WTXS21 PGTW 062230 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/TROPICAL CYCLONE FORMATION ALERT (INVEST 91S)// RMKS/ 1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN 140 NM EITHER SIDE OF A LINE FROM 21.9S 53.0E TO 24.2S 59.0E 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 25 TO 30 KNOTS. METSAT IMAGERY AT 062045Z INDICATES THAT A CIRCULATION CENTER IS LOCATED NEAR 21.9S 53.0E. THE SYSTEM IS MOVING EAST-SOUTHEASTWARD AT 26 KNOTS. 2. REMARKS: THE AREA OF CONVECTION (INVEST 91S) PREVIOUSLY LOCATED NEAR 21.9S 53E IS NOW LOCATED NEAR 22.5S 53.9E, APPROXIMATELY 142 NM WEST-SOUTHWEST OF DES GALETS, LA REUNION. ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY AND A 062025Z GMI 89GHZ SATELLITE IMAGE DEPICT QUICKLY CONSOLIDATING AND FLARING CONVECTION. A 061839Z METOP- C ASCAT PASS SHOWS A MUCH TIGHTER LOW LEVEL CIRCULATION (LLC) WITH RAPIDLY INCREASING WIND SPEEDS. ENVIRONMENTAL ANALYSIS SHOWS 91S IS IN A FAVORABLE ENVIRONMENT WITH DUAL CHANNEL UPPER LEVEL OUTFLOW, MODERATE (15-20KTS) VERTICAL WIND SHEAR (VWS) AND WARM (28-29C) SEA SURFACE TEMPERATURES (SST). GLOBAL MODELS ARE IN GENERAL AGREEMENT THAT 91S WILL TRACK EAST-SOUTHEAST WHILE CONTINUING TO CONSOLIDATE AND INTENSIFY. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 25 TO 30 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 072230Z.// NNNN