000 AXNT20 KNHC 111129 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 705 AM EST FRI DEC 11 2015 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN SECTIONS OF SOUTH AMERICA...AND ATLANTIC OCEAN TO THE AFRICAN COAST FROM THE EQUATOR TO 32N. THE FOLLOWING INFORMATION IS BASED ON SATELLITE IMAGERY...WEATHER OBSERVATIONS...RADAR...AND METEOROLOGICAL ANALYSIS. BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1115 UTC. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH AXIS EXTENDS ALONG SW AFRICA FROM 06N AND THE PRIME MERIDIAN TO SOUTHERN LIBERIA...ENTERING THE ATLC NEAR 06N10W. AT THIS POINT...THE INTERTROPICAL CONVERGENCE ZONE BEGINS AND EXTENDS TO 04N20W TO 04N30W TO 03N43W. A TROUGH IS JUST TO THE WEST AND EXTENDS FROM 08N45W TO THE EQUATOR AT 46W. SCATTERED MODERATE CONVECTION IS FROM 04N-07N BETWEEN 22W-28W. ISOLATED SHOWERS ARE NEAR THE TROUGH AXIS. ...DISCUSSION... GULF OF MEXICO... A 1018 MB HIGH PRES LOCATED OVER THE NE GULF NEAR 29N85W EXTENDS A RIDGE ACROSS THE REGION PRODUCING MAINLY A GENTLE TO MODERATE ANTICYCLONIC WIND FLOW AND GENERALLY FAIR WEATHER. SOUTHERLY RETURN FLOW IN THE 15-20 KT RANGE IS ALREADY NOTED ACROSS THE NW GULF. THE HIGH PRES WILL SHIFT NE INTO THE ATLANTIC OCEAN DURING THE NEXT 24 HOURS KEEPING A RIDGE ACROSS THE GULF WATERS. THE PRESSURE GRADIENT WILL INCREASE OVER THE WESTERN GULF BETWEEN THE HIGH OVER THE ATLC AND A DEVELOPING LOW PRESSURE ACROSS THE CENTRAL UNITED STATES. THE RESULT COULD BE FRESH TO STRONG SOUTHERLY WINDS OVER MUCH OF THE WESTERN HALF OF THE GULF BY SAT AFTERNOON. WINDS WILL FURTHER INCREASE TO 25-30 KT EARLY ON SUN JUST AHEAD OF THE NEXT COLD FRONT FORECAST TO ENTER THE GULF BY SUN MORNING. FRESH TO STRONG NORTHERLY WINDS AND BUILDING SEAS ARE EXPECTED IN THE WAKE OF THE FRONT ON SUN. ALOFT...A MID TO UPPER LEVEL TROUGH EXTENDS FROM CENTRAL FLORIDA ACROSS WESTERN CUBA INTO THE FAR NW CARIBBEAN. NW WINDS AND MODERATE TO STRONG SUBSIDENCE IS NOTED BEHIND THE TROUGH ACROSS MOST OF THE GULF WHILE STRONG SOUTHWESTERLY WINDS ARE AHEAD OF THE TROUGH AXIS. THESE WINDS ARE TRANSPORTING ABUNDANT MID-UPPER LEVEL MOISTURE ACROSS SOUTHERN MEXICO...INCLUDING THE BAY OF CAMPECHE...AND THE NW CARIBBEAN INTO CUBA AND THE BAHAMAS AS NOTED ON WATER VAPOR IMAGERY. CARIBBEAN SEA... THE AFOREMENTIONED MID TO UPPER LEVEL TROUGH IS RESPONSIBLE FOR THE GROWTH OF CONVECTION ACROSS PARTS OF EASTERN CUBA...THE CAYMAN ISLANDS AND JAMAICA. LIGHTNING DATA ALSO INDICATE SOME ACTIVE WEATHER ACROSS THIS REGION. THIS TROUGH ALOFT IS FORECAST TO SHIFT EASTWARD EXTENDING ACROSS CENTRAL CUBA TODAY AND ACROSS EASTERN CUBA ON SAT. AS A RESULT...ABUNDANT MOISTURE AND THE FOCUS FOR CONVECTION WILL PERSIST OVER PARTS OF EASTERN CUBA...THE CAYMAN ISLANDS AND JAMAICA THIS FRI...WITH THESE CONDITIONS EXTENDING OVER HISPANIOLA MAINLY DURING THE UPCOMING WEEKEND. LOCALLY HEAVY RAIN AND GUSTY WINDS MAY OCCUR IN ASSOCIATION WITH THIS ACTIVE WEATHER. PATCHES OF LOW LEVEL MOISTURE EMBEDDED IN THE TRADE WIND FLOW ARE NOTED ACROSS THE REMAINDER OF THE BASIN...MORE CONCENTRATED OVER THE WINDWARD ISLANDS AND THE EASTERN CARIBBEAN...PARTICULARLY E OF 65W. THE ATLC HIGH PRES LOCATED NE OF THE AREA CONTINUES TO PRODUCE FRESH TO STRONG TRADE WINDS ACROSS THE SOUTH-CENTRAL CARIBBEAN. RECENT SCATTEROMETER PASSES CONFIRMED THE PRESENCE OF THESE WINDS. MODERATE TO FRESH WINDS DOMINATE THE REMAINDER OF THE CENTRAL CARIBBEAN WITH GENTLE TO MODERATE WINDS ELSEWHERE. THIS WEATHER PATTERN WILL PERSIST THROUGH THE WEEKEND. ...HISPANIOLA... AS PREVIOUSLY MENTIONED...AN APPROACHING MID-UPPER LEVEL TROUGH FROM THE WEST WILL INCREASE THE LIKELIHOOD OF RAIN ACROSS HISPANIOLA LATER TODAY THROUGH LIKELY SUN. UPPER DIFFLUENCE AHEAD OF THE TROUGH WILL SUPPORT THE DEVELOPMENT OF SHOWER WITH EMBEDDED TSTMS AND GUSTY WINDS ACROSS PARTS OF THE ISLAND. ATLANTIC OCEAN... CONVECTION IS ON INCREASE ACROSS THE BAHAMAS AND REGIONAL WATERS DUE TO UPPER DIFFLUENCE AHEAD OF THE ABOVE MENTIONED MID-UPPER LEVEL TROUGH. A SURFACE TROUGH HAS DEVELOPED VERY CLOSE TO SE FLORIDA IN RESPONSE TO THIS PERSISTENT ACTIVE WEATHER. MOSAIC DOPPLER RADAR FROM THE SE U.S. INDICATES SCATTERED SHOWERS AND TSTMS ALONG THE SURFACE TROUGH THAT EXTENDS FROM 28N79W ALONG THE COAST OF SE FLORIDA INTO THE UPPER FLORIDA KEYS AND THE STRAITS OF FLORIDA TO NEAR THE COAST OF WESTERN CUBA AT 23N83W. CONVECTION IS FORECAST TO CONTINUE OVER THE BAHAMAS AND REGIONAL WATERS AS THE UPPER TROUGH SHIFTS EASTWARD TODAY AND SAT. ON THIS DAY...ANOTHER LOW-LEVEL TROUGH IS EXPECTED TO DEVELOP E OF THE BAHAMAS LIKELY ALONG THE TAIL END OF A COLD FRONT THAT CURRENTLY EXTENDS FROM 31N61W TO THE CENTRAL BAHAMAS. THIS WILL BE ANOTHER FACTOR THAT WILL ENHANCE THE SHOWER AND TSTM ACTIVITY ACROSS THE BAHAMAS AND ADJACENT WATERS. THE COLD FRONT IS ATTACHED TO A GALE CENTER LOCATED E OF BERMUDA NEAR 32N61W. ANOTHER COLD FRONT IS MOVING INTO THE FORECAST AREA FROM THE N AND STRETCHES FROM 31N38W TO 29N45W TO 31N53W. A BAND OF MAINLY LOW CLOUDS IS ASSOCIATED WITH THE FRONT. THE REMAINDER OF THE ATLC IS UNDER THE INFLUENCE OF A RIDGE ANCHORED BY A 1023 MB HIGH LOCATED NEAR 26N46W. THIS SYSTEM WILL SHIFT SE AS THE GALE CENTER DEEPENS AND MOVES MAINLY EASTWARD. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ GR