000 AXNT20 KNHC 151018 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT WED JUL 15 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1015 UTC. ...TROPICAL WAVES... A LOW AMPLITUDE TROPICAL WAVE IS OVER THE E ATLANTIC WITH AXIS EXTENDING FROM 17N34W TO 07N36W...MOVING W AT AROUND 15 KT OVER THE PAST 24 HOURS. A SAHARAN AIRMASS PREVAILS IN THE ENVIRONMENT OF THIS WAVE LIMITING THE CONVECTION TO ISOLATED ON EITHER SIDE OF THE WAVE AXIS FROM 10N-12N BETWEEN 30W-33W. A LARGE AMPLITUDE TROPICAL WAVE IS OVER THE CENTRAL ATLANTIC WITH AXIS EXTENDING FROM 21N55W TO 09N55W...MOVING W AT 15 TO 20 KT OVER THE PAST 24 HOURS. AN INVERTED-V LOW-LEVEL SIGNATURE IS OBSERVED IN SATELLITE IMAGERY. MODERATE MOISTURE IS DEPICTED IN TPW IMAGERY TO THE E OF THE WAVE AXIS. A BROAD AREA OF SAHARAN DUST ALSO SURROUNDS THIS WAVE WHICH CONTINUES INHIBITING CONVECTION. EXPECT FOR THIS WAVE TO ENTER THE E CARIBBEAN WITHIN THE NEXT 24 HOURS ENHANCING CONVECTION ACROSS THE LESSER ANTILLES AND PUERTO RICO. A TROPICAL WAVE EXTENDS FROM THE WINDWARD PASSAGE TO NORTHERN COLOMBIA FROM 20N74W TO 11N76W AND IS MOVING W AT 15 KT OVER THE PAST 24 HOURS. THE WAVE IS WELL DEFINED IN THE TPW PRODUCT AND 700 MB STREAMLINES. SCATTERED CONVECTION PREVAILS ACROSS THE SOUTHERN PORTION OF THE WAVE AFFECTING NORTHERN COLOMBIA WHILE ISOLATED CONVECTION IS OBSERVED BETWEEN 15N-20N AND ALONG 71W. EXPECT FOR THIS WAVE TO CONTINUE MOVING W ACROSS THE W CARIBBEAN WITH ISOLATED CONVECTION. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH ENTERS THE ATLANTIC OCEAN THROUGH GUINEA BISSAU THEN CONTINUES TO NEAR 11N19W. THE ITCZ EXTENDS FROM THAT POINT TO 09N34W THEN RESUMES W OF A TROPICAL WAVE NEAR 08N37W TO 06N57W. SCATTERED MODERATE CONVECTION IS OBSERVED FROM 08N-12N BETWEEN 24W-34W AND FROM 04N-08N BETWEEN 38W-56W. ...DISCUSSION... GULF OF MEXICO... A SURFACE RIDGE EXTENDS ACROSS THE NORTHERN GULF FROM THE ATLANTIC. THIS PATTERN WILL PREVAIL THROUGH THE WEEK MAINTAINING GENERALLY TRANQUIL CONDITIONS. SCATTEROMETER DATA DEPICTS A LIGHT ANTICYCLONIC FLOW PREVAILING ACROSS THE WHOLE BASIN. ALOFT...BROAD UPPER-LEVEL ANTICYCLONE ANCHORED OVER E TEXAS IS PRODUCING MAINLY A NE FLOW ACROSS THE FLORIDA AND GULF OF MEXICO. AN UPPER-LEVEL LOW IS SPINNING OVER THE NORTHERN COAST OF THE YUCATAN PENINSULA. UPPER-LEVEL DIFFLUENCE BETWEEN THESE TWO UPPER-LEVEL FEATURES WILL SUPPORT CONVECTION THIS AFTERNOON OVER PARTS OF THE YUCATAN PENINSULA AND THE NORTHERN PORTION OF CENTRAL AMERICA. UPPER-LEVEL DIFFLUENCE IS ALSO NOTED OVER SOUTHERN GEORGIA AND NORTHERN FLORIDA SUPPORTING ISOLATED CONVECTION ACROSS THE AREA. CARIBBEAN SEA... A TROPICAL WAVE IS OVER THE CENTRAL CARIBBEAN. PLEASE REFER TO THE TROPICAL WAVES SECTION FOR MORE DETAILS. THE COMBINATION OF THE SURFACE HIGH THAT PREVAILS ACROSS THE ATLANTIC AND LOWER PRESSURES ACROSS SOUTH AMERICA IS PRODUCING FRESH TO STRONG WINDS ACROSS THE S-CENTRAL CARIBBEAN MAINLY S OF 16N BETWEEN 66W- 75W. SCATTEROMETER DATA DEPICTS GENTLE TO MODERATE TRADES PREVAILING ELSEWHERE. ALOFT...AN UPPER-LEVEL TROUGH EXTENDS FROM THE W ATLANTIC ACROSS W CUBA INTO THE W CARIBBEAN. TO THE E OF THIS FEATURE...AN UPPER-LEVEL RIDGE EXTENDS FROM SOUTH AMERICA ACROSS THE CENTRAL AND E CARIBBEAN. THESE FEATURES ARE GENERATING A DIFFLUENT FLOW ACROSS THE CENTRAL CARIBBEAN WHICH SUPPORTS CLOUDINESS AND ISOLATED CONVECTION BETWEEN 73W-84W. OVER THE NEXT 24 HOURS...EXPECT FOR THE WAVE OVER THE CENTRAL CARIBBEAN TO CONTINUE MOVING W WHILE THE NEXT TROPICAL WAVE WILL ENTER THE E CARIBBEAN ENHANCING CONVECTION ACROSS THE LESSER ANTILLES AND PUERTO RICO. ...HISPANIOLA... A TROPICAL WAVE IS CURRENTLY OVER THE WINDWARD PASSAGE WITH ISOLATED CONVECTION E OF THE WAVE AXIS AFFECTING THE NORTHERN COAST OF DOMINICAN REPUBLIC AND THE ADJACENT COASTAL WATERS. EXPECT FOR THE WAVE TO CONTINUE MOVING W AWAY FROM THE ISLAND WITHIN THE NEXT 24 HOURS. ISOLATED SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE IN THE AFTERNOON HOURS DUE TO LOCAL EFFECTS. ATLANTIC OCEAN... TWO TROPICAL WAVES ARE OVER THE TROPICAL ATLANTIC. PLEASE SEE THE TROPICAL WAVES SECTION ABOVE FOR MORE DETAILS. AS IT IS NORMAL FOR THIS TIME OF THE YEAR...THE AZORES HIGH EXTENDS A RIDGE ACROSS THE TROPICAL ATLANTIC WITH FAIR WEATHER AS ABUNDANT AFRICAN DUST IS OBSERVED ON THE SAHARAN AIR LAYER TRACKING PRODUCT FROM CIMSS BETWEEN THE COAST OF AFRICA AND THE LESSER ANTILLES. AT UPPER-LEVELS...A TROUGH PREVAILS OVER THE W ATLANTIC SUPPORTING CLOUDINESS AND ISOLATED CONVECTION BETWEEN 70W-75W. THIS TROUGH WILL CONTINUE TO ENHANCE CONVECTION OVER THE SOUTHERN BAHAMAS...E CUBA AND NORTHERN HISPANIOLA OVER THE NEXT 24 HOURS. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ ERA