000 AGXX40 KNHC 170751 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 351 AM EDT SUN JUN 17 2012 MARINE WEATHER DISCUSSION FOR THE GULF OF MEXICO...CARIBBEAN SEA AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W. GULF OF MEXICO... BUOY DATA OVER THE NORTHERN GULF SHOW A WEAK TROUGH MOVING THROUGH THE N CENTRAL GULF INTO THE NW GULF TO BE VERY BROAD THIS MORNING. BUOY OBSERVATIONS AND DATA FROM A 0310 UTC ASCAT PASS SHOW MODERATE TO FRESH EASTERLY WINDS ARE NOTED OVER THE N CENTRAL GULF BETWEEN THE TROUGH AND HIGH PRES CENTERED OVER THE TENNESSEE VALLEY. THE TROUGH WILL MIGRATE INTO THE TEXAS COAST BY LATE SUN. GFS AND ECMWF INDICATE THE HIGH PRES WILL STRENGTHEN SLIGHTLY SUN INTO MON JUST AS A WEAK TROUGH MOVES THROUGH THE YUCATAN INTO THE BAY OF CAMPECHE. THIS WILL ALLOW WINDS AND SEAS TO INCREASE OVER THE EASTERN GULF STARTING MON. FORECAST FAVORS THE SOMEWHAT STRONGER GFS SHOWING 15 TO 20 KT TO SE WINDS IN A BROAD SWATH FROM SW FLORIDA TO TEXAS BY TUE...WITH 20 TO 25 KT IN THE FAR SE GULF LATE TUE. THE MAIN FORECAST ISSUE WED AND THU REMAINS THE MOVEMENT OF LOW PRES FROM NORTHERN CENTRAL AMERICA THROUGH SOUTHERN MEXICO INTO THE SW GULF BY WED...MERGING WITH BROAD TROUGHING ALREADY IN THE AREA. WHILE THE GLOBAL MODELS ARE IN GENERAL ACCORD WITH REGARD TO THIS FEATURE...THE GFS REMAINS THE MOST AGGRESSIVE SHOWING A 1004 MB LOW NEAR 20N94W BY 21/00Z. THE UKMET AND NOGAPS ARE SIMILAR WITH THE ECMWF THE MOST CONSERVATIVE SHOWING A BROAD 1007 MB LOW IN THE SAME AREA. THE OFFICIAL FORECAST FAVORS THE ECMWF WITH THE LOW IN THE SW GULF AND INCLUDES PERSISTENT SE FLOW OVER THE REMAINDER OF THE GULF. GIVEN THE PERSISTENT FETCH AND DURATION OF THE SE FLOW...SEAS FORECAST FAVORS OPERATIONAL AND ENSEMBLE WAVEWATCH SHOWING SEAS TO 8 FT IN THE CENTRAL GULF BY MIDWEEK. SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WILL COVER MUCH OF THE CENTRAL AND SOUTHERN GULF BY WED. CARIBBEAN SEA AND TROPICAL N ATLC W OF 55W... A 0308 UTC ASCAT PASS SHOWED BROAD CYCLONIC TURNING IN THE SW GULF NEAR 12N80W. THE TROPICAL WAVE THAT HAD BEEN MOVING THROUGH FROM THE CENTRAL CARIBBEAN INTO THE SW CARIBBEAN IS BECOMING HARDER TO TRACK AS IT MERGES WITH THE OVERALL CYCLONIC FLOW IN THE SW CARIBBEAN. THE 17/00Z SURFACE ANALYSIS SHOWED A TROUGH OVER THE GULF OF HONDURAS DRIFTING INTO THE YUCATAN PENINSULA. A RIDGE EXTENDING FROM HIGH PRES OVER THE CENTRAL ATLC ALONG 23N TO NE OF THE LEEWARD ISLANDS IS MAINTAINING FRESH SE FLOW ACROSS THE EASTERN CARIBBEAN AND TROPICAL N ATLC W OF 55W. SPEED CONVERGENCE OF THIS SE FLOW ALONG WITH SOME MODEST ASSISTANCE FROM WEAK DIVERGENCE ALOFT IS ENHANCING CLUSTERS OF CONVECTION OVER THE CENTRAL CARIBBEAN N OF 15N. FORECAST PHILOSOPHY REMAINS THE SAME WITH THE LOW OVER THE SW CARIBBEAN MIGRATING WNW ACROSS NICARAGUA AND HONDURAS THROUGH MON. THE GFS IS MORE IN LINE WITH THE ECMWF SHOWING THE LOW STAYING MAINLY OVER LAND AND NOT EMERGING DIRECTLY OVER THE GULF OF HONDURAS AS IT WAS DEPICTING YESTERDAY. THIS WILL KEEP THE LOW FROM DEEPENING APPRECIABLY THROUGH EARLY NEXT WEEK. THROUGH LATE TUE...TROUGHING WILL EXTEND FROM THE LOW PRES THROUGH THE NW GULF TOWARD CUBA...COMING INTO PHASE WITH A TROUGH CURRENTLY OVER THE BAHAMAS. SHORT WAVE RIDGING TO THE EAST OF THE TROUGH WILL EXTEND FROM JAMAICA TO PANAMA...TEMPORARILY SUPPRESSING FURTHER TO THE SOUTH THE MONSOON TROUGH THAT HAS BEEN RESIDENT OVER THE FAR SW CARIBBEAN. MEANWHILE A POORLY ORGANIZED TROPICAL WAVE CURRENTLY NEAR 40W WILL SHIFT WEST OF 55W LATE MON AND INTO THE FAR SE CARIBBEAN BY LATE TUE. FORECAST FAVORS THE STRONGER GFS SHOWING 20 TO 25 KT E TO SE WINDS OVER THE FROM 55W THROUGH THE CENTRAL CARIBBEAN TUE THROUGH THU. WAVEWATCH ENSEMBLES AND WW3/FNMOC ENSEMBLE INDICATE SEAS REACHING 9 FT IN THE CENTRAL CARIBBEAN NEAR 75W BY WED IN RESPONSE TO THE INCREASED E TO SE FLOW. SOUTHWEST NORTH ATLC S OF 31N W OF 55W... SCATTEROMETER DATA SHOW A PERSISTENT BUT WEAKENING 1011 MB LOW PRES AREA NEAR 28N68W. THIS FEATURE IS SUPPORTED BY AN UPPER CYCLONE CENTERED NEAR 31N70W WITH AN UPPER TROUGH EXTENDING TO CENTRAL CUBA. THE DRY MID TO UPPER LEVEL AIR ON THE WEST SIDE OF THE TROUGH IS SUPPRESSING CONVECTIVE DEVELOPMENT OVER THE AREA N OF 22N AND W OF 70W. BUOY AND SCATTEROMETER DATA ALSO SHOW NE WINDS N OF THE BAHAMAS W OF 75W HAVE DIMINISHED TO 10 TO 15 KT...DOWN FROM 15 TO 20 KT YESTERDAY...WITH SEAS TO 6 FT IN N AND NE SWELL AT BUOY 41010 NEAR 29N78W. THE SURFACE LOW IS EXPECTED TO DRIFT N OF THE AREA AS THE UPPER LOW LIFTS NE BY LATE TODAY...LEAVING A QUASI- STATIONARY TROUGH FROM 31N67W TO THE SOUTHERN BAHAMAS. BOUNDARY LAYER RIDGING ALONG 23N FROM THE CENTRAL ATLC WEST TO 65W WILL LIFT N IN CONCERT WITH THE LOW LIFTING N...REACHING 28N BY EARLY MON. GLOBAL MODELS ARE IN CLOSE AGREEMENT SHOWING THE MAIN SYNOPTIC FEATURE FROM MON THROUGH THU BEING THE TROUGH...WHICH SLOWLY DRIFTS NW THROUGH THE BAHAMAS IN PHASE WITH A DEVELOPING TROUGH OVER THE NW CARIBBEAN. MUCH OF THE AREA S OF 28N WILL SEE 15 TO 20 KT E TO SE FLOW THROUGH MID WEEK. OFFICIAL FORECAST FOLLOWS SLIGHTLY STRONGER GFS GUIDANCE. SCATTERED SHOWERS AND ISOLATED TSTMS WILL ACCOMPANY THE TROUGH FROM THE TCI/SOUTHERN BAHAMAS TO THE NORTHERN BAHAMAS MON THROUGH THU. NOTE...GRIDDED MARINE OUTPUT IS AVAILABLE AT WWW.NHC.NOAA.GOV/TAFB/GRIDDED_MARINE (LOWER CASE) GULF OF MEXICO... .NONE. CARIBBEAN SEA... .NONE. SW N ATLANTIC... .NONE. FOR ADDITIONAL INFORMATION PLEASE VISIT WWW.HURRICANES.GOV/MARINE $$ FORECASTER CHRISTENSEN