000 AXNT20 KNHC 162341 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT THU AUG 16 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. ...SPECIAL FEATURES... TROPICAL STORM GORDON IS CENTERED NEAR 34.2N 52.1W AT 16/2100 UTC OR ABOUT 650 NM ENE OF BERMUDA AND ABOUT 1230 NM W OF THE AZORES MOVING ENE AT 15 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 999 MB. MAXIMUM SUSTAINED WIND SPEED IS 55 KT WITH GUSTS TO 65 KT. WIDELY SCATTERED MODERATE CONVECTION IS FROM 33N-36N BETWEEN 49W-53W. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT3/WTNT23 KNHC FOR MORE DETAILS. TROPICAL WAVE EXTENDS FROM 17N93W TO 22N92W MOVING WNW AT 10 KT. THE WAVE REMAINS EMBEDDED WITHIN BROAD LOW-LEVEL CYCLONIC FLOW ACROSS THE YUCATAN PENINSULA AND SW GULF OF MEXICO THIS EVENING. MUCH OF THE MIDDLE TO UPPER LEVEL FLOW ALOFT OVER THE WAVE REMAINS DIFFLUENT AND SUPPORTS SCATTERED MODERATE CONVECTION FROM 18N-22N BETWEEN 88W-94W. ENVIRONMENTAL CONDITIONS REMAIN FAVORABLE FOR GRADUAL DEVELOPMENT OF THIS SYSTEM TO BECOME A TROPICAL CYCLONE IN THE NEXT 48 HOURS. ...TROPICAL WAVES... TROPICAL WAVE EXTENDS FROM 10N31W TO 19N31W MOVING W AT 15-20 KT. THE WAVE REMAINS EMBEDDED WITHIN A LARGE AREA OF ENHANCED DEEP LAYER MOISTURE AS NOTED ON THE TOTAL PRECIPITABLE WATER IMAGERY FROM 07N-17N BETWEEN 15W-37W. GLOBAL MODEL DATA SHOWS THAT THE WAVE COINCIDES WITH A BROAD 700 MB TROUGH AXIS ALONG 31W. DUE TO A LARGE DRY AIRMASS ASSOCIATED WITH A SAHARAN AIR LAYER...NO DEEP CONVECTION IS CURRENTLY ASSOCIATED WITH THE WAVE. TROPICAL WAVE EXTENDS FROM 10N52W TO 17N56W MOVING W AT 20-25 KT. ENERGY FROM THE WAVE CONTINUES TO STRETCH IN A NW-SE ORIENTATION DUE TO BROAD LOW-LEVEL CYCLONIC FLOW ACROSS THE CENTRAL TROPICAL ATLC. A MAXIMUM IN 700 MB GLOBAL MODEL WIND IS NOTED ACROSS THE NORTHERN EXTENT OF THE WAVE AND THIS CONTINUES TO FUEL A SURGE OF SAHARAN DUST LOCATED E OF 63W TO THE AFRICAN COAST. SAHARAN DUST IS WRAPPED AROUND THE WAVE RESULTING IN A LACK OF ANY DEEP CONVECTION AT THIS TIME. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 16N17W TO 10N31W TO 09N42W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 09N42W TO 10N50W. SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS FROM 10N-13N BETWEEN 15W-19W. SCATTERED MODERATE CONVECTION IS FROM 06N-11N BETWEEN 19W-27W. ...DISCUSSION... GULF OF MEXICO... A WEAK MIDDLE TO UPPER LEVEL TROUGH IS NOTED OVER THE SE CONUS AND EXTENDS SOUTHWARD OVER PORTIONS OF THE NORTHERN GULF N OF 28N E OF 90W. THE UPPER LEVEL TROUGH SUPPORTS A STATIONARY FRONT ANALYZED FROM SOUTH CAROLINA TO SOUTHERN ALABAMA THAT CONTINUES TO PROVIDE MAXIMUM LOW-LEVEL MOISTURE CONVERGENCE SOUTH OF THE FRONT ALONG THE GULF COAST RESULTING IN SCATTERED SHOWERS AND TSTMS N OF 29N E OF 92W. THE TROUGHING THEN STRETCHES SW INTO AN UPPER LEVEL TROUGH AXIS FROM 27N92W TO 21N99W. MOSTLY DRY AIR IS FOUND ALOFT NORTH AND WEST OF THIS TROUGH AXIS PROVIDING MUCH OF THE FAR NW GULF WITH CLEAR SKIES THIS EVENING. HOWEVER SOUTH AND EAST OF THIS TROUGH AXIS...AN UPPER LEVEL ANTICYCLONIC CIRCULATION IS CENTERED NEAR 22N88W THAT CONTINUES TO ADVECT MOISTURE FROM OVER THE SW GULF AND THE TROPICAL WAVE LOCATED ALONG 93W NORTHWARD TO 26N92W THEN EASTWARD TOWARDS THE FLORIDA PENINSULA. ISOLATED SHOWERS AND TSTMS ARE OCCURRING FROM 25N-28N BETWEEN 80W-93W...INCLUDING PORTIONS OF THE FLORIDA PENINSULA. BENEATH ALL THE MIDDLE TO UPPER LEVEL DYNAMICS GENERATING MOST OF THE CONVECTION...A SURFACE RIDGE EXTENDS FROM THE SW NORTH ATLC ALONG 27N AND REMAINS ANCHORED IN THE EASTERN GULF BY A 1019 MB HIGH CENTERED NEAR 28N87W. CARIBBEAN SEA... AS MOISTURE ASSOCIATED WITH THE TROPICAL WAVE IN THE SW GULF OF MEXICO FLEETS WESTWARD THIS EVENING...NORTHEASTERLY FLOW ALOFT ASSOCIATED WITH AN UPPER LEVEL ANTICYCLONIC CIRCULATION CENTERED NEAR 22N88W CONTINUES TO PROVIDE AN OVERALL STABLE ATMOSPHERE ACROSS MUCH OF THE WESTERN CARIBBEAN W OF 80W. A FEW ISOLATED SHOWERS AND TSTMS ARE OCCURRING OVER PORTIONS OF CUBA DUE TO PEAK DAYTIME HEATING AND INSTABILITY...HOWEVER THESE ARE EXPECTED TO DIMINISH WITH SUNSET. MOST OF THE CONVECTIVE ACTIVITY ASSOCIATED WITH THE TROPICAL WAVE ALONG 93W IS WELL INLAND ACROSS CENTRAL AMERICA WITH THE POTENTIAL FOR LOCALIZED HEAVY RAINFALL AND FLOODING THROUGH THE OVERNIGHT HOURS. FARTHER EAST...AN INVERTED UPPER LEVEL TROUGH COVERS THE REMAINDER OF THE CARIBBEAN E OF 75W WITH AXIS EXTENDING FROM AN UPPER LEVEL LOW IN THE ATLC NEAR 27N64W TO 20N67W TO 12N72W. SCATTERED SHOWERS AND TSTMS ARE OCCURRING EAST OF THE TROUGH AXIS ACROSS PORTIONS OF PUERTO RICO...HISPANIOLA...AND JAMAICA AND THESE ARE MOST LIKELY THE RESULT OF PEAK DAYTIME HEATING AND INSTABILITY. A SURGE OF SAHARAN DUST IS BEGINNING TO MOVE ITS WAY INTO THE EASTERN CARIBBEAN...CURRENTLY E OF 63W...HOWEVER THE APPROACH OF A TROPICAL WAVE ALONG 54W WILL PROVIDE FOR ISOLATED SHOWERS WELL INTO THE WEEKEND PERIOD. ATLANTIC OCEAN... UPPER LEVEL DIFFLUENCE IS MAXIMIZED ACROSS THE SW NORTH ATLC THIS EVENING AS AN UPPER LEVEL RIDGE EXTENDS FROM 22N88W NE TO 30N71W. WITH AN OVERALL WEAK PRESSURE GRADIENT AT THE SURFACE... ISOLATED SHOWERS AND TSTMS ARE OCCURRING N OF 24N W OF 70W. NORTHEAST OF THIS AREA...A WEAK SURFACE TROUGH IS ANALYZED FROM BERMUDA NEAR 32N65W TO 28N72W AND ALONG WITH AN UPPER LEVEL LOW CENTERED NEAR 27N64W CONTINUES TO PROVIDE FOCUS FOR ISOLATED SHOWERS AND TSTMS N OF 24N BETWEEN 60W-70W. THE REMAINDER OF THE CENTRAL AND EASTERN ATLC IS UNDER THE INFLUENCE OF A SURFACE RIDGE ANCHORED BY A 1022 MB HIGH CENTERED NEAR 28N43W. TROPICAL STORM GORDON TRACKS NORTH OF THIS SURFACE RIDGE...WHILE THE TROPICAL WAVES MOVING WESTWARD IN THE TROPICAL ATLC REMAIN LARGELY S OF 20N AND SHROUDED IN SAHARAN DUST SOUTH OF THE RIDGE. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN