000 AGXX40 KNHC 130758 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 358 AM EDT TUE AUG 13 2013 MARINE WEATHER DISCUSSION FOR THE GULF OF MEXICO...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W...AND THE SW N ATLANTIC INCLUDING THE BAHAMAS. ...GULF OF MEXICO... MODEL PREFERENCE: GFS/ECMWF BLEND WITH HIGH CONFIDENCE THROUGH WED...MODERATE CONFIDENCE THEREAFTER. NWPS THROUGH WED THEN MWW3. A RIDGE EXTENDS FROM THE WESTERN ATLC ACROSS N FLORIDA TO A 1018 MB HIGH PRES CENTER OVER THE NE GULF...TO THE TEXAS/LOUISIANA BORDER. AN UPPER LOW CENTERED OVER THE NORTHERN COAST OF YUCATAN AND DRIFTING W IS SUPPORTING A TROPICAL WAVE MOVING INTO THE NW CARIBBEAN. THE NORTHERN EXTENT OF THIS WAVE WILL APPROACH THE STRAITS OF FLORIDA AND S CENTRAL LATER THIS MORNING. THE GRADIENT BETWEEN THE RIDGE TO THE N AND THE TROPICAL WAVE TO THE SOUTH WILL ALLOW 15 TO 20 KT WINDS ACROSS THE STRAITS OF FLORIDA AND APPROACHES TO THE YUCATAN CHANNEL IN THE S CENTRAL GULF. AN ASCAT PASS FROM 0236 UTC INDICATED WINDS WERE ALREADY STARTING TO REACH 20 KT OVER AREAS OF THE S CENTRAL GULF. CLUSTERS OF CONVECTION ARE PULSING OVER THE SE GULF AS WELL DUE A COMBINATION OF LOWER LEVEL CONVERGENCE DUE TO THE ENHANCED EASTERLY FLOW THROUGH THE STRAITS OF FLORIDA AND ALSO DUE TO DIVERGENCE ALOFT ON THE EASTERN SIDE OF THE UPPER LOW. LITTLE CHANGE IS EXPECTED THROUGH MID WEEK. FOR LATER IN THE WEEK...GLOBAL MODELS ARE IN A LITTLE BETTER AGREEMENT WITH THE GFS NOT AS MUCH OF AN OUTLIER. THE GFS...ALONG WITH THE CANADIAN...REMAIN THE ONLY MODELS INDICATING THE MOVEMENT OF LOW PRES INTO THE S CENTRAL GULF FROM THE WESTERN CARIBBEAN. BUT THE GFS IS A BIT WEAKER WITH THIS FEATURE THAN EARLIER. OFFICIAL FORECAST IS A GFS/ECMWF BLEND RENDERING A SLIGHTLY LOWER INTENSITY ON THE LOW THAN IN THE PREVIOUS OFFICIAL FORECAST. STILL CALLING FOR SOUTHERLY FLOW WITH UP TO 20 TO 25 KT OVER THE EASTERN GULF WITH SEAS REACHING 8 FT IN THE AREA OF STRONGEST WINDS THIS WEEKEND. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... MODEL PREFERENCE: GFS/OFFICIAL BLEND WITH HIGH CONFIDENCE. AN UPPER LOW CENTERED OVER THE NORTHERN COAST OF YUCATAN IS SUPPORTING A TROPICAL WAVE MOVING THROUGH THE CENTRAL CARIBBEAN INTO THE WESTERN CARIBBEAN. THE WAVE IS INTERACTING WITH THE MONSOON TROUGH OVER THE SW CARIBBEAN TO DEVELOP AN AREA OF 1009 MB LOW PRES...CURRENTLY CENTERED NEAR 12N81W. A SECOND TROPICAL WAVE IS MOVING INTO THE EASTERN CARIBBEAN...ALTHOUGH THIS FEATURE WILL LIKELY LOSE IDENTITY THROUGH LATE TODAY AS HIGH PRES BUILDS OVER THE EASTERN CARIBBEAN FROM THE SUBTROPICAL ATLC. THE BUILDING RIDGE IS MAINTAIN 20 TO 25 KT WINDS OVER MUCH OF THE CENTRAL CARIBBEAN...MAINLY S OF HISPANIOLA. AS THE RIDGE BUILD BEHIND THE WESTERNMOST TROPICAL WAVE THROUGH WED...THE BEST AREA FOR 20 TO 25 KT WINDS WILL SHIFT S TO THE COAST OF COLOMBIA. SEAS UP TO 9 FT CAN BE EXPECTED THROUGH THE CENTRAL CARIBBEAN AS A RESULT THROUGH THU. THERE REMAINS GOOD MODEL CONSENSUS IN THE SHORT TERM SHOWING THE LOW PRES REMAINING IN THE SW CARIBBEAN TODAY...THEN WEAKENING SOMEWHAT AS IT DRIFTS NW AWAY FROM SUPPORTING SW FLOW OF THE MONSOON TROUGH TONIGHT INTO THE NW CARIBBEAN AND NORTHERN CENTRAL AMERICA. EXPECT INCREASED E TO SE WINDS TO 20 TO 25 KT OVER THE GULF OF HONDURAS MAINLY OVERNIGHT BY LATE IN THE WEEK. ...SW N ATLANTIC W OF 55W INCLUDING THE BAHAMAS... MODEL PREFERENCE: GFS/ECMWF/OFFICIAL BLEND WITH HIGH CONFIDENCE. MWW3 FOR WAVE HEIGHTS. A RIDGE EXTENDS E TO W ALONG ROUGHLY 30N. THE INTERACTION OF THE RIDGE WITH A TROPICAL WAVE MOVING THROUGH THE CENTRAL CARIBBEAN IS SUPPORTING 15 TO 20 KT WINDS AND SEAS UP TO 6 FT MAINLY OVER THE APPROACHES TO THE WINDWARD PASSAGE. ELSEWHERE LIGHT TO MODERATE FLOW PREVAILS WITH SEAS MAINLY 2 TO 4 FT. THE RIDGE WILL SHIFT S BY WED AS A WEAK FRONTAL BOUNDARY STALLS JUST N OF THE AREA. SW WINDS WILL INCREASE SLIGHTLY OVER THE OFFSHORE WATERS OFF NE FLORIDA TODAY THROUGH THU. OTHERWISE LITTLE CHANGE IS EXPECTED. $$ .WARNINGS...ANY CHANGES IMPACTING COASTAL NWS OFFICES WILL BE COORDINATED THROUGH AWIPS 12 PLANET CHAT OR BY TELEPHONE: .GULF OF MEXICO... GMZ011...NONE. GMZ013...NONE. GMZ015...NONE. GMZ017...NONE. GMZ019...NONE. GMZ021...NONE. GMZ023...NONE. GMZ025...NONE. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... AMZ011...NONE. AMZ013...NONE. AMZ015...NONE. AMZ017...NONE. AMZ019...NONE. AMZ021...NONE. AMZ023...NONE. AMZ025...NONE. AMZ027...NONE. AMZ029...NONE. AMZ031...NONE. AMZ033...NONE. AMZ035...NONE. AMZ037...NONE. AMZ039...NONE. .SW N ATLANTIC INCLUDING THE BAHAMAS... AMZ111...NONE. AMZ113...NONE. AMZ115...NONE. AMZ117...NONE. AMZ119...NONE. AMZ121...NONE. AMZ123...NONE. AMZ125...NONE. AMZ127...NONE. *FOR DETAILED ZONE DESCRIPTIONS PLEASE VISIT: HTTP://WWW.NHC.NOAA.GOV/ABOUTTAFBPROD.SHTML#OWF NOTE: GRIDDED MARINE FORECASTS ARE AVAILABLE IN THE NATIONAL DIGITAL FORECAST DATABASE (NDFD) AT: HTTP://WWW.NHC.NOAA.GOV/MARINE/GRIDS.PHP FOR ADDITIONAL INFORMATION PLEASE VISIT: HTTP://WWW.HURRICANES.GOV/MARINE $$ .FORECASTER CHRISTENSEN. NATIONAL HURRICANE CENTER.