WTPN21 PGTW 230230
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT (INVEST 91W)//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
140 NM EITHER SIDE OF A LINE FROM 19.1N 126.4E TO 21.9N 125.4E
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 18 TO 23 KNOTS. METSAT
IMAGERY AT 230200Z INDICATES THAT A CIRCULATION CENTER IS LOCATED
NEAR 19.1N 126.4E. THE SYSTEM IS MOVING NORTHWESTWARD AT 06
KNOTS.
2. REMARKS: THE AREA OF CONVECTION (INVEST 91W) PREVIOUSLY LOCATED NEAR 
19.0N 126.9E IS NOW LOCATED NEAR 19.1N 126.4E, APPROXIMATELY 442 NM 
SOUTH OF KADENA AB, OKINAWA, JAPAN. ANIMATED MULTISPECTRAL SATELLITE 
IMAGERY AND A 222146Z SSMIS 91GHZ PASS DEPICT A CONSOLIDATING LLCC WITH 
DEEP CONVECTION BUILDING OVER THE CENTER AND FORMATIVE BANDING IN THE 
SOUTHWEST QUADRANT. ENVIRONMENTAL ANALYSIS INDICATES GENERALLY FAVORABLE 
CONDITIONS FOR DEVELOPMENT WITH WARM (29-30C) SST, LOW VERTICAL WIND 
SHEAR (5-10 KTS), AND GOOD OUTFLOW ALOFT. GLOBAL MODELS SHOW A STEADY 
NORTHWARD TRACK WITH GRADUAL DEVELOPMENT OVER THE NEXT 48 HOURS. 
MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 18 TO 23 KNOTS.
MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1005 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 
240230Z.//
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