WTPS21 PGTW 192030
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
140 NM EITHER SIDE OF A LINE FROM 13.4S 155.9E TO 15.8S 152.9E
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 27 TO 33 KNOTS. METSAT
IMAGERY AT 191800Z INDICATES THAT A CIRCULATION CENTER IS LOCATED
NEAR 13.8S 155.5E. THE SYSTEM IS MOVING WESTWARD AT 03 KNOTS.
2. REMARKS:
THE AREA OF CONVECTION (INVEST 90P) PREVIOUSLY LOCATED NEAR 14.2S 
157.0E IS NOW LOCATED NEAR 13.8S 155.5E, APPROXIMATELY 355 NM EAST-
NORTHEAST OF WILLIS ISLAND. ANIMATED EIR IMAGERY AND A 191731Z SSMIS 
91GHZ DEPICT A FORMATIVE SPIRAL BANDING WRAPPING INTO A WELL DEFINED 
LLCC. UPPER-LEVEL ANALYSIS REVEALS A MARGINALLY FAVORABLE ENVIRONMET, 
WITH WEAK POLEWARD DIVERGENCE ALOFT, WARM SSTS (30 C), OFFSET BY HIGH 
VWS (20-30 KT). GLOBAL MODELS ARE IN GOOD AGREEMENT THAT 90P WILL 
CONTINUE TRACKING SOUTHWESTWARD AND FURTHER DEVELOP OVER THE NEXT 24-
36 HOURS. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 27 TO 33 
KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 997 MB. THE 
POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN 
THE NEXT 24 HOURS IS UPGRADED TO HIGH.
3. THIS ALERT WILL BE REISSUED, UPGRADED TO WARNING OR CANCELLED BY 
202030Z.
//
NNNN