Marine Interpretation Message
Issued by NWS

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000
AGNT40 KWNM 291246
MIMATN

MARINE WEATHER DISCUSSION FOR N ATLANTIC OCEAN
NWS OCEAN PREDICTION CENTER WASHINGTON DC
846 AM EDT SAT AUG 29 2015

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

A HIGH PRES RIDGE INVOF 40N IS MAINTAING LITE WINDS (GRNLY 10 KT
OR LESS) ACRS THE NRN WTRS. FURTHER S A STNRY FRONT PERSISTS ACRS
THE SRN NT2 WTRS WITH MAX ASCD WINDS NO HIGHER THAN 15 OR 20 KT AT
MOST PRETTY MUCH AS PREVLY FCSTD. MAX SEAS THRUT ALL THE WTRS ARE
ONLY IN THE 3-5 FT RANGE WHICH ARE BEING HANDLED EQUALLY WELL BY
THE 06Z WAVEWATCH III AND 00Z ECMWF WAM MDLS AT THE MOMENT.

OVER THE SHORT TERM...THE LATEST MDLS FCST THE QUIET PATTERN TO
PERSIST. A BLENDED 06Z/00Z GFS AND 00Z ECMWF SOLUTION LOOKS RSNBL
FOR A WEAK SFC LOW DVLPG ON THE STNRY FRONT AND TRACKING NE ACRS
THE SRN/CNTRL NT2 WTRS TODAY INTO EARLY SUN WITH MAX ASCD WINDS
RMNG IN THE 15-20 KT RANGE. OTHERWISE THE MDLS ARE IN GOOD AGRMT
THAT THE HIGH PRES RIDGE WL DRIFT S INTO THE SRN NT2 WTRS SUN NITE
WITH A WEAK (10-20 KT) WSWLY GRADIENT DVLPG TO ITS N ACRS THE NRN
WTRS. SO SEE NO REASON TO REPOPULATE THE PREVLY USED 00Z GFS 10M
BL WINDS THRU SUN NITE AND WL JUST MAKE SM MINOR INSIG TWEAKS.

IN THE LONG RANGE...PER THE JUST COMPLETED CONFERENCE CALL WITH
NHC AND THEIR PREVLY FCSTD TRACK...FORMER T.S. ERIKA SHULD POSE
NO DIRECT IMPACTS ON THE OFSHR WTRS. OTHERWISE THE 06Z GFS REMAINS
CONSISTENT VS THE SMLR 00Z GFS/ECMWF SOLUTIONS WITH THE MAIN LONG
RANGE FEATURES WHICH ARE EXPECTED TO BE WEAK COLD FRONTAL PASSAGES
ACRS THE NRN WTRS MON NITE/EARLY TUE AND AGAIN ACRS THE FAR NRN
WTRS WED NITE. SO WL STAY THE COURSE WITH THE PREVLY USED 00Z GFS
10M BL WINDS THRU WED NITE AND WL AGAIN MAKE ONLY SM MINOR CHNGS.



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

THE MAIN CONCERN OVR THE OFF WTRS DURING THE NEXT FEW DAYS WILL
CONT TO BE THE FUTURE TRACK AND INTENSITY OF T.S. ERIKA. PLS
CLOSELY MONITOR THE LATEST ADVISORY FROM THE NATIONAL HURRICANE
CENTER.

SHORT TERM...A STNRY FRONT WILL PREVAIL FROM THE FAR SE U.S.
COAST NE OVR NT2 WTRS TODAY INTO SUN. A WEAK LOW IS FCST TO FORM
AND MOVE NE ALONG THE FRONT THIS AFTN INTO SUN. HIGH PRES WILL
DOMINATE NT1 AND NW NT2 OFF WTRS INTO MON. MDLS REMAIN IN
EXCELLENT AGREEMENT IN THE SHORT TERM. WE WILL REMAIN CLOSE TO THE
00Z GFS 10M WINDS FOR THE OFF WTRS FCST TODAY INTO MON...WITH
LITTLE CHANGE FROM THE PAST FEW OPC FCSTS. INITIALLY WE WILL ADJ
WINDS SLIGHTLY HIGHER OFF THE GEORGIA AND CAROLINA COASTS BASED ON
A LATE EVE ASCAT PASS AND OBS OVR THE REGION...BUT OTW REMAIN
CLOSE TO THE 00Z GFS MDL OUTPUT IN THE SHORT TERM. THE LATEST FCST
TRACK OF T.S. ERIKA FROM NHC KEEPS THE SYSTEM WELL TO THE S AND
SW OF THE WTRS...NR THE FLORIDA KEYS AND JUST OFF THE W COAST OF
FLORIDA...SUN INTO MON...WITH NO IMPACT ON OUR OFF WTRS EXPECTED
AT THIS TIME INTO EARLY MON. THE LATEST SATELLITE IMGRY AND
LIGHTNING DATA CONTINUES TO SHOW A FEW SCTD SHWRS AND TSTMS NR
THE STNRY FRONT OVR SRN AND CENTRAL NT2 OFF WTRS. THIS ACTIVITY
WILL PERSIST TODAY INTO SUN...WITH A THREAT FOR LOCALLY GUSTY
WINDS AND ROUGH SEAS IN OR NEAR THE HEAVIER TSTMS.

LONG TERM...A COLD FRONT WILL MOVE OFF THE NEW ENGLAND AND MID
ATLC COASTS LATE MON INTO TUE...FOLLOWED BY HIGH PRES BUILDING OVR
THE WTRS LATE TUE INTO WED. THE HIGH WILL WEAKEN OVR NT2 WTRS LATE
WED AND WED NITE AS THE NEXT COLD FRONT APPROACHES THE NEW ENGLAND
COAST LATE WED...AND MOVES OFFSHORE WED NITE. BASED ON THE LATEST
ADVISORY FROM THE NHC...T.S. ERIKA IS FCST TO MOVE FROM JUST OFF
THE W COAST OF FLORIDA MON NITE TO THE FLORIDA PANHANDLE LATE TUE
NITE OR WED...AND THEN WEAKEN TO A T.D. OVR FAR SW GEORGIA WED
NITE. BASED ON THIS FCST TRACK...NO SIG IMPACT IS EXPECTED OVR
THE OFF WTRS IN THE LONG TERM PORTION OF THE FCST. WE WILL REMAIN
CLOSE TO THE 00Z GFS 10M WINDS FOR LATE MON INTO WED NITE...AS
THE 00Z GFS IS VERY SIMILAR TO THE 00Z ECMWF AND UKMET MDLS.

CONFDC LVLS IN THE EARLY AM OFF FCST ARE NEAR AVERAGE AS THE 00Z
MDLS APPEAR TO BE COMING INTO BETTER AGREEMENT OVR THE REGION.

.SEAS...BOTH THE 00Z WNA WV WATCH III AND 00Z ECMWF WAM APPEAR TO
HAVE INTIALIZED A FT OR TWO ON THE LOW SIDE OFF THE GEORGIA AND S
CAROLINA COASTS BASED ON THE LATEST OBS AND EARLIER ALTIMETER
PASS. OTW...BOTH WV MDLS REMAIN QUITE SIMILAR THRU WED NITE OVR
THE REGION. THEREFORE WE WILL USE A 50-50 BLEND OF THESE TWO WV
MDLS FOR THE EARLY AM PACKAGE...AND ADJUST SEA HTS OFF THE SE
U.S. COAST UPWARD SLIGHTLY TO FIT CURRENT CONDITIONS.

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


.WARNINGS...PRELIMINARY.

.NT1 NEW ENGLAND WATERS...
     NONE.

.NT2 MID ATLC WATERS...
     NONE.

$$

.FORECASTER VUKITS/MILLS. OCEAN PREDICTION CENTER.


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