
WTXS21 PGTW 152000
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
125 NM EITHER SIDE OF A LINE FROM 17.1S 44.3E TO 22.6S 41.0E WITHIN
THE NEXT 06 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 AT 151900Z
INDICATES THAT A CIRCULATION CENTER IS LOCATED NEAR 18.1S 44.4E. THE
SYSTEM IS MOVING SOUTH-SOUTHWESTWARD AT 08 KNOTS.
2. REMARKS:
THE AREA OF CONVECTION PREVIOUSLY LOCATED NEAR 16.5S 43.8E IS NOW
LOCATED NEAR 17.8S 44.6E, APPROXIMATELY 160 NM WEST-NORTHWEST OF
ANTANANARIVO, MADAGASCAR. ANIMATED INFRARED SATELLITE IMAGERY SHOWS
THE SYSTEM HAS DRIFTED INLAND INTO THE WESTERN POINT OF MADAGASCAR
AND IS NOW LOOPING BACK AND EXPECTED TO EXIT INTO THE MOZAMBIQUE
CHANNEL OVER THE NEXT FEW HOURS. THE SYSTEM HAS MAINTAINED A
WELL-DEFINED LOW LEVEL CIRCULATION CENTER AND FORMATIVE BANDS. UPPER
LEVEL ANALYSIS INDICATES THE CYCLONE IS DIRECTLY UNDERNEATH A RIDGE
AXIS IN AN AREA OF LOW (05-10 KNOT) VERTICAL WIND SHEAR AND EXCELLENT
DUAL OUTFLOW - ONE CHANNEL NORTHWESTWARD AND ANOTHER TOWARDS THE
SOUTHEAST. ALL AVAILABLE NUMERIC MODELS PREDICT THE VORTEX TO TRACK
SOUTHWESTWARD INTO THE MOZAMBIQUE CHANNEL; HOWEVER, THEY SPREAD OUT
TOWARDS THE EXTENDED PORTION OF THE PREDICTIONS. MAXIMUM SUSTAINED
SURFACE WINDS ARE ESTIMATED AT 25 TO 30 KNOTS. MINIMUM SEA LEVEL
PRESSURE IS ESTIMATED TO BE NEAR 1004 MB. IN VIEW OF THE HIGHLY
FAVORABLE UPPER LEVEL ENVIRONMENT, IN ADDITION TO WARM SEA SURFACE
TEMPERATURES IN THE CHANNEL (28-30 CELSIUS), 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
162000Z. //
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