000 AXNT20 KNHC 141714 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 105 PM EST FRI DEC 14 2012 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 1415 UTC. ...ITCZ/MONSOON TROUGH... THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM THE AFRICAN COAST NEAR 08N13W TO 02N28W TO 08N45W. SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS S OF THE AXIS TO 03N BETWEEN 10W AND 14W. SCATTERED MODERATE CONVECTION IS FROM 03N TO 05N BETWEEN 22W AND 26W AS WELL AS WITHIN 210 NM S OF THE AXIS AND 45 NM N OF THE AXIS BETWEEN 34W AND 40W. ...DISCUSSION... GULF OF MEXICO... MOSTLY WEST-NORTHWESTERLY UPPER LEVEL FLOW IS OVER THE GULF BASIN TODAY WITH WATER VAPOR IMAGERY INDICATING RELATIVELY DRY AND STABLE CONDITIONS E OF 87W. THE SOUTHWESTERN EXTENT OF AN UPPER LEVEL TROUGH HAS PROGRESSED EASTWARD THROUGH THE FLORIDA PENINSULA AND INTO THE SW NORTH ATLC REGION...CARRYING ITS DISSIPATING SURFACE FRONT SE OF THE GULF OF MEXICO. OTHERWISE...THE REMAINDER OF THE BASIN IS UNDER THE INFLUENCE OF A SURFACE RIDGE ANCHORED BY 1030 MB HIGH CENTERED OVER THE APPALACHIAN MOUNTAINS IN WEST VIRGINIA. MOSTLY NE TO E WINDS PREVAIL E OF 90W...WITH SE WINDS W OF 90W. WEAK LOW-LEVEL MOISTURE CONVERGENCE AND ISOLATED SHOWERS ARE OCCURRING IN THE NW GULF W OF 95W. THE RETURN FLOW IS FORECAST TO CONTINUE SPREADING EASTWARD THROUGH THE WEEKEND AS THE HIGH OVER THE CONUS SLIDES EAST INTO THE NORTH ATLC. UPPER FLOW BETWEEN RIDGING OVER THE GULF AND A MEAN TROUGH TO THE W OF THE AREA IS DIRECTING MIDDLE TO UPPER LEVEL PACIFIC MOISTURE OVER THE WESTERN GULF OF MEXICO. THE TROUGH IS EXPECTED TO WEAKEN AS IT PROGRESSES EASTWARD THROUGH THE CONUS...WITH ITS ASSOCIATED SURFACE FRONT EXPECTED TO REACH THE TEXAS COAST BY THE END OF THE WEEKEND. CARIBBEAN SEA... UPPER LEVEL WESTERLY TO NORTHWESTERLY FLOW DOMINATES THE CARIBBEAN BASIN TODAY BETWEEN AN UPPER LEVEL ANTICYCLONIC CIRCULATION CENTERED IN THE EAST PACIFIC NEAR 13N92W AND AN UPPER LEVEL LOW CENTERED OVER THE CENTRAL ATLC NEAR 21N50W. WATER VAPOR IMAGERY INDICATES THAT VERY DRY AIR AND SUBSIDENCE PREVAILS IN THE MIDDLE AND UPPER LEVELS OF THE ATMOSPHERE OVER THE VAST MAJORITY OF THE CARIBBEAN. AT THE SURFACE...THE PRESSURE GRADIENT IS RELATIVELY RELAXED WITH E-NE TRADES GENERALLY FROM 10 TO 20 KT. WHILE NO SIGNIFICANT DEEP CONVECTION IS OCCURRING...A FEW ISOLATED SHOWERS AND TSTMS ARE NOTED ON SATELLITE IMAGERY S OF 11N IN THE SW CARIBBEAN NEAR THE MONSOON TROUGH AXIS ANALYZED ACROSS EASTERN PANAMA AND INTO COLOMBIA ALONG 10N. SCATTERED SHOWERS PERSIST OVER THE NE CARIBBEAN NEAR A DISSIPATING LOW LEVEL BOUNDARY THAT EXTENDS FROM EASTERN CUBA NEAR 22N83W TO 19N88W. ELSEWHERE...THE GREATEST CONCENTRATION OF LOW-LEVEL MOISTURE IS FOUND OVER MONA PASSAGE WITH WIDELY SCATTERED LOW-TOPPED SHOWERS OCCURRING N OF 15N BETWEEN 67W AND 72W...INCLUDING OVER PORTIONS OF THE DOMINICAN REPUBLIC. THIS OVERALL SYNOPTIC PATTERN OF FAIRLY TRANQUIL WEATHER IS EXPECTED TO CONTINUE THROUGH THE WEEKEND. ATLANTIC OCEAN... A WEAKENING MIDDLE TO UPPER LEVEL SHORTWAVE TROUGH IS OVER THE SW NORTH ATLC WITH ITS AXIS EXTENDING FROM 32N67W TO A BASE OVER NORTHERN CUBA. THIS TROUGHING SUPPORTS A COLD FRONT ANALYZED INTO THE DISCUSSION AREA NEAR 32N64W AND EXTENDS SW TO THE CENTRAL BAHAMAS NEAR 25N77W AND INTO THE FLORIDA STRAITS AS A DISSIPATING STATIONARY FRONT TO 22N82W. LOW LEVEL MOISTURE CONVERGENCE NEAR THE COLD FRONT IS GENERATING SCATTERED SHOWERS PRIMARILY WITHIN 90 NM AHEAD OF THE FRONT E OF THE BAHAMAS WITH MORE ISOLATED SHOWERS FOUND OVER THE BAHAMAS AND WESTWARD INTO THE STRAITS OF FLORIDA. THIS FRONT IS FORECAST TO WEAKEN AS IT PULLS NORTHEASTWARD THROUGH THE WEEKEND. FARTHER EAST...A MIDDLE TO UPPER LEVEL LOW IS CENTERED NEAR 21N50W THAT SUPPORTS AN ILL-DEFINED 1008 MB LOW AT THE SURFACE NEAR 19N52W WITH A SURFACE TROUGH AXIS THAT EXTENDS NE FROM THE LOW TO 23N47W AND SOUTH-SOUTHWEST FROM THE LOW THROUGH 17N52W TO 14N56W. CONVECTION ASSOCIATED WITH THIS SYSTEM IS DISPLACED WELL E OF THE CENTER AND IS FOUND MAINLY WITHIN 120 NM EITHER SIDE OF A LINE FROM 26N40W TO 18N45W. WATER VAPOR IMAGERY INDICATES THAT DRIER AIR IS WRAPPING INTO THE LOW CENTER ALOFT FROM THE WEST AND NORTHWEST. THE FORECAST CALLS FOR THIS UPPER LOW TO WEAKEN AS IT LIFTS NORTHEASTWARD OVER THE WEEKEND INTO THE LEADING EDGE OF THE TROUGH SUPPORTING THE COLD FRONT THAT CURRENTLY EXTENDS TO THE BAHAMAS...LEAVING BEHIND SOME MID LEVEL ENERGY IN THE VICINITY OF THE SURFACE LOW THAT WILL ALSO WEAKEN OVER THE NEXT FEW DAYS. THE REMAINDER OF THE EASTERN ATLC IS UNDER THE INFLUENCE OF A SURFACE RIDGE ANCHORED BY A 1025 MB HIGH CENTERED NEAR 28N35W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ SCHAUER/HUFFMAN