000 AXNT20 KNHC 222349 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT TUE SEP 22 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 20.5N 47.8W AT 22/2100 UTC OR ABOUT 880 NM E-NE OF THE NORTHERN LEEWARD ISLANDS MOVING E-SE AT 4 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1005 MB. MAXIMUM SUSTAINED WIND SPEED IS 40 KT WITH GUSTS TO 50 KT. SCATTERED MODERATE TO NUMEROUS STRONG CONVECTION COVERS THE AREA FROM 16N- 21N BETWEEN 42W-48W. PLEASE SEE THE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT5/WTNT25 KNHC FOR MORE DETAILS. ...TROPICAL WAVES... TROPICAL WAVE EXTENDS ALONG 22W/23W FROM 7N-17N MOVING W LESS THEN 5 KT OF THE PAST 24 HOURS. SSMI TPW INDICATES THE WAVE IS EMBEDDED WITHIN A SURGE OF DEEP MOISTURE. SCATTERED MODERATE/ ISOLATED STRONG CONVECTION IS FROM 14N-16N BETWEEN 20W AND THE WAVE AXIS. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE E TROPICAL ATLC NEAR 15N17W TO E OF THE TROPICAL WAVE NEAR 11N21W THEN RESUMES W OF THE WAVE NEAR 10N23W ALONG 7N30W TO 8N37W. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE FROM 6N-15N BETWEEN 14W-20W. CLUSTERS OF SCATTERED MODERATE CONVECTION ARE FROM 4N-10N BETWEEN 20W-25W. ...DISCUSSION... GULF OF MEXICO... AN UPPER TROUGH EXTENDS FROM THE E CONUS INTO THE GULF OF MEXICO OVER PENSACOLA FLORIDA TO THE N COAST OF THE YUCATAN PENINSULA SUPPORTING A SURFACE TROUGH THAT EXTENDS FROM 29N86W THROUGH A WEAKENING 1013 MB LOW NEAR 25N88W TO 23N90W. CLUSTERS OF SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE E OF A LINE FROM APALACHICOLA FLORIDA ALONG 24N86W TO 23N90W INCLUDING FLORIDA... CUBA...THE YUCATAN CHANNEL...AND THE STRAITS OF FLORIDA. STRONG SUBSIDENCE AND DRY STABLE AIR WITH CLEAR SKIES COVER THE GULF W OF 90W. THE SURFACE TROUGH WILL STALL AND DISSIPATE THROUGH TONIGHT. CARIBBEAN SEA... A NARROW UPPER TROUGH EXTENDS FROM THE UPPER TROUGH OVER THE GULF OF MEXICO THROUGH THE YUCATAN CHANNEL NEAR 22N85W SE ALONG 18N80W TO THE ABC ISLANDS. A WEAK UPPER RIDGE EXTENDS S OF THE ABOVE UPPER TROUGH FROM COLOMBIA NEAR 10N75W ALONG 15N84W TO THE GULF OF HONDURAS. A SECOND UPPER RIDGE EXTENDS FROM E VENEZUELA NEAR 10N65W THROUGH THE WINDWARD PASSAGE INTO THE W ATLC WITH AND UPPER LOW CENTERED N OF THE LEEWARD ISLANDS COVERING THE FAR NE CARIBBEAN. AFTERNOON SHOWERS/THUNDERSTORMS HAVE DEVELOPED INLAND OVER HISPANIOLA...CUBA...AND JAMAICA. THE ACTIVITY THAT DEVELOPED OVER PUERTO RICO HAS MOVED SE INTO THE CARIBBEAN WATERS WITHIN 75 NM ALONG THE SE COAST INCLUDING THE VIRGIN ISLANDS. ISOLATED SHOWERS/THUNDERSTORMS HAVE DEVELOPED OVER THE NW CARIBBEAN N OF 18N BETWEEN 80W-85W. THE MONSOON TROUGH EXTENDS ALONG 10N ACROSS THE SW CARIBBEAN GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS INLAND AND WITHIN 60 NM ALONG THE COAST OF PANAMA. SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS ARE FROM 10N-16N W OF 80W TO OVER CENTRAL AMERICA. THIS IS LEAVING THE REMAINDER OF THE CARIBBEAN E OF 70W WITH CLEAR SKIES THIS EVENING. WEAK SURFACE RIDGE OVER THE SW ATLC WILL SUPPORT GENTLE TO MODERATE TRADE WINDS ACROSS MOST OF THE CARIBBEAN THROUGH THU EXCEPT FOR PULSES OF FRESH TO STRONG WINDS OFF COLOMBIA AND W VENEZUELA MAINLY AT NIGHT. ...HISPANIOLA... NUMEROUS SHOWERS/SCATTERED THUNDERSTORMS ARE ACROSS THE ISLAND THIS EVENING. DAYTIME HEATING COUPLED WITH OROGRAPHIC LIFTING WILL CONTINUE TO GENERATE AFTERNOON SHOWERS/THUNDERSTORMS ACROSS THE ISLAND WED AND THU. ATLANTIC OCEAN... A WEAK UPPER TROUGH REMAINS OVER THE NW ATLC SUPPORTING A REMNANT FRONTAL BOUNDARY THAT EXTENDS TO A WEAK 1013 MB LOW NEAR 31N77W WITH A EQUALLY WEAK COLD FRONT ALONG 30N79W TO OVER FLORIDA NEAR JACKSONVILLE. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE N OF 31N BETWEEN 77W-78W. AN UPPER RIDGE EXTENDS FROM THE CARIBBEAN THROUGH THE WINDWARD PASSAGE ACROSS THE BAHAMAS NEAR 26N76W TO 31N74W AND IS PROVIDING DIFFLUNCE ALOFT TO GENERATE SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS FROM 23N-27N BETWEEN 73W-79W. A WEAK SURFACE 1015 MB HIGH IS OVER THE W/CENTRAL ATLC NEAR 27N62W. A LARGE UPPER LOW IS CENTERED N OF THE LEEWARD ISLANDS NEAR 23N63W GENERATING CLUSTERS OF SCATTERED SHOWERS/ISOLATED THUNDERSTORMS FROM 22N- 29N BETWEEN 57W-71W. A BROAD UPPER TROUGH IS OVER THE E ATLC FROM THE CANARY ISLANDS TO 50W AND IS GENERATING ISOLATED SHOWERS/THUNDERSTORMS FROM 25N-30N BETWEEN 33W-40W. A BROAD SURFACE RIDGE COVERS THE E ATLC N OF 26N E OF 50W ANCHORED BY A 1027 MB HIGH N OF THE AZORES. W ATLC SURFACE FRONT WILL REMAIN NEARLY STATIONARY THROUGH WED THEN BEGIN TO DRIFT W THROUGH THU NIGHT. A WEAK SURFACE RIDGE ALONG 23N/25N WILL PERSIST E OF THE BAHAMAS THROUGH WED. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ PAW