NOAA>NWS>NCEP>OPC>Archived N Atlantic Marine Discussions

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636 
AGNT40 KWNM 271333
MIMATN

MARINE WEATHER DISCUSSION 
NWS OCEAN PREDICTION CENTER WASHINGTON DC
725 AM EDT THU 27 AUG 2009 

.FORECAST DISCUSSION: MAJOR FEATURES/WINDS/SEAS/SIGNIFICANT 
.WEATHER FOR NORTH ATLANTIC OCEAN W OF 50W FROM 30N TO 50N. 

THE LATEST QSCAT PASS SHOWED WINDS SW 15 TO 20 KT IN ADVANCE OF 
THE COLD FRONT NOW ALONG 39N-40N OVER THE FAR N NT2 WATERS. 
ELSEWHERE N TO NE WINDS 10 TO 15 KT ACROSS NT1 AND VARIABLE 10 
KT S OF HATTERAS CANYON OVER NT2. THE ONE EXCEPTION WAS THE FAR 
SE PORTION OF NT2 WHERE WINDS HAD SHIFT TO NE 15 TO 20 KT IN 
ADVANCE OF TROPICAL STORM DANNY. SEAS ACROSS THE AREA WERE 3 TO 
5 FT...EXCEPT FOR THE SE NT2 WATERS 6 TO 8 FT. 

TROPICAL STORM DANNY WILL BE THE MAIN PLAYER FOR THE OFFSHORE 
WATERS OVER THE NEXT COUPLE OF DAYS. THE SYSTEM WILL APPROACH 
THE WATERS FROM THE SE TODAY AND BRING TROPICAL STORM CONDITIONS 
TO THE E PORTION OF CAPE FEAR TO 31N TONIGHT AND HURRICANE 
CONDITIONS TO FARTHER N FRI. FOR SEAS THE SWELL FROM DANNY 
SHOULD BE REACHING THE COAST S OF CAPE HATTERAS BY THE END OF 
THE AFTERNOON AND S OF CAPE COD BY FRI MORNING. 

THE COLD FRONT WILL STALL ACROSS THE N NT2 WATERS TODAY THEN 
LIFT BACK N AS A WARM FRONT FRI. PLAN TO KEEP WINDS TO 20 KT OR 
LESS WITH THIS FRONT.  

FOR THE UPDATE WILL MAKE A FEW MINOR ADJUSTMENTS AND WAIT FOR 
THE CONFERENCE CALL FOR DANNY. PLAN TO HOLD THE FCST UNTIL AFTER 
THE CONFERENCE CALL AT 10 AM. 
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PREVIOUS DISCUSSION

QUIKSCAT PASS FM 23Z SHOWED WINDS TO 20 KT INADVOF CD FNT THAT 
IS CURRENTLY MOVG SE ACROSS THE NEW ENGLAND WTRS AND INTO THE 
NRN MID ATLC BY EARLY MORNING...AND MDL GUID SMLR WITH FNT 
STALLING THIS AFTN OVR THE NRN MID ATLC. A HIGH PRES RDG WL 
EXTEND SE ACROSS THE NEW ENGLAND WTRS TDY...ALTHO NOT MUCH 
STRENGTHENING AS IT EXTENDS SE INTO THE WTRS WHICH KPS WINDS LGT 
AT NO MORE THAN 15 KT. 

IR SATEL SHOWS TROPICAL STORM DANNY TRYING TO GET BETTER 
ORGANIZED...ALTHO CONVECTION IS NOT WRAPPING ARND THE CNTR WITH 
MOST OF THE ACTIVE CONVECTION IN THE IN THE N AND NE QUADS. THE 
MOST RECENT OFFICIAL TRACK FM TPC HAS TROPICAL STORM DANNY 
CROSSING INTO THE SRN WTRS LATE THU NGT/FRI. THE 00Z GFS TRACK 
OF THE SYS FITS WELL WITH OFFICIAL TRACK AND THE FCST PSNS OF 
DANNY FM TPC. THE UKMET IS NOW FURTHER E WITH THE TRACK AND IS 
SOMEWHAT CLOSER TO THE GFS...ALTHO IT IS SLOWER. THE GEM MDL 
TRACKS DANNY FURTHER W THAN THE TRACK WHILE STILL THE STRONGEST 
WITH THE SYS. BOTH THE GFS/UKMET BY SAT NGT TRACK FURTHER E THAN 
THE OFFICIAL TRACK WHILE THE GEM MORE CLOSELY PARELLELS THE 
TRACK. HAV NOT SEEN THE 00Z ECMWF...BUT IT HAS CORRELATED 
CLOSELY TO THE UKMET OVR THE PAST SVRL NGT AND I WUD SUSPECT 
THIS WL BE THE CASE WITH THE 00Z GUID. TRANSITION FM TROPICAL TO 
EXTRATROPICAL WL LIKELY OCCUR AS THE SYS MOVS NE ACROSS THE ERN 
AREAS OF THE NEW ENGLAND WTRS SAT NGT INTO SUN ALTHO LIKELY WL 
DELAYED SINCE SYS WL BE STRENGTHENING FRI NGT INTO SAT. IN ANY 
CASE WL AWAIT THE TPC CONFERENCE CALL AT 4 AM AND ADJST THE FCST 
ACCORDINGLY. 

SEAS...BUOY 41048 JUST E OF THE SRN WTRS HAD BEEN CONSISTENTLY 
HIGHER WITH SE SWELL FM DANNY BY ABT 3 FT. WL CONT TREND OF 
BEING HIGHER THE WWIII GUID WITH THE APPROACH OF DANNY OVR MUCH 
OF THE SRN AND CNTRL AREAS OF THE MID ATLC WTRS TDY INTO FRI. 
CLOSER TO THE CNTR OF THE TS DANNY BUOY 41047 HAS BEEN ABT 3 TO 
4 FT HIGHER THAN THE WWIII GUID. 

ANTICIPATE FCST PACKAGE WL LIKELY BE DELAYED TO PERHAPS AN HOUR 
OR SO FM THE REGULAR FCST TIME ISSUANCE. 

.WARNINGS/FORECAST CONFIDENCE...WARNINGS ARE PRELIMINARY AND ARE 
SUBJECT TO CHANGE. ANY CHANGES WILL BE COORDINATED THROUGH AWIPS 
12 PLANET CHAT OR BY TELEPHONE. 

.NT1 NEW ENGLAND WATERS... 
.GULF OF MAINE...HURCN SAT INTO SUN. 
.GEORGES BANK...HURCN SAT INTO SUN. 
.S OF NEW ENGLAND...HURCN SAT. 

.NT2 MID ATLC WATERS... 
.HUDSON TO BALT CNYN...HURCN SAT. 
.BALT CNYN TO HAGUE LINE...HURCN SAT. 
.BALT CNYN TO HATTERAS CNYN...HURCN FRI NGT INTO SAT. 
.HATTERAS CNYN TO CAPE FEAR...HURCN FRI INTO SAT. 
.CAPE FEAR TO 31N...TRPCL STORM TNGT INTO FRI NGT. 

.FORECASTER OSZAJCA/ROWLAND. OCEAN FORECAST BRANCH.