WTXS21 PGTW 120930 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/TROPICAL CYCLONE FORMATION ALERT (INVEST 92S)// RMKS/ 1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN 160 NM EITHER SIDE OF A LINE FROM 4.5S 89.7E TO 6.4S 82.0E 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 120600Z INDICATES THAT A CIRCULATION CENTER IS LOCATED NEAR 4.7S 89.0E. THE SYSTEM IS MOVING WEST-SOUTHWESTWARD AT 07 KNOTS. 2. REMARKS: THE AREA OF CONVECTION (INVEST 92S) PREVIOUSLY LOCATED NEAR 5.3S 88.8E IS NOW LOCATED NEAR 4.7S 89.0E, APPROXIMATELY 991 NM EAST OF DIEGO GARCIA. ANIMATED MULTISPECTRAL SATELLITE IMAGERY DEPICTS FLARING DEEP CONVECTION AROUND A PARTIALLY EXPOSED, WELL- DEFINED LOW LEVEL CIRCULATION CENTER (LLCC) WITH ROBUST RADIAL OUTFLOW. A 120720Z AMSR2 GW1 89GHZ MICROWAVE IMAGE REVEALS FRAGMENTED DEEP CONVECTIVE BANDING WRAPPING INTO THE LLCC FROM ALL SIDES. 92S IS CURRENTLY IN A FAVORABLE ENVIRONMENT WITH EXCELLENT RADIAL OUTFLOW, LOW (10 TO 20 KNOTS) VERTICAL WIND SHEAR, AND WARM (29 TO 30 CELSIUS) SEA SURFACE TEMPERATURES. GLOBAL MODELS ARE IN GOOD AGREEMENT THAT 92S WILL TRACK WEST-SOUTHWESTWARD, INTENSIFYING TO WARNING THRESHOLD IN 12 TO 24 HOURS. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 25 TO 30 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 130930Z.// NNNN