WTPN21 PGTW 062230
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 18.2N 149.0E TO 18.9N 146.2E
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 061800Z INDICATES THAT A CIRCULATION CENTER IS LOCATED
NEAR 18.4N 148.1E. THE SYSTEM IS MOVING WEST-NORTHWESTWARD AT 03
KNOTS.
2. REMARKS: THE AREA OF CONVECTION (INVEST 98W) PREVIOUSLY LOCATED NEAR 
18.3N 148.4E, IS NOW LOCATED NEAR 18.4N 148.1E, APPROXIMATELY 236 NM 
NORTHEAST OF SAIPAN. ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) 
DEPICTS PERSISTENT CENTRALIZED CONVECTION OVER A COMPACT LOW-LEVEL 
CIRCULATION CENTER (LLCC). ENVIRONMENTAL ANALYSIS REVEALS FAVORABLE 
CONDITIONS WITH LOW VERTICAL WIND SHEAR (5-10 KNOTS), GOOD OUTFLOW 
ALOFT, AND WARM SEA SURFACE TEMPERATURES (29-30 C). DETERMINISTIC AND 
ENSEMBLE MODELS SHOW 98W CONTINUING TO TRACK GENERALLY WESTWARD AND 
DEVELOPING 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 1006 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 
072230Z.
//
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