

088 

AGNT40 KWNM 141218

MIMATN



MARINE WEATHER DISCUSSION FOR N ATLANTIC OCEAN

NWS OCEAN PREDICTION CENTER WASHINGTON DC

818 AM EDT SUN AUG 14 2016



.FORECAST DISCUSSION: MAJOR FEATURES/WINDS/SEAS/SIGNIFICANT

.WEATHER FOR THE NORTH ATLANTIC OCEAN W OF 50W FROM 30N TO 50N.



UPDATE...06Z NCEP SFC ANALYSIS SHOWS A STATIONARY FRONT EXTNDG

ROUGHLY SE TO NW ACROSS THE GULF OF MAINE...WITH A HIGH PRES RIDGE

OVER THE NT2 WTRS AND ANOTHER RIDGE BUILDING SE TOWARDS THE GULF

OF MAINE. LATEST AVAILABLE ASCAT HI-RES AND ASCAT PASSES FROM LAST

NITE SHOW A COUPLE OF AREAS OF WINDS TO 20 KT IN SW FLOW OVER THE

N AND NE PARTS OF THE NT2 WTRS...WITH LIGHT WINDS OF 15 KT OR LESS

OVER THE REMAINING OFSHR WTRS. LIGHTNING DENSITY PRODUCT DATA AT

1100Z SHOWS AN AREA OF SHOWERS OVER THE MASSACHUTSETTS COASTAL

WTRS AND THE SW PART OF THE GULF OF MAINE.



MAIN WEATHER FEATURES...A WEAK LOW WILL MOVE SE TODAY...PASS JUST

N OF THE NT1 AREA THIS EVENING...THEN ACCELERATE OFF TO THE E

TONITE AND MON. THE LOW WILL PULL A COLD FRONT SE OVER THE NT1 AND

NRN NT2 WTRS TONITE AND MON. A HI PRES RIDGE WILL BUILD OVER THE

NT1 WTRS LATE MON AND MON NITE...THEN MOVE E ACROSS THE NT1 AREA

TUE. ANOTHER LOW WILL PASS E OVER THE NRN NT1 WTRS TUE NITE INTO

WED...THEN ACCELERATE OFF TO THE E LATE WED AND WED NITE. A LOW

PRES TROF WILL APPROACH THE COAST WED NITE...THEN MOVE OFSHR INTO

THE NT1 AND NRN NT2 WTRS THU AND THU NITE.



MODELS...THE MED RNG MDLS ARE IN VERY GOOD OVERALL AGREEMNT ACROSS

THE OFSHR WTRS FOR TODAY INTO EARLY TUE. THE GFS IS SIGNIFICANTLY

SLOWER AND WEAKER THAN THE OTHER MDLS WITH THE SECOND LOW FOR

LATER TUE INTO THU...WHILE THE GEM IS SOMEWHAT WEAKER WITH THE LOW

THAN ARE THE ECMWF/UKMET MDLS WHICH ARE IN VERY GOOD AGREEMNT. THE

ECMWF STILL LOOKS LIKE THE MOST REPRESENTATIVE AND CONSISTENT OF

THE MDLS...SO IT WILL BE USED FOR THE WIND GRIDS FOR THE ENTIRE

FCST PERIOD. AM NOT PLANNING TO MAKE ANY SIGNIFICANT CHANGES TO

THE CURRENT FCST TREND.



SEAS...THE 09Z RA1 SEA STATE ANALYSIS INDICATES OBSERVED SEA HTS

CONTINUE TO MATCH UP WELL WITH THE WNA WAVEWATCH III AND ECMWF

WAM. IN ORDER TO STAY CONSISTENT WITH THE PREFERRED ECMWF

SOLN...AM GOING TO USE THE ECMWF WAM FOR THE WAVE HT GRIDS FOR THE

ENTIRE FCST PERIOD.



EXTRATROPICAL STORM SURGE GUIDANCE...N/A.



-----------------------------------------------------------------

PREVIOUS DISCUSSION...



THE 00Z SFC ANALYSIS INDICATED A STATIONARY FRONT EXTENDING ACROSS

THE GEORGES BANK OFFSHORE WATERS...WITH HIGH PRES RIDGE EXTENDING

ACROSS THE NT2 WATERS. ASCAT AND RSCAT PASSES FROM LATE SAT

EVENING INDICATED WINDS 20 KT OR LESS OVER THE ENTIRE OFFSHORE

WATERS AREA. SATELLITE IMAGERY AND LIGHTNING DATA INDICATE A FEW

TSTMS OVER NRN PORTION OF GULF OF MAINE WATERS.



THE 00Z MODELS CONTINUE TO BE IN VERY GOOD AGREEMENT DURING THE

SHORT TERM PERIOD FROM TODAY INTO WED. ALL OF THE MODELS INDICATE

LOW PRES PASSING N OF LATER TODAY AND TONIGHT WITH A WEAK COLD

FRONT PASSING SE ACROSS THE NT1 WATERS TONIGHT INTO MON BEFORE

STALLING OVER THE FAR SRN NT1 WATERS LATE MON AS HIGH PRES BUILDS

ACROSS THE NT1 WATERS TUE AND TUE NIGHT. LOOKING AHEAD TO WED AND

BEYOND...THE GFS CONTINUES TO BE AN OUTLIER SIMILAR TO PAST FEW

MODEL RUNS WITH TIMING OF NEXT LOW TO MOVE OFF THE NE COAST LATER

IN WEEK. THERE CONTINUES TO BE DECENT AGREEMENT WITH THE

ECMWF/UKMET/CMC...AND PLAN ON STAYING WITH THE ECMWF AS IT HAS

SHOWN GOOD CONSISTENCY. WILL CONTINUE TO USE THE ECMWF TO

POPULATE WIND GRIDS DURING THE PERIOD.



.SEAS...THE 06Z SEA STATE ANALYSIS INDICATED THAT OBSERVED SEAS

CONTINUE TO MATCH UP WELL WITH THE MWW3/ECMWF WAM. SIMILAR TO THE

WIND GRIDS...WILL ALSO USE THE ECMWF WAM TO POPULATE WAVE HEIGHT

GRIDS DURING THE PERIOD.



.EXTRATROPICAL STORM SURGE GUIDANCE...



.WARNINGS...PRELIMINARY.



.NT1 NEW ENGLAND WATERS...

     NONE.



.NT2 MID ATLC WATERS...

     NONE.



$$



.FORECASTER SCOVIL/KOSIER. OCEAN PREDICTION CENTER.

