WTPS21 PGTW 101930 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/TROPICAL CYCLONE FORMATION ALERT (INVEST 95P)// RMKS/ 1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN 125 NM EITHER SIDE OF A LINE FROM 20.6S 160.2E TO 23.9S 167.0E 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 28 TO 33 KNOTS. METSAT IMAGERY AT 101930Z INDICATES THAT A CIRCULATION CENTER IS LOCATED NEAR 20.9S 160.7E. THE SYSTEM IS MOVING EASTWARD AT 14 KNOTS. 2. REMARKS: THE AREA OF CONVECTION (INVEST 95P) PREVIOUSLY LOCATED NEAR 20.6S 158.4E IS NOW LOCATED NEAR 20.9S 160.7E, APPROXIMATELY 330 NM WEST-NORTHWEST OF NOUMEA, NEW CALEDONIA. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY (EIR) DEPICTS DEEP RADIAL PLUMES OF DEEP CONVECTION BUILDING OVER THE OBSCURED LOW LEVEL CIRCULATION (LLC). A 101340Z 89GHZ GPM GMI IMAGE REVEALS AN ELONGATED LLC WITH DEEP CONVECTION SHEARED TO THE NORTHEAST. ENVIRONMENTAL ANALYSIS REVEALS FAVORABLE CONDITIONS FOR DEVELOPMENT WITH LOW TO MODERATE VERTICAL WIND SHEAR OF 15-20 KNOTS, GOOD UPPER-LEVEL OUTFLOW AND WARM SEA SURFACE TEMPERATURES (SST) OF 26-27C. 95P IS ALONG THE SOUTH PACIFIC CONVERGENCE ZONE, RESULTING IN AN ELONGATED CIRCULATION. THERE IS A POTENTIAL THAT THE SYSTEM ACQUIRES SUBTROPICAL CHARACTERISTICS PRIOR TO DEVELOPING AS A TROPICAL CYCLONE DUE TO COOLER THAN 26C SEA SURFACE TEMPERATURES SOUTH OF NEW CALEDONIA. AS FOR DETERMINISTIC AND ENSEMBLE MODELS, GFS AND ECMWF INDICATE BRIEF TROPICAL CYCLONE DEVELOPMENT WITH THE NEXT 24 HOURS. HOWEVER, MODELS ALSO PORTRAY 95P SUBTROPICAL TRANSITION IMMEDIATELY FOLLOWING DEVELOPMENT, SO THERE IS A BRIEF WINDOW OF OPPORTUNITY FOR THE SYSTEM TO REACH WARNING CRITERIA. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 28 TO 33 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 998 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 111930Z.// NNNN