Tropical Depression FOURTEEN
ZCZC MIATCDAT4 ALL TTAA00 KNHC DDHHMM TROPICAL DEPRESSION FOURTEEN DISCUSSION NUMBER 2 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 5 PM EDT MON SEP 08 2003 TROPICAL DEPRESSION FOURTEEN HAS NOT BECOME ANY BETTER ORGANIZED THIS AFTERNOON. IN FACT...CONVECTION NEAR THE CENTER HAS DECREASED AND THE BANDING FEATURES HAVE DISAPPEARED. HOWEVER...EARLIER SEAWINDS AND QUIKSCAT OVERPASSES INDICATED A WELL-DEFINED LOW-LEVEL CIRCULATION...AND VISIBLE SATELLITE IMAGERY CONFIRMS THAT A GOOD MID-LEVEL CIRCULATION ALSO EXISTS. THE INITIAL INTENSITY IS MAINTAINED AT 30 KT BASED ON SATELLITE INTENSITY ESTIMATES OF 30 KT FROM BOTH TAFB AND SAB....AND CONTINUITY. THE INITIAL MOTION ESTIMATE IS 270/05. THERE IS NO CHANGE TO THE PREVIOUS FORECAST TRACK REASONING. TD-14 IS STILL EXPECTED TO MOVE SLOWLY WESTWARD THROUGH THE NEXT 24 HOURS OR SO...AND THEN GRADUALLY TURN WEST-NORTHWESTWARD AND EVENTUALLY NORTHWESTWARD AS A MID- TO UPPER-LEVEL TROUGH SLOWLY DIGS SOUTHWARD AND WEAKENS THE SUBTROPICAL RIDGE THAT IS NORTH OF THE CAPE VERDE ISLANDS. HOWEVER ...GIVEN THAT THE DEPRESSION REMAINS FAIRLY FAR TO THE SOUTH...THIS SCENARIO MAY BE SLOW IN DEVELOPING AND MAY NOT EVEN OCCUR AT ALL. THE NOGAPS AND UKMET MODELS SUGGEST THAT BY 96-120 HOURS THE CYCLONE COULD BEGIN TO TURN BACK TOWARD THE WEST-NORTHWEST. THE OFFICIAL FORECAST TRACK IS SLIGHTLY TO THE RIGHT OF AND A LITTLE FASTER THAN THE PREVIOUS TRACK...AND IS CLOSE TO THE GFS SOLUTION. VERTICAL SHEAR IS FORECAST TO REMAIN LOW...BUT NO SIGNIFICANT STRENGTHENING WILL OCCUR UNTIL THE CYCLONE MAINTAINS SOME INNER-CORE CONVECTION. THUNDERSTORM ACTIVITY WILL LIKELY REDEVELOP LATER TONIGHT...BUT THE CLOSE PROXIMITY OF DRY MID-LEVEL AIR MAY INHIBIT DEVELOPMENT AND ORGANIZATION UNTIL THE CYCLONE PULLS FARTHER WEST AWAY FROM THE DRY SOURCE REGION OF WESTERN AFRICA. THE OFFICIAL INTENSITY FORECAST REMAINS A LITTLE LOWER THAN THE SHIPS INTENSITY MODEL...WHICH BRINGS THE SYSTEM UP TO 67 KT IN 48 HOURS. FORECASTER STEWART FORECAST POSITIONS AND MAX WINDS INITIAL 08/2100Z 12.0N 22.8W 30 KT 12HR VT 09/0600Z 12.5N 24.1W 35 KT 24HR VT 09/1800Z 13.3N 25.6W 40 KT 36HR VT 10/0600Z 14.6N 26.9W 45 KT 48HR VT 10/1800Z 16.0N 28.4W 55 KT 72HR VT 11/1800Z 19.5N 31.5W 65 KT 96HR VT 12/1800Z 23.0N 34.0W 70 KT 120HR VT 13/1800Z 27.0N 36.0W 70 KT NNNN