

541 

AGNT40 KWNM 070732

MIMATN



MARINE WEATHER DISCUSSION FOR N ATLANTIC OCEAN

NWS OCEAN PREDICTION CENTER WASHINGTON DC

332 AM EDT WED SEP 7 2016



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

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



THE SAT IMG STILL INDC POST-TROPICAL CYCLONE HERMINE OVER ZONE

ANZ820 ABOUT 80 NM SE OF SANDY HOOK NJ WHILE A HIGH PRES RIDGE

STILL DEPICTED OVER THE SRN WATERS. THE LATEST OBSERVATIONS

INCLUDING ASCAT PASS AT 0245Z NOW SHOW HIGHER WINDS OVER THE

CENTRAL WATERS EXTENDING SE. AT 06Z THE NCEP MAP HAS POST-TROPICAL

HERMINE NEAR 39N72W WITH A FRONT EXTENDING NE ACROSS THE NRN

WATERS. HIGH PRES 1035 MB OVER THE CENTRAL ATLC STILL HAS ITS

RIDGE EXTENDING W TO END JUST E OF THE WATERS. ANOTHER RIDGE STILL

EXTENDS FROM THE S-ERN STATES THRU THE MID ATLC STATES INTO NEW

ENGL. THE PRES GRADIENT IS STILL FAIRLY TIGHT OVER THE CENTRAL

WATERS WHERE THE WINDS ARE IN THE GALE FORCE RANGE BUT QUITE

RELAXED ELSEWHERE.



THE MODELS GFS/ECMWFHR/UKMETHR/CMC STILL INDC SOME ENERGY IN AN

UPPERLEVEL CUT-OFF LOW OVER THE CENTRAL WATERS WITH HIGH PRES

CENTERS TO THE E AND W. IN THE SHORT TERM THE MODELS AGREE ON

WEAKENING THE HIGH PRES TO THE E AND THAT WILL FORCE THE ENERGY TO

BE SPREAD OUT AND WEAKEN THE SYTEM. IN ADDITION MORE ENEGRY

ASSOCIATED WITH AN UPPERLELVEL TROF TO THE NW WILL SHIFT E AND

MERGE WITH THE ENERGY OVER THE WATERS. HERMINE IS NOW N OF THE

GULF STREAM AND IS EXPECTED TO REMAIN IN THE COOL WATERS. AS SUCH

WINDS ASSOCATED WITH HERMINE SHOULD CONTINUE TO DIMINISH TO BELOW

WARNING THRESHOLD TONIGHT.



THE MODELS GFS/ECMWFHR/UKMETHR/CMC HAVE INITIALIZED FAIRLY WELL

WITH THE 06Z OBSERVATIONS IN PARTICULAR THE PRESS FIELD BUT THEY

STILL HAVE MINOR DIFFERENCES ON THE INTENSITY AND AREAL EXTENSION

OF THE WIND FIELD. ALL THE MODELS NOW AGREE ON HIGHER WINDS IN THE

SE SECTOR. IN ADDITION GFS AND CMC STILL HAVE WINDS HIGHER THAN

THE OTHER MODELS. ECMWFHR HAS A SMALLER AREA OF WARNING CRITERIA

WINDS AND THESE SIMILAR DIFFERENCES CONTINUE IN THE SHORT TERM.

OTHERWISE ALL THE MODELS ARE NOW IN GOOD AGREEMENT ON PUSHING THE

SYSTEM N ACROSS THE WRN PARTS OF THE NRN WATERS AND THEN

ACCELERATE NE AS IT WEAKENS AND DISSIPATE IN THE SHORT TERM. IN

THE LONG RANGE A HIGH PRES RIDGE WILL EXTEND FROM THE W INTO THE

SRN WATERS WHILE A COUPLE OF FRONTS WILL PASS E ACROSS THE NRN

WATERS AND WINDS WILL REMAIN BELOW GALE FORCE. WILL POP WINDS

INITIALLY WITH ECMWFHR BUT ADJ WINDS TO DEPICT GALES THRU TONIGHT

BECAUSE GFS IS RATHER TOO FAST INITIALLY WITH HE SYSTEM. WILL USE

GFS IN THE LONG RANGE. 



POST-TROPICAL CYCLONE HERMINE FORECAST POSITIONS...CENTRAL

PRESSURE...MAX WINDS



INITIAL 07/0600Z 39.1N 72.3W 1001 MB 35 KT 

12HR VT 07/1800Z 39.8N 72.3W 1002 MB 35 KT 

24HR VT 08/0600Z 40.1N 71.8W 1004 MB 30 KT 

36HR VT 08/1800Z 40.9N 70.5W 1009 MB 25 KT 

48HR VT 09/0000Z...DISSIPATED  



.SEAS...THE SEAS ARE STILL LARGE OVER THE CENTRAL WATERS WITH NOW

13 FT PEAKS JUST OUTSIDE THE CENTER. THE NWW3 WAVE MODEL FITS

FAIRLY WELL WITH THE 06Z OBSERVED SEAS PATTERN BUT IS STILL

UNDERDDONE NEAR HERMINE ON THE PEAK VALUE NOW BY 2 FT. THE

ECMEWWAVE HAS ALSO INITIALIZED WELL WITH THE OBS SEAS PATTERN BUT

ALSO UNDERDONE NOW BY A FOOT COMPARED WITH THE OBSERVED PEAK

VALUE. OTHERWISE BOTH WAVE MODELS HAVE CONTINUED TO BE QUITE

CONSISTENT AND STILL NEED TO BE BUMPED UP BY A SMALL PERCENTAGE TO

EQUALL THE OBSERVATIONS AND FORECAST. I PLAN ON STAYING CLOSE TO

THE CURRENT FORECAST SEAS SINCE THE FORECAST TRACK OF HERMINE AND

INTENSITY OF THE WINDS ARE VERY CLOSE TO THE FORECAST AND NO MAJOR

CANGES TO THE PREVIOUS TRACK AND FORECAST ARE EXPECTED. WILL STILL

DO MINOR ADJ TO THE SEAS TO FIT HERMINE INTENSITY FORECAST. SO

WILL POP WAVE GRIDS WITH WNA INITIALLY WITH MINOR ADJ THEN USE

NWW3 THRU THE LONG RANGE.





.EXTRATROPICAL STORM SURGE GUIDANCE...POST-TROPICAL HERMINE

HAS CONTINUED TO WEAKEN AND THE DIMINISHING TRENDS DEPICTED IN

THE LATEST ETSS AND ESTOFS ALONG LONG ISLAND LOOK RESOANABLE. BOTH

THE ETSS AND ESTOFS INDICATE DROPPED SURGE TO BELOW 1 FT...WITH

WATER LEVELS ALONG THE NRN MID ATLC AND NEW ENGLAND COASTS TO

REMAIN BELOW MAX ASTRONOMICAL TIDE LEVELS FOR THE NEXT FEW DAYS.





.WARNINGS...PRELIMINARY.



.NT1 NEW ENGLAND WATERS...

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

     GALE TONIGHT INTO THU. 

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

 GALE TODAY.



.NT2 MID ATLC WATERS...

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

 GALE TODAY.

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

 GALE TODAY INTO TONIGHT.

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

 GALE TODAY.



$$



.FORECASTER MUSONDA. OCEAN PREDICTION CENTER.

