WTXS21 PGTW 291230
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT (INVEST 97S)//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
120 NM EITHER SIDE OF A LINE FROM 15.6S 41.7E TO 16.0S 45.3E
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 AT 291200Z INDICATES THAT A CIRCULATION CENTER IS LOCATED
NEAR 15.6S 42.3E. THE SYSTEM IS MOVING EASTWARD AT 02 KNOTS.
2. REMARKS: THE AREA OF CONVECTION (INVEST 97S) PREVIOUSLY LOCATED NEAR 
15.4S 42.9E IS NOW LOCATED NEAR 15.6S 42.3E, APPROXIMATELY 113 NM 
SOUTHEAST OF NACALA, MOZAMBIQUE. ANIMATED ENHANCED INFRARED SATELLITE 
IMAGERY (EIR) DEPICTS AN OBSCURED LOW LEVEL CIRCULATION CENTER WITH 
CONVECTIVE BANDING BEGINNING TO WRAP ALONG THE NORTHERN SEMICIRCLE. 
ENVIRONMENTAL ANALYSIS REVEALS A FAVORABLE ENVIRONMENT FOR DEVELOPMENT 
WITH STRONG EQUATORWARD UPPER-LEVEL OUTFLOW, LOW VERTICAL WIND SHEAR (10 
TO 15 KTS), AND WARM SEA SURFACE TEMPERATURES (28 TO 29 C). GLOBAL 
MODELS SHOW 97S TRACKING EASTWARD INTO THE WESTERN COAST OF MADAGASCAR 
OVER THE NEXT 24 TO 48 HOURS WITH QUICK DEVELOPMENT BEFORE MAKING 
LANDFALL. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 25 TO 30 
KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1003 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 
301230Z.//
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