WTPN21 PGTW 181500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT (INVEST 98W)//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
100 NM EITHER SIDE OF A LINE FROM 24.3N 125.4E TO 29.0N 124.9E
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 15 TO 20 KNOTS. METSAT
IMAGERY AT 181500Z INDICATES THAT A CIRCULATION CENTER IS LOCATED
NEAR 24.7N 125.5E. THE SYSTEM IS MOVING NORTHWARD AT 02 KNOTS.
2. REMARKS: THE AREA OF CONVECTION (INVEST 98W) PREVIOUSLY LOCATED NEAR 
24.9N 126.2E IS NOW LOCATED NEAR 24.7N 125.5E, APPROXIMATELY 158 NM 
SOUTHWEST OF KADENA AB. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY AND 
A 181303Z ASCAT METOP-B 25KM IMAGE REVEAL A CONSOLIDATING CIRCULATION 
WITH FLARING CONVECTION ALONG THE SOUTHERN PERIPHERY AND STRONGER, NON-
WRAPPING GRADIENT WINDS OF UP TO 35 KNOTS PRESENT TO THE SOUTHEAST. 
ENVIRONMENTAL ANALYSIS IS MARGINALLY FAVORABLE, WITH LOW (05-10KTS) 
VERTICAL WIND SHEAR, MODERATE EQUATORWARD UPPER LEVEL OUTFLOW, AND HIGH 
(30-32C) SEA SURFACE TEMPERATURES. DETERMINISTIC AND ENSEMBLE  MODELS ARE 
IN GOOD AGREEMENT THAT INVEST 98W WILL CONTINUE TO TRANSIT NORTHWARD INTO 
THE EAST CHINA SEA AS IT DEVELOPS OVER THE NEXT 24 HOURS. MAXIMUM 
SUSTAINED SURFACE WINDS ARE ESTIMATED AT 15 TO 20 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 
191500Z.
//
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