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 291846
MIMATN

MARINE WEATHER DISCUSSION FOR N ATLANTIC OCEAN
NWS OCEAN PREDICTION CENTER WASHINGTON DC
246 PM EDT FRI AUG 29 2014

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

OVER THE SHORT TERM...THE NEW 12Z MDLS PRESENT NO SIG FCST
PROBLEMS. THE MDLS REMAIN IN GOOD AGRMT THAT A HIGH PRES CENTER
WL PASS E ACRS THE NT1 WTRS TONITE...THEN MOVE OFF TO THE E WHILE
HAVING A TRAILING ASCD RIDGE DRIFT SLOWLY S ACRS THE NT2 WTRS SAT
INTO SUN NITE. BY LATE SAT INTO SUN NITE...AS A WEAK COLD FRONT IS
FCST TO APRCH FROM THE NW...TO VARYING DEGREES THE 12Z MDLS ALL
FCST A STRENGTHENING SSWLY GRADIENT TO DVLP N OF THE RIDGE... BCMG
STRONGEST ACRS THE NT1 WTRS. OVERALL THE 12Z GFS SOLUTION LOOKS
RSNBL FOR THIS GRADIENT...THO PER THE 12Z GEFS BLV THE 12Z GFS IS
LIKELY OVERFCSTG THE STRENGTH OF THE POTENTIAL FRONTAL WAVE SUN
NITE WHICH IN TURN CAUSES IT TO STRENGTHEN THE GRADIENT ACRS THE
NT1 WTRS TOO MUCH. THEREFORE PLAN ON POPULATING OUR SHORT TERM
WIND GRIDS WITH THE 12Z GFS 10M BL WINDS THRU SUN...THEN WL
TRANSITION TO THE 12Z ECMWF BL WINDS SUN NITE. SO THE END RESULT
WL BE ONLY SM MINOR SHORT TERM CHNGS BEING MADE IN THE NEXT OFSHR
FCST PACKAGE.

IN THE LONG RANGE...SM SIG DIFFERENCES START TO DVLP BTWN THE 12Z
MDLS. THE 12Z GEM LOOKS LIKE AN OUTLIER SOLUTION ON MON/MON NITE
AS IT FCSTS A FRONTAL LOW TO CROSS THE NRN NT1 WTRS WITH GALE
FORCE ASCD BL WINDS. ALSO THE WEAK FRONTAL WAVE FCST BY THE 12Z
UKMET TO PASS NE ACRS THE NT1 WTRS MON NITE INTO TUE LOOKS
SPURIOUS. THEREFORE WL INSTEAD FAVOR A BLENDED 12Z GFS/ECMWF
SOLUTION...WHICH COME INTO BETTER AGRMT WITH SMLR BL WINDS...OF A
WEAK FRONT BCMG STNRY ACRS THE GULF OF MAINE MON/MON NITE...THEN
DSIPTG TUE WHICH IS IN LINE WITH THE LATEST WPC MEDIUM RANGE
GUIDANCE. THEN BY LATE TUE NITE INTO WED NITE WL CONT TO FAVOR THE
LESS PROGRESSIVE COLD FRONT FCST BY THE 12Z GFS/GEFS MEAN/ECMWF TO
PUSH SE ACROSS THE NT1 AND NRN/CNTRL NT2 VS THE FASTER 12Z
GEM/UKMET SOLUTIONS. THEREFORE PLAN ON CONTG TO POPULATE OUR LONG
RANGE GRIDS WITH THE 12Z ECMWF BL WINDS (WHICH OVERALL ARE VERY
SMLR TO THE 12Z GFS 10M BL WINDS) THRU WED NITE.

.SEAS...OVERALL THE 12Z WAVEWATCH III AND 12Z ECMWF HV BOTH
INITIALIZED THE CURRENT SEAS WELL...INCLUDING THE LONG PERIOD
SSELY SWELL AFCTG THE NRN WTRS LEFTOVER FM CHRISTOBAL. THEREFORE
WL USE A 50/50 BLEND OF THE TWO MDLS THRU SUN...THEN WL TRANSITION
TO AN ALL 12Z ECMWF WAM SOLUTION SUN NITE THRU WED NITE.

.EXTRATROPICAL STORM SURGE GUIDANCE...N/A.

.WARNINGS...PRELIMINARY.

.NT1 NEW ENGLAND WATERS...
     NONE.

.NT2 MID ATLC WATERS...
     NONE.

$$

.FORECASTER VUKITS. 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.