000 AXNT20 KNHC 161803 RRA TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT SUN AUG 16 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... A 1011 MB LOW IS CENTERED OVER THE EASTERN ATLC NEAR 10N27W...SEVERAL HUNDRED MILES SOUTHWEST OF THE CAPE VERDE ISLANDS. CONVECTION ASSOCIATED WITH THIS LOW HAS REMAINED PERSISTENT THROUGH MUCH OF THE DAY TODAY...WITH NUMEROUS MODERATE CONVECTION FROM 06N TO 13N BETWEEN 24W AND 31W. ENVIRONMENTAL CONDITIONS ARE EXPECTED TO BE CONDUCIVE FOR SOME DEVELOPMENT OF THIS SYSTEM OVER THE NEXT SEVERAL DAYS AS IT CONTINUES W AT 10 TO 15 KT. THE CHANCES OF THIS LOW DEVELOPING INTO A TROPICAL CYCLONE OVER THE NEXT 48 HOURS IS MEDIUM. FOR ADDITIONAL INFORMATION...PLEASE REFER TO THE ATLC TROPICAL WEATHER OUTLOOK UNDER AWIPS/WMO HEADERS MIATWOAT/ABNT20 FOR MORE DETAILS. ...TROPICAL WAVES... A TROPICAL WAVE IS OVER THE E ATLC WITH AN AXIS EXTENDING FROM 19N26W...THROUGH THE LOW DISCUSSED IN THE SPECIAL FEATURES SECTION...TO 07N27W...MOVING W AT 10 TO 15 KT. SSMI TPW SHOWS HIGH MOISTURE S OF 13N WITH A BROAD AREA OF MODERATE MOISTURE N OF 13N. NUMEROUS MODERATE CONVECTION IS FROM 06N TO 13N BETWEEN 24W AND 31W. A TROPICAL WAVE IS OVER THE CENTRAL ATLC WITH AN AXIS EXTENDING FROM 14N44W TO 05N46W...MOVING W AT 10 TO 15 KT. A 850 MB VORTICITY MAXIMUM IS NOTED ALONG THE WAVE AXIS NEAR 10N45W. A POLEWARD SURGE OF HIGH MOISTURE TO 12N IS NOTED IN SSMI TPW ALONG THE WAVE AXIS. SCATTERED MODERATE CONVECTION IS FROM 06N TO 13N BETWEEN 40W AND 49W. A TROPICAL WAVE IS OVER THE CENTRAL CARIBBEAN WITH AN AXIS EXTENDING FROM 20N70W TO 11N72W...MOVING W AT AROUND 15 KT OVER THE PAST 24 HOURS. THE NORTHERN PORTION OF THIS WAVE HAS TRANSITIONED TO A SURFACE TROUGH THAT EXTENDS INTO THE W ATLC WITH CONVECTION. STRONG SW SHEAR AND DRIER AIR S OF HISPANIOLA IS LIMITING DEEP CONVECTION ALONG THE WAVE AXIS. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 16N17W TO A 1011 MB LOW NEAR 10N27W TO 08N35W...WHERE THE ITCZ BEGINS AND CONTINUES TO 08N44W...THEN RESUMES EAST OF A CENTRAL ATLC TROPICAL WAVE NEAR 08N47W TO 07N58W. OTHER THAN CONVECTION ASSOCIATED WITH THE 1011 MB LOW DISCUSSED IN THE SPECIAL FEATURES SECTION...AND THE TROPICAL WAVES...SCATTERED MODERATE CONVECTION IS FROM 07N TO 12N BETWEEN 15W AND 20W. ...DISCUSSION... GULF OF MEXICO... A SHARP MID TO UPPER LEVEL TROUGH EXTENDS FROM THE TN VALLEY SW TO CENTRAL MEXICO. DYNAMIC LIFT DOWNSTREAM OF THE TROUGH AXIS SUPPORTS A SURFACE TROUGH FROM 24N97W TO 30N88W. THE ASCENT ASSOCIATED WITH THE UPPER TROUGH AND CONVERGENCE WITH THE SURFACE TROUGH IS INTERACTING WITH A VERY MOIST ATMOSPHERE TO SUPPORT NUMEROUS THUNDERSTORMS WITH SCATTERED MODERATE CONVECTION OVER MOST OF THE NORTHERN GULF OF MEXICO FROM 22N TO 31N BETWEEN 85W AND THE TEXAS AND MEXICO COASTS. SURFACE RIDGING OVER THE ATLC IS PRODUCING SE WINDS OF 10 TO 15 KT OVER THE SOUTHERN GULF...AND WITH DEEP TROPICAL MOISTURE IN PLACE SUPPORTS ISOLATED THUNDERSTORMS OVER THE SE GULF. OVER THE NEXT 24 HOURS THE UPPER TROUGH WILL REMAIN OVER TEXAS AND WILL CONTINUE TO SUPPORT CONVECTION OVER THE NW GULF W OF 88W. CARIBBEAN SEA... AN UPPER LEVEL ANTICYCLONE CENTERED OVER THE SW CARIBBEAN DOMINATES THE BASIN. UPPER LEVEL DIFFLUENCE UNDER THE CENTER OF THE RIDGE SUPPORTS CLUSTERS OF MODERATE TO STRONG CONVECTION S OF 12N W OF 79W. A TROPICAL WAVE IS OVER THE CENTRAL CARIBBEAN. PLEASE REFER TO THE TROPICAL WAVES SECTION FOR MORE DETAILS. THE REMAINDER OF THE CARIBBEAN IS FREE OF DEEP CONVECTION. GENTLE TO MODERATE TRADE WINDS COVER THE MAJORITY OF THE CARIBBEAN BASIN WITH THE STRONGEST WINDS OVER THE S CENTRAL CARIBBEAN. OVER THE NEXT 24 HOURS EXPECT CONVECTION TO SPREAD E OVER THE GREATER ANTILLES AS THE TROPICAL WAVE CONTINUES W. ...HISPANIOLA... A TROPICAL WAVE MOVING ACROSS THE ISLAND IS BRINGING WITH IT AN INCREASE IN MOISTURE AND CHANCES FOR SHOWERS AND THUNDERSTORMS ACROSS THE ISLAND THIS AFTERNOON. THE BEST CHANCE FOR HEAVY RAINFALL WILL BE TONIGHT...AS MOIST SE FLOW BEHIND THE DEPARTING WAVE SPREADS WEST ACROSS THE ISLAND. LOCALLY HEAVY RAINFALL AND MUDSLIDES WILL BE POSSIBLE TONIGHT THROUGH MONDAY ASSOCIATED WITH PERSISTENT RAIN THAT MAY OCCUR. ATLANTIC OCEAN... WEAK UPPER LEVEL DIFFLUENCE OVER THE BAHAMAS AND SURROUNDING WATERS FROM AN EXTENSION OF UPPER LEVEL RIDGING OVER THE CARIBBEAN IS INTERACTING WITH A MOIST AIRMASS TO SUPPORT SCATTERED SHOWERS THUNDERSTORMS FROM 25N TO 31N W OF 77W...INCLUDING THE NORTHERN BAHAMAS. A SURFACE TROUGH EXTENDS FROM HISPANIOLA TO NEAR 23N69W AND IS ASSOCIATED WITH THE NORTHERN PORTION OF A TROPICAL WAVE MOVING W ACROSS THE CARIBBEAN. SW SHEAR IS DISPLACING CONVECTION TO THE NE OF THE TROUGH AXIS. HOWEVER...THE DEEP MOISTURE IN PLACE SUPPORTS CLUSTERS OF MODERATE AND ISOLATED STRONG CONVECTION FROM 18N TO 23N BETWEEN 63W AND 69W. THREE SURFACE TROUGHS ARE OVER THE CENTRAL ATLC. THE WESTERNMOST TROUGH EXTENDS FROM 26N64W AND NE OUT OF OUR AREA OF DISCUSSION. ISOLATED THUNDERSTORMS ARE FROM 25N TO 27N BETWEEN 61W AND 66W. THE NEXT SURFACE TROUGH EXTENDS FROM 14N55W TO 24N49W. NO DEEP CONVECTION IS ASSOCIATED WITH THIS TROUGH. THE EASTERNMOST TROUGH EXTENDS FROM 27N39W TO 31N35W WITH NO DEEP CONVECTION BEING OBSERVED. TWO TROPICAL WAVES AND A SPECIAL FEATURES 1011 MB LOW ARE OVER THE TROPICAL NORTHERN ATLC. PLEASE REFER TO THE TROPICAL WAVES SECTION AND SPECIAL FEATURES SECTION FOR MORE DETAILS. EXPECT CONVECTION ASSOCIATED WITH THE SURFACE TROUGH NEAR HISPANIOLA TO CONTINUE TO SPREAD WEST TO WEST-NORTHWEST ACROSS THE SE BAHAMAS THROUGH MONDAY. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ LATTO