WTXS21 PGTW 031400 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/TROPICAL CYCLONE FORMATION ALERT (INVEST 99S)// RMKS/ 1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN 080 NM EITHER SIDE OF A LINE FROM 9.9S 124.6E TO 11.3S 122.9E 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 25 TO 30 KNOTS. METSAT IMAGERY AT 031200Z INDICATES THAT A CIRCULATION CENTER IS LOCATED NEAR 10.7S 123.8E. THE SYSTEM IS MOVING NORTHEASTWARD AT 07 KNOTS. 2. REMARKS: THE AREA OF CONVECTION (INVEST 99S) PREVIOUSLY LOCATED NEAR 11.0S 122.3E IS NOW LOCATED NEAR 10.7S 123.8E, APPROXIMATELY 209 NM NORTH OF BROWSE ISLAND, AUSTRALIA. ANIMATED MULTISPECTRAL SATELLITE IMAGERY AND A 031054Z SSMIS F-17 91GHZ MICROWAVE IMAGE DEPICT FLARING DEEP CONVECTION CIRCLING A PARTIALLY OBSCURED LOW LEVEL CIRCULATION CENTER (LLCC) WITH FRAGMENTED FORMATIVE BANDING WRAPPING IN FROM THE SOUTH AND EAST. A 031150Z METOP-A ASCAT PASS REVEALS A TIGHT LLCC WITH A SMALL, BUT ENHANCED, WIND FIELD OF 20 TO 30 KNOTS WITH A COUPLE 35 KNOT WIND BARBS TO THE NORTH. 99S IS CURRENTLY IN A FAVORABLE ENVIRONMENT WITH WARM (30 CELSIUS) SEA SURFACE TEMPERATURES, LOW (10 TO 15 KNOT) VERTICAL WIND SHEAR, AND GOOD RADIAL OUTFLOW. GLOBAL MODELS ARE IN GENERAL AGREEMENT THAT 99S WILL REMAIN LARGELY QUASISTATIONARY WITH SLIGHTLY NORTHEASTWARD MOVEMENT BEFORE TURNING 180 DEGREES TO THE SOUTHWEST IN AROUND 18 TO 24 HOURS. IN THAT TIME, 99S WILL CONTINUE TO INTENSIFY; HOWEVER, MODELS DISAGREE ON TIMING WITH THE MAJORITY PREDICTING 99S REACHING WARNING THRESHOLD IN APPROXIMATELY 36 HOURS, WHILE ECMWF, THE ONLY OUTLIER, PREDICTS A QUICKER INTENSIFICATION, REACHING WARNING THRESHOLD IN 12 TO 24 HOURS. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 25 TO 30 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1000 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 041400Z.// NNNN