WTPN21 PGTW 071500 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 160 NM EITHER SIDE OF A LINE FROM 12.4N 124.6E TO 12.8N 116.6E 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 071200Z INDICATES THAT A CIRCULATION CENTER IS LOCATED NEAR 12.4N 124.1E. THE SYSTEM IS MOVING WEST-NORTHWESTWARD AT 19 KNOTS. 2. REMARKS: THE AREA OF CONVECTION (INVEST 92W) PREVIOUSLY LOCATED NEAR 11.2N 127.4E IS NOW LOCATED NEAR 12.4N 124.1E, APPROXIMATELY 45 NM SOUTH-SOUTHEAST OF LEGAZPI, PHILIPPINES. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY DEPICTS PERSISTENT DEEP CONVECTION SLIGHTLY SHEARED TO THE WEST OF THE LOW LEVEL CIRCULATION (LLC) STRUGGLING AGAINST THE FRICTIONAL EFFECTS OF TRAVERSING THROUGH THE PHILIPPINE ISLANDS. A 071007Z SSMIS F-17 91 GHZ MICROWAVE IMAGE REVEALS DEEP CONVECTION OVERHEAD THE LLC AND SHALLOWER CONVECTIVE BANDING FORMING TO THE EAST. 92W IS CURRENTLY IN AN MARGINAL ENVIRONMENT CONSISTING OF MODERATE UPPER LEVEL OUTFLOW AND WARM (29 TO 30 CELSIUS) SEA SURFACE TEMPERATURES BEING OFFSET BY MODERATE TO HIGH (20 TO 25 KNOTS) VERTICAL WIND SHEAR AND LAND INTERACTION. GLOBAL MODELS ARE IN GOOD AGREEMENT THAT 92W WILL TRACK WESTWARD WITH MINIMAL INTENSIFICATION WHILE OVER THE PHILIPPINES. HOWEVER, AFTER IT MOVES OVER THE SOUTH CHINA SEA IN THE NEXT 24 HOURS, MODELS EXPECT IT TO INTENSIFY TO WARNING THRESHOLD WITH LIMITED FURTHER INTENSIFICATION AS IT CROSSES THE SOUTH CHINA SEA. 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 081500Z.// NNNN