000 AXNT20 KNHC 212355 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT SUN SEP 21 2014 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. ...TROPICAL WAVES... A TROPICAL WAVE CONTINUES OVER THE TROPICAL ATLANTIC EXTENDING FROM 17N34W TO 7N36W. THE WAVE IS MOVING W AT 15 KT. SSMI TPW SHOWS A MOIST AREA S OF 12 N ALONG THE WAVE. SSMI TPW AND METEOSAT SAL IMAGERY INDICATE DRY AIR WITH EMBEDDED DUST N OF 13N. SCATTERED MODERATE CONVECTION IS OCCURRING S OF 13N BETWEEN 31W AND 37W. A TROPICAL WAVE IS CROSSING THE LESSER ANTILLES WITH AXIS EXTENDING FROM 21N59W TO 11N62W...MOVING WEST AT 15-20 KT. SSMI TPW SHOWS A LARGE MOIST AREA FROM 6N-22N BETWEEN 47W-63W. SCATTERED MODERATE CONVECTION AND ISOLATED STRONG CONVECTION ARE FROM 8N-19N BETWEEN 54W AND 65W WHICH INCLUDES THE WINDWARD AND LEEWARD ISLANDS. A TROPICAL WAVE IS OVER THE WESTERN CARIBBEAN SEA WITH AXIS EXTENDING FROM 22N81W TO 10N81W...MOVING W AT 15-20 KT. DEEP LAYER MOISTURE IS IN THE ENVIRONMENT OF THIS WAVE. SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ARE WITHIN 100 NM OF THE WAVE AXIS. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 17N16W TO A 1009 MB LOW S OF THE CAPE VERDE ISLANDS NEAR 13N24W TO 10N35W TO 8N45W. THE ITCZ AXIS EXTENDS FROM 8N45W TO 11N59W. OTHER THAN THE CONVECTION MENTIONED IN THE TROPICAL WAVES SECTION ...WIDELY SCATTERED MODERATE CONVECTION IS FROM 11N-19N BETWEEN 17W AND 31W. SCATTERED MODERATE CONVECTION IS ALSO FROM 7N-14N BETWEEN 37W AND 46W. ...DISCUSSION... GULF OF MEXICO... A QUASI-STATIONARY FRONT EXTENDS FROM CENTRAL FLORIDA NEAR 28N81W TO THE NORTH CENTRAL GULF OF MEXICO NEAR 27N92W. ISOLATED MODERATE CONVECTION IS WITHIN 200 NM OF THE FRONT...INCLUDING CENTRAL AND SOUTH FLORIDA. AN UPPER LEVEL TROUGH EXTENDS ACROSS THE CENTRAL GULF. UPPER LEVEL DIFFLUENCE S OF THE BASE OF THE TROUGH IS ENHANCING CONVECTION ACROSS THE SW GULF S OF 24N BETWEEN 87W AND 91W. A NEARLY STATIONARY SURFACE TROUGH IS OVER THE W GULF AND BAY OF CAMPECHE FROM 25N97W TO 18N96W. SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ARE OCCURRING WITHIN 100 NM OF THE SURFACE TROUGH. OVER THE NEXT 24 HOURS...THE STATIONARY FRONT WILL GRADUALLY DISSIPATE WITH ONGOING CONVECTION EXPECTED IN THE VICINITY OF THE DISSIPATING FRONT. OTHER CONVECTION WILL BE POSSIBLE OVER THE SE GULF UNDER THE BASE OF AN EASTWARD SHIFTING UPPER TROUGH. ANOTHER COLD FRONT IS FORECAST TO ENTER THE N GULF ON TUESDAY. CARIBBEAN SEA... TWO TROPICAL WAVES ARE AFFECTING THE CARIBBEAN. SEE THE TROPICAL WAVES SECTION ABOVE. OTHER THAN THE CONVECTION ASSOCIATED WITH THE TROPICAL WAVES...A SMALL AREA OF UPPER LEVEL DIFFLUENCE IS SUPPORTING A PATCH OF SCATTERED MODERATE CONVECTION OVER THE CENTRAL CARIBBEAN FROM 15N-18N BETWEEN 65W AND 69W. THUNDERSTORMS OVER THE GREATER ANTILLES ARE ASSOCIATED MAINLY WITH DAYTIME HEATING AND THE PRESENCE OF DEEP LAYER MOISTURE. OVER THE NEXT 24 HOURS...THE TROPICAL WAVE OVER THE LESSER ANTILLES WILL SHIFT W WHICH WILL BRING ENHANCED CONVECTION TO THE E CARIBBEAN INCLUDING PUERTO RICO AND SURROUNDING ISLANDS. THE TROPICAL WAVE OVER THE W CARIBBEAN WILL MOVE ONSHORE THE YUCATAN AND CENTRAL AMERICA. ...HISPANIOLA... SCATTERED THUNDERSTORMS ARE OCCURRING OVER HISPANIOLA MAINLY DUE TO DAYTIME LANDMASS HEATING IN A MOIST AIRMASS. EXPECT A TROPICAL WAVE TO PRODUCE ADDITIONAL CONVECTION IN 24-48 HOURS. ATLANTIC OCEAN... A 1009 MB LOW S OF THE CAPE VERDE ISLANDS AND TWO TROPICAL WAVES ARE THE MAIN FEATURES ACROSS THE BASIN. SEE THE TROPICAL WAVES SECTION AND MONSOON/ITCZ SECTION ABOVE. A COLD FRONT EXTENDS FROM 31N73W TO 28N77W. A STATIONARY FRONT CONTINUES FROM 28N77W TO CENTRAL FLORIDA NEAR 28N81W. WIDELY SCATTERED MODERATE CONVECTION IS WITHIN 150 NM S AND E OF THE COLD FRONT. SCATTERED SHOWERS AND THUNDERSTORMS ARE WITHIN 150 NM S OF THE STATIONARY FRONT TO INCLUDE THE N BAHAMAS. AN UPPER LOW CENTERED NEAR 27N50W AND UPPER LEVEL DIFFLUENCE NORTH OF THE UPPER LOW IS SUPPORTING SCATTERED SHOWERS AND THUNDERSTORMS FROM 26N-33N BETWEEN 45W AND 52W. OVER THE NEXT 24 HOURS...THE FRONTS OVER THE W ATLANTIC WILL BEGIN TO DISSIPATE WITH POSSIBLE ONGOING CONVECTION IN THOSE LOCATIONS. A COLD FRONT WILL DIP SOUTH INTO THE CENTRAL ATLANTIC WITH SHOWERS POSSIBLE WITH THIS FRONT. THE UPPER LOW WILL CONTINUE TO PRODUCE SHOWERS AND ISOLATED THUNDERSTORMS AS IT REMAINS NEARLY STATIONARY. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ LATTO