WTPN21 PGTW 291700
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT (INVEST 93W)//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
120 NM EITHER SIDE OF A LINE FROM 15.9N 153.1E TO 16.0N 147.9E
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 18 TO 23 KNOTS. METSAT
IMAGERY AT 291600Z INDICATES THAT A CIRCULATION CENTER IS LOCATED
NEAR 15.9N 152.8E. THE SYSTEM IS MOVING WEST-NORTHWESTWARD AT 14
KNOTS.
2. REMARKS: THE AREA OF CONVECTION PREVIOUSLY LOCATED NEAR 15.4N 155.0E 
IS NOW LOCATED NEAR 15.9N 152.8E, APPROXIMATELY 494 NM EAST-NORTHEAST OF 
GUAM. ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS A 
MOSTLY OBSCURED LOW LEVEL CIRCULATION CENTER WITH DEEP FLARING 
CONVECTION ALONG THE WESTERN PERIPHERY. ENVIRONMENTAL ANALYSIS REVEALS A 
FAVORABLE ENVIRONMENT FOR DEVELOPMENT WITH STRONG POLEWARD UPPER-LEVEL 
OUTFLOW, LOW VERTICAL WIND SHEAR (10-15 KTS), AND WARM SEA SURFACE 
TEMPERATURES (29-30 C). GLOBAL DETERMINISTIC MODELS GENERALLY AGREE ON 
93W CONTINUING TO CONSOLIDATE AS IT TRACKS WESTWARD. OUT OF THE ENSEMBLE 
MODELS, ECENS IS THE MOST AGGRESSIVE REGARDING NEAR-TERM DEVELOPMENT. 
MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 18 TO 23 KNOTS.
MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1007 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 
301700Z.//
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