WTPN21 PGTW 101700 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/TROPICAL CYCLONE FORMATION ALERT (INVEST 96W)// RMKS/ 1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN 180 NM EITHER SIDE OF A LINE FROM 22.4N 125.8E TO 23.2N 117.3E WITHIN THE NEXT 12 TO 24 HOURS. AVAILABLE DATA DOES NOT JUSTIFY ISSUANCE OF NUMBERED TROPICAL CYCLONE WARNINGS AT THIS TIME. WINDS IN THE AREA ARE ESTIMATED TO BE 20 TO 25 KNOTS. METSAT IMAGERY AT 101200Z INDICATES THAT A CIRCULATION CENTER IS LOCATED NEAR 22.7N 124.9E. THE SYSTEM IS MOVING WEST-NORTHWESTWARD AT 30 KNOTS. 2. REMARKS: AN AREA OF CONVECTION (INVEST 96W) HAS PERSISTED NEAR 22.7N 124.9E, APPROXIMATELY 102 NM SOUTH-SOUTHEAST OF ISHIGAKIJIMA. ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS PERSISTENT CONVECTION OBSCURING A LOW LEVEL CIRCULATION CENTER (LLCC). A 101148Z ASCAT-A IMAGE REVEALS AN ASYMMETRIC WIND FIELD WITH SHARPLY CURVED WINDS IN THE NORTHERN PERIPHERY, 25-30 KT WINDS IN THE EASTERN PERIPHERY, AND LIGHT WINDS TO THE WEST OF THE LLCC. INVEST 96W IS EMBEDDED IN THE NORTHERN PERIPHERY OF STY 19W AND IS UNDERGOING FUJIWARA INTERACTION WITH RAPID TRACK SPEEDS. INVEST 96W IS UNDER THE WESTERLY OUTFLOW FROM STY 19W, HOWEVER, VERTICAL WIND SHEAR IS MODERATE (15-20 KNOTS) ALLOWING DEEP CONVECTION TO PERSIST AND WEAKLY ORGANIZE. ADDITIONALLY, SEA SURFACE TEMPERATURES ARE WARM AT 29-30C. GLOBAL MODELS INDICATE INVEST 96W WILL CONTINUE TO ROTATE RAPIDLY AROUND THE PERIPHERY OF STY 19W AND WILL EVENTUALLY DISSIPATE AS IT BECOMES ABSORBED WITHIN THE NEXT 12 TO 18 HOURS. THERE IS A NARROW WINDOW FOR DEVELOPMENT BEFORE THE SYSTEM TRACKS OVER THE MOUNTAINOUS TERRAIN OF TAIWAN. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 20 TO 25 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1004 MB. THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS IS HIGH. 3. THIS ALERT WILL BE REISSUED, UPGRADED TO WARNING OR CANCELLED BY 111700Z.// NNNN