weather.gov     
National Weather Service

Marine Interpretation Message
NWS Homepage
This page is being discontinued on March 12, 2014.
The same data is available at this site. Please update your bookmarks.
Thank you, and we apologize for the inconvenience.
Please send an email to SR-SRH.Webmaster@noaa.gov with any concerns.


Current Version
Previous Version:    01  02  03  04  05  06  07  08  09  10  11  12  13  14  15  16  17  18  19  20  21  22  23  24  25  26  27  28  29  
[Printable]
998
AGNT40 KWNM 301833
MIMATN

MARINE WEATHER DISCUSSION FOR N ATLANTIC OCEAN
NWS OCEAN PREDICTION CENTER WASHINGTON DC
233 PM EDT TUE SEP 30 2014

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

THE 12Z SFC ANALYSIS INDICATED A WEAKENING STATIONARY FRONT OVER
THE NT1 WATERS...WITH WEAK LOW PRES OVER THE SRN NT2 WATERS AND
ANOTHER JUST NW OF BERMUDA. MORNING ASCAT PASS WITH DECENT
COVERAGE OVER THE OFFSHORE WATERS INDICATED WINDS MOSTLY 20 KT OR
LESS...WITH A SWATH OF 20 TO 25 KT WINDS INDICATED OVER THE GULF
OF MAINE. THE MODELS ALL INITIALIZED THESE WINDS TOO LOW OVER THE
GULF OF MAINE BY ABOUT 10 KT...AND ALSO EXPLAINS WHY SEAS WERE
ABOUT 2 TO 3 FT HIGHER THAN MWW3 MODEL.

THE MODELS ARE REASONABLY CLOSE THROUGH ABOUT 24 HOURS...THEN
DIFFERENCES BEGIN TO APPEAR AND CONTINUE THROUGH THE REMAINDER OF
THE PERIOD WITH THE MOST NOTICEABLE DIFFERENCES BEING THE HANDLING
OF LOW NW OF BURMUDA. THE 12Z GFS HAS TRENDED FURTHER W
AGAIN...SIMILAR TO THE 06Z RUN AND CONSIDERABLY FURTHER W THAN THE
00Z GFS. THE CMC AND NAM ARE THE MOST SIMILAR TO THE 12Z GFS...AND
ALL ARE REASONABLY CLOSE WITH THE LOW POSITION AND INTENSITY
DURING THE 36 TO 84 HOUR PERIOD. LOOKING AT THE GFS ENSEMBLE
MEMBERS...A GOOD PORTION OF THE MEMBERS ARE EVEN FURTHER W WITH
THE LOW POSITION THAN THE OPERATIONAL RUN WHICH STRENGTHENS THE
CASE FOR INTRODUCING GALES INTO THE ERN PORTIONS OF OFFSHORE
WATERS THU INTO THU NIGHT. DURING THE EXTENDED PERIOD...THE MODELS
ARE ALL IN AGREEMENT MOVING COLD FRONT OFFSHORE LATE FRI NIGHT
INTO SAT. THE GFS CONTINUES TO BE SLIGHTLY FASTER THAN THE OTHER
MODELS. FOR THE SHORT TERM PERIOD...PLAN ON POPULATING GRIDS USING
THE 12Z GFS 30M WINDS...THOUGH AS USUAL WILL MAKE FINAL
DETERMINATION ON GRIDS AFTER 12Z ECMWF IS AVBL. FOR THE EXTENDED
PERIOD BEGINNING 12Z SAT AND BEYOND...WILL USE THE ECMWF WINDS TO
ACCOUNT FOR THE SLOWER FRONTAL PASSAGE.

.SEAS...THE 15Z SEA STATE ANALYSIS INDICATED OBSERVED SEAS WERE
MOSTLY WITHIN A FT OF THE MWW3. SINCE WILL BE USING THE GFS WIND
GRIDS INITIALLY...WILL USE THE MWW3 VALUES THROUGH 12Z SAT...THEN
WILL TRANSITION TO THE ECMWF WAM FOR THE REMAINDER OF THE PERIOD.

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

.WARNINGS...PRELIMINARY.

.NT1 NEW ENGLAND WATERS...
.ANZ800...GULF OF MAINE...
     GALE POSSIBLE THU NIGHT.
.ANZ900...GEORGES BANK EAST OF 68W...
     GALE THU.
     GALE POSSIBLE THU NIGHT.

.NT2 MID ATLC WATERS...
.ANZ905...THE GREAT SOUTH CHANNEL TO THE HAGUE LINE...
     GALE POSSIBLE THU NIGHT.

$$

.FORECASTER KOSIER. OCEAN PREDICTION CENTER.




U.S. Dept. of Commerce
NOAA National Weather Service
1325 East West Highway
Silver Spring, MD 20910
E-mail: w-nws.webmaster@noaa.gov
Page last modified: May 16, 2007
NATIONAL WEATHER SERVICE: for Safety, for Work, for Fun - FOR LIFE