Marine Interpretation Message
Issued by NWS

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AGNT40 KWNM 300124
MIMATN

MARINE WEATHER DISCUSSION FOR N ATLANTIC OCEAN
NWS OCEAN PREDICTION CENTER WASHINGTON DC
924 PM 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.

THE 18Z GFS AND NAM MDL GUID SHOW LITTLE CHANGE FROM THEIR 12Z
COUNTERPARTS. THE 00Z PRELIM OPC SFC ANALYSIS SHOWS A WEAK LOW
PRES AREA LOCATED ABOUT 75 NM SE OF CAPE HAT...MOVG NE...WITH AN
ASSOC NEARLY STNRY FRONT EXTENDING NE AND SW FROM THE LOW CENTER.
HIGH PRES IS MOVG E FROM NEAR 38N65W...OR JUST E OF THE NE NT2 OFF
WTRS THIS EVE. FOR THE EVE FCST UPDATE LITTLE CHANGE APPEARS
NEEDED FROM THE AFTN PACKAGE. WE WILL MAKE ONLY A MINOR TWEAKS
TO THE PREV FCST TO FIT CURRENT CONDITIONS AND NEARBY COASTAL AND
TAFB FCSTS...BUT OVERALL NO MAJOR CHANGES APPEAR NEEDED AT THIS
TIME. THE LATEST LIGHTNING STRIKE DATA AND SATELLITE IMGRY
INDICATES JUST A FEW SCTD SHWRS AND TSTMS OVR SRN AND CENTRAL NT2
OFF WTRS NR THE LOW AND ASSOC FRONT. THIS ACTIVITY WILL PERSIST
OVR THESE WTRS OVR THE NEXT DAY OR TWO WITH LOCALLY GUSTY WINDS
AND ROUGH SEAS PSBL NR THE HEAVIER TSTMS.

SEAS...SEA HTS RANGE FROM 3 TO 5 FT OVR THE OFF WTRS THIS EVE PER
THE 00Z RA1 SEA STATE ANALYSIS. AGAIN...NO MAJOR CHANGES TO THE
PREV FCST APPEAR NEEDED FOR THE EVE UPDATE.

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

OVER THE SHORT TERM...SEE NO APPRECIABLE CHNGS IN THE NEW 12Z
MDLS AS THEY ALL FCST THE CURRENT QUIET PATTERN TO PERSIST. THE
MDLS CONT TO FCST A WEAK SFC LOW NOW NR 33N76W...WHICH A 1521Z
ASCAT-B PASS CONFIRMED HAD MAX ASCD WINDS GNRLY IN THE 15-20 KT
RANGE...WL TRACK NE ALONG A STNRY FRONT TONITE...THEN PASS E OF
THE CNTRL NT2 WTRS SUN WITH LTL CHNG IN FCST STRENGTH. THEN THE
12Z MDLS REMAIN CONSISTENT AND SHARE SMLR FCST TIMING FOR THE NEXT
SIG SHORT TERM FEATURE BEING A COLD FRONT MOVG TO NR THE NEW ENGLD
COAST LATE MON...THEN PUSHING SSE ACRS THE NT1 WTRS MON NITE WHICH
MAX ASCD WINDS GNRLY IN THE 15-20 KT RANGE. FURTHER S WL DISREGARD
THE 12Z CANADIAN GLOBAL GEM SOLUTION WHICH BRINGS A STRONG SFC LOW
(FRMLY T.S. ERIKA?) NE UP THE SE COAST MON/MON NITE. THEREFORE
PLAN ON POPULATING OUR SHORT TERM FCST WIND GRIDS WITH THE
REPRESENTATIVE 12Z GFS 10M BL WINDS FOR TONITE THRU MON NITE WITH
SM ADDITIONAL MINOR EDITS IN DEFERENCE TO THE SLIGHTLY LOWER 12Z
UKMET/ECMWF BL WINDS. SO AS A RESULT DO NOT ANTICIPATE MAKING ANY
MAJOR SHORT TERM CHNGS TO THE PREV OFSHR FCSTS.

IN THE LONG RANGE...THE 12Z MDLS GNRLY AGREE THAT THE COLD FRONT
WL CONT S ACRS THE NRN NT2 WTRS TUE...THEN STALL ACRS THE CNTRL
NT2 WTRS AND WEAKEN TUE NITE/WED WITH WEAK ASCD GRADIENTS DVLPG.
THE 12Z GFS THEN RMNS CONSISTENT VS ITS PREV RESPECTIVE RUNS IN
FCSTG ANOTHER WEAK COLD FRONT TO PUSH SLOWLY S ACRS THE NT1 WTRS
LATE WED NITE THRU THU NITE. OVERALL THE 12Z UKMET/ECMWF SPRT THIS
12Z GFS SOLUTION FOR THIS FROPA BUT ARE SMWHT WEAKER AND
SLOWER...BUT NOT SIGLY SO. THEREFORE WL CONT TO POPULATE OUR LONG
RANGE FCST WIND GRIDS WITH THE 12Z GFS 10M BL WINDS...WITH AGAIN
SM ADDITIONAL EDITS MAINLY TO TWEAK THE WINDS DOWN SLIGHTLY ACRS
THE NRN WTRS IN DEFERENCE TO THE WEAKER 12Z UKMET/ECMWF SOLUTIONS
ON WED INTO THU NITE.

.SEAS...THE 12Z WAVEWATCH III AND 12Z ECMWF WAM MDLS HV BOTH
INITIALIZED THE CURRENT SEAS WELL. SINCE THE 12Z GFS SOLUTION WL
BE FAVORED FOR THE FCST WINDS...WL POPULATE OUR FCST WAVE GRIDS
WITH THE 12Z WAVEWATCH III FCST SEAS...WHICH NEVER VARY BY MORE
THAN 1-2 FT VS THE SMLR 12Z ECMWF WAM FCST SEAS...THRU THU NITE.

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


.WARNINGS...PRELIMINARY.

.NT1 NEW ENGLAND WATERS...
     NONE.

.NT2 MID ATLC WATERS...
     NONE.

$$

.FORECASTER MILLS/VUKITS. OCEAN PREDICTION CENTER.



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