000 AXNT20 KNHC 280001 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 705 PM EST FRI DEC 27 2013 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC. ...SPECIAL FEATURE... A GALE WARNING IS IN EFFECT FOR THE SW GULF S OF 26N W OF 94W ASSOCIATED WITH A WEAK 1015 MB SURFACE LOW NEAR 21N94W AT 27/2100 UTC. A SURFACE TROUGH EXTENDS FROM THE LOW NE TO 25N87W AND W OF THE LOW TO THE COAST OF MEXICO NEAR TAMPICO. THIS GALE WARNING WILL CONTINUE THROUGH 28/0600 UTC REDUCING TO WITHIN 60 NM OF COAST OF VERACRUZ THEN DIMINISHING COMPLETELY BY 28/1800 UTC. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE TROPICAL ATLC NEAR 6N10W AND CONTINUES TO 5N14W WHERE THE ITCZ BEGINS AND CONTINUES ALONG 5N22W 2N32W TO 2N43W. CLUSTERS OF ISOLATED MODERATE CONVECTION DOT THE AREA WITHIN 60 NM OF THE ITCZ BETWEEN 31W-43W. ...DISCUSSION... GULF OF MEXICO... A BROAD UPPER RIDGE EXTENDS FROM THE CARIBBEAN TO OVER THE W ATLC GIVING THE GULF SW FLOW ALOFT. AT THE SURFACE IS A WEAK 1015 MB SURFACE LOW NEAR 21N94W AT 27/2100 UTC. A SURFACE TROUGH EXTENDS FROM THE LOW NE TO 25N87W AND W OF THE LOW TO THE COAST OF MEXICO NEAR TAMPICO. THE UPPER RIDGE IS PROVIDING DIFFLUENCE ALOFT TO GENERATE A LARGE AREA OF SCATTERED TO HEAVY SHOWERS WITH POSSIBLE ISOLATED THUNDERSTORMS N OF 23N E OF 87W...N OF 21N BETWEEN 87W-91W...AND W OF 91W. THE SURFACE LOW WILL DRIFT N TO NE THROUGH SAT WHILE THE SURFACE TROUGHS LIFTS N. A SECOND LOW WILL THEN FORM ALONG THE TROUGH DURING SAT AND MOVE NE TO THE VICINITY OF THE FAR W FLORIDA PANHANDLE SAT NIGHT. THE SURFACE TROUGH WILL THEN TRANSITION TO A COLD FRONT BY EARLY SUN AS THE LOW MOVES NE AND INLAND AWAY FROM THE AREA. CARIBBEAN SEA... BROAD UPPER RIDGE COVERS THE CARIBBEAN W OF 65W EXTENDING FROM COLOMBIA ACROSS JAMAICA TO OVER THE W ATLC E OF FLORIDA. SATELLITE WATER VAPOR IMAGERY SHOWS DRY STABLE AIR ALOFT ACROSS MOST OF THE BASIN. AT THE SURFACE A SURFACE TROUGH EXTENDS FROM THE YUCATAN CHANNEL NEAR 22N86W ALONG 19N87W TO 16N86W. SCATTERED TO HEAVY SHOWERS WITH EMBEDDED ISOLATED THUNDERSTORMS ARE FROM 21N-22N BETWEEN 82W-87W INCLUDING PORTIONS OF W CUBA AND THE NE YUCATAN PENINSULA. SCATTERED SHOWERS WITH POSSIBLE ISOLATED THUNDERSTORMS ARE W OF THE SURFACE TROUGH TO INLAND OVER THE YUCATAN PENINSULA. AN UPPER TROUGH OVER THE S/CENTRAL ATLC INTO THE W TROPICAL ATLC CLIPS THE FAR E CARIBBEAN. AFTERNOON SHOWERS/THUNDERSTORMS HAVE DEVELOPED INLAND OVER PUERTO RICO AND THE DOMINICAN REPUBLIC BUT ARE BEGINNING TO DISSIPATE. EASTERLY TRADE WINDS ARE DEVELOPING SOME ISOLATED LOW LEVEL SHOWERS DOTTING THE E CARIBBEAN E OF 65W AND IN THE W CARIBBEAN FROM FROM 16N-19N BETWEEN 77W-83W. AS THE W ATLC COLD FRONT MOVES INTO THE CENTRAL ATLC...HIGH PRESSURE WILL SHIFT NE OFF MID ATLC COAST AND BUILD ACROSS THE W ATLC ALLOWING FOR TRADE WINDS TO INCREASE OVER MUCH OF THE CENTRAL CARIBBEAN BEGINNING TONIGHT THROUGH THE FIRST OF THE WEEK. ...HISPANIOLA... CURRENTLY AFTERNOON SHOWERS/THUNDERSTORMS THAT DEVELOPED EARLIER ARE DIMINISHING ACROSS THE DOMINICAN REPUBLIC. NW FLOW ALOFT WILL CONTINUE THROUGH THE WEEKEND. SCATTERED SHOWERS WITH POSSIBLE ISOLATED THUNDERSTORMS WILL CONTINUE THROUGH SAT. CHANCE OF SHOWERS WILL DIMINISH ON SUN THROUGH THE FIRST OF THE WEEK. ATLANTIC OCEAN... AN UPPER TROUGH OVER THE NW ATLC N OF 30N IS SUPPORTING A COLD FRONT THAT ENTERS THE REGION NEAR 32N70W AT 27/2100 UTC AND EXTENDS TO GRAND BAHAMA ISLAND. SCATTERED SHOWERS WITH POSSIBLE ISOLATED THUNDERSTORMS ARE WELL W OF THE FRONT W OF LINE FROM CENTRAL FLORIDA NEAR MELBOURNE TO BEYOND 32N72W. AN UPPER TROUGH EXTENDS FROM THE S/CENTRAL ATLC NEAR 27N57W ALONG 20N58W INTO THE TROPICS TO 7N48W. THIS IS AMPLIFYING AN UPPER RIDGE TO THE E ALONG 5N38W TO 25N50W. THIS UPPER RIDGE IS PROVIDING DIFFLUNCE ALOFT TO GENERATE SCATTERED SHOWERS WITHIN 200 NM OF LINE FROM 12N61W TO 19N45W. THESE SHOWERS COULD EFFECT TRINIDAD... TOBAGO...AND BARBADOS. A BROAD SURFACE RIDGE DOMINATES THE REMAINDER OF THE ATLC ANCHORED BY A 1033 MB HIGH W OF THE AZORES. COLD FRONT WILL MOVE INTO THE CENTRAL ATLC SAT AFTERNOON AS HIGH PRESSURE BUILDS IN ITS WAKE. THE NEXT COLD FRONT WILL MOVE SE OFF THE SE UNITED STATES COAST SUN NIGHT. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ PAW