000 AGXX40 KNHC 160801 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 400 AM EDT SAT JUN 16 2012 MARINE WEATHER DISCUSSION FOR THE GULF OF MEXICO...CARIBBEAN SEA AND TROPICAL N ATLC...AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W. GULF OF MEXICO... A 0330 UTC ASCAT PASS INDICATED THAT A WEAK 1014 MB SURFACE LOW CENTERED NEAR 27N88W AT 16/00Z APPEARS TO HAVE OPENED INTO A TROUGH OVER THE N CENTRAL GULF EXTENDING FROM MOBILE BAY TO 26N ALONG 88W. THE 16/00Z RUNS OF THE GFS...UKMET AND ECMWF SHOW THIS FEATURE MIGRATING W MAKING A LANDFALL ALONG THE TEXAS COAST BY LATE SUN. THE 00Z NAM IS MORE AGGRESSIVE SHOWING THE TROUGH DEEPENING INTO A 1008 LOW OVER THE NW GULF ALTHOUGH THIS IS A LIKELY CONVECTIVE FEEDBACK ISSUE IN THE MODEL. THE 16/00Z UKMET INITIALIZED WELL WITH 15 TO 20 KT BETWEEN THE TROUGH AND A SURFACE RIDGE OVER THE SE UNITED STATES. FORECAST REFLECTS A BLEND OF THE UKMET AND SLIGHTLY WEAKER GFS HOLDING MODERATE TO FRESH E WINDS ON THE NE SIDE OF THE TROUGH THROUGH THE WEEKEND ACROSS THE NORTHERN GULF. A PERSISTING TROUGH WILL LINGER OVER THE SOUTHERN BAY OF CAMPECHE THROUGH MID WEEK...MAINTAINING SCATTERED CONVECTION WITH MAXIMUM CONVECTION IN THE LATE EVENING OVER THE EASTERN PORTION OF THE BAY. BY MON...CONSENSUS OF GFS/ECMWF/UKMET SHOW WEAK LOW PRES DEVELOPING OVER THE NW CARIBBEAN. THE ATLC RIDGE WILL REMAIN IN PLACE ALONG ROUGHLY 32N THROUGH THE CAROLINAS. THE TIGHT PRES GRADIENT BETWEEN THE RIDGE TO THE N AND THE WEAK LOW PRES TO THE S WILL ALLOW MODERATE TO FRESH E TO SE WINDS OVER THE EASTERN PORTION OF THE GULF THROUGH MON. MODELS SHOW A TROUGH MIGRATING INTO THE S CENTRAL GULF BY MID WEEK. FORECAST FOR TUE AND WED REFLECTS A GFS/ECMWF BLEND BRINGING WITH WINDS INCREASING TO 20 TO 25 KT OVER THE N CENTRAL GULF. WAVE ENSEMBLES SHOW SEAS REACHING 8 FT IN THE N CENTRAL GULF BY LATE WED. CARIBBEAN SEA AND TROPICAL N ATLC W OF 55W... A WEAK TROPICAL WAVE OVER THE SE CARIBBEAN ALONG 65W IS DRIFTING W AND MAY BECOMING ABSORBED INTO A BROAD LOW OVER COLOMBIA ALONG AN ACTIVE MONSOON TROUGH EXTENDING ACROSS THE SW CARIBBEAN. BUOY AND SCATTEROMETER DATA INDICATE 15 TO 20 KT FLOW PERSIST OVER THE CENTRAL CARIBBEAN...WITH SEAS TO 8 FT AT BUOY 42058 NEAR 15N75W. 10 TO 15 KT E FLOW COVERS THE TROPICAL N ATLC W OF 55W AND THE FAR EASTERN CARIBBEAN S OF WEAK ATLC RIDGING ALONG 21N. A 0330 UTC ASCAT PASS SHOWED E WINDS TO 20 KT OVER THE GULF OF HONDURAS. THE MAIN FORECAST ISSUE THROUGH MID WEEK WILL BE THE DEVELOPMENT OF LOW PRES OVER THE SW CARIBBEAN ALONG THE MONSOON TROUGH. THE 16/00Z RUNS OF THE GFS AND ECMWF INITIALIZE THE 1009 MB SURFACE LOW OFF COSTA RICA AND SHOW IT DRIFTING NNW TO NE NICARAGUA BY EARLY MON. THE UKMET IS SIMILAR BUT SHOWS THE LOW MOVING INLAND AND WEAKENING. THE ECMWF DIVERGES SLIGHTLY FROM THE GFS MON THROUGH WED...SHOWING A WEAKER LOW MOVING THROUGH HONDURAS AND GUATEMALA...WHILE THE GFS MAINTAINS A 1007 MB LOW OVER THE GULF OF HONDURAS BY EARLY TUE. MEANWHILE THE ATLC RIDGE BUILDS NE OF THE AREA RESULTING IN ENHANCED TO SE FLOW FROM THE TROPICAL N ATLC W OF 55W THROUGH THE CENTRAL CARIBBEAN WITH E WINDS REACHING 25 KT OVER THE S CENTRAL CARIBBEAN. WW3/FNMOC ENSEMBLE WAVE GUIDANCE ALONG WITH DETERMINISTIC MODELS SHOW WAVE HEIGHTS OVER THE CENTRAL CARIBBEAN DIMINISHING SLIGHTLY THROUGH THE WEEKEND...BUT BUILDING AGAIN TO 8 OR EVEN 9 FT MON THROUGH WED AS THE FETCH AND DURATION OF E FLOW INCREASES. THE SLOWLY MIGRATING LOW PRES OVER THE WESTERN CARIBBEAN WILL MAINTAIN SCATTERED CONVECTION THROUGH MID WEEK. SOUTHWEST NORTH ATLC S OF 31N W OF 55W... A WEAK LOW PRES AREA SHOWS UP NEAR 31N65W JUST S OF BERMUDA...WITH A TRAILING TROUGH THROUGH THE NORTHERN BAHAMAS. WEAK RIDGING EXTENDS ALONG 21N FROM THE CENTRAL ATLC TOWARD THE SOUTHERN BAHAMAS. SCATTERED SHOWERS AND TSTMS EXTEND E TO W ALONG 24N W OF 65W...ASSOCIATED WITH A WEAK SHORT WAVE DISTURBANCE IN THE MID LEVELS OF THE ATMOSPHERE INTERACTING WITH THE WEAK SURFACE BOUNDARY. BUOY AND DATA FROM A 0152 UTC ASCAT PASS INDICATE 15 TO 20 KT NE FLOW PERSISTS N OF 29N W OF 75W...BETWEEN THE TROUGH AND HIGH PRES OVER THE CAROLINAS. BUOY AND SCATTEROMETER DATA ALSO SHOW SW WINDS TO 20 KT E OF THE TROUGH AXIS AND SE OF THE LOW N OF 25N BETWEEN 60W AND 65W. SHORT TERM FORECAST REFLECT MODEL CONSENSUS WITH THE WEAK LOW FILLING AND LIFTING NE...LEAVING A TRAILING TROUGH THROUGH THE CENTRAL AND SOUTHERN BAHAMAS INTO EARLY NEXT WEEK. THE TROUGH COMES IN PHASE WITH LOW PRES MOVING INTO THE NW CARIBBEAN BY LATE MON...AND DRIFTS SLOWLY NE TUE AND WED. THE SHORT TERM FORECAST THROUGH THE WEEKEND CALLS FOR NE FLOW N OF THE BAHAMAS TO DIMINISH AS THE LOW FILLS. FOR EARLY NEXT WEEK INTO MID WEEK...GFS AND ECMWF SHOW THE ATLC RIDGE BUILDING AND WITH MODERATE TO FRESH E TO SE FLOW FOLLOWING THE NW MOVING TROUGH. SEAS REMAIN GENERALLY LESS THAN 8 FT. 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