000 AGXX40 KNHC 121849 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 245 PM EDT SUN AUG 12 2012 MARINE WEATHER DISCUSSION FOR THE GULF OF MEXICO...CARIBBEAN SEA AND TROPICAL N ATLC...AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W. GULF OF MEXICO... THE WESTERN EXTENSION OF ATLC HIGH PRES RIDGING PROTRUDES ACROSS THE GULF ALONG 26N...AND IS THE DOMINANT FEATURE OVER THE THE REGION. A COLD FRONT...THE SURFACE REFLECTION OF A DEEP LAYER TROUGH RAPIDLY PROGRESSING EASTWARD ACROSS THE SE UNITED STATES ...EXTENDS FROM NE GEORGIA SW TO JUST W OF THE FLORIDA PANHANDLE WHERE IT BECOMES A STATIONARY FRONT WNW TO FAR ERN TEXAS. A SURFACE TROUGH EXTENDS FROM NEAR APALACHICOLA FLORIDA SSW TO NEAR 26N89W. SCATTERED SHOWERS AND TSTMS IN A VERY MOIST AND UNSTABLE CONTINUE TO BE NOTED OVER MUCH OF THE EASTERN GULF WATERS. CURRENT BUOY AND OIL PLATFORM OBSERVATIONS SHOW RELATIVELY LIGHT WINDS THROUGHOUT. SE-S WINDS OF 10-15 KT ARE S OF THE RIDGE EXCEPT SW IN DIRECTION IN THE FAR WRN PORTION NEAR THE TEXAS COAST. SW WINDS OF 5-10 KT ARE N OF THE RIDGE W OF 88W...AND SW-5 WINDS OF 5-10 KT E OF 88W. THE BUOYS SHOW SEAS IN THE 1-2 FT RANGE E OF 90W...AND 2-3 FT. LATEST MODEL RUNS ARE IN GENERAL GOOD AGREEMENT THAT THE RIDGE WILL SHIFT N TO ALONG 27N TUE...AND FURTHER N TO ALONG 28N WED AND THU AND TO NEAR 29/30N FRI. WEAK FRONTAL BOUNDARIES SHOULD REMAIN N OF THE FORECAST WATERS THROUGH THE PERIOD...WITH RELATED TSTM ACTIVITY REACHING THE FAR NRN FRINGES OF THE WATERS. THE NOAA WAVEWATCH III GUIDANCE LOOKS REASONABLE WITH SEAS BEING OBSERVED THROUGHOUT THE GULF. WILL USE THE LATEST GUIDANCE FOR THIS FORECAST. SW N ATLC S OF 31N W OF 65W... THE PRELIMINARY 18 UTC SURFACE ANALYSIS DEPICTS THE MAIN FEATURE BEING A RIDGE THAT EXTENDS FROM BERMUDA SW TO S FLORIDA. LATEST BUOY OBSERVATIONS ALONG WITH A FEW SHIP REPORTS REVEAL SE WINDS OF 10-15 KT SE OF THE RIDGE...WITH THE EXCEPTION OF NE-E 15 KT WINDS S OF 23N E OF 67W. WINDS ARE SE-S 10-15 KT N OF THE RIDGE E OF 73W...AND SW 5-10 KT W OF 73W. THE OBSERVATIONS ARE REPORTING SEAS IN THE 5-7 FT RANGE S OF THE RIDGE E OF THE BAHAMAS...AND 1-3 FT S OF THE RIDGE W OF THE BAHAMAS. N OF THE RIDGE SEAS ARE IN THE 2-4 FT RANGE EXCEPT W OF 79W WHERE LOWER SEAS OF 2-3 FT ARE OBSERVED. SCATTERED SHOWERS AND TSTMS CONTINUE OVER THE FAR NW PORTION OF THE AREA AHEAD OF A RATHER ROBUST UPPER LEVEL TROUGH MOVING EASTWARD ACROSS THE EASTERN U.S. FOR THIS FORECAST PERIOD...THE RIDGE WILL BE THE DOMINANT WEATHER FEATURE FOR THE AREA. MID/UPPER LEVEL RIDGING OVER THE WESTERN PORTION OF THE AREA WILL BECOME STRETCHED NE TO SW THROUGH FRI AS A LARGER AREA OF UPPER LEVEL RIDGING IN THE EASTERN ATLC BUILDS WESTWARD FORCING AN ELONGATED MID/UPPER LEVEL CYCLONIC CIRCULATION IN BETWEEN BOTH RIDGES TO TRANSLATED NORTHWESTWARD AND SHEAR OUT THROUGH WED. THE SRN TAIL END OF THE CYCLONIC CIRCULATION WILL PINCH OFF INTO AN UPPER LEVEL CYCLONIC CIRCULATION THAT MOVES WESTWARD ACROSS THE NRN CARIBBEAN SEA TUE THROUGH WED AND CENTRAL PORTION OF THEN CARIBBEAN THU AND FRI. THIS UPPER LEVEL SETUP WILL FORCE THE SURFACE RIDGE CURRENTLY FROM BERMUDA TO S FLORIDA WILL TO SHIFT NWD TO NEAR 28N BY TUE...AND REMAIN THERE THROUGH THE END OF THE UPCOMING WEEK KEEPING CONTROL OF THE CURRENT WIND REGIME OVER THE FORECAST WATERS. THE EXCEPTION WILL BE SEEN WITH THE E WINDS S OF THE RIDGE BETWEEN THE SE BAHAMAS AND HISPANIOLA REACHING SPEEDS OF 15-20 KT WHILE SPREADING WESTWARD SOME THROUGH WED AS THE PRES GRADIENT THERE TIGHTENS SOME. THE GRADIENT THEN SLACKENS ENOUGH THU AND FRI TO ALLOW FOR THE WINDS TO DIMINISH TO 10-15 KT. CARIBBEAN SEA AND TROPICAL N ATLC W OF 55W... THE TROPICAL WAVE...REMNANTS OF TROPICAL DEPRESSION SEVEN...IS ROUGHLY ALONG A PSN FROM PUERTO RICO TO 11N69W MOVING W AT 20 KT. SATELLITE IMAGERY SHOWS NUMEROUS SHOWERS AND TSTMS FROM WITHIN 180 NM OF THE WAVE N OF 13N. AN ASCAT PASS FROM 1434 UTC REVEALED A TIGHT PRES GRADIENT IN THE STRONG CONVECTIVE ACTIVITY NOTED FROM 15N TO 17N BETWEEN 65W AND 68W WHERE WINDS IN THE CONVECTION ARE UP TO 25-30 KT. THE WAVE IS FORECAST TO REACH FROM HAITI TO 11N74W MON MORNING...FROM EASTERN CUBA TO 11N78W EARLY MON NIGHT...FROM CENTRAL CUBA TO 11N82W TUE MORNING...FROM NEAR WESTERN CUBA TO INLAND NORTHERN HONDURAS EARLY WED...THEN MOVE INLAND AND W OF THE AREA WED EVENING. A TIGHT GRADIENT SUPPORTING NE-E WINDS OF 20-25 KT WILL PRECEDED THE WAVE TO WITHIN 180 NM W OF IT...AND SLOWLY DIMINISH EARLY ON WED. SEAS THERE WILL BE IN THE RANGE OF 8-10 FT INTO EARLY MON BEFORE SUBSIDING TO 8-9 FT TUE AND WED. BEHIND THE WAVE ...SE WINDS OF 20 KT ARE NOTED FROM 15N-18N. THESE WINDS WILL BLEND IN WITH SE WINDS OF 20 KT S OF 15N E OF 72W THROUGH MON NIGHT PER GFS/ECMWF WIND GUIDANCE...AND SHIFT TO W OF 70W BEHIND THE WAVE THROUGH WED WHILE DIMINISHING TO 15-20 KT INTO THU. FOR THIS FORECAST PERIOD WILL LEAN TOWARDS USING A BLEND OF THE GFS/ECMWF FOR PSN OF THE WAVE ACROSS THE CARIBBEAN AS BOTH MODELS SEEM TO BE IN RATHER CLOSE AGREEMENT. FOR WINDS ASSOCIATED WITH THE WAVE WILL FOLLOW GFS GUIDANCE...AND HIGHLIGHT HIGHER WINDS AND SEAS IN NUMEROUS SHOWERS AND TSTMS WITH THE WAVE. THE TROPICAL WAVE ASSOCIATED WITH WEAK BROAD LOW PRES SYSTEM ON THE FAR EASTERN ATLC IS FORECAST TO MOVE NW ACROSS THE NORTHERN PORTION OF THE TROPICAL N ATLC ZONES WED AND THU BEFORE LIFTING NNE FAR INTO THE N CENTRAL ATLC HIGH SEAS. LITTLE IN THE WAY OF ANY SIGNIFICANT WINDS AND SEAS WILL EXPECTED OVER THAT PORTION OF THE FORECAST WATERS. THE TIGHTER GRADIENT ASSOCIATED WITH IT SHOULD STAY N OF THE OFFSHORE WATERS...AND IN THE CENTRAL HIGH SEAS AREA. NOTE...GRIDDED MARINE FORECAST 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