WTIO21 PGTW 180900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT (INVEST 99B)//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN 120 NM EITHER SIDE OF 
A LINE FROM 19.5N 92.3E TO 21.5N 88.0E 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 180600Z INDICATES THAT A 
CIRCULATION CENTER IS LOCATED NEAR 19.5N 92.2E. THE SYSTEM IS MOVING WEST-NORTHWESTWARD 
AT 12 KNOTS.
2. REMARKS: THE AREA OF CONVECTION (INVEST 99B) PREVIOUSLY LOCATED NEAR 18.9N 93.4E IS 
NOW LOCATED NEAR 19.5N 92.2E, APPROXIMATELY 169 NM SOUTH OF CHITTAGONG, BANGLADESH. 
ENHANCED INFRARED SATELLITE IMAGERY DEPICTS AN EXPOSED, TIGHTLY WRAPPED LOW LEVEL 
CIRCULATION CENTER WITH DEEP CONVECTIVE BANDING ALONG THE WESTERN PERIPHERY WRAPPING 
INTO THE SOUTHEASTERN PERIPHERY. A 180359Z ASCAT-B BULLSEYE PASS REVEALS WIND SPEEDS OF 
UP TO 35KTS IN SOUTHERN PERIPHERY.  ENVIRONMENTAL ANALYSIS INDICATES FAVORABLE 
CONDITIONS FOR DEVELOPMENT CHARACTERIZED BY ROBUST WESTWARD UPPER LEVEL OUTFLOW IN 
ASSOCIATION WITH THE TEJ, A SMALL POCKET OF LOW TO MODERATE (10-20 KTS) VERTICAL WIND 
SHEAR (VWS) AND WARM (29-30C) SEA SURFACE TEMPERATURES. NUMERICAL MODEL GUIDANCE 
INDICATES THAT INVEST 99B WILL TRACK WEST-NORTHWESTWARD TOWARD KOLKATA AND MAKE 
LANDFALL WITHIN THE NEXT 36-48 HOURS. INVEST 99B IS EXPECTED TO PEAK IN INTENSITY 
WITHIN THE NEXT 24-36 HOURS JUST BEFORE MAKING LANDFALL. INVEST 99B IS EXPECTED TO 
TRACK INTO AN AREA OF LOWER VWS ALLOWING THE SYSTEM TO FURTHER INTENSIFY. MAXIMUM 
SUSTAINED SURFACE WINDS ARE ESTIMATED AT 28 TO 33 KNOTS. MINIMUM SEA LEVEL PRESSURE IS 
ESTIMATED TO BE NEAR 994 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 
190900Z.//
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