WTPN21 PGTW 182000
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT (INVEST 97W)//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
095 NM EITHER SIDE OF A LINE FROM 5.4N 148.7E TO 7.4N 148.0E
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 18 TO 22 KNOTS. METSAT
IMAGERY AT 181800Z INDICATES THAT A CIRCULATION CENTER IS LOCATED
NEAR 5.4N 148.6E. THE SYSTEM IS MOVING WESTWARD AT 05 KNOTS.
2. REMARKS: THE AREA OF CONVECTION (INVEST 97W) PREVIOUSLY LOCATED 
NEAR 5.4N 149.5E IS NOW LOCATED NEAR 5.4N 148.6E, APPROXIMATELY 531 NM 
SOUTH-SOUTHEAST OF GUAM, USA. ANIMATED ENHANCED INFRARED SATELLITE 
IMAGERY DEPICTS A VERY BROAD CIRCULATION WITH SEVERAL AREAS OF 
ENHANCED SURFACE VORTICITY WITH NO WELL-DEFINED DOMINANT LOW-LEVEL 
CIRCULATION CENTER (LLCC) AT THIS TIME. DEEP FLARING CONVECTION IS 
WRAPPING AROUND THE BROAD CIRCULATION AS IT GRADUALLY BECOMES BETTER 
ORGANIZED. ENVIRONMENTAL ANALYSIS INDICATES A FAVORABLE ENVIRONMENT 
WITH WARM SEA SURFACE TEMPERATURES (30-31C), LOW VWS (10-15KTS) AND 
MODERATE POLEWARD OUTFLOW ALOFT. GLOBAL MODELS ARE IN GOOD AGREEMENT 
THAT 97W WILL TRACK NORTH-NORTHWESTWARD AS IT DEVELOPS AND INTENSIFIES 
OVER THE NEXT 12-36 HOURS. THERE IS SIGNIFICANT UNCERTAINTY ASSOCIATED 
WITH WHERE THE PRIMARY LLCC WILL EVENTUALLY DEVELOP. HOWEVER, ONCE THE 
LLCC IS ESTABLISHED, IT IS LIKELY THAT THE SYSTEM WILL BECOME A 
RAPIDLY INTENSIFYING TROPICAL CYCLONE.  ANY SUBSEQUENT WARNING AND 
ASSOCIATED TRACK FORECAST WILL BE HIGHLY CONTINGENT UPON THE LOCATION 
OF THE LLCC ONCE IT BECOMES ESTABLISHED. MAXIMUM SUSTAINED SURFACE 
WINDS ARE ESTIMATED AT 18 TO 22 KNOTS.MINIMUM SEA LEVEL PRESSURE IS 
ESTIMATED TO BE NEAR 1006 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 
192000Z.
//
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