000 AXNT20 KNHC 192358 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT SAT SEP 19 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 2315 UTC. ...SPECIAL FEATURES... TROPICAL STORM IDA IS CENTERED NEAR 15.6N 40.8W AT 19/2100 UTC OR ABOUT 970 NM W OF THE CAPE VERDE ISLANDS MOVING WNW AT 12 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/ISOLATED STRONG CONVECTION IS FROM 13N TO 16N BETWEEN 37W AND 41W. 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 09N14W TO 07N20W TO 09N31W. ISOLATED MODERATE CONVECTION IS WITHIN 100 NM OF THE MONSOON TROUGH AXIS. ...DISCUSSION... GULF OF MEXICO... A SHARP UPPER TROUGH EXTENDS FROM THE MID ATLANTIC STATES OF THE US TO FL THEN SW ACROSS THE GULF OF MEXICO TO THE BAY OF CAMPECHE. THIS TROUGH SUPPORTS A 1009 MB SURFACE LOW NEAR 26N85W WITH A SURFACE TROUGH EXTENDING FROM THE SURFACE LOW TO 27N91W. ANOTHER LOW SUPPORTED BY THIS SAME TROUGH IS OVER THE W ATLC WITH A SURFACE TROUGH EXTENDING FROM THIS LOW TO THE BAHAMAS AND ACROSS THE FL STRAITS TO THE SE GULF NEAR 22N85W. ISOLATED THUNDERSTORMS ARE WITHIN 50 NM OF EITHER TROUGH AXIS. WEAK ANTICYCLONIC WINDS OVER THE GULF UNDER 10 KT PREVAIL THIS EVENING. OVER THE NEXT 24 HOURS ISOLATED THUNDERSTORMS WILL REMAIN POSSIBLE OVER THE CENTRAL AND SE GULF. CARIBBEAN SEA... AN UPPER LEVEL ANTICYCLONE IS CENTERED OVER THE NW CARIBBEAN. A SURFACE TROUGH EXTENDS OVER THE NW CARIBBEAN FROM 21N85W TO 16N88W. UPPER DIFFLUENCE FROM THE RIDGE AND CONVERGENCE WITH THE SURFACE TROUGH SUPPORTS ISOLATED MODERATE CONVECTION FROM 14N TO 22N BETWEEN 82W AND 88W. AN UPPER LOW IS MOVING W OVER THE CENTRAL CARIBBEAN NEAR 15N74W. ISOLATED THUNDERSTORMS ARE WITHIN 250 NM OF THE UPPER LOW. MODERATE TO FRESH TRADE WINDS COVER THE CENTRAL CARIBBEAN. GENTLE TO MODERATE TRADE WINDS COVER THE REMAINDER OF THE CARIBBEAN. OVER THE NEXT 24 HOURS EXPECT CONVECTION TO CONTINUE OVER THE NW CARIBBEAN. THE UPPER LOW WILL SLOWLY MOVE W WITH ISOLATED THUNDERSTORMS. ...HISPANIOLA... SCATTERED AFTERNOON THUNDERSTORMS WILL LINGER INTO THE EVENING WHILE WEAKENING. EXPECT GENERALLY FAIR CONDITIONS OVERNIGHT. THE PRESENCE OF AN UPPER LOW TO THE SW OF THE ISLAND WILL SUPPORT SCATTERED THUNDERSTORMS ON SUNDAY AFTERNOON. ATLANTIC OCEAN... A SHARP UPPER TROUGH OVER THE MID ATLANTIC STATES OF THE US SUPPORTS A 1007 MB SURFACE LOW NEAR 30N78W WITH A SURFACE TROUGH EXTENDING FROM THE LOW TO THE NORTHERN BAHAMAS NEAR 26N78W TO THE FL STRAITS NEAR 24N82W. AN UPPER RIDGE IS CENTERED OVER THE SE BAHAMAS WITH AN AXIS THAT EXTENDS NE TO BERMUDA. THE COMBINATION OF FORCING FROM THE LOW AND SURFACE TROUGH...AND THE UPPER LEVEL DIFFLUENCE UNDER THE UPPER RIDGE AXIS SUPPORTS ISOLATED MODERATE CONVECTION FROM 25N TO 31N BETWEEN 65W AND 78W ...AND WITHIN 50 NM OF THE SURFACE TROUGH. AN UPPER LOW IS CENTERED OVER THE CENTRAL ATLC NEAR 23N56W. ISOLATED MODERATE CONVECTION IS FROM 23N TO 31N BETWEEN 42W AND 55W. THE REMNANTS OF T.D. NINE ARE OVER THE CENTRAL ATLC NEAR 19N50W. SCATTERED MODERATE CONVECTION IS FROM 18N TO 23N BETWEEN 48W AND 52W. TROPICAL STORM IDA IS ALSO OVER THE CENTRAL ATLC. PLEASE REFER TO THE SPECIAL FEATURES SECTION FOR MORE DETAILS. OVER THE NEXT 24 HOURS EXPECT CONVECTION TO BE LIKELY TO THE E OF THE UPPER LOW OVER THE CENTRAL ATLC AS THE REMNANTS OF T.D. NINE INTERACT WITH THIS FEATURE. CONVECTION WILL ALSO CONTINUE TO THE E OF THE SURFACE LOW AND TROUGH OVER THE W ATLC. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ LATTO