000 AXNT20 KNHC 162345 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT SUN AUG 16 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC. ...SPECIAL FEATURES... TROPICAL WAVE EXTENDS FROM 10N28W TO 17N27W MOVING W AT 15-20 KT. A 1011 MB LOW IS CENTERED AT THE SOUTHERN EXTENT OF THE WAVE AXIS EMBEDDED WITHIN THE MONSOON TROUGH AND A MAXIMUM IN 850 MB RELATIVE VORTICITY. SCATTERED MODERATE CONVECTION IS FROM 07N- 13N BETWEEN 24W-33W. THE SYSTEM HAS A MEDIUM CHANCE OF DEVELOPING INTO A TROPICAL CYCLONE DURING THE NEXT 48 HOURS. ...TROPICAL WAVES... TROPICAL WAVE EXTENDS FROM 07N46W TO 14N42W MOVING W AT 10-15 KT. THE WAVE COINCIDES WITH VERY SUBTLE 700 MB TROUGHING BETWEEN 43W-48W AND REMAINS A RELATIVELY LOW-AMPLITUDE FEATURE AT THIS TIME. VISIBLE SATELLITE IMAGERY INDICATES AN EXPOSED CYCLONIC CIRCULATION FOCUSED ON A 1013 MB LOW CENTERED ALONG THE WAVE AXIS NEAR 10N. ISOLATED MODERATE CONVECTION IS FROM 06N-12N BETWEEN 43W-49W. TROPICAL WAVE EXTENDS FROM 11N74W TO 19N72W MOVING W AT 15 KT. MOST OF THE ENERGY ASSOCIATED WITH THE WAVE REMAINS AT THE NORTHERN EXTENT OF THE WAVE AXIS AND ANALYZED AS A SURFACE TROUGH...OR FRACTURED ENERGY...ANALYZED FROM 20N72W TO 23N68W. MUCH OF THE SCATTERED MODERATE CONVECTION IS ALSO OCCURRING IN THE VICINITY OF THIS SURFACE TROUGH FROM 17N-23N BETWEEN 63W- 71W. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 19N16W TO THE SPECIAL FEATURES 1011 MB LOW NEAR 10N28W TO 09N36W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 09N36W TO 08N40W TO 09N45W. ASIDE FROM CONVECTION ASSOCIATED WITH THE SPECIAL FEATURES LOW AND TROPICAL WAVE ALONG 44W...ISOLATED MODERATE TO STRONG CONVECTION IS FROM 09N-12N BETWEEN 18W-21W. ...DISCUSSION... GULF OF MEXICO... WATER VAPOR IMAGERY INDICATES A MIDDLE TO UPPER LEVEL LOW CENTERED OVER NE MEXICO NEAR 25N99W THAT CONTINUES TO PROVIDE SOUTH-SOUTHWESTERLY FLOW ALOFT OVER MUCH OF THE GULF THIS EVENING...AND A MAXIMUM IN UPPER LEVEL DIFFLUENCE GENERALLY N OF 25N. THIS DIFFLUENCE ALONG WITH A WEAK SURFACE TROUGH ANALYZED FROM SOUTHERN MISSISSIPPI TO 29N93W TO 25N95W IS GENERATING SCATTERED SHOWERS AND WIDELY SCATTERED TSTMS N OF 24N... INCLUDING INLAND PORTIONS OF THE FLORIDA PENINSULA AND SEVERAL INLAND AREAS ACROSS THE SE CONUS FROM COASTAL TEXAS TO WESTERN GEORGIA. WHILE A WEAK SURFACE RIDGE EXTENDS FROM THE SOUTHERN FLORIDA PENINSULA TO THE SW GULF...MOSTLY GENTLE TO MODERATE SOUTHERLY FLOW PREVAILS THIS EVENING AND IS EXPECTED THROUGH TUESDAY NIGHT LATE. THEREAFTER...THE S-SE WINDS WILL INCREASE SLIGHTLY ACROSS THE WESTERN GULF AS AN AREA OF LOW PRESSURE DEVELOPS ACROSS THE SOUTHERN PLAINS TUESDAY NIGHT INTO WEDNESDAY. CARIBBEAN SEA... AN UPPER LEVEL ANTICYCLONIC CIRCULATION IS CENTERED OVER THE WESTERN CARIBBEAN NEAR 14N83W AND IS PROVIDING INFLUENCE TO MUCH OF THE BASIN W OF 78W. AN OVERALL DIFFLUENT ENVIRONMENT IS NOTED IN CLOSE PROXIMITY TO THE UPPER LEVEL RIDGING AND WITHIN THE WESTERN PERIPHERY GENERATING SCATTERED SHOWERS AND TSTMS S OF 16N W OF 81W...INCLUDING INLAND PORTIONS OF CENTRAL AMERICA... AND ACROSS MUCH OF THE YUCATAN PENINSULA THIS EVENING. OTHERWISE...THE REMAINDER OF THE CARIBBEAN IS UNDER THE INFLUENCE OF NORTHWESTERLY FLOW ALOFT BETWEEN THE ANTICYCLONE AND AN UPPER LEVEL LOW CENTERED NORTH OF HISPANIOLA NEAR 22N71W. AMPLE LIFT GENERATED ON THE SOUTHERN PERIPHERY OF THE UPPER LEVEL LOW AND THE PRESENCE OF A TROPICAL WAVE ALONG 73W IS PRODUCING SCATTERED SHOWERS AND TSTMS FROM 17N-22N BETWEEN 64W- 72W. LOCALIZED HEAVY RAINFALL IS EXPECTED DURING THE NEXT 24 TO 48 HOURS WITH A GREATER POSSIBILITY OF FLASH FLOODING AND MUDSLIDES ACROSS HISPANIOLA AND PUERTO RICO. FINALLY...MODERATE TO FRESH TRADES PERSIST WITH A SMALL AREA OF OCCASIONAL STRONG GENERALLY REMAINING S OF 15N BETWEEN 68W-77W. ...HISPANIOLA... CURRENTLY...SCATTERED SHOWERS AND TSTMS ARE OCCURRING ACROSS THE ISLAND DUE TO THE PRESENCE OF A TROPICAL WAVE ALONG 73W AND AN UPPER LEVEL LOW CENTERED TO THE NORTH NEAR 22N71W. WITH THE ONGOING PRECIPITATION...LOCALLY HEAVY AT TIMES THROUGH THE OVERNIGHT HOURS INTO MONDAY...WILL PROVIDE AN INCREASE IN THE RISK OF FLASH FLOODING AND MUDSLIDES THROUGH MONDAY. ATLANTIC OCEAN... AN UPPER LEVEL RIDGE IS CENTERED OVER THE FLORIDA PENINSULA THIS EVENING AND CONTINUES TO SUPPORT A BROAD AREA OF HIGH PRESSURE ACROSS THE SW NORTH ATLC ANCHORED BY A 1021 MB HIGH CENTERED NEAR BERMUDA. MOSTLY FAIR CONDITIONS ACCOMPANY THE HIGH... HOWEVER A FEW ISOLATED SHOWERS ARE OCCURRING ACROSS THE WATERS N OF 25N W OF 65W. TO THE SE...A FRACTURED PORTION OF A TROPICAL WAVE MOVING ACROSS THE CENTRAL CARIBBEAN SEA EXTENDS FROM 23N68W TO 20N72W AND IS PROVIDING FOCUS FOR SCATTERED SHOWERS AND TSTMS FROM 17N-22N BETWEEN 64W-72W. AN UPPER LEVEL LOW CENTERED N OF HISPANIOLA NEAR 22N71W IS LIKELY ENHANCING THIS CONVECTION WITH MAXIMUM MIDDLE TO UPPER LEVEL DIFFLUENCE ON THE SOUTHERN PERIPHERY OF THE UPPER LEVEL LOW. THE UPPER LEVEL LOW IS AN EXTENSION OF A CENTRAL ATLC UPPER LEVEL TROUGH THAT EXTENDS FROM 30N59W TO 24N65W THAT SUPPORTS A WEAK SURFACE TROUGH BOUNDARY FROM 32N57W TO 26N62W. MOST CONVECTION ASSOCIATED WITH THE BOUNDARY IS NORTH OF THE DISCUSSION AREA...HOWEVER ISOLATED SHOWERS ARE POSSIBLE WITHIN 120 NM EITHER SIDE OF THE TROUGHING. OTHERWISE...THE REMAINDER OF THE EASTERN ATLC IS UNDER THE INFLUENCE OF A SURFACE RIDGE ANCHORED BY A 1028 MB HIGH CENTERED NW OF THE AZORES NEAR 40N33W. 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