000
AGXX40 KNHC 301905
MIMATS

MARINE WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
305 PM EDT MON SEP 30 2013

MARINE WEATHER DISCUSSION FOR THE GULF OF MEXICO...CARIBBEANBEAN
SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND
64W...AND THE SW N ATLANTIC INCLUDING THE BAHAMAS.

...GULF OF MEXICO...

MODEL PREFERENCE: GFS BLENDED WITH PREVIOUS OFFICIAL GRIDS 
THROUGH DAY 3...THEN GFS/ECMWF BLEND DAYS 4 AND 5. 

WEAK HIGH PRES PREVAILS ACROSS THE BASIN AS A WEAK COLD FRONT 
EXTENDS FROM NE TEXAS TO INLAND THE FAR NE MEXICAN COAST JUST S 
OF BROWNSVILLE. LATEST BUOY DATA AND ALONG PARTIAL ASCAT DATA 
SHOW A RATHER GENTLE E-SE WIND FLOW THROUGHOUT. THE OBSERVATIONS 
SHOW SEAS OF 2-3 FT WITH A SMALL POCKET OF 3-4 FT SEAS NEAR 
267N91W PER A SHIP REPORT THERE. LITTLE OVERALL CHANGES ARE 
EXPECTED INTO TUE NIGHT. STILL THE POTENTIAL PROBLEM RELATES TO 
THE BROAD AREA OF LOW PRES CURRENTLY IN THE WESTERN CARIBBEANBEAN. 
THIS FEATURE IS FORECAST BY THE GLOBAL MODELS TO GRADUALLY MOVE 
NORTHWESTWARD TOWARDS SE GULF WED. THE MODELS DO AGREES THAT 
THIS SYSTEM SHOULD NOT BE ON THE STRONG SIDE AS IT ENTERS THE 
GULF. THE MODELS ARE AGREEING THAT IT WILL MOST LIKELY BE A 
TROUGH FEATURE ONCE ENTERS THE GULF...AND SHOULD REMAIN THAT WAY 
AS IT APPROACHES 89W S OF 24N BY THU. BOTH THE 12 UTC GFS AND 
ECMWF AGREE ON THIS SOLUTION. THE TROUGH SHOULD THEN CONTINUE NW 
TO NEAR 91W THU...HOWEVER A CLOSED CIRCULATION IS POSSIBLE TO 
FORM ON THE TROUGH NEAR 27N. THEN THE TROUGH LOW SHOULD 
TRANSITION TO AN EXTRA-TROPICAL FEATURE SAT AS IT INTERACTS WITH 
A NEW COLD FRONT MOVING INTO THE NW PORTION OF THE GULF.
 
THE COLD FRONT CURRENTLY OVER THE NW WATERS WILL SLOWLY BECOME
STATIONARY AND DIFFUSE THROUGH TUE.

A LLVL VORT LOBE FORECAST BY GLOBAL MODELS TO LIFT OUT ACROSS 
CUBA TONIGHT AND TUE THEN SHIFT MORE WNW ACROSS STRAITS WED AND 
INTO SE GULF WHERE IT IS LIKELY TO MERGE WITH TROUGHING 
ASSOCIATED WITH SW CARIBBEANBEAN LOW. SE LLVL WIND SURGE 15-20 
KT WITH SQUALLS LIKELY TO ACCOMPANY THIS FEATURE ACROSS  
THE BAHAMA BANK AND THROUGH STRAITS OF FLORIDA TUE NIGHT AND WED.

...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 
55W AND 65W...

MODEL PREFERENCE: GFS BLENDED WITH PREVIOUS OFFICIAL FORECAST
 
DEEP LAYERED TROUGHING EXTENDS FROM WRN ATLC SSW ACROSS ERN CUBA 
THEN SW TO DEVELOPING LOW SW OF CAYMANS THEN TUTT TO BELIZE. 
BLOCKING PATTERN TO THE E CONTINUES TO INDUCE BROAD ZONE OF 
MOISTURE CONVERGENCE E OF TROUGH FROM CENTRAL CARIBBEANBEAN NNE ACROSS 
HISPANIOLA. WEAK HIGH PRES PREVAILS E OF THE SURFACE ALONG 79W.  
VERY DEEP CONVECTION IS NOTED WITHIN ABOUT 400 NM E OF THROUGH 
WITH FREQUENT  STRIKES. A VERY DEEP AND MOIST DEEP FETCH 
OF E-SE 15-20 KT WINDS WITH GUSTS TO NEAR 30 KT IN THE 
CONVECTION IS E OF THE TROUGH. WITH THE TROUGH FORECAST TO PULL 
FURTHER AWAY THROUGH THEN NEXT 72 HOURS...THE E-SE FLOW ACROSS 
THE CARIBBEANBEANBEAN WILL EXPAND ACROSS MOST OF THE WESTERN AND 
CENTRAL PORTIONS SEAS ARE EXPECTED TO BE UP TO 8 FT THERE WITH 
BRIEFLY HIGHER SEAS IN TSTM ACTIVITY. 
 
...SW N ATLANTIC INCLUDING THE BAHAMAS...

MODEL PREFERENCE: GFS BLENDED WITH PREVIOUS OFFICIAL FORECAST 
THROUGH DAY 3...THEN 50/50 GFS/ECMWF BLEND DAYS 4 AND 5. 

THE PRELIMINARY 18 UTC ANALYSIS HAS A FRONTAL TROUGH EXTENDING 
FROM 31N66W TO NEAR 26N69W AS WEAK HIGH PRES PREVAILS ELSEWHERE. 
LATEST ASCAT DATA ALONG WITH A FEW SHIP REPORTS INDICATED S-SW 
20-25 KT WINDS OVER THE NE PORTION ASSOCIATED WITH DEEP 
CONVECTION E OF A RATHER VIGOROUS UPPER TROUGH THAT COVERS THE 
CENTRAL PORTION OF THE AREA. THIS ACTIVITY IS FORECAST TO SHIFT 
E OF THE AREA EARLY TONIGHT.

MODERATE PERIOD NE SWELL CONTINUES ACROSS PART OF THE NW PORTION 
AND CENTRAL PORTION WITH SEAS AT 3-5 FT. SEAS ARE EXPECTED TO 
REMAIN ON THE LOW ELSEWHERE THROUGH THE PERIOD. THE 3-5 FT SEAS 
ARE EXPECTED SUBSIDE TUE NIGHT INTO WED. E MOSTLY GENTLE WINDS 
ARE FORECAST TO BE OVER MOST OF THE AREA UNDER RELATIVELY WEAK 
HIGH PRES...EXCEPT IN THE FAR S PORTIONS WHERE MODERATE E WINDS 
CONTINUE THROUGH THE PERIOD. TSTMS AND SQUALLS ARE FORECAST TO 
SPREAD NW FROM THE CARIBBEANBEANBEAN ACROSS WESTERN CUBA AND THE 
STRAITS OF FLORIDA TUE THROUGH THU WITH WITH POSSIBLE GUSTY 
WINDS.

$$

.WARNINGS...ANY CHANGES IMPACTING COASTAL NWS OFFICES WILL BE
COORDINATED THROUGH AWIPS 12 PLANET CHAT OR BY TELEPHONE:

.GULF OF MEXICO...
GMZ011...NONE.
GMZ013...NONE.
GMZ015...NONE.
GMZ017...NONE.
GMZ019...NONE.
GMZ021...NONE.
GMZ023...NONE.
GMZ025...NONE.

.CARIBBEANBEANBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN
55W AND 64W...
AMZ011...NONE.
AMZ013...NONE.
AMZ015...NONE.
AMZ017...NONE.
AMZ019...NONE.
AMZ021...NONE.
AMZ023...NONE.
AMZ025...NONE.
AMZ027...NONE.
AMZ029...NONE.
AMZ031...NONE.
AMZ033...NONE.
AMZ035...NONE.
AMZ037...NONE.
AMZ039...NONE.

.SW N ATLANTIC INCLUDING THE BAHAMAS...
AMZ111...NONE.
AMZ113...NONE.
AMZ115...NONE.
AMZ117...NONE.
AMZ119...NONE.
AMZ121...NONE.
AMZ123...NONE.
AMZ125...NONE.
AMZ127...NONE.

*FOR DETAILED ZONE DESCRIPTIONS PLEASE VISIT:
HTTP://WWW.NHC.NOAA.GOV/ABOUTTAFBPROD.SHTML#OWF

NOTE: GRIDDED MARINE FORECASTS ARE AVAILABLE IN THE
NATIONAL DIGITAL FORECAST DATABASE (NDFD) AT:
HTTP://WWW.NHC.NOAA.GOV/MARINE/GRIDS.PHP

FOR ADDITIONAL INFORMATION PLEASE VISIT:
HTTP://WWW.HURRICANES.GOV/MARINE

$$
.FORECASTER AGUIRRE. NATIONAL HURRICANE CENTER.