000 AGXX40 KNHC 040751 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 351 AM EDT THU JUL 4 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 MODERATE CONFIDENCE. RICH TROPICAL MOISTURE CONTINUES TO STREAM NORTHWARD OVER THE EASTERN GULF...BETWEEN A MID TO UPPER LEVEL TROUGH OVER THE CENTRAL PLAINS AND AN UPPER RIDGE OVER THE WESTERN ATLC OFF THE CAROLINAS. THIS CONTINUES TO BRING AREAS OF THUNDERSTORMS OVER THE EASTERN GULF E OF 90W. THE UPPER TROUGH CONTINUES TO SUPPORT A SURFACE TROUGH FROM THE MOUTH OF THE MISSISSIPPI RIVER TO 25N94W...AND A RELATED SURFACE TROUGH OFF THE COAST OF CAMPECHE IN THE SW GULF. SOUTHERLY WINDS OVER THE EASTERN GULF HAVE INCREASED BETWEEN THE TROUGH AND THE HIGH PRES OVER THE WESTERN ATLC. BUOY 42003 NEAR 26N86W INDICATED A PEAK WIND TO 31 KT WITH SEAS TO 10 FT THIS PAST EVENING. HOWEVER...THIS WAS IN AN AREA OF SHOWERS AND THUNDERSTORMS AND OVERALL WINDS ARE LIKELY 20 TO 25 KT IN THIS AREA. THE GFS STILL REMAINS THE MOST AGGRESSIVE MODEL INDICATING A WEAK LOW FORMING OVER THE LOWER MISSISSIPPI VALLEY TODAY...WITH NEAR GALE FORCE WINDS INTO THE COASTAL WATERS OFF THE WESTERN FLORIDA PANHANDLE. FORECAST REFLECTS A MORE MODERATE BLEND WITH THE ECMWF SHOWING THE OBSERVED FRESH TO STRONG WINDS BUT WITH THE SAME PATTERN. LOCALLY STRONGER SHORT TERM WINDS ARE STILL POSSIBLE GIVEN THE ACTIVE THUNDERSTORM ACTIVITY. SEAS TO 9 FT CAN BE EXPECT EARLY TODAY INTO THE NE GULF...SUBSIDING THEREAFTER AS THE GRADIENT WEAKENS AND WINDS DIMINISH. THERE IS HIGHER CONFIDENCE WITH REGARD TO THE FORMATION OF WEAK LOW PRES IN THE BAY OF CAMPECHE BY LATE TODAY...THEN TRACKING WNW INTO VERACRUZ THROUGH FRI. THE TROUGH OVER THE N CENTRAL GULF IS EXPECTED TO DRIFT INTO THE NW GULF. LOOKING AHEAD...WHILE THERE IS GOOD AGREEMENT IN OPERATIONAL GUIDANCE CONCERNING A CUT OFF UPPER LOW FORMING OVER NE MEXICO BY SUN. THERE HAD BEEN SOME THOUGHT EARLIER OF A RELATED WEAK SURFACE LOW PRES AREA FORMING BY SAT IN THE NW GULF...BUT THE LATEST GUIDANCE HAS BACKED OFF ON THIS. THE GFS STILL INDICATES A WEAK LOW OFF SW LOUISIANA BY SAT NIGHT...MOVING ONSHORE THROUGH SUN...BUT THIS SEEMS AN OUTLIER SOLUTION. OFFICIAL FORECAST CONTINUES TO INCLUDE THIS LOW PRES...BUT DOES NOT DEEPEN THE LOW AS MUCH AS THE CURRENT GFS. SENSIBLE WEATHER WILL NOT VARY MUCH INTO EARLY NEXT WEEK...WITH FRESH SOUTHERLY FLOW OVER MUCH OF THE EASTERN AND CENTRAL GULF AND 4 TO 6 FT SEAS WITH AREAS OF SHOWERS AND THUNDERSTORMS. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC... MODEL PREFERENCE: GFS BLEND WITH PREVIOUS OFFICIAL FORECAST WITH HIGH CONFIDENCE. BUOY OBSERVATIONS AND SCATTEROMETER DATA SHOW FRESH TO STRONG TRADES CONTINUING OVER THE CENTRAL CARIBBEAN...FRESH E TO SE WINDS OVER THE NW CARIBBEAN...AND FRESH NE TO E WINDS OVER TROPICAL N ATLC W OF 55W. BUOY OBSERVATIONS SHOW SEAS TO 8 FT OVER THE CENTRAL CARIBBEAN WHERE WINDS THE WINDS ARE THE STRONGEST. THESE WINDS WILL LIKELY DIMINISH A LITTLE TODAY AS A TROPICAL WAVE MOVES INTO THE CENTRAL CARIBBEAN...THEN INCREASE AGAIN FRI AS THE WAVE MOVES INTO THE WESTERN CARIBBEAN FOLLOWED BY BUILDING HIGH PRES TO THE NORTH. THE WAVE IS SUPPORTED BY AN UPPER LOW MIGRATING E TO W ALONG 23N TO THE NORTH OF AREA. HOWEVER THE EASTERN CARIBBEAN AND TROPICAL N ATLC REMAIN FAIRLY DRY WITH LITTLE TO NO ORGANIZED CONVECTION OUTSIDE ISOLATED LOW TOPPED SHOWERS IN THE FRESH E TRADES. SEAS WILL FLUCTUATE WITH THE WINDS...BUILDING AGAIN UP TO 9 FT OVER PORTIONS OF THE S CENTRAL AND SW GULF THIS WEEKEND. SIMILARLY E TO SE WINDS OVER THE GULF OF HONDURAS WILL REACH UP TO 20 KT THROUGH THE WEEKEND AS THE TROPICAL WAVE ADVANCE INTO THE AREA AND WEAKENED. A SECOND TROPICAL WAVE WILL APPROACH THE TROPICAL N ATLC WATERS W OF 55W BY SUN...AND INTO THE EASTERN CARIBBEAN BY MON FOLLOWED BY FRESH TRADES AND SEAS TO 8 FT. ...SW N ATLANTIC W OF 55W INCLUDING THE BAHAMAS... MODEL PREFERENCE: GFS BLEND WITH PREVIOUS OFFICIAL WITH MODERATE TO HIGH CONFIDENCE. AN UPPER LOW IS MIGRATING WESTWARD ALONG 23N THROUGH THE CENTRAL BAHAMAS...PROVIDING ENOUGH LIFT ON ITS SE QUADRANT TO SUPPORT SCATTERED CONVECTION ACROSS THE TCI AND SOUTHERN BAHAMAS. THE NORTHERN PORTION OF A TROPICAL WAVE OVER THE MONA PASSAGE IS SUPPORTED BY THE UPPER LOW...AND IS SOUTH OF AN ATLC RIDGE EXTENDING FROM BERMUDA TO NE FLORIDA. LATEST SATELLITE...SHIP...BUOY OBSERVATIONS AND SCATTEROMETER DATA SUGGESTED MODERATE TO FRESH WINDS OVER THE SOUTHERN PORTION OF THE AREA WITH GENTLE TO MODERATE WINDS PREVAILING OVER THE REMAINDER OF THE FORECAST AREA. SEAS ARE IN THE 4-6 FT RANGE...EXCEPT W OF THE BAHAMAS WHERE SEAS ARE IN THE 3-5 FT RANGE AND S OF 22N WHERE FRESH TRADES ARE SUPPORT 6 TO 8 FT SEAS. THE RIDGE IS STILL FORECAST TO CHANGE LITTLE THROUGH SAT THEN WEAKEN SUN AND MON.THE UPPER LOW WEAKENS TO A SHARP TROUGH THEN DISSIPATES AS IT SHIFTS W OF THE AREA. ANOTHER UPPER LOW WILL CUT OFF FROM THE MAIN UPPER TROUGH OVER THE CENTRAL ATLC AND MIGRATE W ALONG 23N/24N FROM 55W THROUGH THE CENTRAL BAHAMAS FRI THOUGH SUN...POSSIBLY INCREASING CHANCES FOR CONVECTION ALONG ITS PATH. $$ .WARNINGS...ANY CHANGES IMPACTING COASTAL NWS OFFICES WILL BE COORDINATED THROUGH AWIPS 12 PLANET CHAT OR BY TELEPHONE: .GULF OF MEXICO... GMZ011...NONE. GMZ013...NONE. GMZ015...NONE. GMZ017...NONE. GMZ019...NONE. GMZ021...NONE. GMZ023...NONE. GMZ025...NONE. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... AMZ011...NONE. AMZ013...NONE. AMZ015...NONE. AMZ017...NONE. AMZ019...NONE. AMZ021...NONE. AMZ023...NONE. AMZ025...NONE. AMZ027...NONE. AMZ029...NONE. AMZ031...NONE. AMZ033...NONE. AMZ035...NONE. AMZ037...NONE. AMZ039...NONE. .SW N ATLANTIC INCLUDING THE BAHAMAS... AMZ111...NONE. AMZ113...NONE. AMZ115...NONE. AMZ117...NONE. AMZ119...NONE. AMZ121...NONE. AMZ123...NONE. AMZ125...NONE. AMZ127...NONE. *FOR DETAILED ZONE DESCRIPTIONS PLEASE VISIT: HTTP://WWW.NHC.NOAA.GOV/ABOUTTAFBPROD.SHTML#OWF NOTE: GRIDDED MARINE FORECASTS ARE AVAILABLE IN THE NATIONAL DIGITAL FORECAST DATABASE (NDFD) AT: HTTP://WWW.NHC.NOAA.GOV/MARINE/GRIDS.PHP FOR ADDITIONAL INFORMATION PLEASE VISIT: HTTP://WWW.HURRICANES.GOV/MARINE $$ .FORECASTER CHRISTENSEN. NATIONAL HURRICANE CENTER.