WTPN21 PGTW 302130
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
075 NM EITHER SIDE OF A LINE FROM 17.4N 112.1E TO 21.5N 112.3E
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 301800Z INDICATES THAT A CIRCULATION CENTER IS LOCATED
NEAR 17.5N 112.1E. THE SYSTEM IS MOVING WEST-NORTHWESTWARD AT 02
KNOTS.
2. REMARKS:ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS A 
CONSOLIDATED LLCC WITH DEEP CONVECTION BUILDING OVER THE CENTER AND A 
301356Z PARTIAL METOP-B ASCAT IMAGE DEPICTING A SYMMETRICAL CIRCULATION. 
ANALYSIS OF THE ENVIRONMENT IS FAVORABLE DUE TO LOW VERTICAL WIND SHEAR 
(10-15KTS), WARM SEA SURFACE TEMPERATURES (29-30C), AND GOOD UPPER-LEVEL 
DIVERGENCE.  DEVELOPMENT FOR THIS SYSTEM IS  LIMITED BY THE PROXIMITY OF 
THE AREA OF CONVECTION TO MAINLAND CHINA, BUT THE AMERICAN MODEL SHOWS 
DEVELOPMENT OVER THE NEXT 24 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 
312130Z.
//
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