000 AGXX40 KNHC 171840 MIMATS MARINE WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE MIAMI FL 240 PM EDT FRI JUL 17 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 1020 MB SURFACE HIGH PRES AREA IS CENTERED OFF THE SW FLORIDA COAST...WITH A SURFACE RIDGE EXTENDING NW TOWARD THE TEXAS COAST. BUOYS AND SCATTEROMETER DATA SHOW GENERALLY LIGHT WINDS AROUND THE HIGH PRES...WITH SEAS ONLY 1 TO 3 FT OVERALL. THE EXCEPTION IS OVER THE BAY OF CAMPECHE...WHERE A SOMEWHAT TIGHT GRADIENT BETWEEN THE HIGH PRES AND A TROPICAL WAVE MOVING ACROSS THE PACIFIC COAST OF SOUTHERN MEXICO IS ALLOWING E TO SE WINDS TO INCREASE SLIGHTLY TO 10 TO 15 KT. THIS FLOW WILL DIMINISH THROUGH TONIGHT AS THE TROPICAL WAVE MOVES WEST. MEANWHILE AN UPPER TROUGH WILL DEEPEN OVER THE EASTERN U.S. AND PUSH A WEAK COLD FRONT INTO THE NORTHERN GULF WHERE IT WILL STALL BY LATE SUN. AMPLE MOISTURE ALONG THE FRONT WILL ALLOW IT TO BE THE FOCUS OF SCATTERED SHOWER AND TSTMS ACTIVITY SUN INTO MON. GENERALLY LIGHT TO MODERATE FLOW WILL PERSIST INTO EARLY NEXT WEEK...WITH THE STRONGEST WINDS UP TO 15 KT ALONG THE TEXAS COAST ON THE WESTERN EDGE OF THE SURFACE RIDGE. WINDS WILL BRIEFLY INCREASE TO 20 KT DURING THE EVENINGS OFF THE WESTERN YUCATAN COAST AS WELL. CARIBBEAN... LATEST HIGH RESOLUTION QUIKSCAT PASS FROM 11Z SHOWED AN AREA OF 25 TO 30 KT TRADE WINDS OFF THE COLOMBIAN COAST...BUT HINTED THAT THE GALE FORCE WINDS MAY BE ENDING IN THAT AREA. THE STRONG WINDS ARE ON THE EAST SIDE OF A WELL DEFINED TROPICAL WAVE THAT MOVED WEST OF THE AREA LAST NIGHT. WHILE THESE WINDS ARE DIMINISHING BELOW GALE...WINDS TO 30 KT WILL LIKELY PERSIST OVER THE NEXT COUPLE OF DAYS BETWEEN A RIDGE OF HIGH PRES TO THE NORTH AND FAIRLY LOW PRES OVER THE NEARBY PACIFIC WATERS. THESE WINDS WILL DIMINISH FURTHER BY EARLY NEXT WEEK AS THE RIDGING TO THE NORTH WEAKENS. MEANWHILE...A COUPLE OF MORE TROPICAL WAVES WILL APPROACH THE AREA FROM THE CENTRAL ATLC. THE FIRST OF THESE WILL PUSH THROUGH THE LESSER ANTILLES LATE TONIGHT AND REACH THE CENTRAL CARIBBEAN NEAR 70W BY SUNDAY. IN ADDITION A FEW THUNDERSTORMS...THE TROPICAL WAVE WILL MAINTAIN AT LEAST MODERATE TO FRESH WINDS IN THE EASTERN TO CENTRAL CARIBBEAN...WITH SLIGHTLY STRONGER TRADES PERSISTING ALONG THE VENEZUELAN COAST. THE WAVE WILL SHIFT FURTHER EAST AND MOVE INTO THE WESTERN CARIBBEAN TOWARD MIDWEEK. SATELLITE IMAGERY HINTS OF A NARROW SWATH OF SAHARAN DUST ACCOMPANYING THIS WAVE...BUT NOT AS MUCH AS THE LAST WAVE BROUGHT TO THE REGION. A SECOND TROPICAL WAVE LOCATED NEAR 35W IS MOVING EAST AROUND 10 KT. THIS WAVE WILL SHIFT INTO THE EASTERN CARIBBEAN BY MONDAY AFTERNOON...AND INTO THE CENTRAL CARIBBEAN BY MIDWEEK. ATLANTIC S OF 31N W OF 55W... A PROMINENT SURFACE RIDGE EXTENDS FROM THE AZORES THROUGH THE CENTRAL BAHAMAS. A PAIR OF TROPICAL WAVES ARE NOTED OVER THE TROPICAL ATLC WATERS FURTHER SOUTH. THE FIRST IS ALONG 54W MOVING WEST AT 15 KT AND WILL MOVE INTO THE CARIBBEAN LATE TONIGHT. THE SECOND IS AROUND 35W MOVING WEST AT 10 KT...AND WILL SHIFT TO THE NORTH OF GUYANA SUNDAY AND MONDAY. FURTHER NORTH...MODERATE SW FLOW IS EVIDENT OFF THE FLORIDA COAST NORTH OF THE BAHAMAS. THIS WILL INCREASE SLIGHTLY THROUGH EARLY SUNDAY IN RESPONSE TO A TROUGH DIGGING OVER THE EASTERN U.S. ANOTHER UPPER TROUGH WILL DIG OVER THE CENTRAL ATLC...ALLOWING THE RIDGE TO BUILD OVER THE WESTERN ATLC WATERS BY SUN. THIS IN TURN WILL ALLOW THE GRADIENT BETWEEN THE RIDGE AND THE TROPICAL WAVES TO TIGHTEN SUN INTO MON...INCREASING TRADE WIND FLOW THROUGH THE LEEWARD ISLANDS AND SOUTHERN BAHAMAS. BUOYS ARE SHOWING 6 TO 8 FT SEAS OVER THE TROPICAL ATLC WATERS...AND 3 TO 5 OVER SUBTROPICAL WATERS. SEAS WILL BUILD MAINLY S OF 22N THIS WEEKEND INTO EARLY NEXT WEEK AS TRADES INCREASE. WARNINGS ATLC... .NONE. CARIBBEAN... .NONE. GULF OF MEXICO... .NONE. $$ FORECASTER CHRISTENSEN