WTPN21 PHNC 210700
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT (INVEST 91E)//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
160 NM EITHER SIDE OF A LINE FROM 8.4N 113.6W TO 8.6N 118.7W
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 210000Z INDICATES THAT A CIRCULATION CENTER IS LOCATED
NEAR 8.4N 114.0W. THE SYSTEM IS MOVING WESTWARD AT 10 KNOTS.
2. REMARKS: AN AREA OF CONVECTION (INVEST 91E) IS LOCATED NEAR 8.4N 
114.0W, APPROXIMATELY 1464NM SOUTH OF SAN DIEGO, CALIFORNIA. ANIMATED 
ENHANCED INFRARED IMAGERY DEPICTS A SLIGHTLY EXPOSED LOW-LEVEL 
CIRCULATION CENTER (LLCC) OBSCURED BY FLARING CONVECTION. 
ENVIRONMENTAL FACTORS FOR THIS SYSTEM ARE CONDUCIVE FOR DEVELOPMENT 
WITH LOW (10-15 KTS) VERTICAL WIND SHEAR, WARM (28-29 C) SEA SURFACE 
TEMPERATURES, AND MODERATE POLEWARD OUTFLOW ALOFT. GLOBAL 
DETERMINISTIC AND ENSEMBLE MODELS SHOW GRADUAL DEVELOPMENT OF 91E AS 
IT TRANSITS NORTHWESTWARD. MAXIMUM SUSTAINED SURFACE WINDS ARE 
ESTIMATED AT 18 TO 23 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED 
TO BE NEAR 1009 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 
220700Z.//
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