WTXS21 PGTW 301500 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/TROPICAL CYCLONE FORMATION ALERT (INVEST 98S)// REF/A/JOINT TYPHOON WRNCEN PEARL HARBOR HI/300321ZJAN2021// AMPN/REF A IS A TROPICAL CYCLONE FORMATION ALERT (WTPS21 PGTW 300330)// RMKS/ 1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN 140 NM EITHER SIDE OF A LINE FROM 18.5S 124.4E TO 20.0S 119.1E 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 25 TO 30 KNOTS. METSAT IMAGERY AT 301200Z INDICATES THAT A CIRCULATION CENTER IS LOCATED NEAR 18.5S 124.2E. THE SYSTEM IS MOVING WEST-SOUTHWESTWARD AT 06 KNOTS. 2. REMARKS: THE AREA OF CONVECTION (INVEST 98S) PREVIOUSLY LOCATED NEAR 17.5S 125.2E IS NOW LOCATED NEAR 18.5S 124.2E, APPROXIMATELY 114 NM EAST-SOUTHEAST OF BROOME, AUSTRALIA. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY AND A 300838Z SSMIS 91 GHZ MICROWAVE IMAGE DEPICT FORMATIVE BANDING WRAPPING INTO A DEFINED LOW LEVEL CIRCULATION. ENVIRONMENTAL ANALYSIS INDICATES A FAVORABLE ENVIRONMENT FOR DEVELOPMENT WITH LOW (<15KTS) VERTICAL WIND SHEAR AND GOOD OUTFLOW ALOFT. GLOBAL MODELS ARE IN STRONG AGREEMENT THAT INVEST 98S WILL TRACK GENERALLY WEST-SOUTHWESTWARD OVER THE NEXT 24- 30 HOURS AND DEVELOP QUICKLY ONCE OVER WATER. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 25 TO 30 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 995 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 311500Z. 4. SEE REF A FOR DETAILS ON A TROPICAL CYCLONE FORMATION ALERT LOCATED NEAR 13.2S 148.2E.// NNNN