000 AXNT20 KNHC 131807 AAA TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT MON JUL 13 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. ...SPECIAL FEATURES... SATELLITE IMAGERY AND SCATTEROMETER DATA CONFIRM THAT THE LOW PRESSURE SYSTEM SEVERAL HUNDRED MILES E OF N CAROLINA HAS DEVELOPED INTO TROPICAL STORM CLAUDETTE. AS OF 1700 UTC THE CENTER OF THE TROPICAL STORM WAS NEAR 37.4N 68.1W...MOVING NORTHEAST AT 13 KT. MAXIMUM SUSTAINED WINDS ARE 45 KT WITH GUSTS TO 55 KT. SEE THE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT3/WTNT23 FOR MORE DETAILS. ...TROPICAL WAVES... A TROPICAL WAVE IS OVER THE E ATLANTIC WITH AN AXIS EXTENDING FROM 18N22W TO 06N24W...MOVING W AT 10 TO 15 KT. THIS WAVE IS EVIDENT IN 700 MB MODEL STREAMLINE FIELDS WITH SOUNDINGS CONFIRMING THE WAVE PASSAGE AT DAKAR LATE SUNDAY...AND NOT YET ARRIVING AT SENEGAL AS OF 1200 UTC. SSMI TPW IMAGERY INDICATES MODERATE MOISTURE IS ALONG THE NORTHERN HALF OF THE WAVE WITH HIGH MOISTURE S OF 10N. SAHARAN DUST IS ALSO NOTED N OF 17N. ISOLATED MODERATE CONVECTION IS FROM 05N TO 12N BETWEEN 22W AND 26W. A TROPICAL WAVE IS OVER THE CENTRAL ATLANTIC WITH AN AXIS EXTENDING FROM 19N38W TO 07N40W...MOVING W AT AROUND 20 KT OVER THE PAST 24 HOURS. THIS WAVE IS WELL DEFINED BOTH IN THE 70 MB STREAMLINES OF THE MODEL FIELDS AND IN SATELLITE IMAGERY. SSMI TPW INDICATE DRY AIR N OF 11N WITH MOIST AIR S OF 11N IN THE WAVE ENVIRONMENT. ENHANCED METEOSAT IMAGERY INDICATE A SIGNIFICANT AMOUNT OF SAHARAN DUST EMBEDDED IN THE NORTHERN HALF OF THE WAVE. ISOLATED MODERATE CONVECTION IS FROM 06N TO 10N BETWEEN 37W AND 42W. A TROPICAL WAVE OVER THE WESTERN ATLC AT 1200 UTC HAD AN AXIS FROM 19N60W TO 07N61W AND IS NOW CROSSING THE LEEWARD ISLANDS AS OF EARLY THIS AFTERNOON...AS NOTED BY RECENT WIND SHIFT FROM EAST-NORTHEAST TO SOUTHEAST NEAR GUADELOUPE. THIS WAVE IS AT THE LEADING EDGE OF A LOW AMPLITUDE SURGE OF HIGH MOISTURE ACCORDING TO SSMI TPW IMAGERY. 700 MB MODEL STREAMLINES CLEARLY DEPICTS THIS WAVE AXIS. ISOLATED MODERATE CONVECTION IS FROM 08N TO 12N BETWEEN 58W AND 62W. A TROPICAL WAVE EXTENDS ACROSS THE W CARIBBEAN WITH AN AXIS FROM 21N81W TO 09N83W...MOVING W AT 15 TO 20 KT OVER THE PAST 24 HOURS. THE NORTHERN PORTION OF THE WAVE IS INTERACTING WITH A SURFACE TROUGH AND IS UNDER THE AXIS OF A BROAD UPPER TROUGH. MODERATE MOISTURE IS N OF 15N WITH HIGH MOISTURE S OF 15N ALONG THE WAVE. UPPER LEVEL DIFFLUENCE IS INTERACTING WITH THE WAVE AND MOISTURE TO SUPPORT SCATTERED MODERATE CONVECTION S OF 15N W OF 77W. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 10N14W TO 09N22W...THEN W OF A TROPICAL WAVE NEAR 08N26W TO 08N37W. THE ITCZ BEGINS NEAR 07N42W TO 09N59W. SCATTERED MODERATE CONVECTION IS FROM 03N TO 07N BETWEEN 12W AND 36W...INCLUDING THE EASTERN ATLC TROPICAL WAVE. ISOLATED MODERATE CONVECTION IS ELSEWHERE WITHIN 150 NM OF THE MONSOON TROUGH AND ITCZ AXIS. ...DISCUSSION... GULF OF MEXICO... A BROAD UPPER RIDGE CENTERED OVER TX EXTENDS ACROSS MOST OF THE GULF WITH NE WINDS PREVAILING ALOFT. WEAK DISTURBANCES MOVING AROUND THE PERIPHERY OF THIS RIDGE ARE SUPPORTING CLUSTERS OF MODERATE CONVECTION OVER THE CENTRAL GULF FROM 24N TO 29N BETWEEN 85W AND 90W. A 1018 MB HIGH IS CENTERED NEAR 26N92W AND IS PRODUCING ANTICYCLONIC WINDS BETWEEN 5 AND 15 KT OVER THE BASIN...EXCEPT NEAR A SURFACE TROUGH THAT EXTENDS FROM 22N92W TO 18N93W WHERE WINDS UP TO 20 KT ARE POSSIBLE. EXPECT LITTLE CHANGE OVER THE GULF OVER THE NEXT 24 HOURS. CARIBBEAN SEA... A TROPICAL WAVE IS OVER THE WESTERN CARIBBEAN. A SECOND TROPICAL WAVE IS ENTERING THE EASTERN CARIBBEAN. PLEASE SEE THE TROPICAL WAVES SECTION FOR MORE DETAILS. AN UPPER TROUGH EXTENDS FROM THE WESTERN ATLC SW TO NICARAGUA. UPPER RIDGING IS OVER NORTHERN S AMERICA. SW FLOW ALOFT IS DRAWING MID TO UPPER LEVEL MOISTURE ACROSS THE CENTRAL CARIBBEAN WITH SHOWERS LIKELY OCCURRING UNDER THE BROAD AREA OF CLOUDINESS OVER THIS PORTION OF THE BASIN. TRADE WINDS OF 5 TO 10 KT COVER THE WESTERN CARIBBEAN...WITH TRADE WINDS OF 15 TO 20 KT OVER THE CENTRAL AND EASTERN CARIBBEAN. EXPECT CONVECTION TO CONTINUE OVER THE SW CARIBBEAN AND SPREADING INTO THE NW CARIBBEAN OVER THE NEXT 24 HOURS. ...HISPANIOLA... A BROAD UPPER LOW US LIFTING NORTH AND AWAY FROM HISPANIOLA OVER THE OPEN WATERS OF THE WESTERN ATLC...WHICH IS DECREASING CHANCES FOR SHOWERS AND THUNDERSTORMS OVER HISPANIOLA TODAY. ISOLATED SHOWERS AND THUNDERSTORMS WILL REMAIN POSSIBLE OVER THE ISLAND THROUGH TUESDAY IN A MODERATELY MOIST AIRMASS. ATLANTIC OCEAN... THREE TROPICAL WAVES ARE OVER THE TROPICAL ATLANTIC. PLEASE REFER TO THE TROPICAL WAVES SECTION ABOVE FOR MORE INFORMATION. AN UPPER LEVEL LOW OVER THE SW NORTHERN ATLC HAS SPLIT WITH CENTERS NEAR 23N78W AND 27N70W. THE CYCLONIC FLOW ALOFT COMBINED WITH MODERATE MOISTURE SUPPORTS SCATTERED MODERATE CONVECTION FROM 22N TO 30N BETWEEN 66W AND 73W. SCATTERED THUNDERSTORMS ARE FROM 23N TO 31N BETWEEN 73W AND 80W. BROAD RIDGING ANCHORED BY HIGH PRESSURE CENTERED N OF OUR AREA OF DISCUSSION DOMINATES THE CENTRAL AND EASTERN SUBTROPICAL ATLC. NEWLY NAMED TROPICAL STORM CLAUDETTE IS LOCATED SEVERAL HUNDRED MILES E OF NORTH CAROLINA. PLEASE SEE THE SPECIAL FEATURES SECTION FOR MORE DETAILS. THE UPPER LOW WILL OPEN AND MERGE WITH AN UPPER TROUGH OVER THE W ATLC OVER THE NEXT 24 HOURS WITH ONGOING CONVECTION. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ LATTO