000 AXNT20 KNHC 011750 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 105 PM EST SAT DEC 01 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 33N48W TO 24N39W AND SUPPORTS A PARTIALLY EXPOSED LOW-LEVEL CIRCULATION CENTERED ANALYZED AS A 1010 MB LOW NEAR 26N42W. SURFACE TROUGHING EXTENDS N-NE FROM THE LOW TO 30N40W AND S-SW FROM THE LOW TO 18N46W AS DEPICTED ON A RECENT ASCAT PASS FROM 01/1258 UTC. SCATTERED MODERATE CONVECTION IS OCCURRING FROM 26N-32N BETWEEN 35W-45W LOCATED MOSTLY IN THE AREA OF MAXIMUM MIDDLE TO UPPER LEVEL DIFFLUENCE EAST OF THE TROUGH AXIS. ELSEWHERE ISOLATED SHOWERS AND TSTMS ARE OCCURRING WITHIN 240 NM EAST OF THE SOUTHERN SURFACE TROUGH AXIS. THIS SYSTEM IS GRADUALLY BECOMING BETTER ORGANIZED AND FURTHER DEVELOPMENT IS POSSIBLE OVER THE NEXT 24 TO 48 HOURS BEFORE IT MERGES WITH A FRONTAL SYSTEM TO THE NORTHWEST. 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 10N14W TO 06N18W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 06N18W TO 04N23W TO 08N33W TO 06N40W TO 09N48W TO 07N59W. TWO SURFACE TROUGHS ARE EMBEDDED WITHIN THE ITCZ. ONE IS ANALYZED FROM 06N35W TO 12N30W AND SHOWS UP WELL IN AN EARLIER ASCAT PASS FROM 01/1122 UTC. THE OTHER SURFACE TROUGH EXTENDS FROM 07N50W TO A 1010 MB LOW CENTERED NEAR 09N48W TO 12N44W. THE LOW-LEVEL CIRCULATION IS QUITE EVIDENT ON VISIBLE SATELLITE IMAGERY AND AN ASCAT PASS AROUND 01/1302 UTC SHOWED THE EASTERN PORTION OF THE CYCLONIC TURNING OF THE WIND FIELD. WIDELY SCATTERED MODERATE CONVECTION IS FROM THE EQUATOR TO 10N BETWEEN 09W-32W. ...DISCUSSION... GULF OF MEXICO... WATER VAPOR IMAGERY INDICATES THE GULF IS UNDER NORTHWEST TO 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 20N98W WHERE A 1022 MB HIGH IS CENTERED. MOSTLY EAST-NORTHEAST WINDS IN THE RANGE OF 10 TO 20 KT PREVAIL E OF 92W WITH FAIR CONDITIONS OBSERVED...AND EAST- SOUTHEAST WINDS IN THE RANGE OF 5 TO 15 KT PREVAIL W OF 92W UNDER MOSTLY CLEAR SKIES. THE ONLY AREA OF ACTIVE PRECIPITATION IS A FEW ISOLATED SHOWERS AND TSTMS ACROSS THE FLORIDA STRAITS E OF 84W. THIS SYNOPTIC WEATHER PATTERN IS FORECAST TO PERSIST THROUGH WEDNESDAY. CARIBBEAN SEA... AN UPPER LEVEL RIDGE AXIS EXTENDS ALONG 10N BETWEEN 55W-90W THAT PROVIDES INFLUENCE TO THE ENTIRE CARIBBEAN SEA BASIN THIS AFTERNOON WHERE MOSTLY SOUTHWEST TO WESTERLY UPPER LEVEL FLOW PREVAILS. WHILE EASTERN PORTIONS REMAIN DRY ALOFT...ISOLATED LOW-LEVEL LOW-TOPPED SHOWERS CONTINUE PROGRESSING WESTWARD EMBEDDED WITHIN E-NE TRADES IN THE RANGE OF 10 TO 15 KT. THE WESTERN CARIBBEAN IS EXPERIENCING INCREASED CLOUD COVER OVERALL WITH ISOLATED SHOWERS OCCURRING IN THE GULF OF HONDURAS AND SURROUNDING REGION S OF 19N W OF 83W...AND ISOLATED SHOWERS AND TSTMS ACROSS THE SW CARIBBEAN GENERALLY S OF 14N W OF 79W AND WITHIN 90 NM OF THE PANAMA COAST. FINALLY...AN AREA OF LOW-LEVEL MOISTURE CONVERGENCE IS FOUND ACROSS PORTIONS OF THE SE CARIBBEAN AND COAST OF VENEZUELA. ISOLATED SHOWERS AND TSTMS ARE OCCURRING S OF 13N BETWEEN 57W-66W...INCLUDING TRINIDAD AND TOBAGO AS WELL AS NE VENEZUELA. ATLANTIC OCEAN... WATER VAPOR IMAGERY INDICATES VERY WEAK MIDDLE TO UPPER LEVEL TROUGH ACROSS THE SW NORTH ATLC WITH THE TROUGH AXIS EXTENDING FROM 36N73W TO 24N83W. WITH A LACK OF ANY SIGNIFICANT SURFACE FRONT EAST OF THE UPPER LEVEL TROUGH AXIS...INCREASED MID-LEVEL LIFT IS GENERATING CLOUDINESS AND ISOLATED AREAS OF LOW-TOPPED SHOWERS N OF 21N BETWEEN 60W-80W. THE MOST CONCENTRATED AREA OF WIDELY SCATTERED SHOWERS IS OCCURRING ALONG AND NORTH OF A SHEAR LINE ANALYZED FROM 31N49W TO 26N60W TO 23N71W. THIS AREA IS FOUND FROM 23N-28N BETWEEN 55W-72W. A WEAK SURFACE TROUGH IS LOCATED SOUTH OF THE SHEAR LINE FROM 19N-23N ALONG 68W WITH ISOLATED SHOWERS OCCURRING WITHIN 300 NM EAST OF THE BOUNDARY. 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 35W-48W. OTHERWISE...THE REMAINDER OF THE EASTERN ATLC IS UNDER THE INFLUENCE OF A SURFACE RIDGE ANCHORED BY A 1034 MB HIGH CENTERED NE OF THE AZORES NEAR 40N25W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN