WTXS21 PGTW 150600MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//SUBJ/TROPICAL CYCLONE FORMATION ALERT//RMKS/1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN100 NM EITHER SIDE OF A LINE FROM 17.6S 110.4E TO 20.6S 111.7EWITHIN THE NEXT 12 TO 24 HOURS. AVAILABLE DATA DOES NOT JUSTIFYISSUANCE OF NUMBERED TROPICAL CYCLONE WARNINGS AT THIS TIME.WINDS IN THE AREA ARE ESTIMATED TO BE 20 TO 30 KNOTS. METSAT IM-AGERY AT 150000Z INDICATES THAT A CIRCULATION CENTER IS LOCATEDNEAR 18.1S 110.6E. THE SYSTEM IS MOVING SOUTHWESTWARD AT 04 KNOTS.
THE AREA OF CONVECTION PREVIOUSLY LOCATED NEAR 4.4N 109.5E IS NOW LOCATED NEAR 4.9N 107.9E, APPROXIMATELY 345 NM WEST OF BRUNEI. RECENT ANIMATED MULTISPECTRAL SATELLITE IMAGERY SHOWS AN ILL-DEFINED LOW LEVEL CIRCULATION WITH SHALLOW, DISORGANIZED CONVECTION. A 271344Z ASCAT PASS SHOWS A WEAK 10-15 KNOT CIRCULATION CENTER. UPPER LEVEL ANALYSIS INDICATES THE SYSTEM IS EQUATORWARD OF THE SUBTROPICAL RIDGE AXIS IN AN AREA OF MODERATE TO HIGH EASTERLY VERTICAL WIND SHEAR AND WEAK DIVERGENCE ALOFT. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 10 TO 15 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1006 MB. THESE ARE SUPPORTED BY NEARBY SURFACE OBSERVATIONS. DUE TO A LACK OF CONVECTIVE ORGANIZATION AND UPPER LEVEL SUPPORT, THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS REMAINS POOR.