Marine Interpretation Message
Issued by NWS

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
AGNT40 KWNM 290110
MIMATN

MARINE WEATHER DISCUSSION FOR N ATLANTIC OCEAN
NWS OCEAN PREDICTION CENTER WASHINGTON DC
810 PM EST SUN DEC 28 2014

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

GOES IR IMGRY INDC A FRNTL BNDRY OVR NT1...AND ASCAT FM EARLIER
TDA AT 15Z INDC WNDS TO 30 KT IN THE SW FLOW AHD OF THE
BNDRY...MAINLY IN THE UNSTABLE ENVRMT OVR THE GLF STRM. CRNT SFC
RPRTS INDC UP TO 25 KT IN THE OFSHR WTRS...AS THE LOW AND THE
STGST WINDS HAVE MOVED OF THE AREA. THE GFS INDC A FEW 30 KT WINDS
OVR THE FAR NE NT2 WTRS AT 00Z...THEN DCSRS WINDS QUICKLY TNGT AS
THE SYS MOVES OFF QUICKLY TO THE E IN THE PRGRSV PTTN OVR THE W
ATLC. THE 18Z/12Z MDLS AGREE FAIRLY WELL ON THE SHORT TERM
PTTN...SO NOT PLANNING ON MKG ANY MAJOR CHANGES TO THE SHORT TERM
FCST.

OTRW THE 18Z GFS HAS NOT CHANGED MUCH FM 12Z RUN THRUT THE FCST
PD...AND CONT TO INDC A FEW WK FRNTL WAVES MON INTO TUE. 12Z MDLS
NOW IN DECENT AGRMT WITH THE WAVES...LMTG DVLPMT UNTIL LOWS PASS E
OF THE OFSHR WTRS. IN ADDITION...MDLS STILL HVG DIFFICULTY
RESOLVING SHRTWV ENERGY PASSING TO THE N OF THE OFSHR WTRS...WHICH
IMPACTS THE DVLPMT OF SFC FEATURES THRU THE AREA...MAINLY OVR NT1
AND NRN NT2...ESP IN THE EXTENDED PD. THE PREV FCST FAVORED A
BLEND OF THE GFS AND ECWMF...WHICH SEEMS STILL TO BE A RSNBL
CMPRMS...SO WL CONT IN THE UPDATE PKG.

SEAS...GUID A CPL FT LOW E OF THE OFSHR WTRS IN THE CAA S OF THE
LOW OVR NEWFOUNDLAND. WL CONT TO BUMP UP SEAS OVR FAR NE NT2 IN
THE SHORT TERM.

-----------------------------------------------------------------
PREVIOUS DISCUSSION...

1430Z AND 15Z HIGH RES ASCAT OVERPASSES RETURNED SW 25 TO 30 KT
EXTENDING FROM NE OF HATTERAS CNYN N TO NEAR 1000 FM...AND ALSO
OVER GULF OF MAINE. LARGEST EXPANSE OF 30 KT OVER SERN PORTION
ANZ920 WHERE SSTS IN 23C TO 25C RANGE. 12Z MODELS ALL HAVE A
DECENT HANDLE INITIALLY...WITH THE 12Z GFS 30M WINDS LIKELY BEST
OVER AREAS WITH HIGHEST WINDS. HIGHER PRE FRONTAL WINDS WILL
SHIFT S TONIGHT AHEAD OF BOUNDARY. AS FRONT SLOWS OFF CAPE
LOOKOUT WILL LIMIT ASSOCIATED WINDS TO 25 KT PER GFS/ECMWF/
PARALLEL GFS. MODELS ARE THEN IN MUCH BETTER AGREEMENT THAT
YESTERDAYS RUNS WITH DVLPMNT OF SFC LOWS ALONG FRONT AND TRACKS
THROUGH MID ATLC WATERS MON INTO TUE. UPPER SHRTWV CURRENTLY
OVER S TX SHOULD SHEAR AS IT MOVES ENE AND PASSES E OF LOWER MS
VALLEY AND TOWARD MID ATLC COAST TONIGHT INTO MON NIGHT. OVER
PAST COUPLE DAYS MODELS HAVE CONSISTENTLY BEEN TRENDING WEAKER.
WITH THESE FEATURES WILL AGAIN CAP WINDS AT 25 KT WHICH
MAINTAINS OPC CONTINUITY. MODELS THEN CONTINUE TO HAVE
DIFFICULTY WITH TIMING AND STRENGTH OF UPPER SHRTWVS IN
PROGRESSIVE FLOW. 12Z ECMWF AND 12Z GFS ARE IN BETTER AGREEMENT
THO WITH MODERATELY AMPLIFIED UPPER SHRTWV THRU NEW ENGL WED
NIGHT INTO THU AT WHICH TIME W WINDS AT SFC WILL INCREASE AGAIN
TO 25 OR 30 KT NEW ENGL WATERS AT THAT TIME. THEN AT WEEKS END
PREFER THE MORE PROGRESSIVE GFS OR PARALLEL GFS WHICH INDICATE
RETURN FLOW OFFSHORE LATE FRI NIGHT AND EARLY SAT WHICH IS
FASTER THAN ECMWF SHOWS AND IS BETTER SUPPORTED BY GEFS AND
ECMWF EPS MEANS.

SEAS...BUOYS OFF DOWN EAST MAINE COAST HAVE BEEN REPORTING IN 7
TO 10 FT RANGE LAST COUPLE HRS WHICH IS SEVERAL FT HIGHER THAN
EITHER 12Z MULTIGRID WAVEWATCH III OR 12Z ECMWF WAVE MDL. AFTER
THESE INITIAL ADJUSTMENTS THE 12Z MWW3 LOOKS REASONABLE THRU
REMAINDER OF FORECAST.

.EXTRATROPICAL STORM SURGE GUIDANCE...N/A


.WARNINGS...PRELIMINARY.

.NT1 NEW ENGLAND WATERS...
     NONE.

.NT2 MID ATLC WATERS...
     NONE.

$$

.FORECASTER KELLS/CLARK. OCEAN PREDICTION CENTER.


USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.