000 AXNT20 KNHC 132359 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 705 PM EST TUE NOV 13 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 MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 11N15W TO 06N26W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 06N26W TO 07N33W TO 12N40W TO 11N50W TO 10N60W. WIDELY SCATTERED MODERATE CONVECTION IS FROM 04N-12N BETWEEN 19W-28W. A SURFACE TROUGH IS EMBEDDED WITHIN THE ITCZ FROM 11N40W TO 17N38W. WIDELY SCATTERED MODERATE CONVECTION IS FROM 09N-13N BETWEEN 31W-41W. ...DISCUSSION... GULF OF MEXICO... WATER VAPOR IMAGERY INDICATES A MIDDLE TO UPPER LEVEL TROUGH EXTENDS FROM OVER THE FLORIDA PANHANDLE NEAR 30N85W TO OVER WESTERN CUBA NEAR 22N81W THAT AS OF 13/2100 UTC SUPPORTS A COLD FRONT FROM JACKSONVILLE FLORIDA INTO THE NE GULF NEAR 29N83W THEN BECOMES STATIONARY ALONG 29N83W TO 25N90W INTO A 1017 MB LOW NEAR 21N94W THEN INLAND OVER SOUTHERN MEXICO NEAR 18N93W. WHILE MOST OF THE MIDDLE TO UPPER LEVEL DYNAMICS ARE EAST OF THE TROUGH AXIS OVER THE FLORIDA PENINSULA THIS EVENING...ISOLATED SHOWERS ARE OCCURRING WITHIN 75 NM EITHER SIDE OF THE FRONT. IN ADDITION...A SURFACE TROUGH EXTENDS NW FROM THE LOW CENTER TO 24N97W AND IS PROVIDING LOW-LEVEL MOISTURE CONVERGENCE AND FOCUS FOR ISOLATED SHOWERS WEST OF 91W N OF 24N...AND WEST OF THE FRONT S OF 24N. OTHERWISE...THE GULF IS EXPERIENCING PRIMARILY NE WINDS...STRONGER NW OF THE STATIONARY FRONT W OF 90W...AS HIGH PRESSURE REMAINS ANCHORED OVER THE MID-MISSISSIPPI AND OHIO RIVER VALLEYS. AS THE FRONT BECOMES MORE AND MORE DIFFUSE OVER THE NEXT FEW DAYS...THE NE WINDS ARE FORECAST TO PERSIST THROUGH THE REMAINDER OF THE WEEK WITH WHILE GRADUALLY DECREASING IN ASSOCIATION WITH THE FRONT. CARIBBEAN SEA... THE BASE OF AN UPPER LEVEL TROUGH CONTINUES TO PROGRESS OVER THE NW CARIBBEAN AND CUBA THIS EVENING WHILE THE REST OF THE BASIN IS UNDER PRIMARILY WEST-SOUTHWESTERLY UPPER LEVEL FLOW. WATER VAPOR IMAGERY INDICATES THAT MOSTLY DRY AIR AND SUBSIDENCE ALOFT DOMINATES S OF 20N. AT THE SURFACE...BROAD TROUGHING PREVAILS BETWEEN 60W-80W AS AN UPPER LEVEL SHORTWAVE TROUGH OVER THE SW NORTH ATLC NEAR 27N66W IS INDUCING A SURFACE TROUGH AXIS ALONG 70W TO HISPANIOLA AND THEN NORTH-NORTHEAST TO BEYOND 32N63W. ISOLATED SHOWERS AND TSTMS ARE OCCURRING E OF 70W FROM 14N-20N BETWEEN 62W-69W. ANOTHER AREA OF MAXIMUM LOW-LEVEL MOISTURE CONVERGENCE IS LOCATED OVER THE SW CARIBBEAN WHERE ISOLATED SHOWERS AND TSTMS ARE OCCURRING S OF 13N BETWEEN 75W-85W... INCLUDING PORTIONS OF INLAND COSTA RICA AND PANAMA. ATLANTIC OCEAN... A PAIR OF MIDDLE TO UPPER LEVEL SHORTWAVE TROUGHS IMPACT THE SW NORTH ATLC THIS EVENING. THE WESTERNMOST SHORTWAVE SUPPORTS A COLD FRONT ANALYZED INTO THE DISCUSSION AREA NEAR 32N80W AND RUNS PARALLEL ALONG THE GEORGIA COAST TO NEAR JACKSONVILLE FLORIDA. ISOLATED SHOWERS ARE OCCURRING WITHIN 120 NM EITHER SIDE OF THE FRONT AND N OF 23N W OF 77W. THE OTHER UPPER LEVEL SHORTWAVE...WELL EAST OF THE NORTH AMERICAN CONTINENT...IS CENTERED NEAR 27N68W AND INDUCES A SURFACE TROUGH ANALYZED FROM 20N70W NEAR HISPANIOLA NORTH-NORTHEAST ALONG 30N65W TO BEYOND 32N63W. ISOLATED SHOWERS AND POSSIBLE ISOLATED TSTMS ARE OCCURRING FROM 18N-32N BETWEEN 56W-70W. THIS LARGE AREA OF SURFACE TROUGHING IS FORECAST TO LIFT NORTHWARD OVER THE NEXT 24 TO 36 HOURS WITH CYCLOGENESIS OCCURRING IN THE PROCESS NORTH OF THE DISCUSSION AREA OVER THE WESTERN NORTH ATLC WATERS. FARTHER EAST...A WEAK SURFACE TROUGH ANALYZED FROM 20N-25N ALONG 42W CONTINUES TO DRIFT WESTWARD WITH ISOLATED SHOWERS OCCURRING WITHIN 150 NM EITHER SIDE OF THE TROUGH AXIS. WATER VAPOR IMAGERY INDICATES A MIDDLE TO UPPER LEVEL TROUGH AXIS EXTENDS FROM 22N36W TO 05N26W AND IS GENERATING SCATTERED SHOWERS AND WIDELY SCATTERED TSTMS FROM 12N-24N BETWEEN 29W-37W EAST OF THE TROUGH AXIS IN AN AREA OF MAXIMUM UPPER LEVEL DIFFLUENCE. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN