WTPN21 PHNC 191300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT (INVEST 90E)//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
160 NM EITHER SIDE OF A LINE FROM 9.3N 136.4W TO 11.7N 144.1W
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 27 TO 32 KNOTS. METSAT
IMAGERY AT 191200Z INDICATES THAT A CIRCULATION CENTER IS LOCATED
NEAR 9.4N 136.9W. THE SYSTEM IS MOVING WESTWARD AT 09 KNOTS.
2. REMARKS: AN AREA OF CONVECTION (INVEST 90E) IS LOCATED NEAR 9.4N 
136.9W, APPROXIMATELY 1217 EAST SOUTHEAST OF HILO, HAWAII. ANIMATED 
ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS AN ELONGATED LOW-
LEVEL CIRCULATION (LLC) OBSCURED BY FLARING CONVECTION. ENVIRONMENTAL 
ANALYSIS REVEALS FAVORABLE CONDITIONS FOR DEVELOPMENT WITH LOW 
VERTICAL WIND SHEAR (10 TO 15 KTS), WARM SEA SURFACE TEMPERATURES (28 
TO 29C), AND POLEWARD OUTFLOW ALOFT. GLOBAL MODELS ARE ALL IN 
AGREEMENT THAT 90E WILL CONTINUE TO DEVELOP OVER THE NEXT 48 HOUR 
PERIOD AND FOR IT TO TAKE A GENERALLY WEST-NORTHWESTWARD TRACK. 
ENSEMBLE MODELS ALSO SHOW THE QUICK DEVELOPMENT AND SIMILAR TRACK AS 
THE DETERMINISTIC MODELS OVER THE NEXT 24 TO 48 HOURS.
MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 27 TO 32 KNOTS.
MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 999 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 
201300Z.//
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