WTXS21 PGTW 172230
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT (INVEST 90S)//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
140 NM EITHER SIDE OF A LINE FROM 18.6S 119.8E TO 21.2S 113.4E
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 25 TO 30 KNOTS. METSAT
IMAGERY AT 172230Z INDICATES THAT A CIRCULATION CENTER IS LOCATED
NEAR 19.2S 119.9E. THE SYSTEM IS MOVING SOUTHWESTWARD AT 09
KNOTS.
2. REMARKS: THE AREA OF CONVECTION (INVEST 90S) PREVIOUSLY LOCATED 19.2S 
119.5E IS NOW LOCATED 19.2S 119.9E, APPROXIMATELY 371 NM EAST-NORTHEAST 
OF LEARMONTH. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY AND AN 171916Z 
SSMIS F18 91GHZ MICROWAVE SATELLITE IMAGE DEPICT CURVED CLOUD BANDS FROM 
THE NORTH-NORTHWEST WRAPPING INTO A QUICKLY CONSOLIDATING LLCC JUST OFF 
THE COAST OF AUSTRALIA, WITH CONVECTION BUILDING OVER THE CENTER AND JUST 
NORTH OF THE SYSTEM. ENVIRONMENTAL ANALYSIS INDICATES INVEST 90S IS IN A 
CONDUCIVE ENVIRONMENT FOR FURTHER DEVELOPMENT DUE TO VERY WARM (30-32C) 
SEA SURFACE TEMPERATURES, LOW (5-10 KNOTS) VERTICAL WIND SHEAR, AND 
MODERATE POLEWARD OUTFLOW ALOFT. GLOBAL DETERMINISTIC AND ENSEMBLE MODELS 
ARE IN GOOD AGREEMENT THAT 90S WILL CONTINUE TO CONSOLIDATE OVER THE NEXT 
24 HOURS AND TRACK TO THE SOUTHWEST. MAXIMUM SUSTAINED SURFACE WINDS ARE 
ESTIMATED AT 25 TO 30 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 HIGH.
3. THIS ALERT WILL BE REISSUED, UPGRADED TO WARNING OR CANCELLED BY 
182230Z.//
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