WTIO21 PGTW 221800 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/TROPICAL CYCLONE FORMATION ALERT (INVEST 92B)// RMKS/ 1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN 130 NM EITHER SIDE OF A LINE FROM 15.9N 86.8E TO 19.5N 88.7E 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 221730Z INDICATES THAT A CIRCULATION CENTER IS LOCATED NEAR 16.1N 86.9E. THE SYSTEM IS MOVING NORTH-NORTHEASTWARD AT 04 KNOTS. 2. REMARKS: THE AREA OF CONVECTION (INVEST 92B) PREVIOUSLY LOCATED NEAR 14.1N 87.3E IS NOW LOCATED NEAR 16.1N 86.9E, APPROXIMATELY 393 NM SOUTH OF KOLKATA, INDIA. ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS PERSISTENT DEEP CONVECTION OVER THE NORTHERN SEMICIRCLE WRAPPING INTO THE WESTERN QUADRANT OF A PARTIALLY EXPOSED LOW-LEVEL CIRCULATION (LLC). A 221506Z MHS 89 GHZ MICROWAVE IMAGE REVEALS A CURVED DEEP CONVECTIVE BAND OVER THE NORTHERN AND WESTERN QUADRANTS WITH WEAKER, SHALLOW BANDING ELSEWHERE. A 221510Z ASCAT-B IMAGE SHOWS A DEFINED CIRCULATION WITH 25 TO 30 KNOT WINDS OVER THE NORTHERN SEMICIRCLE AND WEAKER 15 TO 25 KNOT WINDS OVER THE SOUTHERN SEMICIRCLE. ENVIRONMENTAL CONDITIONS ARE FAVORABLE WITH LOW (10 TO 15 KNOTS) VERTICAL WIND SHEAR, GOOD POLEWARD OUTFLOW, AND WARM SEA SURFACE TEMPERATURES (29-30 C). GLOBAL MODELS INDICATE A NORTH- NORTHEASTWARD TRACK TOWARD BANGLADESH WITH GRADUAL DEVELOPMENT OVER THE NEXT TWO DAYS. 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 231800Z.// NNNN