000 AXNT20 KNHC 092352 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT THU JUL 09 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 2345 UTC. ...TROPICAL WAVES... A TROPICAL WAVE IS OVER THE E ATLANTIC WITH AXIS EXTENDING FROM 15N29W TO 07N29W...MOVING W AT 10 TO 15 KT. SSMI TOTAL PRECIPITABLE WATER IMAGERY DEPICTS THIS WAVE AT THE LEADING EDGE OF A SURGE OF MODERATE TO HIGH MOISTURE CONTENT BETWEEN 02N-21N AND EXTENDS E REACHING THE AFRICAN COAST. ENHANCED METEOSAT IMAGERY SHOWS SAHARAN DUST IN THE ENVIRONMENT OF THIS WAVE WHICH IS INHIBITING CONVECTION AT THIS TIME. A TROPICAL WAVE IS AT ABOUT 300 NM E OF THE WINDWARD ISLANDS WITH AXIS EXTENDING FROM 16N55W TO 09N56W...MOVING W AT AROUND 20 KT. SAHARAN DUST IS ALSO IN THE ENVIRONMENT OF THIS WAVE WHICH IS INHIBITING CONVECTION. A TROPICAL WAVE IS OVER THE SW CARIBBEAN WITH AXIS EXTENDING FROM 18N83W TO 10N83W. SSMI TPW IMAGERY DEPICTS MODERATE TO HIGH MOISTURE CONTENT SURROUNDING THIS WAVE. SCATTERED MODERATE CONVECTION PREVAILS S OF 16N AND W OF 81W AFFECTING NICARAGUA...COSTA RICA AND PORTIONS OF CENTRAL AMERICA. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 16N16W TO 09N28W...THEN RESUMES W OF A TROPICAL WAVE NEAR 08N31W TO 08N39W ...WHERE THE ITCZ BEGINS AND CONTINUES TO 09N54W. ISOLATED MODERATE CONVECTION PREVAILS WITHIN 100 NM OF THE MONSOON TROUGH AXIS W OF 28W AND WITHIN 50 NM OF THE ITCZ. ...DISCUSSION... GULF OF MEXICO... CYCLONIC FLOW EXTENDS OVER THE WESTERN GULF MAINLY W OF 90W FROM AN UPPER-LEVEL LOW CENTERED OVER SOUTHERN MEXICO NEAR 17N99W. A DIFFLUENT FLOW PREVAILS E OF THIS FEATURE SUPPORTING MODERATE CONVECTION ACROSS THE YUCATAN PENINSULA AND CENTRAL AMERICA. SOME OF THIS ACTIVITY IS MOVING OVER THE BAY OF CAMPECHE S OF 27N. TO THE E...A 1022 MB HIGH IS CENTERED NEAR 29N85W. THE PROXIMITY AN UPPER-LEVEL LOW CENTERED OVER THE SW ATLANTIC IS SUPPORTING SCATTERED CONVECTION ACROSS THE FLORIDA PENINSULA AND THE SOUTHERN CONUS AFFECTING THE E GULF WATERS E OF 84W. SCATTEROMETER DATA DEPICTS A LIGHT TO GENTLE ANTICYCLONIC FLOW ACROSS THE NORTHERN HALF OF THE BASIN WHILE A GENTLE TO MODERATE SE FLOW PREVAILS S OF 25N. OVER THE NEXT 24 HOURS...EXPECT CONVECTION OVER THE SW AND FAR E GULF TO PREVAIL AS THE UPPER LEVEL FEATURES REMAIN IN PLACE. CARIBBEAN SEA... UPPER-LEVEL DIFFLUENCE IS SUPPORTING MODERATE CONVECTION ACROSS CENTRAL AMERICA. THIS ACTIVITY IS ALSO EXTENDING ACROSS THE SOUTHERN CARIBBEAN MAINLY S OF 19N. A TROPICAL WAVE IS OVER THE WESTERN CARIBBEAN S OF 19N. PLEASE REFER TO THE TROPICAL WAVES SECTION FOR MORE DETAILS. A DRY SAHARAN AIRMASS AND STRONG SHEAR CONTINUE TO PREVENT DEEP CONVECTION ACROSS THE BASIN. THE PRESSURE GRADIENT BETWEEN THE ATLANTIC HIGH PRESSURE AND LOWER PRESSURES OVER THE NORTHERN PORTION OF SOUTH AMERICA SUPPORTS FRESH TO STRONG TRADE WINDS ACROSS THE CENTRAL CARIBBEAN MAINLY S OF 16N BETWEEN 72W-84W. GENTLE TO MODERATE TRADES PREVAIL OVER THE REMAINDER OF THE AREA. OVER THE NEXT 24 HOURS...EXPECT FOR CONVECTION TO PREVAIL OVER THE SW CARIBBEAN. A TROPICAL WAVE WILL APPROACH THE WINDWARD ISLANDS WITH ISOLATED CONVECTION. ...HISPANIOLA... AN UPPER-LEVEL LOW CONTINUES N OF THE ISLAND SUPPORTING ISOLATED CONVECTION ACROSS THE AREA. SCATTERED CONVECTION IN THE AFTERNOON IS EXPECTED OVER THE NEXT 24 HOURS. ATLANTIC OCEAN... A 1022 MB SURFACE HIGH PREVAILS ACROSS THE W ATLANTIC CENTERED NEAR 29N71W. TO THE E...A WEAK 1018 MB SURFACE LOW PREVAILS NEAR 31N57W. A SURFACE TROUGH EXTENDS SW FROM THIS LOW TO 28N60W WHILE A STATIONARY FRONT EXTENDS SE FROM THE LOW TO 29N50W TO 34N42W. SATELLITE IMAGERY DEPICTS ISOLATED CONVECTION ALONG THE FRONT. A SURFACE RIDGE PREVAILS ACROSS THE E ATLANTIC. TWO TROPICAL WAVES WERE ANALYZED ACROSS THE BASIN...PLEASE REFER TO THE SECTION ABOVE FOR MORE DETAILS. A BROAD SAHARAN AIRMASS PREVAILS ACROSS THE TROPICAL ATLANTIC WHICH CONTINUES TO INHIBIT ANY SIGNIFICANT CONVECTION. THIS PATTERN IS EXPECTED TO CONTINUE OVER THE NEXT 24 HOURS. THE SURFACE LOW AND FRONT OVER THE CENTRAL ATLANTIC ARE EXPECTED TO DISSIPATE. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ ERA