000 AGXX40 KNHC 261519 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1120 AM EDT THU JUL 26 2012 MARINE WEATHER DISCUSSION FOR THE GULF OF MEXICO...CARIBBEAN SEA AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W. GULF OF MEXICO... NO SIGNIFICANT CHANGE IS EXPECTED IN THE SYNOPTIC PATTERN OVER THE GULF THE NEXT FEW DAYS WITH A RIDGE AXIS SPANNING FROM CENTRAL FL TO CENTRAL TEXAS COAST. A MID LEVEL TROUGH OVER THE NE GULF IS BEGINNING TO BREAK DOWN. THE SHOWERS AND TSTMS IN THE NE GULF ASSOCIATED WITH THIS SYSTEM SHOULD GRADUALLY DIMINISH AND THE SURFACE REFLECTION OF THIS TROUGH SHOULD DISSIPATE BY TONIGHT. MODERATE TO FRESH S-SE RETURN FLOW WILL PREVAIL ACROSS THE W CENTRAL WATERS THROUGH SAT. ENHANCEMENT OF NE WINDS ALONG NW YUCATAN PENINSULA WILL OCCUR DURING EVENING HOURS THE NEXT FEW DAYS. THE GRADIENT WILL BE STRENGTHENED TONIGHT AS THE NORTHERN PORTION OF A TROPICAL WAVE APPROACHES THE BAY OF CAMPECHE. THIS WAVE SHOULD MAKE ITS WAY W OF THE AREA SAT. THE GFS FORECAST LOOKS REASONABLE HERE. CARIBBEAN SEA AND TROPICAL N ATLC W OF 55W... THE TROPICAL WAVE PASSING THROUGH THE NW CARIBBEAN SHOULD EXIT THE AREA BY FRI. SHOWERS AND TSTMS ARE PRIMARILY CONFINED TO THE AREA WITHIN 150 NM N OF HONDURAS NEAR THE WAVE AND ARE BEGINNING TO MOVE INTO THE GULF OF HONDURAS. TO THE E OF THIS WAVE...HIGH PRES N OF THE AREA IS MAINTAINING FRESH TO STRONG E-NE WINDS ACROSS THE BASIN. EXPECT WINDS TO INCREASE TO AROUND 30 KT NEAR COAST OF COLOMBIA LATER OVERNIGHT TONIGHT THROUGH FRI EVENING WITH MAX SEAS BUILDING TO 11-14 FT ACROSS THE SOUTH-CENTRAL CARIBBEAN. THE AREA OF FRESH-STRONG WINDS WILL ALSO EXPAND WESTWARD REACHING THE COAST OF NICARAGUA BY FRI. THE GFS IS DOING A REASONABLY GOOD JOB DEPICTING THE TRADE WINDS AND THE WAVE IN THE NW CARIBBEAN. A SECOND TROPICAL WAVE LIES ALONG 47W. THIS WAVE WILL CONTINUE WESTWARD THROUGH THE TROPICAL N ATLC FRI INTO SAT MORNING...THE E CARIBBEAN SAT AFTERNOON THROUGH SUN...AND INTO THE CENTRAL CARIBBEAN MON. THE WAVE IS EMBEDDED IN AN AREA OF DRY AIR AND AFRICAN DUST THAT IS INHIBITING CONVECTION. WINDS ARE ONLY A MODERATE BREEZE WITH THE SYSTEM. A SIMILAR AIRMASS IS ALSO IMPACTING THE TROPICAL WAVE ALONG 30W. THE CYCLONIC CIRCULATION ASSOCIATED WITH THIS WAVE IS VERY BROAD AT THE MOMENT. THE 06Z GFS AND 00Z UKMET SHOW CONSOLIDATION OF THIS SYSTEM INTO A BETTER DEFINED LOW PRES CENTER AS IT MOVES INTO THE TROPICAL N ATLC SUN/MON COMPARED TO THE 00Z ECMWF. THESE THREE MODELS ARE IN REASONABLE AGREEMENT ON THE TIMING OF THE SYSTEM. GIVEN ITS CURRENT ENVIRONMENT AND STRUCTURE... CONFIDENCE IS LOW IN CARRYING A SYSTEM AS STRONG AS THE GFS/UKMET IN THE MEDIUM RANGE. THE GRIDS WERE ADJUSTED TOWARD A BLEND OF THE GFS AND THE WEAKER ECMWF. SW N ATLC S OF 31N W OF 65W... A COLD FRONT LIES FROM 31N62W TO 29N68W AND BECOMES STATIONARY TO 31N74W. SHIP OBSERVATIONS AND THE 0122 UTC ASCAT AND 0330 UTC OSCAT PASSES SHOW FRESH S TO SW WINDS STILL LIE N OF 29N E OF THE BOUNDARY TO 50W. JASON1 AND JASON2 PASSES ALSO CAPTURED SEAS IN THE 8-9 FT RANGE AHEAD OF THE FRONT. THE FRONT HAS FORCED THE SUBTROPICAL RIDGE SOUTHWARD FROM ITS USUAL POSITION. THE RIDGE AXIS CURRENTLY EXTENDS ACROSS THE REGION FROM 24N65W TO 26N80W BUT WILL LIFT TO 28N BY MON. MODERATE TO FRESH TRADE WINDS WILL PERSIST S OF THE RIDGE AS THE NORTH END OF TWO TROPICAL WAVES MAKE THEIR WAY THROUGH SE WATERS. THE FIRST WAVE IS EXPECTED TO MOVE THROUGH PUERTO RICO EARLY SUN WHILE THE SECOND WAVE WILL BEGIN TO APPROACH FAR SE WATERS MON. SEE THE SECTION ABOVE FOR MORE DETAILS ON THESE ATLC TROPICAL WAVES. NOTE...GRIDDED MARINE FORECAST IS AVAILABLE AT WWW.NHC.NOAA.GOV/TAFB/GRIDDED_MARINE GULF OF MEXICO... .NONE. CARIBBEAN SEA... .NONE. SW N ATLANTIC... .NONE. FOR ADDITIONAL INFORMATION PLEASE VISIT WWW.HURRICANES.GOV/MARINE $$ FORECASTER SCHAUER