WTPN21 PGTW 100900MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//SUBJ/TROPICAL CYCLONE FORMATION ALERT//RMKS/1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN150 NM EITHER SIDE OF A LINE FROM 12.4N 116.6E TO 8.8N 112.1E 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 15 TO 20 KNOTS. METSAT IMAGERY AND SYNOPTIC DATA AT 100830Z INDICATE THAT A CIRCULATION CENTER IS LOCATED NEAR 11.8N 116.1E. THE SYSTEM IS MOVING NORTHWESTWARD AT 04 KNOTS.