WTPS21 PGTW 270230
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT (INVEST 90P)//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
165 NM EITHER SIDE OF A LINE FROM 13.9S 168.6E TO 17.9S 172.7E
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 23 TO 28 KNOTS. METSAT
IMAGERY AT 270000Z INDICATES THAT A CIRCULATION CENTER IS LOCATED
NEAR 14.0S 168.8E. THE SYSTEM IS MOVING SOUTHEASTWARD AT 08
KNOTS.
2. REMARKS: THE AREA OF CONVECTION (INVEST 90P) PREVIOUSLY LOCATED NEAR 
14.0S 168.3E IS NOW LOCATED NEAR 13.4S 168.8E, APPROXIMATELY 225 NM 
NORTH OF PORT VILA, VANUATU. ANIMATED MULTISPECTRAL VISUAL IMAGERY (MSI) 
AS WELL AS A 262145Z METOP-C MHS 89V MICROWAVE IMAGERY DEPICT INVEST 90P 
COALESCING AROUND A LOW LEVEL CIRCULATION CENTER (LLCC). OVERSHOOTING 
TOPS ARE OBSERVED IN THE CURVED FORMATIVE BANDING ON THE NORTHEAST 
PERIMETER, AND CONVECTION IS DEEPENING NEAR THE LLCC. A 262149Z ASCAT 
PASS DEPICTS A FAIRLY SYMMETRICAL CIRCULATION WITH 15-20KT WINDS 
PRIMARILY RELEGATED TO THE SOUTHERN PORTION OF THE CIRCULATION.  THE 
SYSTEM LIES UNDER A BELT OF LOW VERTICAL WINDSHEAR (5-10KTS) WITH DECENT 
OUTFLOW TO THE SOUTHEAST. GLOBAL DETERMINISTIC MODEL GUIDANCE IS 
UNANIMOUS ON A SOUTHEASTWARD TRACK AND STEADY DEVELOPMENT OVER THE NEXT 
24-36 HOURS. THE SYSTEM IS BENEFITTING FROM GRADIENT LEVEL VORTICITY 
SUPPLIED BY EQUATORIAL WESTERLIES ASSOCIATED WITH A MADDEN JULIAN 
OSCILLATION PULSE THAT IS MOVING TOWARDS THE DATELINE. MAXIMUM 
SUSTAINED SURFACE WINDS ARE ESTIMATED AT 23 TO 28 KNOTS. MINIMUM SEA 
LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1001 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 
280230Z.
//
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