000 AXNT20 KNHC 120003 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT TUE SEP 11 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 2345 UTC. ...SPECIAL FEATURES... TROPICAL DEPRESSION FOURTEEN IS CENTERED NEAR 17.5N 43.8W 11/2100 UTC OR ABOUT 1170 MI...1880 KM E OF THE LESSER ANTILLES MOVING W AT 10 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1006 MB. MAXIMUM SUSTAINED WIND SPEED IS 30 KT WITH GUSTS TO 40 KT. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT4/WTNT24 KNHC FOR MORE DETAILS. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS FORM 14N-22N BETWEEN 41W-50W. TROPICAL STORM LESLIE BECAME POST TROPICAL AT 11/1500 UTC. TROPICAL STORM MICHAEL BECAME POST TROPICAL AT 11/2100 UTC. ...TROPICAL WAVES... A TROPICAL WAVE IS ANALYZED FROM THE CAPE VERDE ISLANDS NEAR 15N25W TO 3N25W MOVING W 10-15 KT. WAVE AXIS LIES AHEAD OF A SURGE OF MODERATE MOISTURE VALUES ON TOTAL PRECIPITABLE WATER IMAGERY...WITH BROAD MID LEVEL CYCLONIC ROTATION ALONG THE WAVE AXIS NOTED ON SATELLITE IMAGERY CLOUD PATTERN. SCATTERED WEAK CONVECTION IS WITHIN 130 NM ON EITHER SIDE OF THE WAVE AXIS. ...ITCZ/MONSOON TROUGH... THE OCEANIC MONSOON TROUGH IS DISRUPTED BY THE LARGE CYCLONIC WIND FIELD ASSOCIATED TO TROPICAL DEPRESSION FOURTEEN AND A TROPICAL WAVE MOVING ACROSS THE ERN TROPICAL ATLC. A SMALL SECTION OF ITCZ IS NOTED WELL SW OF T.D. FOURTEEN FROM 9N55W TO INLAND PORTIONS OF NRN VENEZUELA ALONG 9N61W. NO CONVECTION IS NOTED ALONG THE ITCZ AXIS. ...DISCUSSION... GULF OF MEXICO... A STATIONARY FRONT EXTENDS WNW ACROSS THE SOUTHERN FLORIDA PENINSULA AND INTO THE GULF ALONG 25N81W TO THE NORTH CENTRAL BASIN NEAR 27N90W TURNING SSW TO NEAR THE COAST OF MEXICO AROUND 24N97W. SCATTERED SHOWERS AND THUNDERSTORMS ARE WITHIN 70 NM ON EITHER SIDE OF THE FRONT W OF 87W. THE ACTIVITY IN THIS REGION WITHIN THE FRONT IS FURTHER ENHANCED BY AN UPPER LEVEL TROUGH NOTED ON WATER VAPOR IMAGERY W OF 90W. SIMILAR CONVECTION IS OVER THE BAY OF CAMPECHE S OF 22N W OF 92W. DOPPLER RADAR IMAGERY ALSO INDICATES SEVERAL LINES OF STRONG CONVECTION MOVING OFF THE W COAST OF THE FLORIDA PENINSULA E OF 84W. MARINE OBSERVATIONS ACROSS THE GULF SHOW EASTERLY WINDS 10-15 KT N OF THE FRONT AND SOUTHERLY WINDS UP TO 10 KT S OF THE FRONT. SHORT RANGE COMPUTER MODELS SUGGEST THE AREA OF CONVECTION OVER THE NW GULF WILL MOVE SLOWLY MOVE NNW DURING THE NEXT 24 HOURS. IN THE MEAN TIME...THE FRONT IS EXPECTED TO REMAIN NEAR STATIONARY WITH MODERATE TO STRONG CONVECTION LINGERING OVER THE ERN BASIN. CARIBBEAN SEA... DRY AIR ALOFT AND STRONG SUBSIDENCE IS NOTED ACROSS THE BASIN ON WATER VAPOR IMAGERY...SUPPRESSING DEEP CONVECTION AND ONLY ALLOWING FOR WIDELY SCATTERED LOW-TOP SHOWERS DOTTING THE DISCUSSION AREA NOTED ON LAST VISIBLE SATELLITE PICTURES OF THE DAY. LOW-MID LEVEL MOISTURE INCREASES OVER THE FAR SW BASIN ON TOTAL PRECIPITABLE WATER IMAGERY. SCATTERED MODERATE TO HEAVY SHOWERS ARE NOTED WITHIN 40-60 NM ACROSS THE COASTAL WATERS OF COLOMBIA...PANAMA ...COSTA RICA AND SRN NICARAGUA. THE ACTIVITY IS ASSOCIATED TO THE ERN PACIFIC MONSOON TROUGH EXTENDING ACROSS INLAND PORTIONS OF CENTRAL AMERICA TO NRN COLOMBIA. FAIR WEATHER CONDITIONS WITH A FEW ISOLATED SHOWERS WILL PREDOMINATE ACROSS THE DISCUSSION AREA DURING THE NEXT 24 HOURS. MODERATE TO ISOLATED STRONG CONVECTION WILL LINGER OVER THE SW BASIN DURING THE FORECAST PERIOD. ATLANTIC OCEAN... AN UPPER LEVEL TROUGH MOVES ACROSS THE OPEN WATERS OF THE WRN NORTH ATLANTIC SUPPORTING A COLD FRONT EXTENDING INTO OUR DISCUSSION AREA ALONG 31N60W 25N70W TO ACROSS THE NW BAHAMAS NEAR 25N77W AND INTO THE GULF OF MEXICO AS STATIONARY ACROSS THE SOUTHERN FLORIDA PENINSULA NEAR 25N81W. SCATTERED MODERATE TO HEAVY SHOWERS AND THUNDERSTORMS ARE NOTED WITHIN 120 NM W OF THE FRONT E OF 70W...AND WITHIN 150 NM N OF THE FRONT W OF 70W. LOW LEVEL CONVERGENCE AHEAD OF THE FRONT DEVELOPS AS THE COOLER AIRMASS ALOFT BEHIND THE FRONT COLLIDES WITH THE TROPICAL AIRMASS...GENERATING SIMILAR CONVECTION WITHIN 80 NM ON EITHER SIDE OF AN IMAGINARY LINE EXTENDING FROM 30N57W TO 20N62W. THE FRONT IS EXPECTED TO LOOSE MOMENTUM OVERNIGHT AND BECOME STATIONARY WITHIN THE NEXT 12-24 HOURS. HOWEVER...THE ENERGY ASSOCIATED TO THIS SYSTEM WILL REMAIN WITH SCATTERED MODERATE TO ISOLATED STRONG CONVECTION LINGERING ALONG THE FRONT DURING THE TIME PERIOD. ASIDE TROPICAL DEPRESSION FOURTEEN...THE REMAINDER OF THE ATLC BASIN DISCUSSION AREA IS DOMINATED BY A SURFACE RIDGE OF HIGH PRESSURE ANCHORED BY A 1022 MB HIGH NEAR 32N40W AND AN UPPER LEVEL ANTICYCLONIC CIRCULATION CENTERED NEAR 20N36W. THE OVERALL FAIR WEATHER IS ENHANCED ALOFT BY THICK LAYER OF SAHARAN DUST NOTED ON METEOSAT-9 SAL PRODUCT E OF 45W S OF 20N. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ GARCIA