Madagascar

Madagascar: Tropical cyclone formation alert WTPS21

WTPS21 PGTW 092030

MSGID/GENADMIN/NAVPACMETOCCEN PEARL HARBOR HI/JTWC// SUBJ/TROPICAL CYCLONE FORMATION ALERT/092021ZFEB2006// RMKS/

1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN 120 NM EITHER SIDE OF A LINE FROM 15.9S 172.0W TO 18.9S 169.5W 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 30 TO 35 KNOTS. METSAT IM=AD AGERY AT 091730Z INDICATES THAT A CIRCULATION CENTER IS LOCATED NEAR 16.2S 171.6W. THE SYSTEM IS MOVING SOUTHEASTWARD AT 05 KNOTS.

2. REMARKS: AN AREA OF CONVECTION NEAR 16.2S 171.6W, APPROXIMATELY 120 NM SOUTH-SOUTHWEST OF PAGO PAGO, AMERICAN SAMOA HAS PERSISTED OVER THE PAST 12 HOURS. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY REVEALS INCREASING DEEP CONVECTION IN THE VICINITY OF A WELL DEFINED LOW LEVEL CIRCULATION CENTER (LLCC). THE SYSTEM IS LOCATED IN AN AREA OF EXCELLENT UPPER LEVEL DIFFLUENCE IN THE POLEWARD AND EQUAT- ORWARD DIRECTIONS. VERTICAL WIND SHEAR IS LOW TO MODERATE AND SEA SURFACE TEMPERATURES ARE MORE THAN ADEQUATE FOR DEVELOPMENT. MAX- IMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 30 TO 35 KNOTS. MIN- IMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE 1001 MB. DUE TO EXCELLENT UPPER LEVEL DIVERGENCE AND INCREASING CONVECTION, THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS IS GOOD.

3. THIS ALERT WILL BE REISSUED, UPGRADED TO WARNING OR CANCELLED BY 102030Z.//