WTXS21 PGTW 062200
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT (INVEST 91S)//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
170 NM EITHER SIDE OF A LINE FROM 7.3S 62.9E TO 6.8S 57.2E 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
062200Z INDICATES THAT A CIRCULATION CENTER IS LOCATED NEAR 7.3S
62.5E. THE SYSTEM IS MOVING WESTWARD AT 05 KNOTS.
2. REMARKS: THE AREA OF CONVECTION (INVEST 91S) PREVIOUSLY LOCATED NEAR 
6.2S 62.1E IS NOW LOCATED NEAR 7.3S 62.5E, APPROXIMATELY 595 NM WEST OF 
DIEGO GARCIA. ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS 
PERSISTENT DEEP CONVECTION OVER AN OBSCURED LOW-LEVEL CIRCULATION 
CENTER (LLCC). A 061709Z METOP-C ASCAT IMAGE SHOWS AN ASYMMETRIC WIND 
FIELD WITH STRONGER (30-35 KTS) WINDS WITHIN THE SOUTHERN SEMICIRCLE. 
ENVIRONMENTAL ANALYSIS REVEALS FAVORABLE CONDITIONS WITH LOW TO 
MODERATE EASTERLY VERTICAL WIND SHEAR (15-20 KNOTS), STRONG POLEWARD 
OUTFLOW ALOFT, AND WARM SEA SURFACE TEMPERATURES (28-29 C). GLOBAL 
MODELS ARE IN GOOD AGREEMENT THAT INVEST 91S WILL CONTINUE TO TRACK 
GENERALLY WESTWARD OVER THE NEXT 24 HOURS AND CONTINUE TO DEVELOP.
MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 28 TO 33 KNOTS.
MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1004 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 
072200Z.
//
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