WTPN21 PGTW 111200 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 090 NM EITHER SIDE OF A LINE FROM 17.9N 113.0E TO 19.3N 107.8E 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 18 TO 23 KNOTS. METSAT IMAGERY AT 110820Z INDICATES THAT A CIRCULATION CENTER IS LOCATED NEAR 18.0N 112.2E. THE SYSTEM IS MOVING WEST-NORTHWESTWARD AT 07 KNOTS. 2. REMARKS: THE AREA OF CONVECTION (INVEST 92W) PREVIOUSLY LOCATED NEAR 17.9N 113.4E IS NOW LOCATED NEAR 18.0N 112.2E, APPROXIMATELY 282 NM SOUTH-SOUTHWEST OF HONG KONG. ANIMATED MULTISPECTRAL SATELLITE IMAGERY AND A 110820Z SSMIS 91 GHZ MICROWAVE IMAGE REVEAL A MONSOON DEPRESSION, BUT CONVECTIVE BANDS PREVIOUSLY DISPLACED NEARLY 100NM ARE NOW DEEPENING AND CONSOLIDATING AROUND THE SYSTEM CENTER. THE SYSTEM STILL EXISTS UNDER A MARGINALLY FAVORABLE ENVIRONMENT WITH LOW TO MODERATE VERTICAL WIND SHEAR (VWS) (10-20 KTS) OFFSET BY A LACK OF DIVERGENCE ALOFT. 92W REMAINS IN A FAVORABLE AREA OF WARM SEA SURFACE TEMPERATURES (SST) (30-31C). GLOBAL MODELS ARE IN GOOD AGREEMENT THAT 92W WILL CONTINUE DEVELOPING ALONG ITS WEST-NORTHWESTWARD TRACK AND INTENSIFY PRIOR TO MOVING OVER HAINAN ISLAND. AFTER A BRIEF PERIOD OF WEAKENING DUE TO FRICTIONAL EFFECTS AS 92W PASSES OVER HAINAN ISLAND, 92W WILL RE- INTENSIFY WHEN IT ENTERS AN AREA OF EVEN WARMER WATERS AND LOWER VWS OVER THE GULF OF TONKIN. FURTHERMORE, AN UPPER-LEVEL ANTICYCLONE TO THE NORTH WILL RETROGRADE EASTWARD AND IMPROVE OUTFLOW ALLOWING FOR FURTHER INTENSIFICATION. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 18 TO 23 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1005 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 121200Z. // NNNN