000
AGXX40 KNHC 190748
MIMATS

MARINE WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
348 AM EDT FRI JUL 19 2013

MARINE WEATHER DISCUSSION FOR THE GULF OF MEXICO...CARIBBEAN
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/ECMWF/OFFICIAL BLEND WITH GOOD CONFIDENCE.
NWPS FOR WAVE HEIGHTS.

A PERSISTENT UPPER LOW IS CENTERED OVER THE N CENTRAL GULF OF
MEXICO...AFTER MIGRATING ACROSS FLORIDA AND THE EASTERN GULF OVER
THE PREVIOUS TWO TO THREE DAYS. IT IS SUPPORTING A SURFACE TROUGH
EXTENDING FROM 26N80W TO 22N95W. ASCAT DATA FROM 03 UTC SHOW THE
SURFACE TROUGH WELL...AND INDICATE FRESH SE FLOW OFF THE WESTERN
COAST OF THE YUCATAN PENINSULA. AREAS OF CONVECTION ARE NOTED OVER
THE N CENTRAL AND EASTERN GULF. THE COUPLED UPPER LOW AND SURFACE
TROUGH WILL MIGRATE THROUGH THE WESTERN GULF THROUGH TONIGHT. A
RIDGE WILL BUILD WEST ALONG 28N THROUGH THE EASTERN GULF THIS
WEEKEND. GLOBAL MODELS ARE IN GOOD AGREEMENT SHOWING GENERALLY
LIGHT FLOW AROUND THE RIDGE ACROSS THE GULF INTO EARLY NEXT
WEEK...WITH OCCASIONALLY MODERATE TO FRESH FLOW NEAR THE YUCATAN
RELATED TO THE NORTHERN PORTION OF TROPICAL WAVE MOVING INTO THE
NW CARIBBEAN AND INTERACTING WITH RESIDENT TROUGHING OVER THE
WESTERN YUCATAN. SHOWERS AND A FEW THUNDERSTORMS WILL BE ACTIVE
OVER THE NW GULF THIS WEEKEND AS THE UPPER LOW DRIFTS W.

...CARIBBEAN SEA AND TROPICAL N ATLANTIC...                    
MODEL PREFERENCE: GFS/ECMWF/OFFICIAL BLEND WITH GOOD CONFIDENCE.
NWPS FOR WAVE HEIGHTS OVER CARIBBEAN.

A TROPICAL WAVE IS MIGRATING W THROUGH THE WINDWARD PASSAGE THIS
MORNING. THE WAVE WILL START TO LOSE DEFINITION AS IT MIGRATES
INTO THE NW CARIBBEAN THROUGH THE WEEKEND. HIGH PRES CENTERED OVER
THE WESTERN N ATLANTIC WILL BUILD N OF THE AREA IN THE WAKE OF THE
WAVE...MAINTAINING FRESH TO STRONG TRADE WINDS OVER MAINLY THE S
CENTRAL CARIBBEAN INTO EARLY NEXT WEEK. SCATTEROMETER DATA AND
SHIP OBSERVATIONS OVER THE PAST SEVERAL HOURS CONFIRM WINDS OF 25
TO 30 KT OFF THE COAST OF COLOMBIA. THE PERSISTENT STRONG TRADE
WIND FLOW WILL ALLOW SEAS TO BUILD AS HIGH AS 13 FT BY SUN OVER
PORTIONS OF THE SW CARIBBEAN. FRESH TRADES ARE ALSO LIKELY ACROSS
THE GULF OF HONDURAS IN THE WAKE OF THE TROPICAL WAVE AS THE RIDGE
BUILDS INTO THE AREA. BUOY AND ALTIMETER DATA SHOW SEAS TO 8 FT IN
PLACE OVER THE TROPICAL ATLC WATERS W OF 55W...WHERE FRESH TRADES
HAVE PERSISTED FOR SEVERAL DAYS. A SECOND TROPICAL WAVE WELL E OF
THE AREA WILL PASS 55W BY EARLY SUN AND MOVE INTO THE LESSER
ANTILLES BY LATE SUN. WINDS ACROSS THE TROPICAL N ATLC W OF 55W
INTO THE EASTERN CARIBBEAN WILL TEMPORARILY DIMINISH TO 15 KT OR
LESS SUN INTO MON AS THE WAVE MOVES ACROSS THE AREA...THEN
INCREASE AGAIN AFTER THE WAVE PASSES. NO SIGNIFICANT CHANGES IN
MODEL OUTPUT OR FORECAST PHILOSOPHY.

...SW N ATLANTIC W OF 55W INCLUDING THE BAHAMAS...               
MODEL PREFERENCE: GFS/ECMWF/OFFICIAL BLEND WITH GOOD CONFIDENCE.

A SURFACE RIDGE EXTENDS ALONG ROUGHLY 28N AND WILL PERSIST INTO
EARLY NEXT WEEK. THIS WILL KEEP WINDS AND SEAS MINIMAL FOR THE
MOST PART N OF 24N WITH THE EXCEPTION OF AMZ111 OFF NE FLORIDA
WHERE FRESH SW FLOW IS EXPECTED BY LATE TODAY BETWEEN THE RIDGE
AND TROUGHING OVER THE SE UNITED STATES. S OF 24N...THE NORTHERN
PORTION OF A TROPICAL WAVE MOVING THROUGH THE WINDWARD PASSAGE IS
INTERACTION WITH THE RIDGE N OF THE AREA TO SUPPORT FRESH TO
OCCASIONALLY STRONG TRADES FROM THE N COAST OF HISPANIOLA INTO THE
SOUTHERN BAHAMAS AND TCI...AND SEAS TO 8 FT THROUGH TONIGHT.
MODERATE TO FRESH E FLOW WILL PREVAIL OTHERWISE S OF 24N THROUGH
EARLY NEXT WEEK...DIMINISHING SLIGHTLY EARLY NEXT WEEK AHEAD OF A
SECOND TROPICAL WAVE APPROACHING THE EASTERN CARIBBEAN. NO MAJOR
DIFFERENCES IN MODEL OUTPUT OR FORECAST PHILOSOPHY.

$$

.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.

.CARIBBEAN 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 CHRISTENSEN. NATIONAL HURRICANE CENTER.