Marine Interpretation Message
Issued by NWS

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AGNT40 KWNM 120046
MIMATN

MARINE WEATHER DISCUSSION FOR N ATLANTIC OCEAN
NWS OCEAN PREDICTION CENTER WASHINGTON DC
846 PM EDT FRI JUL 11 2014

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

GOES IR/VIS IMGRY INDC A WK FRNTL BNDRY ACRS NT2 ATTM...AND THE WV
IMGRY INDC A WK UPR TROF BEHIND THE ALNG THE COAST. THE LGTNG DATA
INDC TSTM ACTIVITY IN THE UNSTABLE ENVRMT S AND E OF THE
FRNT...MANLY OVR THE WARMER WATERS OF THE GLF STRM. THE ASCAT DATA
FM ABT 15Z THIS AFTN IS ALSO INDICATIVE OF THE CNVCTV
ACTVTY...WITH WNDS UP TO 20 KT OVR MOST OF THE OFSHR WTRS...AND
A FEW RAIN-FLAGGED INVOF OF THE STG MXG WITH THE TSTMS. THE PREV
FCST HAD TSTMS AHD OF THIS BNDRY FOR TNGT INTO SAT...WHICH STILL
LOOKS GOOD...SO WL CONT IN THE UPDATE PKG.

THE 12Z/18Z MDLS AGREE FAIRLY WELL IN THE SHORT TERM...AND
MAINTAIN A WK UPR RDG TO THE E OF THE OFSHR WTRS WITH A GENLY
MERIODIONAL FLOW. THE MDLS INDC A WK DISTURBANCE ALONG THE FRNTL
BNDRY WL MAINTAIN A WK FRNTL WAVE...BUT WNDS ARE XPCTD TO RMN
MOSTLY VRNL AND LESS THAN 15 KT OVR THE OFSHR WTRS WITH HIGH PRES
BLDG IN FM THE W.

THE BIGGEST FCST PRBLM RMNS THE SW FLOW AHD OF THE NEXT FRNTL
BNDRY APRCHG THE AREA STARTING LATE SUN INTO EARLY NEXT WEEK. THE
GFS IS A BIT OF AN OUTLIER WITH HANDLING THE UPR ENERGY
DIFFERENTLY...AND KEEPS THE NEXT UPR TROF IN ONE PIECE AS THE REST
OF THE GUID SPLITS IT INTO 2 PARTS AS IT MOVES INTO THE ERN
CONUS MON INTO TUE. AT THE SFC...THE GFS IS A BIT FASTER THAN THE
REST OF THE MDLS WITH THE ASSOC FRNTL BNDRY...AND INCRS THE WNDS
OVR THE OFSHR WTRS IN SW FLOW FASTER. THE GFS ALSO INDC ABT 30 KT
IN SW FLOW OVR THE CD SHELF WTRS N OF THE GULF STREAM...BUT THIS
SEEMS A BIT STG FOR THIS TIME OF YEAR...ESP OVR AN AREA THAT IS
FAIRLY STABLE. THE PREV FCST FAVORED THE 12Z ECWMF/UKMET
SOLN...WHICH KEEP WNDS 25 KT OR LESS. IN ADDITION...THE PREV FCST
WENT NO HIGHER THAN 22 KT...AS RECENT SITUATIONS SIMILAR TO THE
CRNT ONE INDC MDL WNDS HAVE A HIGH BIAS IN GENL. ATTM NOT PLANNING
ON MKG ANY SIG CHANGES FM THE PREV FCST...WHICH SEEMS VRY RSNBL
ATTM...AND WL CONT WITH THE ECMWF/UKMET BLEND FOR THE FCST IN THE
EXTENDED PD.

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

QUIET CLIMATOLOGICAL OR SEASONAL CONDS WILL CONTINUE TO PREVAIL  ACROSS
THE WRN ATLC THROUGH THE FCST. UPR HIGH NR 40N50W WILL RMN NEARLY
STNRY THRU THE FCST PERIOD

WEAK NE TO SW STNRY FRONT XTNDG FM JUST W OF SABLE ISLAND TO NEAR
THE VA CAPES WILL MOVE LTTL AND GRADU DSIPT OVER THE NEXT 24 TO 48
HRS. N OF THE FRONT...LGT AND VRBL WINDS WILL GRADU BCN S TO TO SW
LATE SAT INTO SUN. NEXT FTR TO AFFECT THE WATERS IS APPCHNG COLD
FRONT...FCST TO MOV TO NR THE COAST BY 12Z WED. EXCPET S TO SW
WINDS TO SLOWLY INCRS LATE SUN AND MON. THE GFS10M/ECMWF/UKMET
WINDS ARE IN GD AGRMNT ON WINDS INCRSNG TO 20 KT N OF HTTRS CNYN
BY LATE SUN AND WITH MAINLY S TO SW 15 TO 20 20 KT CONTG THRU MON.
SOME MINOR MODEL DISAGRMNT NOTED WITH THE SPEED OF THE ADVCNG COLD
FRNT TUE...AS THE GFS IS A BIT FASTER. IF THE NEW ECMWF FLLWS...
WILL STAY WITH GFS BUT OTW WILL BLEND GFS WITH UKMET OR ECMWF FOR
TUE ONWARD. THE GFS INCRSES WINDS TO 25 KT BY EARLY TUE. RECENT
SRLY FLOW EVENTS HV BN OVERDN BY THE MODEL...SO WL CAP WINDS AT 22
KT N OF THE GULF STREAM. JUST SAW THE NEW ECMWF. CORDNATN WITH OPC
OUTLOOK DESK...WILL USE UKMET FOR TUE AND WED.

.SEAS...E 12Z MULTIGRID WAVEWATCH III INITILIZED WELL THIS MRNG.
GUIDANCE LOOKS GOOD THRU SUN NGT...THEN APPEARS OVERDONE OVER THE
NTHRN WATERS IN THE SRLY FLOW. WL TRIM BACK THE WAVE MODEL BY 10
TO 20 PCT FM MON ONWARD.

.EXTRATROPICAL STORM SURGE GUIDANCE...

.WARNINGS...PRELIMINARY.

.NT1 NEW ENGLAND WATERS...
     NONE.

.NT2 MID ATLC WATERS...
     NONE.

$$

.FORECASTER KELLS/PROSISE. OCEAN PREDICTION CENTER.



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