000 AXNT20 KNHC 152352 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 705 PM EST THU NOV 15 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC. ...ITCZ/MONSOON TROUGH... THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM THE AFRICAN COAST NEAR 10N15W TO 10N46W TO 09N60W. SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS FROM 07N-09N BETWEEN 18W-25W. WIDELY SCATTERED MODERATE CONVECTION IS FROM 04N-12N BETWEEN 24W-32W. ...DISCUSSION... GULF OF MEXICO... A MIDDLE TO UPPER LEVEL TROUGH AXIS EXTENDS ALONG 85W WITH WATER VAPOR IMAGERY INDICATING THAT MOSTLY DRY AIR ACCOMPANIES THIS FEATURE. AS OF 15/2100 UTC...THE UPPER LEVEL TROUGHING SUPPORTS A DISSIPATING STATIONARY FRONT ANALYZED FROM THE SOUTHERN FLORIDA PENINSULA NEAR 27N81W SW TO THE NORTHERN YUCATAN PENINSULA COAST NEAR 22N89W WITH VERY LITTLE PRECIPITATION NOTED. ISOLATED SHOWERS ARE OCCURRING OVER THE EXTREME FAR SOUTHEASTERN GULF WATERS FROM 22N-24N BETWEEN 84W-87W...HOWEVER THESE REMAIN FEW AND FAR BETWEEN. ELSEWHERE...MUCH OF THE REMAINDER OF THE GULF IS UNDER THE INFLUENCE OF SURFACE RIDGING ANCHORED OVER MUCH OF THE MIDWEST...MIDDLE...AND LOWER MISSISSIPPI RIVER VALLEY. THE RIDGE AXIS EXTENDS TO SOUTHERN PORTIONS OF TEXAS...THEN ALONG THE EASTERN COAST OF MEXICO. MUCH OF THE GULF IS UNDER NORTHEASTERLY WINDS WITH LOW-LEVEL MOISTURE CONVERGENCE OCCURRING OFFSHORE OF THE EASTERN MEXICO COAST ALONG A SURFACE TROUGH ANALYZED FROM 19N95W TO 25N97W. ISOLATED SHOWERS ARE OCCURRING WITHIN 75 NM EITHER SIDE OF THE SURFACE TROUGH AXIS AND N OF 25N W OF 93W OVER THE NW GULF WATERS. CARIBBEAN SEA... MUCH OF THE CARIBBEAN SEA IS UNDER THE INFLUENCE OF SOUTHWESTERLY TO WESTERLY FLOW ALOFT BETWEEN A MIDDLE TO UPPER LEVEL TROUGH ANCHORED OVER THE EASTERN GULF OF MEXICO AND AN UPPER LEVEL RIDGE AXIS EXTENDING NORTH-NORTHEAST FROM NORTHERN SOUTH AMERICA NEAR 10N65W TO BEYOND 20N64W. MIDDLE TO UPPER LEVEL MOISTURE CONTINUES TO ADVECT FROM THE MONSOON TROUGH AXIS REGION OF THE FAR EASTERN PACIFIC OVER PORTIONS OF THE WESTERN CARIBBEAN WITH UPPER LEVEL DIFFLUENCE GENERATING WIDELY SCATTERED SHOWERS AND ISOLATED TSTMS FROM 10N-17N BETWEEN 73W-83W. THIS CONVECTION IS ALSO LIKELY ENHANCED BY EAST- NORTHEAST TRADES E OF 75W CONVERGING WITH NORTH-NORTHEAST WINDS W OF 75W. OTHER THAN PASSING ISOLATED SHOWERS OVER PORTIONS OF THE EASTERN CARIBBEAN AND THE LESSER ANTILLES...AND PORTIONS OF THE NW CARIBBEAN...THE CARIBBEAN REMAINS FAIRLY TRANQUIL THIS EVENING WITH THE AFOREMENTIONED SYNOPTIC PATTERN TO CHANGE LITTLE OVER THE NEXT 24 TO 36 HOURS. ATLANTIC OCEAN... WATER VAPOR IMAGERY INDICATES A MIDDLE TO UPPER LEVEL TROUGH IS OVER THE EASTERN GULF OF MEXICO...FLORIDA PENINSULA...AND PORTIONS OF THE SW NORTH ATLC WATERS THIS EVENING WITH AN EMBEDDED SHORTWAVE TROUGH PROGRESSING NORTHEAST OVER NORTH CAROLINA. WITH MUCH OF THE ENERGY ASSOCIATED WITH THE TROUGHING NORTH OF THE DISCUSSION AREA...THE BROADER UPPER LEVEL TROUGH SUPPORTS A STATIONARY FRONT ANALYZED ALONG 32N77W TO 30N79W TO THE FLORIDA PENINSULA COAST NEAR 28N80W. ISOLATED SHOWERS ARE OCCURRING WITHIN 75 NM EITHER SIDE OF THE FRONT. FARTHER EAST OVER THE REMAINDER OF THE SW NORTH ATLC...SURFACE TROUGHING IS NOTED IN THE PRESSURE PATTERN BETWEEN 60W-70W WITH A SURFACE TROUGH AXIS ANALYZED FROM 28N70W TO 31N67W. ISOLATED SHOWERS ARE OCCURRING FROM 28N-32N BETWEEN 66W-70W. ANOTHER EMBEDDED MIDDLE TO UPPER LEVEL SHORTWAVE TROUGH IS N OF 30N ALONG 58W AND IS PROVIDING FOCUS FOR SCATTERED SHOWERS AND ISOLATED TSTMS N OF 25N BETWEEN 53W-59W. THIS AREA CONTINUES TO BE LOCATED ON THE WESTERN PERIPHERY OF A SURFACE RIDGE WHICH IMPACTS MUCH OF THE CENTRAL ATLC N OF 18N BETWEEN 30W-60W. THE RIDGE IS ANCHORED BY A 1033 MB HIGH CENTERED WELL NORTH OF THE AREA NEAR 42N42W. BETWEEN THE RIDGE AND THE ITCZ AXIS...A SURFACE TROUGH IS ANALYZED FROM 11N46W TO 17N42W AND CONTINUES TO SHOW WEAK LOW-LEVEL CYCLONIC TURNING OF THE LOW-LEVEL CLOUD FIELD. ISOLATED SHOWERS AND TSTMS ARE OCCURRING EAST OF THE SURFACE TROUGH AXIS FROM 12N-16N BETWEEN 36W-44W. THE REMAINDER OF THE EASTERN ATLC IS UNDER THE INFLUENCE OF MIDDLE TO UPPER LEVEL DIFFLUENCE PRIMARILY FROM AN UPPER LEVEL TROUGH AXIS EXTENDING FROM 15N45W TO 32N30W. SCATTERED SHOWERS AND ISOLATED TSTMS ARE OCCURRING S OF 25N E OF 37W. THE TAIL END OF A DISSIPATING COLD FRONT EXTENDS FROM THE IBERIAN PENINSULA NEAR 37N09W TO 26N16W WITH ISOLATED SHOWERS OCCURRING WITHIN 60 NM EITHER SIDE OF THE FRONT. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN