAL GALES ACROSS 

THE OUTER NT2 WATERS S OF BALTIMORE CANYON TODAY. WILL THEN BE 

RELYING ON LATEST NHC ADVISORY TO MAKE ANY NECESSARY ADJUSTMENTS 

TO WIND GRIDS AS HERMINE EXITS THE MID ATLC COAST SAT. 06Z 

WAVEWATCH III AND 00Z ECMWF WAM ARE WELL INITIALIZED WITH THE W 

ATLC WAVE HEIGHTS THIS MORNING. 



.EXTRATROPICAL STORM SURGE GUIDANCE...WITH MODELS ALL INDICATING 

THAT POST-TROPICAL HERMINE WILL SLOW AND NEARLY STALL OFF THE 

NRN MID ATLC COAST SUN THROUGH NEXT WEEK...THERE IS A HIGH 

LIKLIHOOD THAT A SIGNIFICANT SURGE EVENT WILL DEVELOP. RECENT 

RUNS OF THE ESTOFS ARE MUCH HIGHER THAN THE ETSS AND AT THIS 

TIME THESE HIGHER VALUES LOOK MORE REPRESENTATIVE.   



--------------------------------------------------------------

...PREVIOUS DISCUSSION...



NOTE: OPC IS PROVIDING NHC POST-TROPICAL FORECAST POINTS FOR 

HURCN GASTON...T.S. HERMINE...AND T.D. 8 SO WL BE BRIEF. 



OVER THE SHORT TERM...PER THE NEW 00Z MDLS...T.D. 8 SHULD BE FAR 

ENUF E THAT IT WL ONLY AFFECT THE FAR NERN MOST NT2 WTRS EARLY 

TODAY. ELSWHR THE 00Z GFS LOOKS LIKE A RSNBL COMPROMISE BTWN THE 

MR PROGRESSIVE 00Z GEM AND SLIGHTLY SLOWER 00Z UKMET/ECMWF FOR 

FCSTG A SLOWLY DVLPG SFC LOW TO TRACK NE ACRS THE SRN NT2 WTRS 

TODAY...THEN PASS E OF THE CNTRL NT2 WTRS TONITE. THEREFORE PLAN 

ON POPULATING OUR FCST WIND GRIDS WITH THE REPRESENTATIVE 00Z 

GFS 10M BL WINDS FOR TODAY AND TONITE. 



THEN LATER IN THE FCST PERIOD THE FCST SHIFTS TO T.S. HERMINE. 

AS HAS BEEN THE CASE IN PREV RUNS...THE 00Z GLOBAL MDLS IN GNRL 

AGREE THAT THE SYSTEM WL BCM CAPTURED BY A NRN STREAM UPR TROF 

WHICH WL TRANSITION INTO A CLOSED UPR LOW SAT INTO MON 

NITE...BUT DUE TO DIFFERENCES IN EXACTLY WHEN THIS WL OCCUR 

CAUSES EACH MDL TO CONT TO FCST A DIFFERENT FCST TRACK FOR THE 

T.S.. VS ITS PREV 18Z RUN...THE 00Z GFS FCST TRACK IS SLIGHTLY 

MR PROGRESSIVE AND FURTHER OFSHR SAT INTO MON NITE...WHICH IS 

SUPPORTED BEST BY THE 00Z GEM THRU EARLY MON. BUT LIKE ITS PREV 

18Z RUN...THE 00Z GEFS MEAN INDICATES THAT THE 00Z GFS TRACK MAY 

BE SLIGHTLY TOO FAST INITIALY. LIKE ITS PREV 12Z RUN...THE 00Z 

UKMET STIL LOOKS LIKE AN ERN OUTLIER SOLUTION SAT AND BEYOND. 

LIKE THE 00Z GFS...THE 00Z ECMWF FCST TRACK HAS TRENDED FURTHER 

OFSHR ALSO SAT INTO SUN... THEN BCMS QSTNRY MON/MON NITE FURTHER 

W THAN THE 00Z GFS. TO SAY FCST CONFIDENCE IN THE FCST TRACK OF 

THIS SYSTEM IS LOW WOULD BE AN UNDERSTATEMENT. BUT IF FORCED TO 

CHOOSE AT THE MOMENT WULD FAVOR A COMPROMISE 00Z GFS/GEF 

MEAN/ECMWF SOLUTION. SO WL WAIT TO SEE THE NEXT NHC ADVSRY 

BEFORE MAKING ANY SIG CHNGS TO THE PREV FCST WIND GRIDS. 



.SEAS...PER THE LATEST SFC OBS AND THEIR ASCD GFS/ECMWF 

SOLUTIONS...WL POPULATE OUR FCST WAVE GRIDS WITH A 50/50 BLEND 

OF THE 00Z WAVEWATCH III AND 00Z ECMWF WAM MDLS FOR TODAY AND 

TONITE. THEN DEPENDENT ON THE NEXT NHC ADVSRY FOR HERMINE WL 

DECIDE LATER OF WHETHER TO CONT WITH THIS BLEND. 



.WARNINGS...PRELIMINARY. 



.NT1 NEW ENGLAND WATERS...

.ANZ810...SOUTH OF NEW ENGLAND...

     GALE POSSIBLE MON INTO MON NIGHT. 

.ANZ815...SOUTH OF LONG ISLAND...

     GALE POSSIBLE SUN INTO MON NIGHT. 



.NT2 MID ATLC WATERS...

.ANZ820...HUDSON CANYON TO BALTIMORE CANYON...

     GALE POSSIBLE SAT NIGHT INTO MON NIGHT. 

.ANZ915...HUDSON CANYON TO THE GREAT SOUTH CHANNEL...

     GALE POSSIBLE SAT NIGHT INTO MON NIGHT. 

.ANZ920...BALTIMORE CANYON TO THE GREAT SOUTH CHANNEL...

     GALE POSSIBLE SAT NIGHT INTO MON NIGHT. 

.ANZ905...THE GREAT SOUTH CHANNEL TO THE HAGUE LINE...

     GALE POSSIBLE MON NIGHT.

.ANZ910...EAST OF THE GREAT SOUTH CHANNEL AND SOUTH OF 39N...

     GALE POSSIBLE MON NIGHT.

.ANZ825...INNER WATERS FROM BALTIMORE CANYON TO CAPE CHARLES 

LIGHT...

     GALE POSSIBLE SAT INTO SAT NIGHT. 

.ANZ828...INNER WATERS FROM CAPE CHARLES LIGHT TO CURRITUCK 

BEACH LIGHT...

     GALE POSSIBLE SAT INTO SAT NIGHT. 

.ANZ925...OUTER WATERS FROM BALTIMORE CANYON TO HATTERAS 

CANYON...

     GALE TODAY.

     GALE POSSIBLE SAT INTO MON. 

.ANZ830...INNER WATERS FROM CURRITUCK BEACH LIGHT TO CAPE 

HATTERAS...

     GALE POSSIBLE SAT INTO SAT NIGHT. 

.ANZ833...INNER WATERS FROM CAPE HATTERAS TO CAPE FEAR...

     TROPICAL STORM FRI NIGHT.

     GALE POSSIBLE SAT.

.ANZ930...OUTER WATERS FROM HATTERAS CANYON TO CAPE FEAR...

     GALE TODAY.

     GALE POSSIBLE SAT INTO SAT NIGHT. 

.ANZ835...INNER WATERS FROM CAPE FEAR TO 31N...

     TROPICAL STORM FRI INTO FRI NIGHT. 



$$ 



.FORECASTER CLARK/VUKITS. OCEAN PREDICTION CENTER.

