000 AXNT20 KNHC 150533 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0530 UTC. ...SPECIAL FEATURES... AS OF 0300 UTC...CLAUDETTE BECAME A POST TROPICAL CYCLONE CENTERED NEAR 43.8N 57.8W MOVING NE AT 18 KT. MAXIMUM SUSTAINED WINDS ARE 40 KT WITH GUSTS UP TO 50 KT. THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 1004 MB. SATELLITE IMAGERY SHOWS A VERY WEAK CLAUDETTE WITH SCATTERED CONVECTION PREVAILING TO THE E OF ITS CENTER. DISSIPATION IS EXPECTED ON WEDNESDAY. SEE THE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT3/WTNT23 FOR MORE DETAILS. ...TROPICAL WAVES... A LOW AMPLITUDE TROPICAL WAVE IS OVER THE E ATLANTIC WITH AXIS EXTENDING FROM 17N31W TO 07N32W...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 21N51W TO 10N51W...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 NORTHERN HAITI TO NORTHERN COLOMBIA FROM 20N72W TO 10N74W AND IS MOVING W AT 20 TO 25 KT OVER THE PAST 24 HOURS. THE WAVE IS WELL DEFINED IN THE TPW PRODUCT...THE 700 MB STREAMLINES AND LOW-LEVEL WIND DATA. SCATTERED CONVECTION PREVAILS ACROSS THE SOUTHERN PORTION OF THE WAVE AFFECTING NORTHERN COLOMBIA. 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. A TROPICAL WAVE HAS MOVED FROM THE YUCATAN PENINSULA INTO THE SW GULF OF MEXICO AND CURRENTLY EXTENDS FROM 23N92W INTO THE EPAC NEAR 13N93W...MOVING W AT AROUND 20-25 KT. TPW IMAGERY DEPICTS AN INCREASE IN MOISTURE TO THE E OF THE WAVE AXIS SUPPORTING SCATTERED CONVECTION ACROSS THE WESTERN PORTION OF THE YUCATAN PENINSULA. THIS WAVE WILL CONTINUE MOVING WESTWARD INTO THE EPAC REGION DURING THE NEXT 24 HOURS. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH ENTERS THE ATLANTIC OCEAN THROUGH GUINEA BISSAU THEN CONTINUES TO NEAR 10N28W. THE ITCZ EXTENDS FROM 08N33W TO THE COAST OF SOUTH AMERICA NEAR 06N55W. ISOLATED MODERATE CONVECTION IS NOTED ALONG THE MONSOON TROUGH WHILE SCATTERED MODERATE CONVECTION IS OBSERVED FROM 04N-07N BETWEEN 34W-50W. ...DISCUSSION... GULF OF MEXICO... A 1016 MB SURFACE HIGH LOCATED OVER THE CENTRAL GULF DOMINATES THE BASIN. THIS FEATURE IS EXPECTED TO DISSIPATE TONIGHT BUT A RIDGE WILL PERSIST ACROSS THE NORTHERN GULF THROUGH THE WEEK MAINTAINING GENERALLY TRANQUIL CONDITIONS. ACROSS THE SOUTHERN GULF...A TROPICAL WAVE EXTENDS ACROSS THE BAY OF CAMPECHE. FOR MORE DETAILS...PLEASE REFER TO THE SECTION ABOVE. SCATTEROMETER DATA DEPICTS A LIGHT ANTICYCLONIC FLOW PREVAILING ACROSS THE 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 YUCATAN CHANNEL. UPPER DIFFLUENCE BETWEEN THESE TWO UPPER-LEVEL FEATURES IS SUPPORTING THE CONVECTION OBSERVED OVER PARTS OF THE YUCATAN PENINSULA AND THE NORTHERN PORTION OF CENTRAL AMERICA. 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 MODERATE TO GENTLE TRADES PREVAILING ELSEWHERE. ALOFT...AN UPPER-LEVEL TROUGH EXTENDS FROM THE W ATLANTIC ACROSS THE W CARIBBEAN. TO THE E OF THIS FEATURE...AN UPPER-LEVEL RIDGE EXTENDS FROM SOUTH AMERICA ACROSS THE 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 EXTENDING ACROSS HAITI 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 AFTERNOON SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE IN THE AFTERNOON HOURS DUE TO LOCAL EFFECTS. ATLANTIC OCEAN... POST-TROPICAL CYCLONE CLAUDETTE IS OVER THE NW ATLANTIC. PLEASE SEE THE SPECIAL FEATURES SECTION FOR MORE DETAILS. 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 BAHAMAS AND CUBA OVER THE NEXT 24 HOURS. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ ERA