000 AGXX40 KNHC 150733 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 325 AM EDT SUN JUL 15 2012 MARINE WEATHER DISCUSSION FOR THE GULF OF MEXICO...CARIBBEAN SEA AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W. GULF OF MEXICO... WEAK SURFACE RIDGING REMAINS NE OF THE GULF AS THE WRN EXTENT OF THE ATLC RIDGE EXTENDS WWD TO THE SE UNITED STATES. A NARROW UPPER TROUGH EXTENDS S ACROSS ERN TEXAS TO NE MEXICO. A SURFACE TROUGH EXTENDS FROM 31N89W S TO 25N88W. ISOLATED SHOWERS AND WEAK TSTMS ARE ALONG AND WITHIN 120 NM W OF THE TROUGH. LATEST BUOY OBSERVATIONS AND OIL RIG PLATFORMS SHOW GENERALLY E-SE WINDS OF 10-15 KT OVER MUCH OF THE GULF AS ALSO REVEALED BY A PARTIAL ASCAT PASS FROM 0330 UTC LAST NIGHT. SEAS ARE IN THE RANGE OF 2-3 FT...EXCEPT A SMALL POCKET OF HIGHER SEAS IN THE 3-5 FT RANGE IN THE FAR SE PART OF THE GULF S OF 25N E OF 83W. NO MAJOR CHANGES WILL BE MADE TO THE FORECAST FOR THIS PACKAGE AS MODELS IN GOOD AGREEMENT THAT THE WRN EXTENSION OF THE ATLC RIDGE WILL WILL STAY N OF THE AREA...THEN SLIDES S AND WEAKEN AS IT REACHES TO NEAR 28N MON THROUGH THU. THE SURFACE TROUGH WILL TRACK WWD ACROSS THE CENTRAL GULF THROUGH MON NIGHT AS IT GRADUALLY BECOMES DIFFUSE. THE PRES DIFFERENCE BETWEEN THE RIDGE AND BROAD LOW PRES OVER SE MEXICO AND THE FAR SW GULF WILL ALLOW FOR SE WINDS TO INCREASE TO 15 KT IN THE SW GULF TUE AND TO 15-20 KT WED AND THU. THE MULTIGRID NOAA WAVEWATCH III GUIDANCE WILL BE USED FOR FOR THIS FORECAST PACKAGE AS IT HAS INITIALIZED CLOSE TO REPORTED SEA STATE VALUES. SW N ATLC S OF 31N W OF 65W... THE PRELIMINARY 0600 UTC ANALYSIS HAS A RIDGE AXIS TO THE N OF THE REGION. SATELLITE WATER VAPOR IMAGERY SHOWS AN UPPER LEVEL LOW AT 31N76W MOVING WNW. THIS HAPPENS TO BE THE MAIN FEATURE OF THE AREA. THE ASCAT PASS FROM 0150 UTC LAST NIGHT ALONG WITH WRN ATLC BUOY OBSERVATIONS SUGGEST THAT THE ASSOCIATED SURFACE TROUGH EXTENDS FROM NEAR 31N77W TO BETWEEN GRAND BAHAMA ISLAND AND WEST PALM BEACH FLORIDA. AMPLE ATMOSPHERIC MOISTURE TO THE E AND S OF THE TROUGH IS LEADING TO SCATTERED SHOWERS AND TSTMS OVER MUCH OF THE WRN ATLC AS CURRENTLY SEEN ON RADAR AND SATELLITE IMAGERY...WITH THE BULK OF THE ACTIVITY FROM THE BAHAMAS WWD TO NEAR THE S FLORIDA COAST. THE SURFACE TROUGH WILL CONTINUE WNW IN TANDEM WITH THE UPPER LEVEL LOW. THE TROUGH WILL GRADUALLY BECOME DIFFUSE AS IT APPROACHES THE FAR NW PORTION OF THE AREA TONIGHT. A NE TO SE WIND SHIFT WILL ATTEND THE TROUGH...BUT RELATED WIND SPEEDS WILL BE LIGHT ON THE ORDER OF 10-15 KT. MODELS FORECAST A HIGH PRES CENTER OF 1021 MB TO MATERIALIZE AT 28N64W BY TONIGHT WITH A RIDGE EXTENDING NWD. S OF THE RIDGE...E-SE 10-15 KT WINDS WILL PREVAIL E OF THE BAHAMAS WITH POCKETS 15-20 KT TROUGH THU. A TROPICAL WAVE ALONG 66W/67W IS JUST TO THE S OF THE AREA MOVING QUICKLY WWD...AND IT IS ENHANCING THE PRES GRADIENT IN THE FAR SRN WATERS. THE LATEST GFS MODEL RUN LOOKS REASONABLE GIVEN THE CURRENT AND FORECAST SYNOPTIC SCENARIO. I PLAN TO COMBINE THIS GUIDANCE INTO THE LATEST GRIDDED DATA FORECAST. CARIBBEAN SEA AND TROPICAL N ATLC W OF 55W... A RATHER WEAK TROPICAL WAVE MOVING W NEAR 20 KT IS ALONG 66W/67W S OF 18N...WHILE BROAD LOW PRES COVERS THE FAR SW CARIBBEAN AND ADJACENT AREAS OF CENTRAL AMERCIA AND S AMERICA. ANOTHER TROPICAL WAVE...RAPIDLY WEAKENING...IS IN THE CENTRAL TROPICAL ATLC EXTENDING FROM 16N51W TO 10N49W MOVING W AT 15-20 KT. THE ASCAT PASS FROM 0150 UTC LAST NIGHT INDICATED A BROAD SWATH OF NE-E 20-25 KT WINDS OVER MUCH OF THE CENTRAL AND SW PORTIONS OF THE CARIBBEAN...AND SUSTAINED NE 20 KT WINDS OVER MUCH OF THE NRN AND CENTRAL TROPICAL N ATLC ZONES. BUOYS REVEAL SEAS OF 5-7 FT OVER MUCH OF THE ERN CARIBBEAN AND TROPICAL N ATLC ZONES WITH SOME POCKETS OF 8-9 FT SEAS IN THE CENTRAL PORTION OF THE TROPICAL N ATLC...AND IN THE FAR SW CARIBBEAN ZONE. E TRADES ELSEWHERE ACROSS THE CARIBBEAN ARE AT LIGHTER SPEEDS OF 10-15 KT...AND LIGHTER E-SE 5-10 KT WINDS IN THE WRN CARIBBEAN W OF ABOUT 82W PER THE 0330 UTC ASCAT PASS AND BUOYS 42056 AT 19.7N85W AND 42057 AT 17N81.5W. IN THE TROPICAL N ATLC N OF 10N NE-E WINDS OF 15 KT ARE PRESENT OUTSIDE THE NE 20 KT WINDS STATED ABOVE. IN THE CENTRAL CARIBBEAN SEA HEIGHTS ARE IN THE RANGE OF 4-6 FT OUTSIDE THE HIGHER SEAS OF 6-8 FT IN THE SW PORTION. SEAS ARE LOWER..IN THE 2-4 FT RANGE...IN THE WRN PORTION. THE TROPICAL WAVE ALONG 66W/67W IS FORECAST TO REACH FROM HAITI TO NRN COLOMBIA TONIGHT BEFORE AS IT FURTHER LOSES ITS SURFACE SIGNAL. THE TROPICAL WAVE CURRENTLY E OF THE TROPICAL N ATLC ZONES WILL BE FORECAST TO REACH A POSITION FROM 18N57W TO 10N55W TONIGHT...THEN MOVE INTO THE FAR ERN CARIBBEAN EARLY MON...AND WWD TO A POSITION FROM NEAR THE MONA PASSAGE TO 10N65W BY EARLY MON EVENING. THIS WAVE...SIMILARLY TO THE FIRST ONE...WILL QUICKLY LOSE ITS SURFACE SIGNAL AS IT TRACKS WWD ACROSS THE CENTRAL CARIBBEAN THROUGH WED. NEVERTHELESS...THE PASSAGE OF THESE WAVES WILL HELP SUSTAIN THE MODERATE TO FRESH TRADES THROUGHOUT MUCH OF THE CARIBBEAN AND TROPICAL N ATLC WITH NE-E WINDS EXPECTED TO BE MOSTLY IN THE RANGE OF 20-25 KT OVER MUCH OF THE CENTRAL AND SW PORTIONS OF THE SEA...WITH THE POSSIBILITY OF A FEW INSTANCES OF 25-30 KT ALONG OR NEAR THE COAST OF COLOMBIA THROUGH THU. THE MULTIGRID NOAA WAVEWATCH III MODEL GUIDANCE BUILDS SEAS RATHER HIGH...UP TO 13 FT IN THE SW CARIBBEAN WED AND THU. THE RELATED WAVEWATCH MAXIMUM SIGNIFICANT WAVE HEIGHT ENSEMBLES FROM THE NOAA WAVEWATCH III PLUS THE FNMOC ENSEMBLE MEMBERS HAS 13 FT SEAS FOR WED AND THU. THE ENSEMBLE MEAN FORECASTS SEAS UP TO 11 FT ON WED AND 10 FT ON THU IN THE SW CARIBBEAN. FOR THIS FORECAST PACKAGE WILL LEAN TOWARDS TOWARDS THE 11 FT MAX SEA FORECAST FOR WED AND THU. THE NE-E TRADES OF 20 KT NOTED OVER THE THE NRN AND CENTRAL TROPICAL ATLC ZONES ARE EXPECTED TO PERSIST THROUGH MON AFTERNOON BEFORE DIMINISHING TO 10-15 KT MON NIGHT INTO WED. THESE WINDS THEN INCREASE BACK TO 20 KT WED NIGHT AND THU WITH THE CURRENT MAX SEAS THERE OF 8 FT SUBSIDING TO 6-7 FT MON EVENING...TO 5-6 FT TUE AND WED THEN BUILD BACK UP TO 6-7 FT ON THU. NOTE...GRIDDED MARINE OUTPUT IS AVAILABLE AT WWW.NHC.NOAA.GOV/TAFB/GRIDDED_MARINE GULF OF MEXICO... .NONE. CARIBBEAN SEA... .NONE. SW N ATLANTIC... .NONE. FOR ADDITIONAL INFORMATION PLEASE VISIT WWW.HURRICANES.GOV/MARINE $$ FORECASTER AGUIRRE