WTXS21 PGTW 151800
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT (INVEST 90S)//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
145 NM EITHER SIDE OF A LINE FROM 4.2S 74.1E TO 6.9S 70.1E 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
151700Z INDICATES THAT A CIRCULATION CENTER IS LOCATED NEAR 5.2S
73.9E. THE SYSTEM IS MOVING SOUTHWARD AT 07 KNOTS.
2. REMARKS: THE AREA OF CONVECTION (INVEST 90S) PREVIOUSLY LOCATED NEAR 4.0S 74.5E IS NOW LOCATED NEAR 5.2S 73.9E, APPROXIMATELY 155 NM NORTH-NORTHEAST OF DIEGO GARCIA. ENHANCED INFRARED SATELLITE IMAGERY AND 151132Z SSMIS 91GHZ SATELLITE IMAGERY DEPICTS AN AREA OF FLARING CONVECTION, WITH A PARTIALLY EXPOSED LOW LEVEL CIRCULATION WITH PERSISTENT CONVECTION. ENVIRONMENTAL ANALYSIS REVEALS AN AREA THAT IS MARGINALLY FAVORABLE FOR DEVELOPMENT WITH, WARM (28-29C) SEA SURFACE TEMPERATURES, HIGH (30-40 KTS) VERTICAL WIND SHEAR, AND GOOD EQUATORWARD OUTFLOW ALOFT. GLOBAL MODELS ARE IN GOOD AGREEMENT THAT INVEST 90S WILL CONTINUE TO GRADUALLY INTENSIFY AND GENERALLY TRACK SOUTHWESTWARD OVER THE NEXT 24-48 HOURS. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 28 TO 33 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1004 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
161800Z.//
NNNN