000 AXNT20 KNHC 242332 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT THU SEP 24 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 2330 UTC. ...SPECIAL FEATURES... THE CENTER OF TROPICAL DEPRESSION IDA AT 24/2100 UTC IS NEAR 21.2N 45.0W. IDA IS MOVING TOWARD THE N...OR 25 DEGREES...AT 4 KT. THE MINIMUM CENTRAL PRESSURE IS 1006 MB. THE MAXIMUM SUSTAINED WIND SPEEDS IS 30 KNOTS WITH GUSTS TO 40 KNOTS. SCATTERED MODERATE CONVECTION IS OBSERVED FROM 15N-23N BETWEEN 38W-51W. PUBLIC ADVISORIES ABOUT TROPICAL STORM IDA ARE BEING ISSUED UNDER THE WMO HEADER WTNT35 KNHC...AND UNDER THE AWIPS HEADER MIATCPAT5. FORECAST/ADVISORIES ABOUT TROPICAL STORM IDA ARE BEING ISSUED UNDER THE WMO HEADER WTNT25 KNHC...AND UNDER THE AWIPS HEADER MIATCMAT5. ...TROPICAL WAVES... A TROPICAL WAVE IS OVER THE E ATLANTIC NEAR THE CAPE VERDE ISLANDS WITH AXIS EXTENDING FROM 16N27W TO 05N28W...MOVING W AT 5-10 KT WITHIN THE LAST 24 HOURS. TPW IMAGERY DEPICTS AN AREA OF SIGNIFICANT MOISTURE E OF THE WAVE AXIS AND WITH UPPER-LEVEL DIFFLUENCE ALOFT...ISOLATED CONVECTION IS DEVELOPING FROM 06N- 13N AND E OF 27W. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH PASSES THROUGH THE COAST OF AFRICA NEAR 12N16W AND EXTENDS OVER ATLANTIC WATERS TO 08N26W THEN RESUMES W OF A TROPICAL WAVE NEAR 07N30W TO 07N37W. SCATTERED MODERATE CONVECTION IS OBSERVED FROM 06N-12N BETWEEN 22W-25W. ...DISCUSSION... GULF OF MEXICO... AN UPPER-LEVEL ANTICYCLONE PREVAILS ACROSS MEXICO AND EXTENDS ACROSS THE WESTERN GULF WATERS MAINLY W OF 90W. TO THE E...AN UPPER-LEVEL CYCLONE CENTERED OVER THE FLORIDA PANHANDLE NEAR 31N85W EXTENDS ITS TROUGH ACROSS THE EASTERN GULF WATERS E OF 90W. THIS TROUGH IS SUPPORTING ISOLATED MODERATE CONVECTION ACROSS THE E GULF AND INDUCING A DIFFLUENT FLOW ACROSS THE STRAITS OF FLORIDA AND THE SOUTHERN PORTION OF THE FLORIDA PENINSULA WHICH IS SUPPORTING SCATTERED MODERATE CONVECTION AFFECTING NOT ONLY THE ADJACENT SE GULF WATERS BUT THE SOUTHERN PORTION OF THE FLORIDA PENINSULA. AT THE SURFACE...A SURFACE TROUGH EXTENDS ACROSS THE W GULF FROM 28N93W TO 20N94W. NO CONVECTION IS RELATED TO THIS FEATURE. SCATTEROMETER DATA DEPICTS A GENTLE E-NE WIND FLOW OVER THE NORTHERN PORTION OF THE BASIN N OF 26N WHILE LIGHT AND VARIABLE WINDS ARE OVER THE REMAINDER GULF. OVER THE NEXT 24 HOURS...SURFACE RIDGING WILL START TO BUILD ACROSS THE THE BASIN. A SURFACE TROUGH CURRENTLY E OF NICARAGUA IS EXPECTED TO DEVELOP A LOW PRESSURE CENTER THAT IS EXPECTED TO ENTER THE SOUTHERN GULF BY THE WEEKEND. CARIBBEAN SEA... A DIFFLUENT FLOW PREVAILS ACROSS THE W CARIBBEAN SUPPORTING SCATTERED MODERATE CONVECTION MAINLY W OF 80W. A SURFACE TROUGH WAS ANALYZED ACROSS THE SW CARIBBEAN EXTENDING FROM 16N83W TO 11N83W. THE PROXIMITY OF THE MONSOON TROUGH ACROSS THE SOUTHERN CARIBBEAN IS SUPPORTING SCATTERED MODERATE TO STRONG CONVECTION MAINLY S OF 14N AND W OF 76W. AN UPPER-LEVEL TROUGH EXTENDS FROM A LOW CENTERED OVER THE SW ATLANTIC ACROSS THE EASTERN PORTION OF THE CARIBBEAN. WITH THIS...SCATTERED MODERATE CONVECTION IS OBSERVED ACROSS PUERTO RICO AND HISPANIOLA. SCATTEROMETER DATA DEPICTS GENTLE TRADES DOMINATING BETWEEN 70W-80W WHILE LIGHTER WINDS PREVAIL ELSEWHERE. SHOWERS ARE FORECAST TO PREVAIL OVER THE NW AND SW CARIBBEAN. CURRENT GUIDANCE SHOWS THAT THE SURFACE TROUGH NEAR NICARAGUA WILL MOVE W-NW TOWARDS THE YUCATAN PENINSULA WITH AN ASSOCIATED LOW PRESSURE CENTER TO DEVELOP BY THIS WEEKEND. ...HISPANIOLA... AN UPPER-LEVEL CYCLONIC CIRCULATION OVER THE SW ATLANTIC EXTENDS A TROUGH S ACROSS THE EASTERN CARIBBEAN THAT ALONG WITH SHALLOW MOISTURE SUPPORT SCATTERED SHOWERS AND TSTMS OVER THE ISLAND. SHOWERS ARE EXPECTED TO CEASE WITHIN THE NEXT 24 HOURS AS THE UPPER-LEVEL LOW MOVES E TOWARD THE CENTRAL ATLANTIC. ATLANTIC OCEAN... THE MAIN FEATURE IN THE BASIN IS TROPICAL DEPRESSION IDA...WHICH WAS ALREADY DISCUSSED IN THE SPECIAL FEATURES SECTION ABOVE. ACROSS THE W ATLANTIC...A 1011 MB SURFACE LOW CENTERED NEAR 30N80W EXTENDS A SURFACE TROUGH ACROSS THE FLORIDA PENINSULA NEAR 25N81W. THESE FEATURES COMBINED WITH UPPER-LEVEL DIFFLUENCE W OF 75W ARE SUPPORTING SCATTERED MODERATE CONVECTION ACROSS THIS AREA. TO THE E...AN UPPER-LEVEL LOW CENTERED NEAR 26N67W IS SUPPORTING SCATTERED MODERATE CONVECTION FROM 22N-29N BETWEEN 58W-70W. THE REMAINDER BASIN IS BEING INFLUENCED BY A SURFACE HIGH CENTERED N OF OUR AREA AND EXTENDING S ACROSS THE E ATLANTIC. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ ERA