000 AXNT20 KNHC 121742 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT WED AUG 12 2015 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. ...TROPICAL WAVES... TROPICAL WAVE EXTENDS FROM 09N27W TO 17N26W MOVING W AT 10 KT. THE WAVE COINCIDES WITH 700 MB TROUGHING AND MAXIMUM 850 MB RELATIVE VORTICITY BETWEEN 25W-29W. NO SIGNIFICANT CONVECTION IS OCCURRING WITH THE WAVE AT THIS TIME. TROPICAL WAVE EXTENDS FROM 07N49W TO 15N47W MOVING W AT 15 KT. THE WAVE COINCIDES WITH VERY SUBTLE 700 MB TROUGHING BETWEEN 44W- 50W ON THE SOUTHWESTERN PERIPHERY OF A MID-LEVEL RIDGE ANCHORED NEAR 17N40W. ISOLATED MODERATE CONVECTION IS FROM 10N-13N BETWEEN 44W-50W. TROPICAL WAVE EXTENDS FROM 08N76W TO 18N72W MOVING W AT 15 KT. THE WAVE COINCIDES WITH BROAD 700 MB TROUGHING BETWEEN 70W-80W WITH MUCH OF THE 850 RELATIVE VORTICITY ENERGY NOTED S OF 13N. NO SIGNIFICANT CONVECTION IS ASSOCIATED WITH THE WAVE AT THIS TIME. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 14N17W TO 13N20W TO 08N30W TO 09N41W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 09N41W TO 09N45W TO 05N53W. SCATTERED MODERATE CONVECTION 10N-15N BETWEEN 12W-18W. ISOLATED MODERATE CONVECTION IS FROM 05N-08N BETWEEN 25W-30W...AND FROM 05N-09N BETWEEN 33W- 39W. ...DISCUSSION... GULF OF MEXICO... AN FAIRLY EXPANSIVE MIDDLE TO UPPER LEVEL RIDGE IS CENTERED OVER THE TEXAS PANHANDLE AND EXTENDS A RIDGE AXIS SOUTHEASTWARD TO THE FLORIDA PENINSULA. PRIMARILY NE FLOW ALOFT SOUTH OF THIS RIDGE AXIS INFLUENCES MUCH OF THE GULF THIS AFTERNOON. WATER VAPOR IMAGERY INDICATES MOST MOISTURE NOTED ACROSS THE NORTHERN HALF OF THE BASIN FOCUSED AROUND SCATTERED SHOWERS AND ISOLATED TSTMS OCCURRING N OF 27N BETWEEN 84W-94W. THIS ACTIVITY LIES IN CLOSE PROXIMITY TO MAXIMUM LOW-LEVEL CONVERGENCE AND A SURFACE TROUGH ANALYZED FROM THE FLORIDA PANHANDLE NEAR 30N84W W-SW TO 29N90W TO 26N95W. OTHERWISE...THE ONLY OTHER AREA OF CONVECTION IS OCCURRING ALONG THE MEXICO COAST WITHIN FOCUSED WITHIN 60 NM EITHER SIDE OF A SURFACE TROUGH EXTENDING FROM 19N94W TO 24N97W. OUTSIDE AREAS OF ACTIVE CONVECTION...A SURFACE RIDGE AXIS EXTENDS ALONG 25N/26N FROM THE SW NORTH ATLC REGION TO A 1017 MB HIGH NEAR 26N88W TO AN INLAND 1018 MB HIGH NEAR 22N100W. MOSTLY LIGHT TO GENTLE BREEZE CONDITIONS PREVAIL AND ARE EXPECTED TO PERSIST IN THE VICINITY OF THE RIDGING THROUGH SATURDAY. CARIBBEAN SEA... AN UPPER LEVEL LOW CENTERED NEAR 19N75W INFLUENCES MUCH OF THE CARIBBEAN BASIN THIS AFTERNOON. TO THE EAST...SOUTHERLY FLOW ALOFT CONTINUES TO PROVIDE A DIFFLUENT ENVIRONMENT ALOFT FOR SCATTERED SHOWERS AND ISOLATED TSTMS OCCURRING FROM 12N-16N BETWEEN 61W-69W. TO THE WEST...CONDITIONS ARE MORE STABLE AS NW FLOW ALOFT CONTINUES TO PROVIDE RELATIVELY DRY CONDITIONS...EVEN AS A TROPICAL WAVE ALONG 74W BEGINS TO ENTER THE WESTERN CARIBBEAN THIS AFTERNOON AND EVENING. OTHERWISE...THE PRIMARY IMPACT REMAINS FRESH TO STRONG TRADES ACROSS CENTRAL PORTIONS OF THE BASIN. THE AREA OF TRADES WILL PERSIST THROUGH FRI AND GRADUALLY INCREASE IN AREAL COVERAGE DUE TO STRONGER RIDGING BUILDING SOUTHWESTWARD FROM THE CENTRAL ATLC. ...HISPANIOLA... CURRENTLY...SKIES REMAIN MOSTLY CLEAR THIS AFTERNOON...HOWEVER THE PRESENCE OF AN UPPER LEVEL LOW CENTERED NEAR 19N75W IS CONTINUING TO PROVIDE A DIFFLUENT ENVIRONMENT ALOFT THAT WILL LIKELY PROMOTE SCATTERED LATE AFTERNOON AND EARLY EVENING SCATTERED SHOWERS AND TSTMS. ATLANTIC OCEAN... WATER VAPOR IMAGERY INDICATES AN UPPER LEVEL TROUGH EXTENDS OVER THE EASTERN CONUS WITH A BASE REACHING OFFSHORE OF THE CAROLINAS NEAR 32N79W. THIS TROUGHING SUPPORTS A COLD FRONT EXTENDING FROM OFFSHORE OF NORTH CAROLINA NEAR 36N75W SW ALONG THE COAST TO SOUTHERN GEORGIA. A PRE-FRONTAL SURFACE TROUGH EXTENDS FROM 31N78W TO 28N80W. SCATTERED SHOWERS AND TSTMS ARE OCCURRING N OF 30N BETWEEN 72W-79W...AND WITHIN MAXIMUM LOW-LEVEL CONVERGENCE N OF 27N BETWEEN 66W-76W. THE REMAINDER OF THE SW NORTH ATLC IS UNDER THE INFLUENCE OF A SURFACE RIDGE WITH AXIS EXTENDING FROM 32N57W SW TO THE FLORIDA STRAITS NEAR 24N80W. FARTHER EAST...A VERY SHALLOW FRONT EXTENDS FROM 34N27W TO 28N34W TO 29N40W TO 32N42W. ISOLATED SHOWERS ARE POSSIBLE WITHIN 120 NM SW OF THE COLD FRONT AS IT CONTINUES TO MOVE SW AND WEAKEN. ALSO...A SURFACE TROUGH EXTENDS FROM 23N24W TO 30N28W AND IS SUPPORTED ALOFT BY AN UPPER LEVEL LOW CENTERED NEAR 29N22W. POSSIBLE ISOLATED SHOWERS ARE OCCURRING NE OF THE SURFACE TROUGH FROM 27N- 32N BETWEEN 16W-24W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN