000 AXNT20 KNHC 241148 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 705 AM EST TUE DEC 24 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1115 UTC. ...SPECIAL FEATURES... A COLD FRONT EXTENDS ACROSS THE GULF OF MEXICO FROM THE TAMPA BAY REGION OF FLORIDA NEAR 28N83W SW INTO TO THE SW GULF NEAR 20N92W TO 18N93W. STRONG NORTHERLY WINDS ARE NOTED NORTH OF THE FRONT WITH GALE FORCE WINDS OCCURRING S OF 21N W OF THE FRONT. SEE LATEST NWS HIGH SEAS FORECAST UNDER AWIPS/WMO HEADERS MIAHSFAT2/FZNT02 KNHC FOR MORE DETAILS. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 06N10W TO 05N14W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 05N14W TO 04N17W TO 04N26W TO THE EQUATOR NEAR 47W. SCATTERED MODERATE CONVECTION IS FROM 03N-06N BETWEEN 20W-26W. ISOLATED MODERATE CONVECTION IS FROM 02N-06N BETWEEN 34W-48W. ...DISCUSSION... GULF OF MEXICO... WATER VAPOR IMAGERY INDICATES MIDDLE TO UPPER LEVEL TROUGHING OVER THE EASTERN CONUS THAT SUPPORTS A COLD FRONT ANALYZED FROM THE TAMPA BAY REGION OF FLORIDA NEAR 28N83W SW INTO THE SW GULF NEAR 20N92W TO 18N93W. STRONG NORTHERLY WINDS ARE NOTED NORTH OF THE FRONT WITH GALE FORCE CONDITIONS OCCURRING ACROSS PORTIONS OF THE SW GULF THIS MORNING. PLENTY OF SOUTHWESTERLY FLOW ALOFT IS ADVECTING MOISTURE NORTHEASTWARD OVER THE GULF PRODUCING EXTENSIVE CLOUDINESS WITH EMBEDDED ISOLATED SHOWERS OCCURRING WITHIN 300 NM NORTHWEST OF THE BOUNDARY. THE ONLY AREA OF MORE INTENSE CONVECTION IS FOUND S OF 22N BETWEEN 89W-94W...INCLUDING PORTIONS OF THE YUCATAN PENINSULA AND SOUTHERN MEXICO. OTHERWISE...AS THE FRONT CONTINUES TO MOVE EASTWARD OVER THE NEXT 24 TO 36 HOURS...NORTHERLY WINDS WILL GRADUALLY SHIFT NORTH- NORTHEASTERLY AND REMAIN GENERALLY IN THE RANGE OF 20 TO 30 KT...OUTSIDE OF THE GALE WARNING AREA...AS A STRONG RIDGE ANCHORED TO THE NORTH OVER THE MID-MISSISSIPPI RIVER VALLEY DRIFTS SLOWLY EASTWARD THROUGH EARLY WEDNESDAY. THEREAFTER THE PRESSURE GRADIENT WILL RELAX SOMEWHAT WEDNESDAY ONLY TO BE REINFORCED EARLY THURSDAY AS ANOTHER SURFACE RIDGE SAGS SOUTHEASTWARD OUT OF THE INTERMOUNTAIN WEST. CARIBBEAN SEA... THE MAIN FEATURE IMPACTING THE CARIBBEAN THIS EVENING IS A MIDDLE TO UPPER LEVEL LOW CENTERED OVER PUERTO RICO NEAR 18N67W. WATER VAPOR IMAGERY INDICATES VERY DRY AND STABLE AIR ON THE WESTERN PERIPHERY OF THE UPPER LEVEL LOW WHILE IN THE VICINITY OF THE LOW CENTER AND PORTIONS OF THE NORTHEAST QUADRANT OF THE LOW CARRY MOST OF THE MIDDLE TO UPPER LEVEL MOISTURE. THIS MOISTURE CONTINUES TO GENERATE CLOUDINESS AND ISOLATED SHOWERS AND TSTMS ACROSS THE NE CARIBBEAN N OF 13N E OF 71W. THE LOW IS STRONG ENOUGH ALOFT TO REFLECT A BROAD SURFACE TROUGH ANALYZED FROM 13N64W TO 20N63W. THE REMAINDER OF THE BASIN IS UNDER THE INFLUENCE OF EAST-NORTHEAST TRADES IN THE RANGE OF 10 TO 20 KT WITH POSSIBLE HIGHER WINDS TO 25 KT ALONG THE COAST OF COLOMBIA. THE LOW AND ASSOCIATED SURFACE TROUGH ARE EXPECTED TO DRIFT WESTWARD OVER THE NEXT 24 TO 48 HOURS PROVIDING FOCUS FOR ISOLATED SHOWERS AND TSTMS OVER THE NEXT FEW DAYS FOR THE NORTH- CENTRAL AND NE CARIBBEAN. ...HISPANIOLA... CURRENTLY ISOLATED SHOWERS ARE OCCURRING ACROSS EASTERN PORTIONS OF THE ISLAND AS A MIDDLE TO UPPER LEVEL LOW IS CENTERED OVER PUERTO RICO NEAR 18N67W. THE LOW IS FORECAST TO DRIFT WESTWARD DURING THE NEXT FEW DAYS BRINGING AN INCREASED CHANCE FOR ISOLATED SHOWERS AND TSTMS DUE TO THE FAVORABLE MIDDLE TO UPPER LEVEL DYNAMICS AND DIFFLUENCE ALOFT. ATLANTIC OCEAN... UPPER LEVEL TROUGHING IS OVER THE EASTERN CONUS THAT SUPPORTS A COLD FRONT ANALYZED FROM 32N79W TO THE FLORIDA PENINSULA NEAR 29N81W AND INTO THE GULF OF MEXICO. ISOLATED SHOWERS AND TSTMS ARE OCCURRING WITHIN 90 NM EITHER SIDE OF THE FRONT AS IT CONTINUES TO SLOWLY MOVE EASTWARD. THE ONLY OTHER SIGNIFICANT FEATURE IS A MIDDLE TO UPPER LEVEL LOW CENTERED OVER PUERTO RICO NEAR 18N67W. MIDDLE TO UPPER LEVEL DIFFLUENCE IS MAXIMIZED IN THE VICINITY OF THE LOW AND TO THE NORTHEAST OF THE LOW CENTER GENERATING CLOUDINESS AND WIDELY SCATTERED SHOWERS AND TSTMS FROM 15N-24N BETWEEN 54W-68W. OTHERWISE...THE REMAINDER OF THE CENTRAL AND EASTERN ATLC IS UNDER THE INFLUENCE OF A VERY BROAD SURFACE RIDGE ANCHORED BY A 1032 MB HIGH CENTERED NEAR 33N51W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN