000 AXNT20 KNHC 022346 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 705 PM EST MON DEC 02 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. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH AXIS EXTENDS FROM THE AFRICAN COAST NEAR 07N12W TO 07N20W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 07N20W TO 04N32W TO 06N48W TO 05N53W. ISOLATED MODERATE TO STRONG CONVECTION IS FROM 05N-08N BETWEEN 12W-16W. WIDELY SCATTERED MODERATE CONVECTION IS FROM 02N-08N BETWEEN 23W- 47W. ...DISCUSSION... GULF OF MEXICO... WATER VAPOR IMAGERY INDICATES THAT UPPER LEVEL WEST- NORTHWESTERLY FLOW DOMINATES OVER THE GULF BASIN THIS EVENING. THIS REGIME IS PROVIDING OVERALL STABLE CONDITIONS FOR THE GULF THAT FURTHER SUPPORTS A WEAK SURFACE RIDGE ANCHORED BY A 1016 MB HIGH CENTERED NEAR 24N91W. THE RESULTING WEAK PRESSURE GRADIENT ACROSS THE BASIN SUPPORTS ANTICYCLONIC WIND IN THE RANGE OF 5-15 KT WITH SOUTHERLY WINDS BEGINNING TO TAKE HOLD ACROSS THE FAR NW CORNER. DURING THE NEXT 24 TO 36 HOURS...THE HIGH PRESSURE CENTER IS FORECAST TO DRIFT NE INTO THE SW NORTH ATLC ALLOWING THE SOUTHERLY RETURN FLOW TO SPREAD EASTWARD BY LATE TUESDAY INTO EARLY WEDNESDAY AS AN AREA OF LOW PRESSURE DEVELOPS ACROSS THE CENTRAL PLAINS. CARIBBEAN SEA... CONDITIONS ACROSS THE CARIBBEAN THIS EVENING REMAIN FAIRLY QUIET AND TRANQUIL AS WATER VAPOR IMAGERY IMAGERY INDICATES MOSTLY DRY AND STABLE AIR ALOFT WITHIN NORTHWEST FLOW N OF 15N W OF 70W AND WITHIN SOUTHWESTERLY FLOW EAST OF A LINE FROM 18N70W TO 12N84W. THE UPPER LEVEL FLOW OVER THE FAR WESTERN CARIBBEAN SUPPORTS A SMALL AMOUNT OF MIDDLE TO UPPER LEVEL DIFFLUENCE THAT ALONG WITH WEAK LOW-LEVEL MOISTURE CONVERGENCE IS PROVIDING FOCUS FOR INCREASED CLOUDINESS AND ISOLATED SHOWERS E OF 68W THIS EVENING. OTHERWISE...THE ONLY OTHER AREAS EXPERIENCING ISOLATED SHOWERS ARE ALONG THE FAR WESTERN CARIBBEAN WHERE LOW-LEVEL MOISTURE CONVERGENCE IS STRONGEST FROM THE GULF OF HONDURAS REGION SOUTH- SOUTHEASTWARD TO THE WESTERN COAST OF PANAMA AND IN CLOSE PROXIMITY TO A SURFACE TROUGH WITH AXIS FROM 15N75W TO 20N71W. LOOKING AHEAD...A FAIRLY RELAXED PRESSURE GRADIENT WILL MAINTAIN ITSELF THROUGH WEDNESDAY WITH TRADES REMAINING GENERALLY IN THE 10 TO 15 KT RANGE. ...HISPANIOLA... THE AXIS OF AN ELONGATED UPPER-LEVEL TROUGH EXTENDS FROM THE SW NORTH ATLC NEAR 20N67W SW TO 12N84W. THIS TROUGHING ALOFT SUPPORTS A WEAK SURFACE TROUGH EXTENDING FROM 15N75W NE TO BEYOND 21N70W WHICH CONTINUES TO GENERATE ISOLATED SHOWERS ACROSS HISPANIOLA AND THE ADJACENT COASTAL WATERS THIS EVENING. THE SURFACE TROUGH IS FORECAST TO DRIFT W-NW OVERNIGHT AND GRADUALLY DISSIPATE ON TUESDAY. ATLANTIC OCEAN... A BROAD MIDDLE TO UPPER LEVEL TROUGH IS NOTED ON WATER VAPOR IMAGERY OVER THE SW NORTH ATLC WITH AXIS EXTENDING ALONG 78W TO A BASE NEAR 26N78W. THIS TROUGHING SUPPORTS A 1008 MB LOW CENTERED OFF THE CAROLINAS NEAR 34N75W WITH THE ASSOCIATED COLD FRONT EXTENDING SW FROM THE LOW CENTER TO THE FLORIDA PENINSULA COAST NEAR 28N80W. A PRE-FRONTAL SURFACE TROUGH IS ANALYZED FROM 31N75W TO 24N79W. LOW-LEVEL MOISTURE CONVERGENCE EAST OF AND IN THE VICINITY OF THE FRONT ALONG WITH MAXIMIZED MIDDLE TO UPPER LEVEL DIFFLUENCE IN ASSOCIATION WITH THE UPPER LEVEL TROUGH IS GENERATING A BROAD AREA OF SCATTERED SHOWERS AND TSTMS FROM 25N TO BEYOND 32N BETWEEN 65W-77W. ISOLATED SHOWERS ARE ALSO NOTED FARTHER SOUTHEAST IN THE VICINITY OF ANOTHER SURFACE TROUGH EXTENDING FROM ACROSS HISPANIOLA NEAR 19N72W TO 26N67W. ISOLATED SHOWERS ARE OCCURRING WITHIN 90 NM EITHER SIDE OF THE BOUNDARY. ANOTHER MID-LEVEL SHORTWAVE TROUGH IS NOTED ON WATER VAPOR IMAGERY IN THE VICINITY OF 32N56W THAT IS SUPPORTING WIDELY SCATTERED SHOWERS AND ISOLATED TSTMS FROM 24N-32N BETWEEN 48W- 62W ON THE SOUTHWESTERN PERIPHERY OF A SURFACE RIDGE ANCHORED ACROSS MUCH OF THE CENTRAL ATLC. OTHERWISE...OVER THE EASTERN ATLC...A MIDDLE TO UPPER LEVEL LOW IS CENTERED NEAR 33N25W THAT SUPPORTS A 1003 MB LOW CENTERED NEAR 32N24W AND AN ASSOCIATED SURFACE TROUGH AXIS EXTENDING SE FROM THE LOW CENTER TO WEST OF THE CANARY ISLANDS NEAR 27N19W. DURING THE NEXT 24 HOURS THIS AREA OF LOW PRESSURE IS EXPECTED TO REMAIN NEARLY STATIONARY JUST NORTH OF THE DISCUSSION AREA. ISOLATED SHOWERS AND TSTMS ARE OCCURRING WITHIN 180 NM NE OF THE SURFACE TROUGH AXIS. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN