000 AXNT20 KNHC 200536 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT SUN SEP 20 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... TROPICAL STORM IDA IS CENTERED NEAR 15.8N 42.4W AT 20/0300 UTC OR ABOUT 1060 NM W OF THE CAPE VERDE ISLANDS MOVING WNW AT 13 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1006 MB. MAXIMUM SUSTAINED WIND SPEED IS 35 KT WITH GUSTS UP TO 45 KT. A CLUSTER OF MODERATE CONVECTION EXTENDS FROM 12N-18N BETWEEN 35W-45W. PLEASE SEE THE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT5/WTNT25 KNHC FOR MORE DETAILS. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM WESTERN AFRICA NEAR 09N13W TO 09N31W. ISOLATED MODERATE CONVECTION IS WITHIN 100 NM OF THE MONSOON TROUGH AXIS. ...DISCUSSION... GULF OF MEXICO... AN UPPER-LEVEL ANTICYCLONE PREVAILS ACROSS NORTHERN MEXICO AND EXTENDS E REACHING THE WESTERN GULF. TO THE E...A SHARP UPPER- LEVEL TROUGH EXTENDS SW FROM THE EASTERN US COAST ACROSS THE FLORIDA PENINSULA AND REACHING THE GULF OF MEXICO TO THE BAY OF CAMPECHE. THIS TROUGH IS REFLECTED AT THE SURFACE AS A TROUGH THAT EXTENDS ACROSS THE E GULF FROM 27N82W TO 26N90W. ISOLATED CONVECTION IS OBSERVED ALONG THIS BOUNDARY. ANOTHER LOW SUPPORTED BY THIS SAME TROUGH IS OVER THE W ATLANTIC WITH A SURFACE TROUGH EXTENDING FROM THIS LOW TO THE BAHAMAS AND ACROSS THE FL STRAITS REACHING THE STRAITS OF FLORIDA NEAR 24N81W. A LIGHT TO GENTLE ANTICYCLONIC FLOW PREVAILS ACROSS THE BASIN AS NOTED IN SCATTEROMETER DATA. OVER THE NEXT 24 HOURS...ISOLATED THUNDERSTORMS WILL REMAIN POSSIBLE OVER THE CENTRAL AND SE GULF. CARIBBEAN SEA... UPPER-LEVEL DIVERGENCE SUPPORTS SCATTERED MODERATE CONVECTION ACROSS THE WESTERN CARIBBEAN AFFECTING PORTIONS OF CUBA AND CENTRAL AMERICA AS WELL AS THE CARIBBEAN WATERS MAINLY W OF 78W. TO THE E...AN UPPER LOW IS CENTERED OVER THE CENTRAL CARIBBEAN NEAR 15N75W. THIS LOW IS SUPPORTING ISOLATED MODERATE CONVECTION ACROSS THE SOUTHERN PORTION OF THE BASIN S OF 13N BETWEEN 77W- 82W. FAIR WEATHER PREVAILS ACROSS THE REMAINDER OF THE BASIN. SCATTEROMETER DATA DEPICTS GENTLE TO MODERATE TRADES ACROSS THE AREA. OVER THE NEXT 24 HOURS...EXPECT FOR CONVECTION TO CONTINUE OVER THE NW CARIBBEAN. THE UPPER-LEVEL LOW WILL SLOWLY MOVE W WITH ISOLATED THUNDERSTORMS. ...HISPANIOLA... FAIR WEATHER PREVAILS ACROSS THE ISLAND AT THIS TIME. THE PRESENCE OF AN UPPER-LEVEL LOW TO THE SW OF THE ISLAND WILL SUPPORT SCATTERED AFTERNOON THUNDERSTORMS ONCE AGAIN ON SUNDAY. ATLANTIC OCEAN... A SHARP UPPER-LEVEL TROUGH OVER THE EASTERN US COAST SUPPORTS A 1006 MB SURFACE LOW LOCATED NEAR 32N76W WITH A SURFACE TROUGH EXTENDING FROM THE LOW TO THE STRAITS OF FLORIDA NEAR 24N81W. THIS SURFACE FEATURES COMBINED WITH UPPER LEVEL DIFFLUENCE PREVAILING ACROSS THE W ATLANTIC SUPPORT ISOLATED MODERATE CONVECTION MAINLY W OF 66W. TO THE E...AN UPPER-LEVEL LOW IS CENTERED NEAR 22N57W AND COMBINED WITH THE REMNANTS T.D. NINE CENTERED NEAR 19N50W ARE GENERATING SCATTERED MODERATE CONVECTION FROM 19N-31N BETWEEN 42W-53W. T.S. IDA CONTINUES ACROSS THE E-CENTRAL ATLANTIC. PLEASE REFER TOT HE SECTION ABOVE FOR MORE DETAILS. HIGH PRESSURE AND FAIR WEATHER PREVAILS ACROSS THE REMAINDER OF THE BASIN. OVER THE NEXT 24 HOURS...EXPECT CONVECTION ACROSS THE W AND CENTRAL ATLANTIC TO CONTINUE. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ ERA