000 AXNT20 KNHC 021748 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 105 PM EST SUN DEC 02 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 1715 UTC. ...SPECIAL FEATURES... A MIDDLE TO UPPER LEVEL TROUGH AXIS EXTENDS FROM 35N47W TO 24N39W AND SUPPORTS A LOW-LEVEL CIRCULATION CENTER ANALYZED AS A 1008 MB LOW NEAR 30N43W. SURFACE TROUGHING EXTENDS N-NE FROM THE LOW TO 35N41W AND S-SW FROM THE LOW TO 26N42W TO 18N47W. AN AREA OF SCATTERED MODERATE CONVECTION IS WELL DISPLACED FROM THE LOW CENTER OCCURRING FROM 32N-38N BETWEEN 36W-45W LOCATED MOSTLY IN THE AREA OF MAXIMUM MIDDLE TO UPPER LEVEL DIFFLUENCE NORTH OF THE TROUGH AXIS. TO THE EAST OF THE LOW CENTER...WIDELY SCATTERED MODERATE CONVECTION IS OCCURRING FROM 20N-32N BETWEEN 33W-40W. THIS SYSTEM IS FORECAST TO MOVE NORTH-NORTHEASTWARD AND GRADUALLY MERGE WITH A FRONTAL SYSTEM TO THE NORTH CURRENTLY ALONG 37N. THIS SYSTEM HAS A MEDIUM CHANCE OF BECOMING A TROPICAL CYCLONE OR A SUBTROPICAL CYCLONE DURING THE NEXT 48 HOURS. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH AXIS EXTENDS FROM THE AFRICAN COAST NEAR 08N13W TO 06N17W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 06N17W TO 05N21W TO 08N35W TO 07N40W TO 10N50W TO 08N60W. TWO SURFACE TROUGHS ARE EMBEDDED WITHIN THE ITCZ. ONE IS ANALYZED FROM 07N37W TO 11N32W WITH MOSTLY WIDELY SCATTERED MODERATE CONVECTION OCCURRING EAST OF THE AXIS FROM 04N-14N BETWEEN 11W-33W. THE OTHER SURFACE TROUGH EXTENDS FROM 07N52W TO A 1009 MB LOW CENTERED NEAR 10N50W TO 14N46W. THE LOW-LEVEL CIRCULATION IS EVIDENT ON VISIBLE SATELLITE IMAGERY AND AN WINDSAT PASS AROUND 02/0946 UTC SHOWED THE CYCLONIC AXIS OF THE WIND FIELD. ISOLATED MODERATE CONVECTION IS FROM 09N-12N BETWEEN 44W-50W. ...DISCUSSION... GULF OF MEXICO... WATER VAPOR IMAGERY INDICATES THE GULF IS UNDER WESTERLY UPPER LEVEL FLOW AND THAT A RELATIVELY DRY AND STABLE AIRMASS REMAINS IN CONTROL. AT THE SURFACE...STABILITY REMAINS THE OVERALL THEME AS A HIGH PRESSURE RIDGE AXIS EXTENDS FROM THE CAROLINAS THROUGH THE MISSISSIPPI DELTA REGION TO THE EAST-CENTRAL MEXICO COAST NEAR 21N99W WHERE A 1022 MB HIGH IS CENTERED. THE RIDGING OVERALL IS ANCHORED BY A 1029 MB HIGH CENTERED OVER WESTERN SOUTH CAROLINA NEAR 34N82W. MOSTLY EAST WINDS IN THE RANGE OF 10 TO 20 KT PREVAIL E OF 90W WITH FAIR CONDITIONS OBSERVED...AND EAST-SOUTHEAST WINDS IN THE RANGE OF 5 TO 15 KT PREVAIL W OF 90W UNDER MOSTLY CLEAR SKIES. THE ONLY AREA OF ACTIVE PRECIPITATION IS A FEW ISOLATED SHOWERS AND TSTMS ACROSS PORTIONS OF THE WESTERN GULF FROM 23N-27N BETWEEN 91W-94W. THIS SYNOPTIC WEATHER PATTERN IS FORECAST TO PERSIST THROUGH WEDNESDAY. CARIBBEAN SEA... AN UPPER LEVEL RIDGE AXIS EXTENDS ALONG 10N BETWEEN 50W-90W THAT PROVIDES INFLUENCE TO THE ENTIRE CARIBBEAN SEA BASIN THIS AFTERNOON WHERE MOSTLY SOUTHWEST TO WESTERLY UPPER LEVEL FLOW PREVAILS. WHILE MOST OF THE BASIN REMAINS UNDER FAIRLY TRANQUIL CONDITIONS...A MIDDLE TO UPPER LEVEL TROUGH OVER THE SW NORTH ATLC SUPPORTS A SURFACE TROUGH ANALYZED FROM SOUTH OF PUERTO RICO NEAR 17N66W TO 24N66W. LOW-LEVEL MOISTURE CONVERGENCE IN THE VICINITY OF THE SURFACE TROUGH IS GENERATING ISOLATED SHOWERS N OF 15N BETWEEN 63W-70W. ELSEWHERE...NORTHEASTERLY WINDS OVER THE WESTERN CARIBBEAN ARE PUSHING AREAS OF ISOLATED SHOWERS ONSHORE ALONG THE CENTRAL AMERICA COAST WITH THE MOST CONCENTRATED AREAS IN THE GULF OF HONDURAS S OF 17N W OF 81W...AND OVER THE SW CARIBBEAN WITHIN 90 NM EITHER SIDE OF A LINE FROM 13N78W TO 11N84W. FINALLY...AN AREA OF LOW-LEVEL MOISTURE CONVERGENCE IS FOUND ACROSS PORTIONS OF THE SE CARIBBEAN AND COAST OF VENEZUELA. SCATTERED SHOWERS AND ISOLATED TSTMS ARE OCCURRING S OF 12N BETWEEN 57W-65W...INCLUDING TRINIDAD AND TOBAGO AS WELL AS NE VENEZUELA. ATLANTIC OCEAN... WATER VAPOR IMAGERY INDICATES A MIDDLE TO UPPER LEVEL TROUGH IS PROGRESSING SOUTHEASTWARD ACROSS THE SW NORTH ATLC WITH THE TROUGH AXIS EXTENDING FROM 34N62W TO 25N76W. THE UPPER LEVEL FEATURE SUPPORTS A SURFACE TROUGH ANALYZED FROM WESTERN PUERTO RICO NEAR 18N67W TO 24N66W. LOW-LEVEL MOISTURE CONVERGENCE IN THE VICINITY OF THE SURFACE TROUGH AXIS AND MORE SO MAXIMIZED MIDDLE TO UPPER LEVEL DIFFLUENCE IS GENERATING A BROAD AREA OF SCATTERED SHOWERS AND ISOLATED TSTMS FROM 18N-32N BETWEEN 54W-70W. FARTHER EAST...THE SPECIAL FEATURES LOW PRESSURE SYSTEM IS CONTINUING TO TRACK SLOWLY NORTHWARD AND IS EXPECTED TO IMPACT THE AREA N OF 20N BETWEEN 33W-46W. OTHERWISE...THE REMAINDER OF THE EASTERN ATLC IS UNDER THE INFLUENCE OF A SURFACE RIDGE ANCHORED BY A 1035 MB HIGH CENTERED EAST OF THE AZORES NEAR 38N23W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN