WTXS21 PGTW 200730
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT (INVEST 98S)//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
120 NM EITHER SIDE OF A LINE FROM 25.1S 37.8E TO 23.5S 46.5E
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 200700Z INDICATES THAT A CIRCULATION CENTER IS LOCATED
NEAR 25.0S 37.9E. THE SYSTEM IS MOVING NORTHEASTWARD AT 11 KNOTS.
2. REMARKS: THE AREA OF CONVECTION (INVEST 98S) PREVIOUSLY LOCATED NEAR 
26.0S 37.2E IS NOW LOCATED NEAR 25.0S 37.9E, APPROXIMATELY 334 NM WEST-
SOUTHWEST OF TOLIARA, MADAGASCAR. ANIMATED MULTISPECTRAL SATELLITE 
IMAGERY (MSI) REVEALS A COMPACT LOW LEVEL CIRCULATION CENTER (LLCC) WITH 
FLARING CONVECTION OVER THE SOUTHERN SEMICIRCLE. ENVIRONMENTAL ANALYSIS 
DEPICTS A FAVORABLE ENVIRONMENT FOR DEVELOPMENT WITH STRONG POLEWARD AND 
EQUATORWARD UPPER-LEVEL OUTFLOW, LOW TO MODERATE VERTICAL WIND SHEAR (15 
TO 20 KTS), AND WARM SEA SURFACE TEMPERATURES (27 TO 28 C). GLOBAL 
MODELS AGREE ON 98S TRACKING EASTWARD INTO SOUTHERN MADAGASCAR AS IT 
QUICKLY CONSOLIDATES OVER THE NEXT 24 HOURS. MAXIMUM SUSTAINED SURFACE 
WINDS ARE ESTIMATED AT 28 TO 33 KNOTS. MINIMUM SEA LEVEL PRESSURE IS 
ESTIMATED TO BE NEAR 999 MB. THE POTENTIAL FOR THE DEVELOPMENT OF A 
SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS IS HIGH.
MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 28 TO 33 KNOTS.
MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 998 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 
210730Z.//
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