WTPN21 PGTW 051500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT (INVEST 97W)//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
160 NM EITHER SIDE OF A LINE FROM 26.2N 158.4E TO 35.0N 156.6E
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 051200Z INDICATES THAT A CIRCULATION CENTER IS LOCATED
NEAR 26.7N 158.7E. THE SYSTEM IS MOVING WEST-NORTHWESTWARD AT 11
KNOTS.
2. REMARKS: THE AREA OF CONVECTION (INVEST 97W) PREVIOUSLY LOCATED 
NEAR 26.2N 159.8E IS NOW LOCATED NEAR 26.7N 158.7E, APPROXIMATELY 625 
NM NORTHWEST OF WAKE. ENHANCED INFRARED SATELLITE (EIR) IMAGERY 
DEPICTS A DISORGANIZED LOW-LEVEL CIRCULATION CENTER BEING SHEERED 
LIGHTLY FROM THE PRIMARY CONVECTION TO THE NORTHEAST. A 051051Z ASCAT-
C PASS INDICATES A SYMMETRIC, DEFINED CIRCULATION WITH 20-25 KNOT 
WINDS ON THE SOUTHERN MOST PERIPHERY OF THE LOW-LEVEL CIRCULATION 
CENTER (LLCC). ENVIRONMENTAL ANALYSIS REVEALS FAVORABLE CONDITIONS 
THAT IS CHARACTERIZED BY MODERATE VERTICAL WIND SHEAR (15-20 KNOTS), 
GOOD EQUATORWARD OUTFLOW ALOFT, AND WARM SEA SURFACE TEMPERATURE (28-
29C). GLOBAL MODELS ARE AGREEING THAT INVEST 97W WILL CONTINUE TO 
DEVELOP OVER THE NEXT 24 HOURS, BUT ARE NOT IN AGREEMENT WITH THE 
OVERALL TRACK, WITH THE GFS AND ECENS ENSEMBLE MODELS AGREEING WITH A 
NORTHWESTWARD TRACK. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 
18 TO 23 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 
1005 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 
061500Z.//
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