000 AGXX40 KNHC 160714 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 310 AM EDT MON JUL 16 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 HIGH PRES IS JUST NE OF THE AREA OVER THE SE UNITED STATES...WHILE AN UPPER LEVEL LOW MOVING W IS NOTED AT 25N85W. A SURFACE TROUGH EXTENDS FROM 27N87W SSW TO INLAND THE NW SECTION OF THE YUCATAN PENINSULA. THE UPPER LOW AND SURFACE TROUGH ARE THE MAIN FEATURES IMPACTING MUCH OF THE CENTRAL AND EASTERN WITH RESPECT TO WEATHER. SCATTERED SHOWERS AND TSTMS ARE OVER MUCH OF THE ERN GULF S OF 27N E OF 87W...AND ISOLATED SHOWERS AND TSTMS ARE N OF 27N E OF 85W. LATEST BUOY OBSERVATIONS AND OIL RIG PLATFORMS GENERALLY SHOW E-SE WINDS OF 10-15 KT OVER MUCH OF THE GULF AS ALSO REVEALED BY A PARTIAL ASCAT PASS FROM 0310 UTC LAST NIGHT. WINDS ARE MORE SE-S IN DIRECTION IN THE SE PORTION. OBSERVED SEAS ARE MOSTLY AT 2 FT...EXCEPT FOR SMALL POCKETS OF SEAS TO 3 FT IN THE ERN GULF PORTION AND LOWER SEAS OF 1-2 FT IN THE NE PORTION. ONLY MINOR TWEAKS WILL BE MADE FOR THIS NEXT ISSUANCE OF THE OFFSHORES FORECAST AS MODELS ARE IN PRETTY GOOD AGREEMENT WITH RIDGE NE OF AREA WEAKENING AS IT BEGINS TO SLIDE SWD TODAY ...REACHING TO NEAR 28N TONIGHT E OF 89W...AND FARTHER S TO NEAR 27N BY TUE THROUGH FRI. THE SURFACE TROUGH WILL TRACK WWD ACROSS THE CENTRAL GULF THROUGH TONIGHT 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 ZONE TUE...AND TO 15-20 KT LATE WED THROUGH FRI. THE NRN PORTION OF CARIBBEAN TROPICAL WAVE MAY MOVE INTO THE FAR SE GULF LATE WED NIGHT INTO THU...AND ACROSS THE YUCATAN PENINSULA LATER THU AND FRI POSSIBLY ENHANCING THE ELY WINDS THERE. THE MULTIGRID NOAA WAVEWATCH III GUIDANCE WILL BE USED FOR THE THE OFFSHORES FORECAST AS IN THE PREVIOUS IT HAS INITIALIZED CLOSE TO REPORTED SEA STATE VALUES...AND ITS FORECAST THROUGH FRI (DAY 5) LOOKS REASONABLE. 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 JUST NW OF THE BASIN NEAR 31N80W MOVING W. PARTIAL HIGH RESOLUTION ASCAT DATA FROM 0128 UTC LAST NIGHT ALONG WITH WRN ATLC BUOY OBSERVATIONS REVEALED SE-S WINDS OF 10 KT W OF ABOUT 73W...AND E-SE WINDS OF 10-15 KT E OF 73W. A SMALL POCKET OF E 15-20 KT WINDS IS PRESENT OVER THE FAR SRN WATERS BETWEEN THE SE BAHAMAS AND PUERTO RICO DUE TO THE SLIGHTER TIGHTER PRES GRADIENT THERE. DEEP ATMOSPHERIC MOISTURE PREVAILS OVER THE FAR WRN PORTION OF THE BASIN TO THE S OF THE UPPER LEVEL...AND E OF THE UPPER LOW OVER THE GULF OF MEXICO WHERE UPPER LEVEL DIVERGENCE CAN BE FOUND. RESULTANT SCATTERED SHOWERS AND TSTMS WITH POSSIBLE GUSTY WINDS ARE OVER MUCH OF THESE THE FAR WRN ATLC WATERS AS CURRENTLY SEEN ON NWD RADAR DISPLAYS AND ON SATELLITE IMAGERY. THE MOST CONCENTRATED PORTION OF THIS ACTIVITY CURRENTLY EXTENDS FROM THE W SIDE OF THE BAHAMA ISLAND CHAIN TO ALONG THE SE FLORIDA COAST. MODELS ARE PERSISTENT IN FORECASTING THE RIDGE N OF THE AREA TO SHIFT S TO NEAR 27N THROUGH FRI AS A 1019 MB TO 1020 MB HIGH CELL BECOMES ESTABLISHED ON THE RIDGE NEAR 27N67W THROUGH WED NIGHT. S OF THE RIDGE...E-SE 10-15 KT WINDS WILL PREVAIL E OF THE BAHAMAS WITH POCKETS OF E 15-20 KT WINDS BETWEEN THE BAHAMAS AND PUERTO RICO TROUGH FRI. THE NRN PORTION OF A CARIBBEAN WAVE IS MOVING W THROUGH THE SE BAHAMAS AND WINDWARD PASSAGE EARLY THIS MORNING. IT MARKS THE LEADING EDGE OF THE 15-20 KT E WINDS. THIS WAVE WILL BE FORECAST ON THE MANUAL TAFB GRAPHICS TO BE ACROSS ERN CUBA BY EARLY TONIGHT...ACROSS CENTRAL CUBA TUE AND TUE NIGHT AND PASSING THROUGH WRN CUBA WED INTO WED NIGHT BEFORE MOVING INTO THE FAR SE GULF WATERS LATE WED NIGHT INTO THU. THESE FORECAST POSITIONS ARE ABOUT 1.5 DEGREES SLOWER THAN THE GFS FORECAST. THE SHOWERS AND TSTMS OVER THE FAR WRN ATLC WATERS WILL LINGER INTO EARLY TUE BEFORE SAHARAN DUST (SAL) BEGINS TO ADVECT WWD ACROSS MUCH OF THE SRN WATERS AND CONTINUE THROUGH THE NEXT FEW DAYS. CARIBBEAN SEA AND TROPICAL N ATLC W OF 55W... A RATHER WEAK TROPICAL WAVE MOVING W NEAR 18 KT IS PASSING OVER THE W SIDE OF HAITI AND EXTENDS S TO 16N ALONG 74W. BROAD LOW PRES COVERS THE FAR SW CARIBBEAN AND ADJACENT AREAS OF CENTRAL AMERCIA AND S AMERICA. ASIDE FROM A FEW LOW TOP ISOLATED SHOWERS OVER SW HAITI AND AND NEARBY WATERS...THE WAVE IS ABSENT OF ANY DEEP CONVECTION. IT S MOVING THROUGH A BROAD AREA OF NE-E 20-25 KT WINDS THAT COVERS MUCH OF THE CENTRAL CARIBBEAN SEA. BUOY OBSERVATIONS LOCATED ACROSS THE CENTRAL AND ERN CARIBBEAN SEA REVEAL MOSTLY NE-E 20 KT WINDS WITH SEAS OF 5-7 FT. THE HIGH RESOLUTION ASCAT PASS FROM 0124 UTC LAST SHOWED NE 20 KT WINDS ACROSS THE CENTRAL AND MUCH OF THE NRN PORTIONS OF THE TROPICAL N ATLC WHERE COMBINED WAVE HEIGHTS AS REPORTED BY THE BUOYS ARE 8-9 FT. MAX SEAS OF 9 FT ARE ALSO IN THE FAR SW CARIBBEAN SEA. 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 0306 UTC ASCAT PASS AND AS REPORTED BY BUOYS 42056 AT 19.7N85W AND 42057 AT 17N81.5W. ELSEWHERE ACROSS THE TROPICAL N ATLC AND CARIBBEAN SEA LIGHTER NE WINDS OF 10-15 KT ARE NOTED WHERE CORRESPONDING REPORTED COMBINED SEA HEIGHT VALUES ARE IN THE RANGE OF 4-6 FT...AND LOWER RANGES OF 2-3 FT IN THE WRN PORTION OF THE CARIBBEAN. 3-5 FT SEAS ARE NOTED ELSEWHERE IN THE TROPICAL N ATLC ZONES. THE TROPICAL WAVE WILL BE FORECAST TO REACH A POSITION FROM ERN CUBA TO 15N75.5W BY EARLY TONIGHT...FROM CENTRAL CUBA TO 15N81.5W BY EARLY TUE NIGHT...THEN REACH THE FAR NW TIP OF CUBA TO GULF OF HONDURAS BY EARLY WED NIGHT BEFORE ENTERING THE FAR SE GULF LATER WED NIGHT AND INTO THU. WITH THE WAVE PASSING ACROSS THE CARIBBEAN THE MODERATE TO FRESH TRADES THROUGHOUT MUCH OF THE CENTRAL CARIBBEAN WATERS WILL BE FURTHER REINFORCED INTO MOST OF THU AS ATLC RIDING N OF THE AREA SLIDES SWD ALLOWING FOR THE PRES GRADIENT BETWEEN IT AND RELATIVELY LOWER PRES OVER THE SW CARIBBEAN SEA...AND ALONG WITH THE TIGHTER PRES GRADIENT LEFT BEHIND BY THE WAVE TO COMBINE ALLOWING FOR THIS REINFORCEMENT OF THE TRADES TO TAKE PLACE. THE MULTIGRID NOAA WAVEWATCH III MODEL GUIDANCE BRIEFLY BUILDS SEAS RATHER HIGH...UP TO 13 FT IN THE SW CARIBBEAN WED BEFORE LOWERING THEM TO 10-11 FT THU AND FRI. WILL FORECAST A MAX SEA HEIGHT OF 12 FT FOR WED AND THU AND THEN LOWER OF 10 FT FOR FRI. THE NE-E TRADES OF 20 KT NOTED OVER THE THE NRN AND CENTRAL TROPICAL ATLC ZONES ARE EXPECTED TO PERSIST THROUGH THIS AFTERNOON BEFORE DIMINISHING TO 10-15 KT TONIGHT THROUGH WED. THESE WINDS THEN INCREASE BACK TO 15-20 KT WED NIGHT THROUGH FRI WITH THE CURRENT MAX SEAS THERE OF 8 FT SUBSIDING TO 6-7 FT TUE ...AND TO 5-6 FT TUE NIGHT AND WED THEN BUILD BACK UP TO 5-7 FT THU AND FRI. 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