000 AXNT20 KNHC 160003 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 705 PM EST SUN DEC 15 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC. ...SPECIAL FEATURES... GALE WARNING FOR THE GULF OF MEXICO S OF 22N W OF 94W ASSOCIATED WITH A COLD FRONT EXTENDING FROM 26N82W TO 19N92W AT 15/2100 UTC. THE WARNING IS VALID UNTIL 16/0000 UTC WHEN WINDS ARE EXPECTED TO SUBSIDE. SEE THE HIGH SEAS FORECAST... MIAHSFAT2/FZNT02 KNHC...AND THE OFFSHORE FORECAST... MIAOFFNT4/FZNT24 KNHC...FOR MORE DETAILS. ...THE ITCZ/THE MONSOON TROUGH... THE MONSOON TROUGH AXIS EXTENDS ACROSS AFRICA INTO THE TROPICAL EASTERN ATLC NEAR 08N13W AND CONTINUES TO 06N15W. THE ITCZ AXIS EXTENDS FROM 06N15W AND CONTINUES ALONG 03N29W TO 02N40W TO 0N50W. SCATTERED MODERATE CONVECTION AND ISOLATED TSTMS ARE FROM 02N-11N E OF 27W AND FROM 02N-06N BETWEEN 28W-41W. ...DISCUSSION... GULF OF MEXICO... A MIDDLE TO UPPER LEVEL TROUGH WITH AXIS EXTENDING ALONG THE EASTERN CONUS INTO THE CENTRAL GULF CONTINUE TO SUPPORT A COLD FRONT THAT AT 15/2100 UTC EXTENDS FROM 25N81W SW TO 23N85W TO 19N91W OVER THE EASTERN BAY OF CAMPECHE. LOW-LEVEL MOISTURE CONVERGENCE ALONG THE FRONTAL BOUNDARY SUPPORTS RAINSHOWERS AND TSTMS WITHIN 120 NM S OF IT. A PRE-FRONTAL TROUGH EXTENDS FROM 21N86W...ALONG THE EASTERN YUCATAN PENINSULA TO CENTRAL GUATEMALA NEAR 15N90W TO ENHANCE SHOWERS IN THE YUCATAN CHANNEL. A HIGH PRESSURE SYSTEM ANCHORED BY THREE HIGH PRESSURE CENTERS...ONE IN THE LOWER MISSISSIPPI VALLEY...ANOTHER OVER THE SOUTHERN PLAINS AND A THIRD OVER NE MEXICO EXTENDS A RIDGE ACROSS THE GULF. THIS HIGH PRESSURE SYSTEM IS PUSHING AN ARCTIC AIRMASS INTO THE NORTHERN AND CENTRAL GULF WHICH CONTINUE TO SUPPORT FAIR WEATHER BASIN WIDE BEHIND THE COLD FRONT. A TIGHT PRESSURE GRADIENT FROM THIS RIDGE OVER THE SW GULF SUPPORTS GALE FORCE WINDS. SEE THE SPECIAL FEATURES FOR MORE DETAILS ABOUT THE GALE WARNING. HIGH PRESSURE WILL CONTINUE ACROSS THE GULF THROUGHOUT WED AFTERNOON. THE PORTION OF THE COLD FRONT IN THE SE GULF IS EXPECTED TO STALL WITHIN THE NEXT 24 HOURS WHILE IT SLOWLY DISSIPATES. CARIBBEAN SEA... LOW-LEVEL MOISTURE CONVERGENCE ASSOCIATED WITH A SURFACE PRE- FRONTAL TROUGH FROM 21N86W...ALONG THE EASTERN YUCATAN PENINSULA TO CENTRAL GUATEMALA NEAR 15N90W ENHANCES RAINSHOWERS IN THE YUCATAN CHANNEL THAT EXTENDS TO THE NW CARIBBEAN W OF 83W. LOW- LEVEL MOISTURE CONVERGENCE IS ALSO ALONG THE COAST OF EASTERN HONDURAS TO THE COAST OF SOUTHERN NICARAGUA WHICH ALONG WITH UPPER-LEVEL DIFFLUENCE SUPPORT SCATTERED MODERATE CONVECTION AND TSTMS FROM 11N-17N W OF 80W. IN THE SW BASIN...THE MONSOON TROUGH AXIS EXTENDS ACROSS COSTA RICA TO NORTHERN COLOMBIA AND SUPPORT ISOLATED SHOWERS AND TSTMS S OF 11N W OF 78W. WATER VAPOR IMAGERY DEPICT STRONG SUBSIDENCE FROM THE MIDDLE LEVELS ACROSS THE REMAINDER BASIN WHICH SUPPORTS FAIR WEATHER CONDITIONS. A RELATIVELY STRONG PRESSURE GRADIENT ACROSS THE CENTRAL AND EASTERN BASIN SUPPORTS EASTERLY WINDS IN THE RANGE OF 20-25 KT. A COLD FRONT CURRENTLY OVER THE SE GULF IS FORECAST TO TRANSITION INTO A STATIONARY FRONT OVER THE NW CARIBBEAN WITHIN THE NEXT 24 HOURS. HISPANIOLA... FAIR WEATHER CONTINUES OVER HISPANIOLA SUPPORTED BY DRY AIR AT THE LOWER AND MIDDLE LEVELS. WEATHER CONDITIONS ARE FORECAST TO DEGRADE BY MONDAY MORNING WHEN A VERY MOIST AIRMASS IS EXPECTED TO MOVE ACROSS THE ISLAND ENHANCING SHOWERS. ATLANTIC OCEAN... A MIDDLE TO UPPER LEVEL TROUGH WITH AXIS EXTENDING ALONG THE EASTERN CONUS INTO THE CENTRAL GULF SUPPORTS A COLD FRONT ANALYZED IN THE SW N ATLC FROM 30N74W SW TO SOUTHERN FLORIDA NEAR 26N79W. SCATTERED MODERATE CONVECTION AND TSTMS ARE WITHIN 110 NM SE OF FRONT. SURFACE HIGH PRESSURE RIDGING IS OVER THE REMAINDER ATLC N OF 15N THAT ALONG WITH DRY AIR AT THE LOW AND MIDDLE LEVELS CONTINUE TO SUPPORT FAIR WEATHER. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ NR