WTPN21 PHNC 071900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT//
REF/A/JOINT TYPHOON WRNCEN PEARL HARBOR HI/071900Z OCT 24//
AMPN/REF IS TROPICAL CYCLONE FORMATION ALERT (WTPN21 PGTW 071900)//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
120 NM EITHER SIDE OF A LINE FROM 17.2N 105.1W TO 20.9N 108.4W
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 28 TO 33 KNOTS. METSAT
IMAGERY AT 071900Z INDICATES THAT A CIRCULATION CENTER IS LOCATED
NEAR 17.3N 105.2W. THE SYSTEM IS MOVING WEST-NORTHWESTWARD AT 06
KNOTS.
2. REMARKS:
AN AREA OF CONVECTION (INVEST 99E) IS LOCATED NEAR 16.9N 
103.7W, APPROXIMATELY 110NM SOUTHEAST OF MANZANILLO, MEXICO. 
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS DEEP CONVECTION 
BUILDING NEAR THE LOW LEVEL CIRCULATION CENTER (LLCC. ENVIRONMENTAL 
ANALYSIS INDICATES THAT 99E IS IN AN OVERALL FAVORABLE AREA FOR 
DEVELOPMENT WITH WARM (28-29C) SEA SURFACE TEMPERATURES, GOOD OUTFLOW 
ALOFT, AND LOW TO MODERATE (15-20 KNOTS) VERTICAL WIND SHEAR. 
DETERMINISTIC MODELS ARE IN AGREEMENT THAT 99E WILL CONTINUE TO TRACK 
NORTH-NORTHWESTWARD AND INTENSIFY OVER THE NEXT 24-36 HOURS. MAXIMUM 
SUSTAINED SURFACE WINDS ARE ESTIMATED AT 23 TO 28 KNOTS. MINIMUM SEA 
LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1001 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 
081900Z.
//
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