WTXS21 PGTW 220400 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/TROPICAL CYCLONE FORMATION ALERT (INVEST 90S)// RMKS/ 1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN 120 NM EITHER SIDE OF A LINE FROM 12.5S 108.3E TO 13.8S 107.0E 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 28 TO 33 KNOTS. METSAT IMAGERY AT 220000Z INDICATES THAT A CIRCULATION CENTER IS LOCATED NEAR 12.7S 108.2E. THE SYSTEM IS MOVING SOUTH-SOUTHEASTWARD AT 06 KNOTS. 2. REMARKS:AN AREA OF CONVECTION (INVEST 90S) HAS PERSISTED NEAR 12.7S 108.2E, APPROXIMATELY 200 NM SOUTHEAST OF CHRISTMAS ISLAND. ANIMATED ENHANCED MULTISPECTRAL SATELLITE IMAGERY (MSI) AND A 220153Z ASCAT METOP-B PASS DEPICT A WELL STRUCTURED SYSTEM WITH CONVECTION AND EMBEDDED 30-35KT WINDS WRAPPING INTO A CONSOLIDATED LOW-LEVEL CIRCULATION CENTER. ENVIRONMENTAL ANALYSIS SHOWS FAVORABLE CONDITIONS WITH EXCELLENT POLEWARD OUTFLOW DUE TO THE DISTURBANCE BEING NEAR THE DIVERGENT QUADRANT OF A COL REGION, LOW (10-15KT) VERTICAL WIND SHEAR, AND WARM (28-29C) SEA SURFACE TEMPURTURES. GLOBAL MODELS ARE IN AGREEMENT THAT THIS SYSTEM WILL REACH A PEAK INTENSITY OF 35KTS AND DISSIPATE BY TAU 96. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 28 TO 33 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 998 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 230400Z. // NNNN