000 AGXX40 KNHC 191826 MIMATS MARINE WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE MIAMI FL 226 PM EDT SUN JUL 19 2009 MARINE WEATHER DISCUSSION FOR THE GULF OF MEXICO...CARIBBEAN SEA AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W. GULF OF MEXICO... A COLD FRONT IS SLOWLY PUSHING INTO THE NORTHERN GULF OF MEXICO...AND IS ORIENTED EAST TO WEST ALONG ROUGHLY 29N. THE FRONT IS ACCOMPANIED BY A CLUSTERS OF THUNDERSTORMS NOTED MAINLY N OF 27N. AN UPPER TROUGH SUPPORTING THE FRONT IS BECOMING MORE AMPLIFIED OVER THE EASTERN U.S. WEAK DISTURBANCES ARE MIGRATING SOUTH ALONG THE WEST SIDE OF THE TROUGH...AND WILL KEEP THUNDERSTORMS ACTIVE FOR THE NEXT COUPLE OF DAYS OVER THE NORTHERN GULF. THE FRONT WILL STALL AND DISSIPATE MON INTO TUE. A 1019 MB SURFACE HIGH PRES AREA IS CENTERED JUST SOUTH OF THE FRONTAL BOUNDARY NEAR 26N87W. THIS IS PART OF A SURFACE RIDGE THAT EXTENDS FROM THE CENTRAL ATLC THROUGH S FLORIDA...AND CONTINUES ON TO THE TEXAS COAST. THE SURFACE RIDGE IS MAINTAINING GENERALLY LIGHT TO MODERATE WINDS ACROSS THE GULF...AND LITTLE CHANGE IS EXPECTED THROUGH THE UPCOMING WEEK. THE EXCEPTION TO ALL THIS REMAINS IN THE SE BAY OF CAMPECHE WHERE A 12Z QUIKSCAT SHOWED 15 TO 20 KT SE WINDS FOR THE SECOND MORNING IN A ROW. THIS COINCIDES WITH A PERSISTENT 20 TO 25 KT FLOW THROUGH THE GULF OF TEHUANTEPEC. THE THEORY A COUPLE OF DAYS AGO PINNED THE TEHUANTEPEC FLOW ON A TROPICAL WAVE PASSING WESTWARD THROUGH NORTHERN CENTRAL AMERICA...ALTHOUGH THIS IS NOW WELL WEST OF THE AREA. THE CURRENT THEORY TO EXPLAIN THE PERSISTENT WINDS IN THE BAY OF CAMPECHE AND TEHUANTEPEC HINGES ON THE FACT THAT SEA LEVEL PRESSURES ARE SLIGHTLY HIGHER THAN NORMAL IN THE GULF...AND SLIGHTLY LOWER OVER THE EASTERN PACIFIC OFF THE COASTS OF SOUTHERN MEXICO AND NORTHERN CENTRAL AMERICA. THERE WAS SOME THOUGHT TO INTRODUCE HIGHER SE WINDS FOR MONDAY OVER THE SE BAY OF CAMPECHE...BUT THE HIGH PRES IS EXPECTED TO WEAKEN FURTHER AS THE UPPER TROUGH DIGS INTO THE EASTERN U.S. CARIBBEAN... LAND BASED OBSERVATIONS AND REPORTS FROM BUOY 42060 INDICATE 20 KT WINDS FROM JUST WEST OF THE LEEWARDS THROUGH PUERTO RICO...ON THE EAST SIDE OF A TROPICAL WAVE ALONG ROUGHLY 70W MOVING INTO THE CENTRAL CARIBBEAN. SAN JUAN RADAR SHOWS CLUSTERS OF SHOWERS MIGRATING WESTWARD THROUGH THE VIRGIN ISLANDS TOWARD PUERTO RICO. HOWEVER...SATELLITE IMAGERY AND LIGHTNING DATA SHOW LARGER CLUSTERS OF SHOWERS AND TSTMS ARE DEVELOPING SOUTH OF THE DOMINICAN REPUBLIC CLOSER TO THE WAVE AXIS. PER BUOY REPORTS SEAS REMAIN 6 TO 7 FT OVER THE NE CARIBBEAN. FURTHER SW...A 14Z ASCAT PASS SHOWED 20 TO 25 KT PERSISTING OFF THE COLOMBIAN COAST. SEAS WERE STILL UP TO 8 FT AT BUOY 42058 BETWEEN JAMAICA AND COLOMBIA...AND SEAS ARE ESTIMATED TO BE UP TO 12 FT IN E SWELL OFF THE COLOMBIAN COAST ALTHOUGH THIS WILL SUBSIDE TO LESS THAN 8 FT BY TUE. THE FORECAST CALLS FOR THE WAVE ALONG 70W TO SLOW DOWN A LITTLE AS IT PUSHES WEST...REACHING JAMAICA TOMORROW AFTERNOON...THE NICARAGUAN COAST BY EARLY TUE...AND THE GULF OF HONDURAS ON WED. THE TROPICAL WAVE WILL MAINTAIN 20 TO 25 KT WINDS THROUGH THE CENTRAL CARIBBEAN...BUT WINDS OVER THE WESTERN CARIBBEAN WILL DIMINISH EVEN AS THE WAVE MOVES THROUGH THE AREA DUE TO WEAKENING HIGH PRES OVER THE GULF OF MEXICO. A SECOND WAVE WILL MOVE INTO THE EASTERN CARIBBEAN LATE MON...REACHING 70W BY EARLY WED...AND JAMAICA THU. CONVECTION ASSOCIATED WITH THIS FEATURE LOOKS A LITTLE MORE ORGANIZED THAN IT DID EARLIER. ALTHOUGH TROPICAL CYCLONE DEVELOPMENT IS NOT EXPECTED AT THIS TIME...THE MAIN ISSUE WITH THIS WAVE WILL BE THE POTENTIAL FOR HEAVY RAINFALL OVER THE LESSER ANTILLES MON INTO TUE AS IT MOVES WEST. A THIRD TROPICAL WAVE OVER THE CENTRAL ATLC WILL ENTER THE EASTERN CARIBBEAN ON WED. THIS LATTER PAIR OF TROPICAL WAVES WILL KEEP 20 TO 25 KT WINDS OVER MUCH OF THE EASTERN CARIBBEAN TUE THROUGH THU. WINDS AND SEAS OVER THE CENTRAL CARIBBEAN WILL INCREASE AGAIN WED THROUGH FRI AS THE TROPICAL WAVES MOVE THROUGH THE AREA...AND AS HIGH PRES INCREASES NORTH OF THE AREA. ATLANTIC S OF 31N W OF 55W... A SURFACE RIDGE EXTENDING FROM THE CENTRAL ATLC THROUGH THE NORTHERN BAHAMAS AND INTO SOUTH FLORIDA. A WEAK COLD FRONT IS MOVING OFF THE GEORGIA COAST. THIS FRONT WILL STALL AND DISSIPATE OFF OF N FLORIDA MON INTO TUE...BUT WILL BE THE FOCUS FOR SHOWERS AND THUNDERSTORMS OVER THE WATERS N OF THE BAHAMAS AND E OF NORTH FLORIDA. THE RIDGE WILL SHIFT NORTH SLIGHTLY AS THE FRONT WEAKENS...AND AS SERIES OF TROPICAL WAVES MIGRATE SOUTH OF THE AREA IN THE CARIBBEAN. GLOBAL MODELS CONTINUE TO INDICATE THAT THE NORTHERN EXTENT OF A TROPICAL WAVE NEAR 70W MOVING WEST TOWARD THE TURKS AND CAICOS ISLANDS WILL SPLIT OFF AND MOVE NW THROUGH THE LENGTH OF THE BAHAMAS...DELIVERING INCREASED SHOWERS AND TSTMS. A PAIR OF TROPICAL WAVES BEHIND THIS WILL MIGRATE ACROSS THE CARIBBEAN THROUGH MIDWEEK..MAINTAINING 20 TO 25 KT EASTERLY WINDS MAINLY S OF 23N TO INCLUDE THE SOUTHERN BAHAMAS AND TURKS AND CAICOS. THE PERSISTENT STRONG EAST FLOW WILL ALLOW SEAS TO BUILD TO 10 FT IN E SWELL OVER MUCH OF THE AREA BETWEEN THE LEEWARDS AND THE SOUTHERN BAHAMAS THROUGH MIDWEEK. DECAYING SE SWELL MIGRATES NW TO THE EAST OF THE BAHAMAS THU AND FRI. THE RIDGE AXIS SHIFTS SOUTHWARD THU AND FRI...WITH WINDS AND SEAS DIMINISHING. WARNINGS ATLC... .NONE. CARIBBEAN... .NONE. GULF OF MEXICO... .NONE. $$ FORECASTER CHRISTENSEN