WTPN21 PGTW 060030
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
095 NM EITHER SIDE OF A LINE FROM 15.6N 112.6E TO 17.9N 110.5E
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 051800Z INDICATES THAT A CIRCULATION CENTER IS LOCATED
NEAR 15.6N 112.5E. THE SYSTEM IS MOVING WEST-NORTHWESTWARD AT 05
KNOTS.
2. REMARKS: THE AREA OF CONVECTION (INVEST 97W) PREVIOUSLY LOCATED 
NEAR 15.4N 113.0E IS NOW LOCATED NEAR 15.6N 112.5E, APPROXIMATELY 
298NM SOUTH-SOUTHEAST OF HAINAN. ANIMATED MULTISPECTRAL SATELLITE 
IMAGERY AND A 052108Z SSMI 85GHZ MICROWAVE IMAGE DEPICTS A BROAD LOW 
LEVEL CIRCULATION (LLC) WITH FLARING CONVECTION SHEARED ALONG THE 
WESTERN SEMICIRCLE OF THE LLC. UPPER-LEVEL ANALYSIS REVEALS A 
FAVORABLE ENVIRONMENT FOR DEVELOPMENT WITH LOW TO MODERATE VERTICAL 
WIND SHEAR (VWS), GOOD POLEWARD OUTFLOW, AND WARM SEA SURFACE 
TEMPERATURES (30-31C). GLOBAL DYNAMIC MODELS ARE IN GOOD AGREEMENT 
THAT 97W WILL CONTINUE TO TRACK ALONG THE PERIPHERY OF A SUBTROPICAL 
RIDGE SITUATED TO THE NORTHEAST AS IT CONSOLIDATES AND TRACKS 
TOWARDS HAINAN. 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 
070030Z.//
NNNN