000 AGXX40 KNHC 281903 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 300 PM EDT THU JUL 28 2011 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... TROPICAL STORM DON CONTINUES TO MOVE NW THIS AFTERNOON...NOW AT ABOUT 12 KT...AND CONTINUES TO STRUGGLE CONVECTIVELY...WITH DRY AIR AND LACK OF LLVL CONVERGENCE ACROSS WRN SEMICIRCLE WORKING AGAINST IT. STLT IMAGERY ALSO CONTINUES TO SHOW SQUALLS RACING N AND NW WELL AHEAD OF DON...ACROSS THE NE SEMICIRCLE...AIDED BY SOME MID LEVEL AIR AND MID TROPOSPHERIC SELY JET. SQUALLS SEEN YESTERDAY PROPAGATING AWAY FROM DON HAVE MOVED INTO ALABAMA...FL PANHANDLE THIS MORNING. EXPECTED THESE SQUALLS TO CONTINUE TO AFFECT TO OFFSHORE AND NEAR SHORE WATERS FROM CENTRAL LA TO APALACHICOLA THROUGH TONIGHT...WITH POTENTIAL FOR GUSTS 30 KT AND HIGHER. WIND FIELD OF DON REMAINS SMALL AND COMPACT AND IS NOT GENERATING A LARGE WAVE FIELD. BUOY 42001 RECENTLY JUMPED TO 9 FT AFTER SQUALL PASSAGE BUT NOT REALLY REPRESENTATIVE TO BROAD WAVE FIELD. WAVE FIELDS GENERATED FROM GLOBAL MODELS NEED TO BE SHIFTED SW...INCLUDING WWIII NAH....WITH LIMITED WAVE GROWTH ON SW SEMICIRCLE. TRAILING MOISTURE AND CONVECTION WILL CONTINUE TO SPREAD NW ACROSS THE YUCATAN AND INTO THE GULF NEXT 24-36 HOURS EVEN AFTER DON MOVES INLAND EARLY SAT. SW N ATLC... SURFACE RIDGE REMAINS ALONG ABOUT 30N...WITH FRESH E TO SE TRADES S OF 25N GENERATING ROUGH SEAS S THROUGH SW OF THE BAHAMAS AND ACROSS BAHAMA BANKS AND INTO THE STRAITS. MORE STABLE AIR HAS MOVED INTO THIS REGION AHEAD OF NEXT TROPICAL WAVE MOVING ACROSS THE ERN CARIBBEAN ATTM. HOWEVER THIS MOISTURE WILL BEGUN TO AFFECT SE PORTIONS LATE FRI INTO SAT WITH SHOWERS AND SQUALLS. RIDGE TO REMAIN IN PLACE NEXT FEW DAYS IN TERMS OF ALIGNMENT BUT WILL WEAKEN ACROSS WRN END AND RELAX GRADIENT SOME ACROSS THE REGION...ALLOWING WINDS AND SEAS TO DIMINISH SLIGHTLY S OF THE RIDGE. A LOW LEVEL WEAKNESS DEVELOP ALONG ABOUT 65W BY SAT...S OF A WEAK FRONTAL TROUGH ACROSS THE ATLC AND WILL FURTHER RELAX GRADIENT E AND SE PORTIONS. CARIBBEAN AND TROPICAL N ATLC W OF 55W... WINDS AND SEAS DIMINISHING ACROSS THE NW CARIB AS DON MOVES AWAY BUT WITH CNVTN PERSISTING...AND WILL CONTINUE THROUGH THIS EVENING BEFORE BEGINNING TO SHIFT AWAY TONIGHT. TROPICAL WAVE ACROSS THE ERN CARIB WILL CONTINUE W WITH FRESH ENE FLOW AHEAD AND ESE WINDS BEHIND IT...AND REMAIN ACTIVE CONVECTIVELY UNTIL REACHING THE CENTRAL CARIB SAT. EPAC MONSOON TROF EXPECTED TO LIFT N INTO THE SW CARIB NEXT SEVERAL DAYS WITH GLOBAL MODELS INDICATING A BROAD CYCLONIC CIRCULATION DEVELOPING. ATTM TROPICAL CYCLOGENESIS IS NOT EXPECTED WITH THIS...AS THE FOCUS IS EXPECTED TO BE ANOTHER MONSOONAL LOW FURTHER W IN THE EPAC. THIS BROAD CIRCULATION IN THE SW CARIB WILL LIFT FRESH TRADE N OF THEIR USUAL POSITION N OF 12N...AND GRADIENT WILL RELAX. SAL AND FRESH TRADES DOMINATING THE TROPICAL N ATLC ATTM AHEAD OF NEXT LARGE TROPICAL WAVE. GLOBAL MODELS HAVE BACKED OFF OF DEVELOPMENT...IN GENERAL OF THIS TROPICAL WAVE CURRENTLY ACROSS THE CENTRAL ATLC. HOWEVER...STRONG NELY WINDS AND BUILDING SEAS 9 TO 10 FT AND POSSIBLY HIGHER WILL SPREAD INTO THE AREA SUNDAY WITH THIS WAVE. GFS IS FASTER BY 5 DEGREES OR SO WITH THIS WAVE...WITH UKMET JUST BEHIND...AND ECMWF SLOWEST. WARNINGS... GULF OF MEXICO... .NONE. SW N ATLC... .NONE. CARIBBEAN AND TROPICAL N ATLC... .NONE. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ FORECASTER STRIPLING