000 AGXX40 KNHC 200758 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 358 AM EDT WED JUN 20 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 AND SCATTEROMETER DATA FROM THE PAST SEVERAL HOURS SHOW FRESH EASTERLY WINDS ACROSS THE EASTERN GULF...BETWEEN HIGH PRES OFF THE CAROLINAS AND A SHARP TROUGH MOVING OVER THE NW CARIBBEAN AND POISED TO CROSS THE YUCATAN AND YUCATAN CHANNEL THIS MORNING AND ENTER THE SE GULF. GLOBAL MODELS ARE IN GOOD AGREEMENT AS LEAST IN THE SHORT TERM SHOWING THE TROUGH FROM NE YUCATAN PENINSULA TO SW FLORIDA BY EARLY THIS AFTERNOON. THE GFS AND ECMWF ARE IN DECENT AGREEMENT SHOWING A LOW EMERGING OFF THE N COAST OF YUCATAN THROUGH THU WITH THE ATTENDANT TROUGH EXTENDING THROUGH THE FLORIDA BIG BEND AREA. THE UKMET IS SHOWING THE MAIN LOW CENTER A LITTLE FURTHER TO THE N BY LATE THU. THE UKMET POORLY INITIALIZES A MID LEVEL LOW OVER THE SE GULF AND TRACKS IT NNW WITH THE LOW PRES TRAILING THROUGH THU. THE NOGAPS THE WEAKEST SHOWING A TROUGH OVER THE WESTERN GULF EMERGING FROM A WEAK LOW OVER SOUTHERN MEXICO. THE OFFICIAL FORECAST CONTINUES TO BE A BLEND OF THE ECMWF AND GFS REGARDING THE POSITION...STRENGTH AND MOVEMENT OF THE LOW PRES. WIND FORECAST WILL CONTINUE TO FAVOR SLIGHTLY STRONGER GFS SOLUTION OVER THE EASTERN GULF...DUE TO A TIGHTER GRADIENT BETWEEN THE LOW PRES AND THE ATLC RIDGE. SCATTERED TO NUMEROUS SHOWERS WITH SCATTERED THUNDERSTORM WILL FOLLOW THE TROUGH INTO THE SE GULF TODAY. EXPECT SCATTERED CONVECTION ACROSS MUCH OF THE EASTERN GULF INTO THE WEEKEND AS RICH TROPICAL MOISTURE PUSHES N ON THE EAST SIDE OF THE LOW AND AHEAD OF AN UPPER TROUGH MOVING THROUGH THE DEEP SOUTH STATES. CARIBBEAN SEA AND TROPICAL N ATLC W OF 55W... A SHARP SURFACE TROUGH EXTENDS FROM WESTERN CUBA TO THE GULF OF HONDURAS THIS MORNING...AND WILL MOVE NW THROUGH THE YUCATAN PENINSULA AND YUCATAN CHANNEL INTO THE SE GULF LATER TODAY. SW FLOW ALOFT CONTINUE TO DISPLACE A LARGE AREA OF STRONG CONVECTION WELL TO THE NE OF THE TROUGH BETWEEN CENTRAL CUBA...JAMAICA AND GRAND CAYMAN. THIS CONVECTION IS AIDED IN PART BY DIVERGENCE ALOFT ON THE SE SIDE OF AN UPPER TROUGH CURRENTLY EXTENDING FROM THE N CENTRAL GULF OF MEXICO TO WESTERN CUBA. THIS MOISTURE WILL MIGRATE ACROSS WESTERN CUBA TODAY AND INTO THE FAR SE GULF. FARTHER EAST...FRESH TRADE WINDS ARE BEING ENHANCED OVER PRIMARILY THE EASTERN AND CENTRAL CARIBBEAN BY THE ADVANCE OF A TROPICAL WAVE ENTERING THE SE CARIBBEAN THIS MORNING. RECENT OBSERVATION FROM BUOY 42058 NEAR 15N75W SHOW SUSTAINED WINDS HOLDING AT 20 KT. FORECAST MAINTAINS 15 TO 20 KT E FLOW ACROSS THE FROM 55W TO THE CENTRAL CARIBBEAN...WITH UP TO 25 KT CLOSER TO THE VENEZUELAN AND COLOMBIAN COASTS. THE TROPICAL WAVE WILL MOVE THROUGH THE CENTRAL CARIBBEAN LATER TODAY THEN WILL BECOME DIFFUSE AS IT ENTERS THE SW CARIBBEAN AND INTERACTS WITH THE MONSOON TROUGH. A SECOND TROPICAL WAVE WELL E OF THE AREA WILL PUSH WEST OF 55W BY EARLY FRI...AND ENTER THE SE CARIBBEAN BY EARLY SAT. SOUTHWEST NORTH ATLC S OF 31N W OF 55W... A PERSISTENT SURFACE TROUGH IS WELL DEFINED BY LATEST SCATTEROMETER AND SURFACE DATA EXTENDING FROM 30N67W TO THE UPPER FLORIDA KEYS. BUOY OBSERVATIONS AND DATA FROM A 0208 UTC ASCAT PASS SHOW 15 TO 20 KT WINDS OVER THE AREA W OF 77W...BETWEEN THE TROUGH AND A 1022 MB SURFACE HIGH CENTERED OFF THE CAROLINAS. FURTHER WEST THE ATLC RIDGE EXTENDS E-W ALONG 27N...WEAKENED SOMEWHAT AS TROPICAL STORM CHRIS WELL N OF THE AREA NEAR 38N55W MOVES EASTWARD INTO THE N CENTRAL ATLC. THIS IS ALLOWING FAIRLY LIGHT FLOW BETWEEN THE TROUGH AND 65W. GLOBAL MODELS CONTINUE TO SHOW THE SURFACE TROUGH MIGRATING TO THE W-NW THROUGH THE NW BAHAMAS AND SE FLORIDA ACCOMPANIED BY A LARGE AMOUNT OF TROPICAL MOISTURE. THE FORECAST IS A MODEL BLEND OF THE GFS AND ECMWF CALLING FOR WINDS TO DIMINISH AFTER THU AS THE TROUGH PUSHES TO THE NW AND DAMPENING OUT AS THE HIGH PRES OFF THE CAROLINAS DRIFTS S TO A POSITION BETWEEN NE FLORIDA AND BERMUDA ALONG 30N THU INTO FRI BEFORE MERGING WITH THE ATLC RIDGE SAT AND SUN. THE LATEST GFS IS SHOWING STRONG SE TO S RETURN FLOW OFF NE FLORIDA SUN BETWEEN THE ATLC RIDGE AND DEEPENING LOW PRES RELATED TO A TROUGH IN THE GULF MOVING ACROSS NE FLORIDA. GIVEN UNCERTAINTY REGARDING THE DEVELOPMENT OF LOW PRES CENTERED ALONG THIS TROUGH IN THE MID TO EXTENDED RANGE MODELS...THE OFFICIAL FORECAST MODERATE THE SOUTHERLY FLOW AND INCLUDES 15 TO 20 KT WINDS BY SUN AFTERNOON...IN LINE WITH THE MORE CONSERVATIVE ECMWF. 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