000 AGXX40 KNHC 141854 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 250 PM EDT TUE AUG 14 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 STATIONARY FRONT EXTENDS FROM SE GEORGIA SW TO ALONG THE FLORIDA PANHANDLE COAST AND NW TO NEAR MOBILE BAY. A RATHER DEEP LAYER TROUGH FOR THIS TIME OF YEAR IS RAPIDLY PROGRESSING EASTWARD ACROSS THE SE UNITED STATES. A VERY MOIST AND UNSTABLE AIR MASS AHEAD OF THE TROUGH IS PRESENTLY SUPPORTING ISOLATED SHOWERS AND TSTMS OVER MUCH OF THE NRN AND CENTRAL GULF ZONES. RATHER ACTIVE CONVECTION IN THE FORM OF SCATTERED STRONG TSTM ACTIVITY EARLIER NOTED IN THE SW GULF HAS WEAKENED SIGNIFICANTLY DURING THE MORNING AND EARLY AFTERNOON. CURRENT BUOY AND OIL PLATFORM OBSERVATIONS SHOW RELATIVELY LIGHT WINDS THROUGHOUT. E-SE WINDS OF 10-15 KT ARE S OF THE RIDGE... WHILE SW W WINDS OF 5-10 KT ARE N OF THE RIDGE...EXCEPT MORE OF A S-SW COMPONENT W OF 94W. THE BUOYS SHOW SEAS IN THE 1-2 FT RANGE EXCEPT 3-4 FT IN THE SW PART OF THE GULF WITH THE OCCASIONAL SEAS TO 5 FT. LATEST MODEL RUNS REMAIN 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 29N OR 30N FRI THROUGH SUN. 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 AGAIN 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 CENTRAL FLORIDA AND CONTINUES W TO THE GULF. 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 22N E OF 75W. 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 TSTMS ARE NOTED OVER THE NE PORTION OF THE ZONES N OF ABOUT 27N E OF 73W TO THE S OF A SHORTWAVE TROUGH PASSING JUST TO THE N OF THE FORECAST WATERS. 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 TRANSLATES NORTHWESTWARD AND SHEAR OUT THROUGH WED. THIS UPPER LEVEL SET UP 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 FORECAST PERIOD. 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 BRIEFLY DIMINISH TO 10-15 KT FRI BEFORE INCREASING TO 15-20 KT AGAIN SAT AND SUN. CARIBBEAN SEA AND TROPICAL N ATLC W OF 55W... THE TROPICAL WAVE OF THE PAST PREVIOUS...REMNANTS OF TROPICAL DEPRESSION SEVEN...IS ROUGHLY ALONG A PSN FROM JUST S OF WRN CUBA TO NEAR THE NRN PART OF PANAMA MOVING WNW AT 20 KT AT 18 UTC. SATELLITE IMAGERY SHOWS INCREASING NUMEROUS TSTMS S OF 16N BETWEEN THE WAVE AND 79W...AND ALSO S OF 16N BETWEEN 79W AND 73W. AN ASCAT PASS FROM VERY NEAR 14 UTC THIS MORNING REVEALED A SHARP NE TO SE WIND SHIFT ASSOCIATED WITH THE WAVE...BUT WITH WITH WIND VELOCITIES DOWN TO 10-15 KT N OF 15N. THE TROPICAL WAVE IS FORECAST TO REACH NEAR 88W WED MORNING... THEN MOVE INLAND THE YUCATAN PENINSULA AND BELIZE WED EVENING. WEAK LOW PRES OF 1010 MB ON THE WAVE AXIS 15N82W WILL MOVE INLAND AS WELL WITH THE WAVE. THERE IS UNCERTAINTY AS TO HOW STRONG THE LOW MAY BECOME...SO WILL KEEP STEADY STATE WITH PRES FOR TONIGHT AND WED. FUTURE FORECASTS MAY BE SUBJECT TO UPDATES AND/OR REVISIONS BASED ON THIS POSSIBLE UPCOMING SCENARIO WITH TROPICAL WAVE. BEHIND THE WAVE...E-SE 20 KT WINDS WILL LINGER INTO THE END OF THE WEEK WITH SEAS OF ABOUT S FAR E AS 70W WITH SEAS IN THE RANGE OF 5-7 FT. FOR THIS FORECAST PERIOD WILL BLEND THE LATEST GFS MODEL RUN WITH PREVIOUS OFFICIAL FORECAST FOR ALL ZONES. A TROPICAL WAVE FROM 16N56W TO 10N58W IS MOVING W AT AROUND 18 KT. THIS WAVE WILL MOVE ACROSS THE EASTERN TROPICAL ATLC ZONES THROUGH TONIGHT...AND ENTER THE ERN CARIBBEAN SEA WED MORNING. THE WAVE WILL REACH NEAR 70W WED NIGHT...AND MOVE ACROSS THE CENTRAL CARIBBEAN SEA THU AND FRI AND WRN CARIBBEAN SEA SAT AND SUN. THE WAVE SHOULD HAVE LITTLE IMPACTS ON THE ALREADY ONGOING 15-20 KT TRADES THROUGHOUT. 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