WTXS21 PGTW 171800
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT (INVEST 94S)//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN 150 NM 
EITHER SIDE OF A LINE FROM 6.9S 75.9E TO 9.5S 68.8E 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 171730Z INDICATES THAT A 
CIRCULATION CENTER IS LOCATED NEAR 7.0S 75.4E. THE SYSTEM IS MOVING 
WEST-SOUTHWESTWARD AT 12 KNOTS.
2. REMARKS: THE AREA OF CONVECTION (INVEST 94S) PREVIOUSLY LOCATED NEAR 
7.0S 77.0E IS NOW LOCATED NEAR 7.0S 75.4E, APPROXIMATELY 175 NM EAST OF 
DIEGO GARCIA. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY AND A 171241Z 
WSFM 37GHZ COLOR COMPOSITE MICROWAVE IMAGE DEPICT A CONSOLIDATING LOW-
LEVEL CIRCULATION CENTER (LLCC) WITH IMPROVED FRAGMENTED CONVECTIVE 
BANDING. A 171632Z ASCAT-B IMAGE SHOWS AN ELONGATED CIRCULATION WITH 25-
30 KT WINDS OVER THE NORTHEASTERN QUADRANT, AND PATCHY 35 KT WINDS 
DISPLACED 100 NM TO THE SOUTH. UPPER-LEVEL ANALYSIS INDICATES A 
FAVORABLE ENVIRONMENT, CHARACTERIZED BY ENHANCED POLEWARD OUTFLOW INTO 
THE WESTERLIES TO THE SOUTH AND IMPROVING EQUATORWARD OUTFLOW, WARM (27-
28 C) SEA SURFACE TEMPERATURES, LOW (10-15 KTS) VERTICAL WIND SHEAR. 
GLOBAL DETERMINISTIC MODELS ARE IN GOOD AGREEMENT THAT 94S WILL CONTINUE 
TO CONSOLIDATE AND INTENSIFY OVER THE NEXT 24-48 HOURS WITH A GENERALLY 
WEST-SOUTHWESTWARD TRACK. THE SYSTEM IS EXPECTED TO TRACK SOUTH OF DIEGO 
GARCIA BUT COULD PRODUCE 25-30 KT SUSTAINED WESTERLIES DURING THE 
180000Z-190000Z TIMEFRAME. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED 
AT 25 TO 30 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 
1005 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 
181800Z.//
NNNN