WTPN21 PGTW 091100 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/TROPICAL CYCLONE FORMATION ALERT (INVEST 92W)// RMKS/ 1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN 140 NM EITHER SIDE OF A LINE FROM 13.1N 116.2E TO 14.7N 113.1E 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 15 TO 20 KNOTS. METSAT IMAGERY AT 090900Z INDICATES THAT A CIRCULATION CENTER IS LOCATED NEAR 13.1N 115.6E. THE SYSTEM IS MOVING WESTWARD AT 18 KNOTS. 2. REMARKS: THE AREA OF CONVECTION (INVEST 92W) PREVIOUSLY LOCATED NEAR 13.1N 117.4E IS NOW LOCATED NEAR 13.1N 115.6E, APPROXIMATELY 466 NM EAST-SOUTHEAST OF DANANG, VIETNAM. ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS FLARING CONVECTION WITH LOW LEVEL BANDING WRAPPING INTO A PARTIALLY OBSCURED LOW LEVEL CIRCULATION CENTER (LLCC). THE FORMATIVE BANDS ARE ALSO PRESENT IN A 090525Z ATMS 183GHZ IMAGE WHICH FURTHER CONSTRAINS THE CURRENT POSITION. INVEST 92W IS CURRENTLY TRACKING THROUGH AN ENVIRONMENT THAT IS MARGINALLY FAVORABLE FOR FURTHER DEVELOPMENT WITH MODERATE (15-25 KTS) VERTICAL WIND SHEAR (VWS) OFFSET BY WARM (28-30 CELSIUS) SEA SURFACE TEMPERATURES (SST) AND ROBUST EQUATORWARD OUTFLOW ALOFT. NUMERICAL MODELS ARE IN FAIR AGREEMENT THAT INVEST 92W WILL CONTINUE TO TRACK GENERALLY WESTWARD OVER THE NEXT 24 HOURS AND CONTINUE TO CONSOLIDATE AS THE VWS WEAKENS BELOW 15 KTS. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 15 TO 20 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1007 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 101100Z.// NNNN