WTPN21 PGTW 021500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT (INVEST 95W//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
180 NM EITHER SIDE OF A LINE FROM 21.0N 131.8E TO 30.0N 130.6E
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 20 TO 25 KNOTS. METSAT
IMAGERY AT 021430Z INDICATES THAT A CIRCULATION CENTER IS LOCATED
NEAR 21.8N 132.0E. THE SYSTEM IS MOVING NORTH-NORTHEASTWARD AT 13
KNOTS.
2. REMARKS: THE AREA OF CONVECTION (INVEST 95W) PREVIOUSLY LOCATED NEAR 
19.9N 131.8E IS NOW LOCATED NEAR 21.8N 132.0E, APPROXIMATELY 356 NM 
SOUTHEAST OF KADENA, JAPAN. ANIMATED MULTISPECTRAL SATELLITE IMAGERY 
(MSI) DEPICTS A BROAD AREA OF TROUGHING WITH PERSISTENT CONVECTION. A 
RECENT 021252Z ASCATC IMAGE SHOWS A BROAD CIRCULATION HAS FORMED BELOW 
THE PERSISTENT CONVECTION ADJACENT TO A SWATH OF 25-30 KNOT GRADIENT 
WINDS ENVIRONMENTAL ANALYSIS REVEALS A MARGINAL FAVORABLE ENVIRONMENT 
FOR DEVELOPMENT WITH LOW TO MODERATE VERTICAL WIND SHEAR (VWS) OF 15-20 
KNOTS, DUAL-CHANNEL UPPER-LEVEL OUTFLOW, AND WARM SEA SURFACE 
TEMPERATURES (SST) OF 29-30 C. DETERMINISTIC MODELS INDICATE A CLOSED 
CIRCULATION FORMING ADJACENT TO A SWATH OF 25-30 KNOT GRADIENT WINDS 
OVER THE NEXT 24-36 HOURS, WITH SLOW INTENSIFICATION AND A NORTHWARD 
TRACK TOWARD WESTERN JAPAN. THE GEFS AND ECENS ENSEMBLES ALSO SUPPORT A 
NORTHWARD TRACK TOWARD KYUSHU OVER THE NEXT TWO DAYS. MAXIMUM SUSTAINED 
SURFACE WINDS ARE ESTIMATED AT 20 TO 25 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 
031500Z.//
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