000 AXNT20 KNHC 121752 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT SAT SEP 13 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. ...TROPICAL WAVES... A TROPICAL WAVE OVER THE EASTERN ATLC HAS AN AXIS THAT EXTENDS FROM 17N25W TO 08N27W...MOVING W AT 10 TO 15 KT. SSMI TPW SHOWS HIGH MOISTURE S OF 15N. A TILTED 700 MB TROUGH EXTENDS FROM NEAR THE CAPE VERDE ISLANDS TO NEAR 06N29W WHICH INCLUDES THE ENVIRONMENT OF THE WAVE. SCATTERED MODERATE CONVECTION IS FROM 07N TO 14N BETWEEN 22W AND 30W. A TROPICAL WAVE OVER THE CENTRAL ATLC HAS AN AXIS THAT EXTENDS FROM 16N47W TO 08N49W MOVING W AT 15 TO 20 KT. A BROAD 700 MB TROUGH IS EVIDENT BETWEEN 40W AND 52W. HIGH MOISTURE IS EVIDENT S OF 15N WITH A POLEWARD SURGE OF MODERATE MOISTURE N OF 15 E OF THE WAVE. SCATTERED MODERATE CONVECTION IS FROM 07N TO 14N BETWEEN 45W AND 52W. A TROPICAL WAVE OVER THE SW N ATLC AND EASTERN CARIBBEAN HAS AN AXIS THAT EXTENDS FROM 20N67W TO 13N68W MOVING W AT AROUND 15 KT. A SHARP 700 MB TROUGH IS EVIDENT BETWEEN 64W AND 70W. ISOLATED MODERATE CONVECTION IS FROM 14N TO 22N BETWEEN 61W AND 70W. A TROPICAL WAVE OVER THE SW CARIBBEAN AND E PACIFIC HAS AN AXIS THAT EXTENDS FROM 0615N82W TO 06N83W...MOVING W AT 15 TO 20 KT. A SUBTLE 700 MB TROUGH IS EVIDENT BETWEEN 77W AND 85W. ISOLATED THUNDERSTORMS ARE S OF 15N BETWEEN 79W AND 85W. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 18N16W TO 10N25W TO 07N34W TO 10N42W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 10N42W TO 10N46W TO 09N54W. SCATTERED MODERATE CONVECTION IS FROM 15N-18N BETWEEN 15W-21W AND FROM 05N-10N BETWEEN 30W-38W. ISOLATED MODERATE CONVECTION IS FROM 08N-14N BETWEEN 40W-58W. ...DISCUSSION... GULF OF MEXICO... A BROAD MID TO UPPER LEVEL TROUGH EXTENDS FROM THE OHIO VALLEY SW TO THE NW AND N CENTRAL GULF. THIS TROUGH SUPPORTS A COLD FRONT THAT EXTENDS FROM 31N87W TO 29N92W TO 28N97W. A PAIR OF PRE-FRONTAL SURFACE TROUGHS ARE S OF THE FRONT AND EXTEND FROM 27N90W TO 24N98W...AND FROM 30N84W TO 27N88W. SCATTERED MODERATE CONVECTION IS WITHIN 125 NM S OF THE TROUGH AXIS E OF 93W. SCATTERED MODERATE AND ISOLATED STRONG CONVECTION ARE WITHIN 250 NM S OF THE TROUGH AXIS W OF 93W. N TO NE WINDS AROUND 15 KT ARE N OF THE COLD FRONT. N TO NW WINDS OF 15 TO 20 KT ARE BETWEEN THE FRONT AND SURFACE TROUGHS. SW TO SE WINDS OF 10 TO 15 KT ARE S OF THE TROUGHS. OVER THE NEXT 24 HOURS THE COLD FRONT WILL MOVE OVER THE CENTRAL GULF. CONVECTION WILL REMAIN LIKELY ALONG AND WITHIN A COUPLE HUNDRED MILES S OF THE COLD FRONT. CARIBBEAN SEA... AN UPPER TROUGH OVER HISPANIOLA AND THE CENTRAL CARIBBEAN IS INTERACTING WITH A TROPICAL WAVE TO PRODUCE ISOLATED MODERATE CONVECTION OVER THE NE CARIBBEAN...INCLUDING PUERTO RICO. ISOLATED THUNDERSTORMS OVER THE SW CARIBBEAN ARE ASSOCIATED WITH ANOTHER TROPICAL WAVE. PLEASE REFER TO THE TROPICAL WAVES SECTION FOR MORE DETAILS. GENTLE TO MODERATE TRADE WINDS COVER THE MAJORITY OF THE CARIBBEAN TODAY...EXCEPT FOR A SMALL AREA OF MODERATE TO FRESH TRADE WINDS N OF 15N WITHIN 150 NM OF THE AXIS OF THE TROPICAL WAVE OVER THE EASTERN CARIBBEAN. OVER THE NEXT 24 HOURS EXPECT GUSTY WINDS AND CONVECTION TO SPREAD W ACROSS PUERTO RICO...HISPANIOLA...AND CARIBBEAN WATERS N OF 15N IN THE AREA OF THE TROPICAL WAVE OVER THE E CARIBBEAN. ...HISPANIOLA... MOISTURE WILL INCREASE THROUGH THIS AFTERNOON AND EVENING AS A TROPICAL WAVE APPROACHES FROM THE WEST. AS THE MOISTURE ASSOCIATED WITH THE WAVE INTERACTS WITH HIGHER TERRAIN OVERNIGHT TONIGHT INTO SUNDAY MORNING...HEAVY RAINFALL MAY OCCUR. THIS COULD RESULT IN FLASH FLOODING AND MUD SLIDES IN THOSE AREAS PRONE TO THESE HAZARDS. ATLANTIC OCEAN... AN UPPER TROUGH OVER THE OHIO VALLEY IS PRODUCING SW FLOW ALOFT W OF 75W OVER THE SW N ATLC N OF 26N. ASCENT ASSOCIATED WITH THIS FLOW ALOFT SUPPORTS ISOLATED MODERATE CONVECTION NW OF A LINE FROM 24N80W TO 20N70W. AN UPPER LOW CENTERED NEAR 30N59W SUPPORTS ISOLATED MODERATE CONVECTION FROM 27N TO 31N BETWEEN 51W AND 62W. A 1017 MB LOW CENTERED NEAR 28N41W HAS A SURFACE TROUGH THAT EXTENDS FROM THE LOW CENTER TO 31N39W. ISOLATED MODERATE CONVECTION IS FROM 28N TO 31N BETWEEN 39W AND 43W. TWO TROPICAL WAVES ARE OVER THE TROPICAL ATLC. PLEASE REFER TO THE TROPICAL WAVES SECTION FOR MORE DETAILS. OVER THE NEXT 24 HOURS CONVECTION WILL INCREASE E OF FL AS THE TROUGH OVER THE OHIO VALLEY MOVES E AND A COLD FRONT NEARS THE AREA. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ LATTO