000 AGXX40 KNHC 120727 MIMATS MARINE WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 330 AM EDT WED AUG 12 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 WEAK RIDGE ACROSS THE NORTHERN WATERS WILL CONTINUE TO SHIFT S AS A BROAD LOW LEVEL TROUGH IMPINGES FROM THE NORTH...WITH THE REMNANTS OF THE TROUGH GRADUALLY DISSIPATING THROUGH FRI. THE RIDGE WILL SHIFT BACK N ACROSS THE NORTHERN WATERS FRI NIGHT...WITH THE RIDGE AXIS MOVING JUST INLAND OVER THE NORTHERN GULF COAST OVER THE WEEKEND. THE NORTHERN VORT CENTER ASSOCIATED WITH THE TROPICAL WAVE CURRENTLY OVER THE EASTERN CARIBBEAN IS EXPECTED TO LIFT NORTHWESTWARD AWAY FROM THE WAVE OVER THE NEXT TWO DAYS AND SENDING A SURFACE TROUGH THROUGH THE FL PENINSULA AND INTO THE EASTERN GULF OF MEXICO OVER THE WEEKEND. THE MODELS VARY WITH THE TRACK AND INTENSITY OF THIS TROUGH...WITH THE GFS AMONG THE STRONGER SOLUTIONS. A TONED-DOWN VERSION OF ITS FORECAST IS PREFERRED. ELSEWHERE...EXPECTING LIGHT AND VARIABLE WINDS AT 5 TO 10 KT AND SEAS 1 TO 3 FT ACROSS THE NORTHERN GULF WATERS EXCEPT FOR SE RETURN FLOW TO OCCASIONALLY REACH 15 KT ALONG TEXAS COAST. GENERALLY E TO SE WINDS AT 10 TO 15 KT ARE EXPECTED WELL S OF THE RIDGE EXCEPT FOR THE LATE AFTERNOON AND EARLY EVENING BACKING OF WINDS TO NE AT 15 TO 20 KT ALONG THE NE COAST YUCATAN PENINSULA. CARIBBEAN AND TROPICAL ATLC...ELY TRADES HAVE RELAXED OVER THE N CENTRAL CARIBBEAN WITH TRADES OF CONCERN...SOLIDLY ABOVE 20 KT...NOW CONCENTRATED S OF 15N BETWEEN 70W AND THE TROPICAL WAVE ALONG 80W. WINDS ON THE NORTHERN EDGE OF THE TROPICAL WAVE BETWEEN JAMAICA AND THE CAYMAN ISLANDS ARE ALSO ABOVE 20 KT ACCORDING TO SHIP OBSERVATIONS TBWUK31 AND C6VQ8. THE TROPICAL WAVE HAS VERY LITTLE CONVECTION ALONG ITS AXIS AS IT MOVES W IN PHASE WITH THE SUBSIDENT SIDE OF AN UPPER ANTICYCLONE OVERHEAD. BUT TSTMS ARE FLARING IN THE GULF OF HONDURAS IN ASSOCIATION WITH AN UPPER LOW NEAR 18N95W. A SECOND WAVE ALONG 66W HAS BEEN MOVING W AT 10 KT WHICH SHOULD MOVE IT THROUGH THE CENTRAL AND W CARIBBEAN THROUGH THE WEEKEND. ASSOCIATED CONVECTION IS NOT NEARLY AS IMPRESSIVE AS THIS TIME YESTERDAY...BUT CONTINUES S OF 13N E OF THE WAVE AXIS TO THE LESSER ANTILLES. A THIRD WAVE ALONG 56W HAS A PRONOUNCED NE TO E WIND SHIFT ASSOCIATED WITH ITS PASSAGE N OF 13N. STILL BELIEVE THE GFS IS OVERDOING WIND AND SEAS ASSOCIATED WITH THE VORT CENTER CURRENTLY PASSING THROUGH THE VIRGIN ISLANDS...AND HAVE TONED DOWN FORECAST MORE IN LINE WITH UKMET. THIS NORTHERN VORT IS EXPECTED TO MOVE ON A WNW PATH BRUSHING THE GREATER ANTILLES AND N CARIBBEAN THU THROUGH SUN. MEANWHILE...THE CENTER OF NEWLY FORMED TROPICAL DEPRESSION TWO WILL CLIP THE TROPICAL N ATLC ZONE ON SUN AFTERNOON/EVENING ACCORDING TO THE LATEST NHC FORECAST. FORECAST BEGINS TO BUILD SOME WINDS AND SEAS ON SAT AS THE FORECAST TROPICAL STORM APPROACHES. SW N ATLC...1018 MB HIGH PRES NEAR 30N73W N OF THE TROUGH CURRENTLY DISSIPATING OVER NE WATERS WILL OPEN INTO AN E TO W RIDGE ACROSS THE NORTHERN WATERS WED THROUGH FRI THEN SHIFT N OF AREA SAT AND SUN. THE NORTHERN PORTION OF A TROPICAL WAVE WILL PASS W THROUGH THE SOUTHERN WATERS THU THROUGH SUN ACCOMPANIED BY ELY 15 TO 20 KT WINDS. AS PREVIOUSLY DISCUSSED...THE GFS IS A STRONGER SOLUTION WITH THE VORT CENTER ASSOCIATED WITH THE NORTHERN PORTION OF THE WAVE AND IS BELIEVED TO BE OVERDONE WITH ITS WINDS AND WW3 SEAS...SO A BLEND WITH THE SIMILARLY TIMED UKMET WAS USED FOR THE FORECAST. LOOK FOR WIDESPREAD SHOWERS AND TSTMS IN THE BAHAMAS FRI AND MOVING INTO FL OVER THE WEEKEND ASSOCIATED WITH THE WAVE/TROUGH. WARNINGS ATLC... .NONE. TS WRNG E OF AREA. CARIBBEAN... .NONE. GULF OF MEXICO... .NONE. $$ FORECASTER SCHAUER CLARK/NELSON