WTPS21 PGTW 162230
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT (INVEST 91P)//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
A 210 NM RADIUS OF 14.8S 146.4E 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 28 TO 33 KNOTS. METSAT IMAGERY AT 161800Z INDICATES THAT A
CIRCULATION CENTER IS LOCATED NEAR 14.8S 146.4E. THE SYSTEM IS
MOVING SOUTH-SOUTHWESTWARD AT 02 KNOTS.
2. REMARKS: THE AREA OF CONVECTION (INVEST 91P) PREVIOUSLY LOCATED 
NEAR 14.4S 146.3E IS NOW LOCATED NEAR 14.8S 146.4E, APPROXIMATELY 
133 NM NORTH-NORTHEAST OF CAIRNS, AUSTRALIA. ANIMATED MULTISPECTRAL 
SATELLITE IMAGERY AND A 162042Z SSMIS 91GHZ MICROWAVE IMAGE REVEALS 
CONVECTIVE BANDING WRAPPING INTO A WELL DEFINED, SMALL LOW LEVEL 
CIRCULATION CENTER (LLCC) WITH FLARING CONVECTION IN THE WESTERN 
PERIPHERY. A 161531Z AMSR2 WIND SPEED ESTIMATE REVEALS WINDS OF 28-
33 KNOTS ASSOCIATED WITH THE LLCC. INVEST 91P IS IN A FAVORABLE 
ENVIRONMENT FOR TROPICAL DEVELOPMENT WITH GOOD SOUTHEASTWARD OUTFLOW 
ALOFT, WEAK (5-10KT) VERTICAL WIND SHEAR, AND WARM (29-30C) SEA 
SURFACE TEMPERATURES. GLOBAL MODELS SHOW LITTLE TO NO TROPICAL 
DEVELOPMENT. HOWEVER, HISTORICALLY THE MODELS DO NOT HANDLE SYSTEMS 
OF THIS SIZE WELL, THEREFORE CONFIDENCE IS MODEL GUIDANCE CURRENTLY 
LOW. 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.
3. THIS ALERT WILL BE REISSUED, UPGRADED TO WARNING OR CANCELLED BY 
172230Z.//
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