000 AGXX40 KNHC 261853 MIMATS MARINE WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 300 PM EDT TUE MAY 26 2009 MARINE WEATHER DISCUSSION FOR THE GULF OF MEXICO...CARIBBEAN SEA AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W. GULF OF MEXICO... SFC OBSERVATIONS AND SCATTEROMETER DATA SHOW GENERALLY 10-15 KT SLY FLOW ACROSS THE AREA...THOUGH HIGHER GUSTS HAVE BEEN REPORTED IN SCATTERED TSTMS ACROSS THE NE WATERS...TRIGGERED BY AN UPPER SHORTWAVE TROUGH. VISIBILITIES ARE RESTRICTED OVER THE BAY OF CAMPECHE IN SMOKE EXTENDING N FROM WILD FIRES OVER SOUTHERN MEXICO. MAIN FORECAST ISSUE INVOLVES THE TIMING... LOCATION AND STRENGTH OF AN APPROACHING FRONT. MANY OF THE GLOBAL MODELS ARE IN AGREEMENT IN FORECASTING A FRONT TO MOVE INTO THE FAR NW GULF WED EVENING OR WED NIGHT THEN PUSH ACROSS THE N GULF WATERS THU AND FRI. GFS SHOWS THE FRONT SLIDING SLIGHTLY S INTO THE CENTRAL GULF BY SAT. BOTH THE GFS AND ECMWF DEVELOP A FRONTAL WAVE OVER THE N GULF COAST. THESE MODELS ARE SHOWING OUTPUT OF 20+ KT IN THE VICINITY OF LOW. OUR FORECAST DOES NOT REFLECT THESE SMALL SCALE LOWS...BUT GENERALLY AGREES WITH THE FRONTAL POSITIONS IN THE GFS AND ECMWF. SW 15-20 KT WINDS ARE EXPECTED ACROSS THE N WATERS AHEAD OF THE FRONT. SCATTERED SHOWERS AND TSTMS ARE ALSO FORECAST AHEAD OF THE FRONT IN AN UPPER DIFFLUENT ZONE. CARIBBEAN AND TROPICAL ATLC W OF 55W... A 10Z QUIKSCAT PASS SHOWED 20-25 KT TRADES PERSISTING OFF THE VENEZUELAN COAST. THE FRESH TO STRONG TRADES HAVE BEEN OCCURRING IN THAT REGION FOR THE PAST FEW DAYS DUE TO THE PRESSURE GRADIENT BETWEEN A NEARLY STATIONARY HIGH JUST E OF BERMUDA AND LOWER PRESSURE OVER NRN SOUTH AMERICA. A TROPICAL WAVE ALONG 68W IS TRACKING W NEAR 15 KT THROUGH THE SOUTHERN CARIBBEAN. E TO SE 15-20 KT WINDS ARE PRESENT ACROSS MUCH OF THE REMAINDER OF THE EASTERN AND CENTRAL CARIBBEAN AND E OF THE WINDWARDS. ELSEWHERE IN THE WESTERN CARIBBEAN AND OVER ATLC WATERS N OF 15N BETWEEN 55W AND THE ISLANDS...WINDS REMAIN 10-15 KT DUE TO REMNANT TROUGHING N-NE OF THOSE AREAS. THE W ATLC LOW/TROUGH IS EXPECTED TO PUSH N...ALLOWING RIDGING TO BUILD N OF THE AREA. THIS PATTERN WILL ALLOW WINDS TO INCREASE ACROSS MUCH OF THE CARIBBEAN... REMAINING STRONGEST OVER THE S CENTRAL AND E CARIBBEAN...WED THROUGH SAT. ACCORDINGLY...SEAS WILL BUILD TO 8-10 FT OVER THE S CENTRAL WATERS. SUBTROPICAL ATLANTIC W OF 55W... SURFACE LOW PRES FORMED EARLIER THIS MORNING NEAR 29N75W AND SINCE HAS BEEN TRACKING NWD...NOW CENTERED NEAR 30N75W. A HI-RES QSCAT PASS FROM AROUND 1030 Z REVEALED A SWATH OF 20-25 KT E TO SE WINDS N AND E OF AN ELONGATED AND ILL-DEFINED SFC CENTER/TROUGH AXIS. THERE ARE HIGHER WIND VECTORS IN THE PASS ...BUT THESE ARE RAIN FLAGGED. CONVECTION IS HIGHLY DISORGANIZED AND MAINLY CONFINED TO THE N AND E OF THE TROUGH AXIS. A LARGER AREA OF CONVECTION HAS RECENTLY BLOSSOMED JUST E OF THE BAHAMAS FROM 23N-26N BETWEEN 70W-73W. THIS ACTIVITY IS MAINLY FUELED BY DIFFLUENCE ALOFT. GFS DEVELOPS THIS CONVECTIVE AREA AND DRIFTS IT NWD. GIVEN THE RATHER POOR PERFORMANCE OF THE GFS WITH THE CURRENT LOW...DID NOT INCLUDE THE DEVELOPMENT OF A SECONDARY SFC LOW DEVELOPING AS IT APPEARS TO BE MAINLY CONVECTIVE FEEDBACK. HIGH PRES WILL BUILD IN THE WAKE OF THE LOW WED THROUGH SAT. WARNINGS ATLC... .NONE. CARIBBEAN... .NONE. GULF OF MEXICO... .NONE. FORECASTER CANGIALOSI. TROPICAL PREDICTION CENTER.