000 AXNT20 KNHC 142350 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT MON SEP 14 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 2345 UTC. ...SPECIAL FEATURE... A 1012 MB LOW PRESSURE AREA IS CENTERED NEAR 10N40W AT THE BASE OF A TROPICAL WAVE EXTENDING NORTHWARD TO 18N40W. LITTLE SHOWER ACTIVITY IS RELATED TO THESE FEATURES DUE TO DRY AIR NEARBY. DESPITE THIS...UPPER-LEVEL WINDS ARE EXPECTED TO BECOME CONDUCTIVE FOR SOME TROPICAL CYCLONE FORMATION DURING THE NEXT 48 HOURS WHILE THE LOW AND WAVE MOVE NW ACROSS THE CENTRAL TROPICAL ATLANTIC. WITH THIS...THE CHANCE FOR DEVELOPMENT OF THIS FEATURE IS MEDIUM. ...TROPICAL WAVES... A TROPICAL WAVE IS OVER THE E TROPICAL ATLANTIC WITH AXIS THAT EXTENDS FROM 17N21W TO A 1012 MB SURFACE LOW NEAR 09N21W...MOVING W AT ABOUT 12 KT OVER THE PAST 12 HOURS. SCATTERED MODERATE CONVECTION REMAINS AROUND THE LOW PRESSURE CENTER FROM 05N-12N BETWEEN 18W-30W. DRY AIR PREVAILS IN THE NORTHERN ENVIRONMENT OF THE WAVE LIMITING CONVECTION IN THIS AREA. A TROPICAL WAVE EXTENDS ACROSS THE CENTRAL ATLANTIC RELATED TO THE LOW PRESSURE DISCUSSED IN THE SPECIAL FEATURES SECTION. PLEASE REFER TO THE SECTION ABOVE FOR DETAILS. A TROPICAL WAVE IS MOVING ACROSS THE LESSER ANTILLES WITH AXIS EXTENDING FROM 20N61W TO 11N61W...MOVING W AT 10-15 KT OVER THE PAST 24 HOURS. THE POSITION OF THIS WAVE IS CLEARLY DEPICTED IN SATELLITE IMAGERY WHERE THE CLASSIC INVERTED V IS NOTICED ENTERING THE E CARIBBEAN. SCATTERED LIGHT TO MODERATE CONVECTION IS FROM 13N-19N BETWEEN 57W-64W. A TROPICAL WAVE IS ANALYZED IN THE W CARIBBEAN WITH AXIS EXTENDING FROM 19N80W TO 10N79W...MOVING W AT ABOUT 10-15 KT OVER THE PAST 24 HOURS. NO SIGNIFICANT CONVECTION IS RELATED TO THIS WAVE AT THIS TIME. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM 12N17W TO A 1012 MB LOW NEAR 09N21W TO 12N33W TO A 1012 MB SURFACE LOW CENTERED NEAR 10N40W. THE ITCZ BEGINS FROM THAT LAST POINT TO THE COAST OF SOUTH AMERICA NEAR 06N57W. ASIDE FROM THE CONVECTION RELATED TO THE LOWS AND WAVES...NO SIGNIFICANT CONVECTION IS OBSERVED ELSEWHERE. ...DISCUSSION... GULF OF MEXICO... A FRONTAL SYSTEM WAS ANALYZED ACROSS THE GULF WATERS AS A WEAKENING STATIONARY FRONT FROM 27N96W TO 27N91W...THEN AS STATIONARY FRONT FROM THAT POINT TO 27N82W. THIS BOUNDARY COMBINED WITH UPPER-LEVEL DIFFLUENCE ARE SUPPORTING SCATTERED MODERATE CONVECTION ACROSS THE WESTERN HALF OF THE BASIN W OF 87W. TO THE SW...A 1012 MB SURFACE LOW IS CENTERED NEAR 22N97W. SCATTEROMETER DATA DEPICTS A GENTLE TO MODERATE EASTERLY FLOW ACROSS THE WHOLE BASIN. OVER THE NEXT 24 HOURS...EXPECT FOR THE FRONTAL BOUNDARY TO WEAKEN. CONVECTION IS STILL POSSIBLE ACROSS THE WESTERN GULF AS UPPER-LEVEL DIFFLUENCE WILL CONTINUE ACROSS THE AREA. CARIBBEAN SEA... A SURFACE RIDGE EXTENDS FROM THE ATLANTIC ACROSS THE CARIBBEAN WATERS. TWO TROPICAL WAVES ARE ACROSS THE BASIN...PLEASE REFER TO THE SECTION ABOVE FOR DETAILS. AN ELONGATED UPPER-LEVEL LOW IS ACROSS THE CENTRAL CARIBBEAN SUPPORTING SCATTERED CONVECTION OVER THE NW CARIBBEAN AFFECTING CUBA..JAMAICA AND W-CENTRAL HISPANIOLA. SCATTEROMETER DATA DEPICTS GENTLE TO MODERATE TRADES OVER THE BASIN EXCEPT BETWEEN 69W-76W WHERE MODERATE TO FRESH WINDS PREVAIL. OVER THE NEXT 24 HOURS...EXPECT FOR THE WAVE ACROSS THE EASTERN CARIBBEAN TO CONTINUE ENHANCING CONVECTION AFFECTING THE LESSER ANTILLES...PUERTO RICO AND EASTERN HISPANIOLA. ...HISPANIOLA... AN UPPER-LEVEL TROUGH EXTENDS ACROSS THE CENTRAL AND WESTERN PORTION OF THE ISLAND AND OVER THE CENTRAL CARIBBEAN. THIS FEATURE IS SUPPORTING SCATTERED CONVECTION ACROSS HAITI AND THEIR ADJACENT WATERS. EXPECT FOR THIS UPPER TROUGH TO MOVE W OVER THE NEXT 24 HOURS HENCE THE PROBABILITIES FOR CONVECTION WILL DECREASE BEFORE INCREASING AGAIN AS A TROPICAL WAVE APPROACHES FROM THE E. ATLANTIC OCEAN... AN UPPER-LEVEL TROUGH EXTENDS ACROSS THE W ATLANTIC SUPPORTING A FRONTAL SYSTEM ANALYZED AS A STATIONARY FRONT FROM 28N80W TO 28N78W AND AS A COLD FRONT FROM 28N78W TO 32N70W. A PRE-FRONTAL TROUGH EXTENDS ACROSS THE FLORIDA STRAITS AND NORTHERN BAHAMAS FROM 24N81W TO 27N78W. SCATTERED MODERATE CONVECTION IS OBSERVED WITHIN 100 NM OF THESE BOUNDARIES. UPPER-LEVEL DIFFLUENCE IS SUPPORTING SCATTERED CONVECTION ACROSS THE W ATLANTIC MAINLY W OF 75W. TO THE E...AN UPPER-LEVEL LOW IS REFLECTED AT THE SURFACE AS A TROUGH THAT EXTENDS FROM 28N57W TO 24N61W. SCATTERED MODERATE CONVECTION IS OBSERVED FROM 25N-28N BETWEEN 59W-63W. FAIR WEATHER AND SURFACE RIDGING PREVAILS ACROSS THE REMAINDER OF THE BASIN ANCHORED BY A 1022 MB HIGH CENTERED NEAR 36N40W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ ERA