000 AXNT20 KNHC 162353 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 705 PM EST WED DEC 16 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2345 UTC. ...SPECIAL FEATURE... A COLD FRONT MOVING ACROSS THE NW GULF OF MEXICO WILL CONTINUE TO MOVE ACROSS THE BASIN WATERS AND WILL START TO MOVE ACROSS THE FLORIDA PENINSULA STARTING THU AFTERNOON THROUGH SAT MORNING WHEN THE TAIL OF THE FRONT ENTERS THE NW CARIBBEAN. STRONG HIGH PRESSURE BUILDING OVER NORTHERN TEXAS WILL INCREASE THE GRADIENT BEHIND THE FRONT AND GALE-FORCE WINDS ARE FORECAST TO DEVELOP OVER THE SW GULF LATE THU NIGHT. SEAS IN THAT REGION WILL RANGE FROM 8 TO 11 FEET. SEE LATEST NHC HIGH SEAS FORECAST UNDER AWIPS/WMO HEADERS MIAHSFAT2/FZNT02 KNHC FOR MORE DETAILS. ...ITCZ/MONSOON TROUGH... THE ITCZ EXTENDS FROM THE COAST OF WEST AFRICA NEAR 04N08W TO 04N20W...THEN RESUMES WEST OF A SURFACE TROUGH FROM 03N23W TO 02N38W TO THE COAST OF NORTHERN BRAZIL NEAR 01S49W. SCATTERED SHOWERS AND ISOLATED TSTMS ARE FROM 03N TO 14N BETWEEN 18W AND 31W. ...DISCUSSION... GULF OF MEXICO... A MIDDLE LEVEL LOW OVER EASTERN NORTH DAKOTA AND ASSOCIATED TROUGH EXTENDING S-SW ACROSS THE CENTRAL AND SOUTHERN CENTRAL UNITED STATES WITH BASE OVER NW MEXICO SUPPORTS A COLD FRONT THAT THIS EVENING MOVES OVER THE NW GULF WATERS FROM LOUISIANA TO VALLE HERMOSO MEXICO. MOISTURE INFLOW FROM THE CARIBBEAN CONVERGES ALONG THE BOUNDARY TO SUPPORT FOG N OF 27N W OF 89W...DEPICTED ALSO BY GOES SATELLITE IFR PRODUCT. RADAR IMAGERY SHOW SCATTERED SHOWERS AND ISOLATED TSTMS OVER SE LOUISIANA AND ADJACENT COASTAL WATERS. UPPER LEVEL RIDGING AND SUBSIDENCE SUPPORT CLEAR SKIES AND FAIR WEATHER ELSEWHERE. SOUTHEASTERLY GENTLE TO MODERATE WIND IS AHEAD OF THE FRONT WHILE NORTHERLY FRESH TO STRONG WINDS ARE WEST OF THE BOUNDARY. THE FRONT WILL CONTINUE TO MOVE ACROSS THE BASIN THROUGH EARLY SATURDAY WHEN ITS TAIL MOVES OVER NW CARIBBEAN WATERS. STRONG HIGH PRESSURE BUILDING OVER NORTHERN TEXAS WILL INCREASE THE GRADIENT BEHIND THE FRONT AND GALE-FORCE WINDS ARE FORECAST TO DEVELOP OVER THE SW GULF LATE THU NIGHT. SHOWERS OVER THE NORTHERN BASIN ARE EXPECTED THROUGH THU WHEN THE FRONT WILL ENTER THE FLORIDA PANHANDLE. SEE SPECIAL FEATURES SECTION FOR MORE DETAILS. CARIBBEAN SEA... A MIDDLE-LEVEL LOW IS OVER THE NORTHERN CENTRAL CARIBBEAN WHILE RIDGING DOMINATES THE WESTERN CARIBBEAN WATERS ALONG WITH FAIR WEATHER. WEAK RIDGING ALOFT OVER THE EASTERN CARIBBEAN IS GENERATING A DIFFLUENT ENVIRONMENT THAT ALONG WITH LOW LEVEL MOISTURE SUPPORT CLOUDINESS...PASSING SHOWERS AND ISOLATED TSTMS ACROSS HISPANIOLA...LA MONA PASSAGE AND PUERTO RICO. HOWEVER OVER THE CENTRAL CARIBBEAN...S OF HISPANIOLA A LINE OF HEAVY SHOWERS AND TSTMS IS NOTED BETWEEN 68W AND 71W. OTHERWISE...STRONG HIGH PRESSURE OVER THE ATLC TIGHTENS THE GRADIENT OVER THE SOUTH-CENTRAL BASIN...THUS SUPPORTING FRESH TO STRONG TRADES. GENTLE TO MODERATE TRADES DOMINATE ELSEWHERE. SHOWERS IN THE NORTH-CENTRAL CARIBBEAN WILL CONTINUE THROUGH LATE THU...SHIFTING TO THE NW BASIN EARLY FRIDAY. FRESH TO STRONG TRADES WILL CONTINUE OVER THE S-SW BASIN SLIGHTLY INCREASING IN AREA THROUGH FRIDAY. A COLD FRONT WILL ENTER THE NW CARIBBEAN EARLY SATURDAY WITH SHOWERS. ...HISPANIOLA... CLOUDINESS...SCATTERED SHOWERS AND ISOLATED TSTMS CONTINUE ACROSS THE ISLAND...MAINLY FOCUSED OVER THE DOMINICAN REPUBLIC BEING SUPPORTED BY A DIFFLUENT ENVIRONMENT ALOFT. THE MIDDLE TO UPPER LEVEL LOW WILL PREVAIL IN THE AREA THROUGH LATE THU...THUS SUPPORTING THE CONTINUATION OF SHOWERS IN THE ISLAND. ATLANTIC OCEAN... A BROAD MIDDLE LEVEL TROUGH OVER THE CENTRAL-NORTHERN ATLC SUPPORT A PAIR OF COLD FRONTS...ONE ENTERING THE AREA OF DISCUSSION NEAR 30N53W AND CONTINUING TO 30N70W WHERE IT BECOMES STATIONARY TO SOUTHERN GEORGIA. A PRE-FRONTAL TROUGH IS AHEAD OF THE COLD FRONT FROM FROM 30N50W TO 28N54W. ANOTHER SURFACE TROUGH IS OVER NE ATLC WATERS FROM 30N24W TO 25N29W. NO CONVECTION IS ASSOCIATED WITH ANY OF THESE FEATURES. OTHERWISE...A MIDDLE TO UPPER LEVEL LOW NEAR HISPANIOLA SUPPORTS SCATTERED SHOWERS OVER NORTHERN HISPANIOLA AND PUERTO RICO ADJACENT ATLC WATERS. THE COLD FRONT WILL CONTINUE TO SINK OVER THE CENTRAL BASIN THROUGH THU AND WILL START DISSIPATING FRI WHILE A NEW COLD FRONT STARTS EMERGING FROM THE SE CONUS. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ NR