WTXS21 PGTW 172100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
090 NM EITHER SIDE OF A LINE FROM 16.5S 40.3E TO 19.9S 39.9E
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 25 TO 30 KNOTS. METSAT
IMAGERY AND SYNOPTIC DATA AT 171800Z INDICATE THAT A CIRCULATION
CENTER IS LOCATED NEAR 16.7S 40.4E. THE SYSTEM IS MOVING SOUTH-
SOUTHEASTWARD AT 03 KNOTS.
2. REMARKS: THE AREA OF CONVECTION PREVIOUSLY LOCATED NEAR 16.4S
40.9E, IS NOW LOCATED NEAR 16.7S 40.4E, APPROXIMATELY 400 NM WEST-
NORTHWEST OF ANTANANARIVO, MADAGASCAR. RECENT ANIMATED INFRARED
SATELLITE IMAGERY SHOWS CONVECTION FLARING OVER A CONSOLIDATING LOW
LEVEL CIRCULATION CENTER (LLCC) EVIDENT IN A 171706Z SSMIS PASS.
THIS DISTURBANCE LIES NEAR AN UPPER-LEVEL RIDGE AXIS, IN AN AREA OF
LOW VERTICAL WIND SHEAR AND FAVORABLE OUTFLOW ALOFT. ALONG-TRACK SEA
SURFACE TEMPERATURES EXCEED 28 DEGREES CELSIUS, FAVORING FURTHER
DEVELOPMENT. MULTIPLE NUMERICAL MODELS INDICATE TROPICAL CYCLONE
FORMATION FROM THIS DISTURBANCE WITHIN THE NEXT ONE TO TWO DAYS.
MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 25 TO 30 KNOTS.
MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1001 MB. BASED ON
FAVORABLE ENVIRONMENTAL CONDITIONS AND MULTIPLE MODEL DEVELOPMENT,
THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE
WITHIN THE NEXT 24 HOURS IS HIGH.
- JTWC
