WTPN21 PHNC 160100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT (INVEST 90E) REISSUED//
REF/A/JOINT TYPHOON WRNCEN PEARL HARBOR HI/150100ZAUG2023//
AMPN/REF A IS A TROPICAL CYCLONE FORMATION ALERT.//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN 160 NM 
EITHER SIDE OF A LINE FROM 10.1N 98.1W TO 13.5N 107.1W 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 23 TO 30 KNOTS. METSAT IMAGERY AT 151800Z INDICATES THAT A 
CIRCULATION CENTER IS LOCATED NEAR 10.3N 98.8W. THE SYSTEM IS MOVING 
WEST-NORTHWESTWARD AT 11 KNOTS.
2. REMARKS: THE AREA OF CONVECTION (INVEST 90E) PREVIOUSLY LOCATED NEAR 
9.5N 94.5W IS NOW LOCATED NEAR 10.3N 98.8W, APPROXIMATELY 467NM SOUTH-
SOUTHEAST OF ZIHUATANEJO, MEXICO. ANIMATED MULTISPECTRAL SATELLITE 
IMAGERY (MSI) AND A 152225Z SSMIS 91GHZ MICROWAVE IMAGE SHOWS DEEP 
CONVECTION TO THE WEST, AND AN ELONGATED AREA OF CONVECTIVE BANDS TO THE 
SOUTHEAST, BOTH SLOWLY WRAPPING INTO A FULLY OBSCURED LOW LEVEL 
CIRCULATION CENTER (LLCC). ENVIRONMENTAL ANALYSIS REVEALS THAT 90E IS IN 
A RELATIVELY FAVORABLE ENVIRONMENT FOR DEVELOPMENT DUE TO LOW (10-15KT) 
VERTICAL WIND SHEAR, WARM (29-30C) SEA SURFACE TEMPERATURES, AND GOOD 
EQUATORWARD OUTFLOW. BOTH DETERMINISTIC AND ENSEMBLE MODELS ARE IN 
AGREEMENT THAT 90E WILL CONTINUE INTENSIFYING WHILE TRACKING  
NORTHWESTWARD. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 23 TO 30 
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 REMAINS HIGH. THIS SUPERSEDES REF A (WTPN21 PHNC 
150100).
3. THIS ALERT WILL BE REISSUED, UPGRADED TO WARNING OR CANCELLED BY 
170100Z.
//
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