000 AXNT20 KNHC 300550 TWDAT TROPICAL WEATHER DISCUSSION NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT MON SEP 30 2013 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 0515 UTC. ...SPECIAL FEATURES... TROPICAL DEPRESSION ELEVEN IS CENTERED NEAR 27.0N 47.0W AT 30/0300 UTC OR ABOUT 980 NM ESE OF BERMUDA AND ABOUT 1035 NM NE OF THE NORTHERN LEEWARD ISLANDS MOVING ENE AT 8 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1010 MB. MAXIMUM SUSTAINED WIND SPEED IS 30 KT WITH GUSTS TO 40 KT. SCATTERED MODERATE CONVECTION IS FROM 26N-30N BETWEEN 44W-47W. SEE LATEST NHC FORECAST/ ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT1/WTNT21 KNHC FOR MORE DETAILS. ...TROPICAL WAVES... TROPICAL WAVE EXTENDS FROM 08N33W TO 20N30W MOVING W AT 15 KT. THE WAVE IS EMBEDDED WITHIN A VERY MOIST ENVIRONMENT AS NOTED TOTAL PRECIPITABLE WATER IMAGERY FROM 08N-23N BETWEEN 25W-35W AND CONTINUES TO COINCIDE WITH SURFACE TO 700 MB TROUGHING AND A RELATIVE VORTICITY MAXIMUM ALONG THE WAVE AXIS NEAR 14N. ISOLATED MODERATE CONVECTION IS FROM 07N-17N BETWEEN 27W-35W. TROPICAL WAVE EXTENDS FROM 11N70W TO 20N66W MOVING W-NW AT 20 KT. THE WAVE IS LOCATED SOUTH OF SUBTROPICAL TROUGHING AS A SURFACE LOW PRESSURE SYSTEM DEVELOPS ACROSS THE SW NORTH ATLC THAT IS FORECAST TO MOVE NORTHWARD OVER THE NEXT 24 TO 36 HOURS. AS A RESULT...ENERGY FROM THE WAVE IS FRACTURING NORTHWARD INTO THIS LOW-LEVEL TROUGHING WHILE ANY REMAINING ENERGY IS EXPECTED TO BECOME DIFFUSE ACROSS THE CENTRAL CARIBBEAN SEA. WIDELY SCATTERED MODERATE CONVECTION IS FROM 15N-23N BETWEEN 66W-75W. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 12N16W TO 08N20W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 08N20W TO 12N26W THEN FROM 08N35W TO 06N54W. ISOLATED MODERATE CONVECTION IS FROM 05N-11N BETWEEN 17W-25W. SCATTERED MODERATE CONVECTION IS FROM 07N-09N BETWEEN 34W-46W. A SURFACE TROUGH IS ANALYZED NEAR THE WESTERN EXTENT OF THE ITCZ AXIS FROM 06N57W TO 11N56W AND IS PROVIDING FOCUS FOR ISOLATED MODERATE CONVECTION FROM 03N-13N BETWEEN 50W-61W. ...DISCUSSION... GULF OF MEXICO... WATER VAPOR IMAGERY INDICATES MUCH OF THE GULF BASIN IS UNDER THE INFLUENCE OF A MIDDLE TO UPPER LEVEL RIDGE ANCHORED OVER THE WESTERN GULF NEAR 25N95W. OVERALL THIS IS PROVIDING MUCH OF THE BASIN WITH STABLE CONDITIONS THIS EVENING...HOWEVER AN UPPER LEVEL TROUGH AXIS NOTED EXTENDING FROM OVER THE OHIO RIVER VALLEY SW TO OVER OKLAHOMA AND THE TEXAS PANHANDLE CONTINUES TO MOVE SOUTHEASTWARD AND EVENTUALLY WILL INTERACT WITH A STATIONARY FRONT ANALYZED FROM THE TEXAS GULF COAST NEAR 29N96W TO NEAR BROWNSVILLE AND INLAND OVER NE MEXICO. WIDELY SCATTERED SHOWERS AND ISOLATED TSTMS ARE OCCURRING N OF 24N W OF 96W WITH ONLY ISOLATED LOW-TOPPED SHOWERS OCCURRING ELSEWHERE AT THIS TIME DUE TO THE OTHERWISE STABLE CONDITIONS ALOFT. WEAK SURFACE RIDGING IS EXPECTED TO REMAIN IN PLACE EXTENDING FROM THE SE CONUS TO THE SW GULF WATERS PROVIDING GENERALLY 10 TO 15 KT E-SE WINDS THROUGH WEDNESDAY. CARIBBEAN SEA... A MIDDLE TO UPPER LEVEL TROUGH AXIS EXTENDS FROM OVER THE SW NORTH ATLC NEAR 23N74W SW TO 20N78W TO A BASE NEAR 16N85W. WEST OF THE TROUGH AXIS...WATER VAPOR IMAGERY INDICATES VERY DRY AIR ALOFT AND OVERALL STABLE CONDITIONS THIS EVENING FOR THE NW CARIBBEAN WITH ONLY A FEW ISOLATED SHOWERS NOTED ACROSS EASTERN CUBA AND THE ADJACENT COASTAL WATERS N OF 20N BETWEEN 77W-83W. BENEATH THE UPPER LEVEL TROUGHING AND AREAS TO THE EAST...MOIST SOUTHWESTERLY FLOW ALOFT CONTINUES TO ADVECT MOISTURE AND CLOUDINESS FROM THE CENTRAL CARIBBEAN N-NE INTO A DEVELOPING LOW PRESSURE SYSTEM IN THE VICINITY OF BERMUDA IN THE SW NORTH ATLC. THIS MOISTURE...ALONG WITH A SURFACE TROUGH ALONG 79W AND A WEAKENING TROPICAL WAVE ALONG 68W IS PROVIDING FOCUS FOR A BROAD AREA OF WIDELY SCATTERED SHOWERS AND ISOLATED TSTMS FROM 10N-14N BETWEEN 70W-85W...AND FROM 14N-20N BETWEEN 66W-79W. CONVECTION OCCURRING ACROSS THE SW CARIBBEAN IS LIKELY ENHANCED DUE TO THE CLOSE PROXIMITY OF THE MONSOON TROUGH ANALYZED FROM NORTHERN COLOMBIA WESTWARD TO COSTA RICA THEN NORTHWESTWARD TO SOUTHWESTERN HONDURAS. FINALLY...WATER VAPOR IMAGERY SHOWS AN UPPER LEVEL LOW CENTERED OVER THE SE CARIBBEAN NEAR 10N63W THAT CONTINUES TO DRIFT WEST AND PROVIDE TRINIDAD AND TOBAGO...ALONG WITH THE SOUTHERN WINDWARD ISLANDS WITH INCREASED MOISTURE AND CLOUDINESS. ISOLATED SHOWER ACTIVITY IS EXPECTED TO INCREASE OVERNIGHT INTO MONDAY GENERALLY SOUTH OF 13N E OF 64W. HISPANIOLA... CURRENTLY MOIST SOUTHWESTERLY FLOW ALOFT EAST OF AN UPPER LEVEL TROUGH AXIS EXTENDING FROM OVER THE SE BAHAMAS SOUTHWEST TO OVER 16N84W IS PROVIDING THE ISLAND WITH PLENTY OF MOISTURE AND CLOUDINESS OVERHEAD THIS EVENING. WITH AN OVERALL UPPER LEVEL DIFFLUENT ENVIRONMENT IN PLACE...SCATTERED SHOWERS AND ISOLATED TSTMS ARE ONGOING AND EXPECTED TO PERSIST THROUGH THE OVERNIGHT HOURS INTO MONDAY. THE APPROACH OF A TROPICAL WAVE ALONG 68W IS EXPECTED TO INVIGORATE AFTERNOON AND EVENING CONVECTION MONDAY. AS THIS AREA OF CLOUDINESS AND PRECIPITATION TRAINS FROM THE S- SW OVER HISPANIOLA AND INTO THE SW NORTH ATLC...ANY PROLONGED HEAVY PRECIPITATION OVER A PARTICULAR AREA WILL RESULT IN LOCALIZED FLOODING AND A HIGHER POTENTIAL FOR MUD SLIDES. ATLANTIC OCEAN... A MIDDLE TO UPPER LEVEL LOW IS CENTERED OFF THE COAST OF THE CAROLINAS NEAR 34N72W THAT EXTENDS A TROUGH AXIS SOUTHWARD ALONG 73W TO OVER THE SE BAHAMAS THEN SW TO A BASE OVER THE NW CARIBBEAN SEA. THE TROUGHING SUPPORTS A 1009 MB LOW CENTERED NORTH OF BERMUDA NEAR 34N65W WITH A DISSIPATING STATIONARY FRONT EXTENDING INTO THE DISCUSSION AREA NEAR 32N62W TO 23N72W. A SURFACE TROUGH REMAINS TO THE WEST ANALYZED FROM 31N67W TO 23N74W. WITH LARGE-SCALE MOISTURE TRANSPORT ONGOING AND LOW- LEVEL MOISTURE CONVERGENCE IN THE VICINITY OF THE BOUNDARIES... SCATTERED SHOWERS AND ISOLATED TSTMS ARE OCCURRING FROM 19N-32N BETWEEN 58W-74W. THE REMAINDER OF THE SW NORTH ATLC WEST OF THE SURFACE TROUGH REMAINS UNDER MOSTLY FAIR SKIES AND ONLY A FEW ISOLATED SHOWERS. FARTHER EAST...ASIDE FROM TROPICAL DEPRESSION ELEVEN...THE CENTRAL ATLC IS UNDER THE INFLUENCE OF A SURFACE RIDGE ANCHORED BY A 1019 MB HIGH CENTERED NEAR 26N55W AND ANOTHER SURFACE RIDGE ACROSS THE EASTERN ATLC ANCHORED BY A 1020 MB HIGH CENTERED NEAR 25N24W. A COLD FRONT CONTINUES TO PASS MAINLY TO THE NORTH OF 30N BETWEEN 30W-38W...WITH ONLY A FEW ISOLATED SHOWERS POSSIBLE N OF 28N BETWEEN 28W-42W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN