WTPS23 PGTW 012300 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/TROPICAL CYCLONE FORMATION ALERT// REF/A/MSG/JOINT TYPHOON WRNCEN PEARL HARBOR HI/312251ZDEC2018// NARR/REF A IS A TROPICAL CYCLONE FORMATION ALERT.// RMKS/ 1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN 280 NM EITHER SIDE OF A LINE FROM 6.9S 170.1E TO 10.3S 180.0E 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 011800Z INDICATES THAT A CIRCULATION CENTER IS LOCATED NEAR 7.0S 170.7E. THE SYSTEM IS MOVING EAST-NORTHEASTWARD AT 19 KNOTS. 2. REMARKS: ANIMATED MULTISPECTRAL SATELLITE IMAGERY AND A 012145Z 89GHZ MHS MICROWAVE IMAGE DEPICT FORMATIVE BANDING FEATURES WRAPPING INTO A CENTRAL AREA OF DEEP CONVECTION LOCATED OVERTOP OF, AND OCCLUDING, A LOW LEVEL CIRCULATION CENTER. UPPER LEVEL ANALYSIS SHOWS 98P IS LOCATED IN AN AREA OF STRONG VERTICAL WIND SHEAR (30-40 KTS), WHICH IS OFFSET BY RADIAL OUTFLOW FROM A POINT SOURCE ALOFT AND A FORMATIVE POLEWARD OUTFLOW CHANNEL. SEA SURFACE TEMPERATURES REMAIN WARM (28-30 CELSIUS) AND CONDUCIVE FOR FUTURE DEVELOPMENT. GLOBAL MODELS GENERALLY AGREE WITH AN EASTERN TRAJECTORY FOR THE FIRST 24-48 HOURS FOLLOWED A FAIRLY SHARP TURN SOUTHWARD AFTERWARDS. MODELS INDICATE GRADUAL STRENGTHENING FOR 98P INITIALLY. BEYOND TAU 48, MODELS SHOW A POSSIBLE MERGER WITH INVEST 99P, CURRENTLY LOCATED TO THE EAST, FOLLOWED BY THE COMBINED SYSTEM TRACKING TO THE SOUTHEAST. 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. THIS SUPERSEDES REF A. 3. THIS ALERT WILL BE REISSUED, UPGRADED TO WARNING OR CANCELLED BY 022300Z. // NNNN