000 AXNT20 KNHC 230603 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT TUE JUL 23 2013 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0525 UTC. ...SPECIAL FEATURES... A TROPICAL WAVE ACCOMPANIED WITH A SURFACE LOW IS OVER THE EASTERN TRPCL ATLC WITH AXIS EXTENDING FROM 16N22W TO 07N23W. THIS SYSTEM IS EMBEDDED IN A HIGH MOIST ENVIRONMENT AT THE LOWER AND MIDDLE LEVELS WHICH COMBINED WITH UPPER LEVEL DIFFLUENCE IS SUPPORTING CLUSTERS OF MODERATE/ISOLATED STRONG CONVECTION FROM 09N-15N BETWEEN 21W-25W AND SCATTERED MODERATE CONVECTION FROM 05N-10N BETWEEN 21W-27W. ENVIRONMENTAL CONDITIONS ARE EXPECTED TO BECOME MORE FAVORABLE FOR TROPICAL CYCLONE DEVELOPMENT. AT THE MOMENT...THERE IS A MEDIUM CHANCE FOR THIS SYSTEM TO BECOME A TROPICAL CYCLONE DURING THE NEXT 48 HOURS. ...TROPICAL WAVES... AS OF 0300 UTC...A TROPICAL WAVE IS MOVING ACROSS THE DOMINICAN REPUBLIC WITH A TILTED AXIS EXTENDING ALONG 21N66W TO 16N70W AND MOVING NEAR 10 KT. THE WAVE IS EMBEDDED IN A MODERATE MOIST ENVIRONMENT AND AT THE MOMENT ONLY ISOLATED SHOWERS ARE OVER THE EASTERN DOMINICAN REPUBLIC AS WELL THE MONA PASSAGE. HOWEVER...MIDDLE LEVEL DIVERGENT FLOW MAY ASSIST IN DEVELOPING CONVECTION AS THE WAVE CONTINUE A W-NW TRACK ACROSS THE ISLAND TODAY. ...THE ITCZ/THE MONSOON TROUGH... THE MONSOON TROUGH AXIS EXTENDS ACROSS AFRICA INTO THE E TROPICAL ATLC NEAR 14N17W AND CONTINUES TO 14N21W. THE ITCZ AXIS EXTENDS W OF A TROPICAL WAVE NEAR 11N24W TO 08N31W 06N38W. BESIDES THE CONVECTION ALREADY DISCUSSED ASSOCIATED WITH THE TROPICAL WAVE...SCATTERED MODERATE CONVECTION WITH ISOLATED TSTMS IS FROM 07N-15N E OF 19W. SIMILAR CONVECTION IS WITHIN 110 NM S OF THE ITCZ AXIS BETWEEN 33W-37W. ...DISCUSSION... GULF OF MEXICO... SURFACE RIDGING DOMINATES THE GULF ANCHORED BY A 1019 MB HIGH NEAR 27N84W THAT IS PROVIDING RETURN FLOW IN THE RANGE OF 5-15 KT. EXCEPT FOR THE NE GULF N OF 28N...VERY DRY AIR AT THE LOWER AND MIDDLE LEVELS ACROSS THE BASIN IS SUPPORTING FAIR WEATHER. OVER THE NE GULF...A HIGH MOIST ENVIRONMENT AT THE LOWER AND MIDDLE LEVELS AND UPPER LEVEL DIFFLUENCE ARE SUPPORTING A CLUSTER OF MODERATE CONVECTION WITH ISOLATED TSTMS N OF 28N BETWEEN 84W-89W. THE HIGH IS EXPECTED TO PERSIST OVER THE GULF WATERS UNTIL VERY EARLY THURSDAY WHEN IT STARTS TO DISSIPATE. RAINSHOWERS OVER THE NE GULF ARE EXPECTED TO CONTINUE UNTIL VERY LATE ON TUESDAY BUT THE REST OF THE BASIN WILL ENJOY FAIR WEATHER AS DRY AIR CONTINUES TO BE ADVECTED FROM THE CARIBBEAN INTO THE GULF. THE CARIBBEAN SEA... A TROPICAL WAVE IS MOVING ACROSS THE DOMINICAN REPUBLIC THIS MORNING GENERATING ISOLATED SHOWERS AND ADVECTING MODERATE MOISTURE ACROSS THE HISPANIOLA. RAINSHOWERS MAY DEVELOPED OVER THE ISLAND AS THE DAY PROGRESSES ASSISTED BY MIDDLE LEVEL DIVERGENT FLOW. A VERY MOIST ENVIRONMENT IN THE LOWER LEVELS CONTINUES OVER THE SOUTHERN CARIBBEAN S OF 14N WHICH COMBINED WITH UPPER LEVEL DIFFLUENCE IS SUPPORTING NUMEROUS MODERATE/ISOLATED STRONG CONVECTION WITH EMBEDDED TSTMS OVER NICARAGUA. SCATTERED MODERATE CONVECTION EXTENDS WITHIN 80 NM OF THE NICARAGUA...COSTA RICA AND PANAMA COASTLINES W OF 81W. ISOLATED RAINSHOWERS AND TSTMS ARE WITHIN 60 NM OF THE SOUTHERN COAST OF CUBA BETWEEN 78W-83W. OVER THE REMAINDER OF THE BASIN...DRY AIR IN THE LOWER AND MIDDLE LEVELS IS SUPPORTING FAIR WEATHER. OTHERWISE...TRADEWINDS UP TO 25 KT PREVAIL OVER THE CENTRAL-SOUTHERN CARIBBEAN WITH LIGHTER WINDS UP TO 15 KT ELSEWHERE. THE TROPICAL WAVE WILL MOVE OFF THE COAST OF HAITI LATE THIS AFTERNOON AND MOVE TO EASTERN CUBA WHERE INTERACTION WITH THE TERRAIN AND VERY DRY AIR MAY ACT TO VANISH THIS WAVE. HISPANIOLA... A TROPICAL WAVE IS MOVING ACROSS THE DOMINICAN REPUBLIC THIS MORNING WITH AXIS EXTENDING FROM 21N66W TO 16N70W. THE WAVE IS GENERATING ISOLATED SHOWERS AND IS ADVECTING MODERATE MOISTURE ACROSS THE ISLAND. RAINSHOWERS MAY DEVELOPED OVER THE ISLAND AS THE DAY PROGRESSES ASSISTED BY MIDDLE LEVEL DIVERGENT FLOW. WEATHER IMPROVES ON WEDNESDAY BUT AFTERNOON/EVENING SHOWERS ARE EXPECTED. THE ATLANTIC OCEAN... A BROAD UPPER LEVEL LOW IS N OF 24N BETWEEN 46W-66W SUPPORTING SCATTERED SHOWERS AND ISOLATED TSTMS N OF 28N BETWEEN 51W-61W. A SURFACE TROUGH EXTENDS FROM A 1021 MB LOW NEAR 30N31W TO 27N34W 27N39W...NO CONVECTION IS ASSOCIATED WITH IT AT THE TIME. OTHERWISE...SURFACE RIDGING IS ACROSS THE REMAINDER BASIN ANCHORED BY A PAIR OF HIGHS N OF THE AREA OF DISCUSSION. BESIDES THE AREAS FORMERLY DISCUSSED...FAIR WEATHER IS ACROSS THE REMAINDER ATLC SUPPORTED BY DRY AIR AT THE LOWER AND MIDDLE LEVELS. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ RAMOS