000 AXNT20 KNHC 091756 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT TUE SEP 09 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. ...SPECIAL FEATURES... TROPICAL WAVE EXTENDS FROM 09N27W TO 20N27W MOVING W AT 10 KT. A 1009 MB LOW IS CENTERED ALONG THE WAVE AXIS NEAR 12N. VERY HIGH MOISTURE CONTENT IN THE VICINITY OF THE LOW IS SUPPORTING SCATTERED MODERATE CONVECTION FROM 10N-16N BETWEEN 23W-34W. THE OVERALL ORGANIZATION OF THIS SYSTEM HAS BEEN IMPROVING SLOWLY OVER THE PAST 24 HOURS...WITH A WELL DEFINED MID LEVEL ROTATION EVIDENT ON MORE RECENT VISIBLE SATELLITE IMAGERY. THE CHANCE OF THIS FEATURE DEVELOPING INTO A TROPICAL CYCLONE DURING THE NEXT 48 HOURS IS MEDIUM. ...TROPICAL WAVES... TROPICAL WAVE EXTENDS FROM 10N48W TO 23N45W MOVING W AT 10-15 KT. THIS WAVE IS ENTERING A REGION OF HIGHER SHEAR...WHICH IS LIMITING CONVECTION WITH THE WAVE. ISOLATED THUNDERSTORMS ARE OCCURRING ALONG THE NORTHERN PORTIONS OF THE WAVE WITHIN 100NM OF THE WAVE AXIS N OF 16N. TROPICAL WAVE EXTENDS FROM 10N85W TO 22N84W MOVING W AT 10-15 KT. UPPER LEVEL DIFFLUENCE COMBINED WITH DEEP LAYER MOISTURE IS SUPPORTING SCATTERED MODERATE TO ISOLATED STRONG CONVECTION FROM 12N-19N BETWEEN 78W-83W. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM 18N16W TO 12N28W TO 07N39W. THE ITCZ AXIS EXTENDS FROM 07N39W TO 06N56W. OTHER THAN CONVECTION MENTIONED IN THE TROPICAL WAVES SECTION ABOVE...ISOLATED MODERATE CONVECTION IS OCCURRING FROM 05N-08N BETWEEN 34W-49W. ...DISCUSSION... GULF OF MEXICO... A SURFACE TROUGH EXTENDS ALONG THE NORTHERN GULF COAST FROM MS EASTWARD ACROSS N FL. CONVERGENCE ASSOCIATED WITH THE SURFACE TROUGH IS SUPPORTING SCATTERED THUNDERSTORMS OCCURRING WITHIN 100NM OF THIS TROUGH E OF 87W. THE BASE OF A N- S ORIENTED UPPER TROUGH EXTENDS ACROSS THE E GULF. DIFFLUENCE ASSOCIATED WITH THIS UPPER TROUGH IS COMBINING WITH AN UNSTABLE AIRMASS WHICH IS ENHANCING SHOWERS AND THUNDERSTORMS IN THE SE GULF FROM 24-28N E OF 87W. SOME OF THIS CONVECTION MAY ALSO BE A RESULT OF THE NORTHERN EXTENT OF A WESTWARD MOVING TROPICAL WAVE MENTIONED IN THE TROPICAL WAVES SECTION. OVER THE NEXT 24 TO 48 HOURS...UPPER LEVEL DIFFLUENCE BETWEEN AN UPPER LEVEL ANTICYCLONE OVER TX/MEXICO AND A BROAD UPPER LEVEL TROUGH OVER THE W ATLANTIC WILL MAINTAIN THE CHANCE FOR SCATTERED SHOWERS AND THUNDERSTORMS IN THE E GULF. CARIBBEAN SEA... BROAD WESTERLY UPPER LEVEL FLOW IS OCCURRING ACROSS THE CENTRAL AND E CARIBBEAN. STRONG NORTHERLY UPPER LEVEL FLOW REMAINS ACROSS THE W CARIBBEAN. A PERSISTENT AND NEARLY STATIONARY MID TO UPPER LEVEL LOW IS CENTERED S OF THE BAHAMAS NEAR 22N75W. OTHER THAN CONVECTION ASSOCIATED WITH A TROPICAL WAVE MENTIONED IN THE TROPICAL WAVES SECTION...SCATTERED MODERATE CONVECTION IS N OF 17N INTO W CUBA BETWEEN 75W-78W. THIS CONVECTION IS BEING AIDED BY UPPER LEVEL DIFFLUENCE ON THE S SIDE OF THE MID TO UPPER LEVEL LOW. THE W CARIBBEAN TROPICAL WAVE WILL MOVE INTO CENTRAL AMERICA AND MEXICO OVER THE NEXT 24 HOURS. A BROAD AREA OF UPPER LEVEL DIFFLUENCE WILL REMAIN OVER THE W CARIBBEAN THROUGH WEDNESDAY WHICH WILL HELP TO MAINTAIN ENHANCED CONVECTION OFF THE COASTS OF HONDURAS AND NICARAGUA. EASTERN CARIBBEAN WEATHER IS EXPECTED TO REMAIN FAIR THROUGH WEDNESDAY. ...HISPANIOLA... UPPER LEVEL DIFFLUENCE REMAINS OVER THIS AREA ON THE SOUTHEAST SIDE OF A MID TO UPPER LEVEL LOW NEAR 22N75W. SSMI TPW INDICATES SOME DRIER AIR HAS BEEN WORKING ITS WAY WEST ACROSS HISPANIOLA OVER THE PAST 24 HOURS. THIS DRIER AIR HAS BEEN HELPING TO INHIBIT CONVECTION ACROSS THE AREA TODAY. HOWEVER...IT APPEARS THAT MOISTURE WILL INCREASE FROM THE NORTH TONIGHT AND WEDNESDAY AS AN UPPER TROUGH DIGS SOUTHWEST TOWARD THE AREA. THIS WILL HELP TO INCREASE CHANCES FOR SHOWERS AND THUNDERSTORMS IN HISPANIOLA TONIGHT AND TUESDAY. ATLANTIC OCEAN... A PERSISTENT MID TO UPPER LEVEL LOW IS CENTERED NEAR 22N75W. A SURFACE TROUGH HAS DEVELOPED TO THE EAST OF THIS LOW EXTENDING FROM NEAR 21N73N TO 25N75W. LOW LEVEL CONVERGENCE FROM THE TROUGH INTERACTING WITH THE CIRCULATION AROUND THE UPPER LOW IS PRODUCING SCATTERED THUNDERSTORMS FROM 21N-25N BETWEEN 68W-78W. THE UPPER LOW IS EXPECTED TO MOVE SLOWLY OVER THE NEXT TWO DAYS WHILE WEAKENING. THE SURFACE TROUGH IS EXPECTED TO REMAIN IN TACT AND MOVE GRADUALLY NORTHWESTWARD ACROSS THE BAHAMAS. SCATTERED SHOWERS AND THUNDERSTORMS SHOULD CONTINUE IN THE VICINITY OF THE SURFACE TROUGH OVER THE NEXT COUPLE OF DAYS. ANOTHER UPPER LOW IS CENTERED NEAR 26N57W. ISOLATED THUNDERSTORMS ARE OCCURRING WITHIN 350NM OF THIS UPPER LOW FROM 25N-21N BETWEEN 50W-59W. A COLD FRONT EXTENDS ALONG 31N40W TO 27N29W TO 32N16W FROM A SURFACE LOW NE OF THE AZORES. NO DEEP CONVECTION IS ASSOCIATED WITH THIS FRONT. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ LATTO