000 AXNT20 KNHC 202351 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 705 PM EST SUN DEC 20 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 PRESSURE GRADIENT GENERATED BY THE INTERACTION OF A HIGH PRESSURE OVER THE ATLANTIC AND LOWER PRESSURES OVER SOUTH AMERICA CONTINUE TO SUPPORT GALE FORCE WINDS ACROSS THE S- CENTRAL CARIBBEAN FROM 10.5N-13N BETWEEN 73W-78W WITH SEAS RANGING FROM 10-14 FT. THESE CONDITION S ARE EXPECTED TO CONTINUE THROUGH THE NEXT 48 HOURS. FOR MORE INFORMATION PLEASE REFER TO THE HIGH SEAS FORECAST PRODUCT UNDER AWIPS/WMO HEADER MIAHSFAT2/FZNT02 KNHC. ...ITCZ/MONSOON TROUGH... THE ITCZ EXTENDS FROM 04N08W TO 05N36W TO 05N52W. SCATTERED LIGHT TO MODERATE CONVECTION IS ALONG THE AXIS FROM 03N-05N BETWEEN 19W-40W. ...DISCUSSION... GULF OF MEXICO... A BROAD SURFACE RIDGE ANCHORED BY A 1033 MB HIGH CENTERED OVER E GEORGIA EXTENDS SW ACROSS THE BASIN. WITH THIS...A MODERATE TO FRESH ANTICYCLONIC FLOW PREVAILS ACROSS MOST OF THE AREA. THE ONLY EXCEPTION IS ACROSS THE FLORIDA STRAITS WHERE THE TIGHT PRESSURE GRADIENT BETWEEN THE RIDGE AND LOWER PRESSURES TO THE S ARE SUPPORTING FRESH TO STRONG NE WINDS BETWEEN 80W-85W. THE TAIL OF A WEAK STATIONARY FRONT EXTENDS FROM NORTHERN YUCATAN NEAR 22N89W TO W CUBA NEAR 22N84W. ISOLATED CONVECTION IS OBSERVED ALONG THIS BOUNDARY. WESTERN CUBA TO THE NORTHERN YUCATAN PENINSULA. OVER THE NEXT 24 HOURS...EXPECT FOR THE FRONTAL BOUNDARY ALONG THE SOUTHER PORTION OF THE BASIN TO DISSIPATE. WINDS WILL WEAKEN AS THE SURFACE RIDGE DRIFTS E. CARIBBEAN SEA... THE PRESSURE GRADIENT BETWEEN HIGH PRESSURE CURRENTLY OVER THE ATLANTIC AND LOWER PRESSURES OVER THE NORTHERN PORTION OF SOUTH AMERICA CONTINUE TO SUPPORT GALE FORCE WINDS ACROSS THE S- CENTRAL CARIBBEAN WHILE MODERATE TO FRESH TRADES PREVAIL ACROSS THE REMAINDER OF THE BASIN. PLEASE REFER TO THE SPECIAL FEATURES SECTION FOR MORE DETAILS ABOUT THE GALE CONDITIONS. AN UPPER- LEVEL TROUGH ALONG THE W ATLANTIC SUPPORTS A WEAK STATIONARY FRONT THAT EXTENDS ACROSS THE YUCATAN CHANNEL AND W CUBA. WITH ISOLATED CONVECTION. SHALLOW MOISTURE TRANSPORTED BY THE TRADES ARE ENHANCING ISOLATED CONVECTION ACROSS THE BASIN. EXPECT A SIMILAR WEATHER PATTERN TO PREVAIL OVER THE NEXT 24 HOURS. ...HISPANIOLA... SHALLOW MOISTURE AND A DIFFLUENT ENVIRONMENT ALOFT ARE GENERATING ISOLATED MODERATE CONVECTION ACROSS THE NORTHERN PORTION OF THE ISLAND AT THIS TIME. THIS ACTIVITY WILL CONTINUE OVER THE NEXT 24 HOURS. ATLANTIC OCEAN... AN UPPER-LEVEL TROUGH EXTENDS ALONG THE W ATLANTIC SUPPORTING A STATIONARY FRONT ANALYZED FROM 23N79W TO 30N57W. THE BOUNDARY THEN BECOMES A COLD FRONT AND EXTENDS NE ACROSS THE W AND CENTRAL ATLANTIC. SCATTERED MODERATE CONVECTION IS OBSERVED WITHIN 150 NM OF THE STATIONARY FRONT AFFECTING THE BAHAMAS AND ADJACENT WATERS. TO THE E...A BROAD SURFACE RIDGE EXTENDS ACROSS THE CENTRAL AND E ATLANTIC ANCHORED BY A 1030 MB HIGH CENTERED NEAR 33N30W. A WEAK STATIONARY FRONT WAS ANALYZED S OF THIS HIGH ACROSS THE E ATLANTIC FROM 20N41W TO 28N13W. EXPECT OVER THE NEXT 24 HOURS FOR THE FRONTAL BOUNDARIES TO CONTINUE WEAKENING AND DISSIPATE. HIGH PRESSURE WILL PREVAIL ACROSS MOST OF THE BASIN. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ ERA