WTPN21 PHNC 290830
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT (INVEST 99E)//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
080 NM EITHER SIDE OF A LINE FROM 13.7N 119.9W TO 13.4N 126.6W
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 25 TO 30 KNOTS. METSAT
IMAGERY AT 290800Z INDICATES THAT A CIRCULATION CENTER IS LOCATED
NEAR 13.8N 121.5W. THE SYSTEM IS MOVING WEST-NORTHWESTWARD AT 07
KNOTS.
2. REMARKS:
ANIMATED ENHANCED INFRARED SATELLITE IMAGERY SHOWS AN EXPOSED
LOW-LEVEL CENTER (LLC) LOCATED TO THE WEST OF AN AREA OF DEEP
CONVECTION. ENVIRONMENTAL CONDITIONS ARE MARGINALLY FAVORABLE
FOR DEVELOPMENT, WITH NORTHWESTERLY FLOW ALOFT IMPARTING 15-20
KTS OF VERTICAL SHEAR, AND A DRY AIR MASS LOCATED WEST OF AND
OVER THE LLC. HOWEVER, THE CURRENTLY WELL-DEFINED CIRCULATION
AND NEARBY DEEP CONVECTION INDICATE THAT FORMATION OF A TROPICAL
CYCLONE IS POSSIBLE OVER THE NEXT DAY OR TWO. MAXIMUM SUSTAINED 
SURFACE WINDS ARE ESTIMATED AT 25 TO 30 KNOTS. MINIMUM SEA LEVEL 
PRESSURE IS ESTIMATED TO BE NEAR 1000 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 
300830Z.
//
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