WTXS21 PGTW 150830 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/TROPICAL CYCLONE FORMATION ALERT (INVEST 93S)// RMKS/ 1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN 130 NM EITHER SIDE OF A LINE FROM 8.6S 66.7E TO 10.4S 72.8E 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 20 TO 25 KNOTS. METSAT IMAGERY AT 150600Z INDICATES THAT A CIRCULATION CENTER IS LOCATED NEAR 8.8S 67.1E. THE SYSTEM IS MOVING EAST-SOUTHEASTWARD AT 08 KNOTS. 2. REMARKS: THE AREA OF CONVECTION (INVEST 93S), PREVIOUSLY LOCATED NEAR 7.9S 66.7E IS NOW LOCATED NEAR 8.8S 67.1E, APPROXIMATELY 328 NM WEST-SOUTHWEST OF DIEGO GARCIA. ANIMATED MULTISPECTRAL IMAGERY DEPICTS LOW LEVEL TURNING AROUND A LOW LEVEL CIRCULATION CENTER (LLCC) THAT IS PARTIALLY OBSCURED BY CONVECTION THAT IS SHEARED TO THE SOUTHWEST. A 150221Z SSMIS 91GHZ SATELLITE IMAGE DEPICTS LOW LEVEL BANDING WRAPPING INTO THE LLCC. INVEST 93S IS IN A MARGINAL ENVIRONMENT WITH WARM (30-31C) SEA SURFACE TEMPERATURES, AND POLEWARD OUTFLOW ALOFT OFFSET BY HIGH (30-40 KTS) VERTICAL WIND SHEAR (VWS). GLOBAL MODELS GENERALLY AGREE THAT 93S WILL REMAIN AT ITS CURRENT INTENSITY AS IT INTERACTS WITH TC 01S, AND LOSING STRENGTH BEFORE TURNING SOUTH-SOUTHWESTWARD. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 20 TO 25 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1002 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 160830Z.// NNNN