000 AGXX40 KNHC 080634 MIMATS MARINE WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 245 AM EDT SAT AUG 08 2009 MARINE WEATHER DISCUSSION FOR THE GULF OF MEXICO...CARIBBEAN SEA AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W. SW ATLC W OF 55W... A WEAK RIDGE EXTENDING ALONG 30N CONTINUES TO BE THE DOMINANT FEATURE OF THE AREA MAINTAINING GENERALLY LIGHT CONDITIONS AS SEEN IN BUOY AND SHIP OBSERVATIONS TONIGHT AND THE 0130 ASCAT PASS. THE SAME PASS SHOWS THE FAR SOUTHERN WATERS IN THE AREA WITH E TO SE WINDS IN THE 15-20 KT RANGE. THE RIDGE IS FORECAST TO WEAKEN AS THE FRONTAL BOUNDARY CURRENTLY JUST NORTH OF THE AREA DISSIPATES BUT CARRIES ITS REMNANT SURFACE TROUGH INTO NORTH WATERS SAT WITH THE TROUGHING LINGERING THROUGH TUE. TROPICAL ATLC AND CARIBBEAN SEA... A TROPICAL WAVE IS CURRENTLY ALONG 74W MOVING W 15 KT. THE WAVE WILL MOVE ACROSS THE REMAINDER OF THE CENTRAL CARIBBEAN SEA THROUGH TONIGHT...THEN ACROSS THE WESTERN DURING THE WEEKEND...EXITING THE AREA MON. ANOTHER TROPICAL WAVE 56W AND IS MOVING W ABOUT 15 KT. THERE IS LITTLE CONVECTION ASSOCIATED WITH THIS WAVE. INSTEAD...MOISTURE AND CONVECTIVE ACTIVITY CAN BE FOUND WITH THE SURFACE TROUGH APPROXIMATELY 350-450 NM E OF THE WAVE. GLOBAL MODELS ARE RATHER PERSISTENT IN HINTING AT THE DEVELOPMENT OF A SURFACE LOW FORMING ALONG THE TROUGH AS IT LIES UNDER THE REAR RIGHT QUADRANT OF THE UPPER JET ON THE S SIDE OF THE UPPER LOW NEAR 27N45W. THERE IS SOME AGREEMENT ON TRACKING THE LOW/TROUGH WNW TO NEAR 15N55W BY SUN AFTERNOON...BUT THE MODELS HAVE BACKED OFF ON THE STRENGTH OF ANY LOW. THIS SLOW MOVING TROUGH WILL JAM UP THE WESTWARD PROGRESS OF ANY RIPPLES WITHIN THE ITCZ FOR THE NEXT FEW DAYS UNTIL THE STRONG TROPICAL WAVE CURRENTLY PASSING THROUGH THE CAPE VERDES MOVES INTO THE HIGH SEAS AREA EARLY NEXT WEEK. TRADES WILL CONTINUE IN THE 20-25 KT RANGE OVER MUCH OF THE CENTRAL CARIBBEAN...WITH THE POSSIBILITY OF 25-30 KT WINDS OVER A SMALL AREA ALONG THE COAST OF COLOMBIA THROUGH MON MORNING. LATEST WAVEWATCH BUILDS SEAS NEAR THE COAST OF COLOMBIA TO 13 FT DURING THE WEEKEND...AND THEN DROPS THEM QUITE RAPIDLY EARLY NEXT WEEK TO ABOUT 8 OR 9 FT AS GRADIENT RELAXES OVER JUST ABOUT THE ENTIRE CARIBBEAN. THIS APPEARS REASONABLE AT THE PRESENT TIME. GULF OF MEXICO... WEAK RIDGE REMAINS IN TRACT ACROSS THE NORTHERN GULF COASTAL PLAIN. BOTH BUOY OBSERVATIONS AND A ASCAT PASS 0310 UTC SHOWED MOSTLY LIGHT WINDS WITH THE BUOYS REPORTING SEAS OF 1-2 FT. THE EXCEPTION LIES IN THE BAY OF CAMPECHE WHERE WINDS IN THE 20 TO 25 KT RANGE CAN BE FOUND NEAR THE NORTHERN EDGE OF THE TROPICAL WAVE ALONG 92W. BOTH THE GLOBAL MODELS AND THE REGIONAL NAM GUIDANCE ARE IN VERY GOOD AGREEMENT THAT THE RIDGE WILL HOLD ACROSS THE NORTHERN GULF THROUGH EARLY NEXT WEEK WITH LITTLE OVERALL CHANGE IN PRESENT OBSERVED CONDITIONS. THE ONLY UNCERTAINTY IN THE LONG RANGE OF THIS FORECAST PACKAGE IS WHETHER THE NORTHERN PORTION OF CARIBBEAN TROPICAL WAVE CURRENTLY ALONG 74W MOVES INTO THE FAR SE GULF WATERS. MODELS...FOR THE MOST PART...ARE VERY LOW KEY WITH THIS SCENARIO IN SHOWING A SLIGHT WIND SHIFT OVER THE FAR SE GULF LATE TUE INTO WED. FOR THIS FORECAST WILL STATE TROPICAL WAVE MAY ENTER THE SE GULF AT THAT TIME...AND WAIT TO SEE HOW FUTURE MODEL GUIDANCE HANDLES THIS FEATURE. WARNINGS ATLC... .NONE. CARIBBEAN... .NONE. GULF OF MEXICO... .NONE. $$ FORECASTER SCHAUER CLARK/AGUIRRE