WTIO21 PGTW 310300 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/TROPICAL CYCLONE FORMATION ALERT (INVEST 90B)// RMKS/ 1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN 110 NM EITHER SIDE OF A LINE FROM 8.5N 84.6E TO 7.7N 81.2E 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 26 TO 31 KNOTS. METSAT IMAGERY AT 310000Z INDICATES THAT A CIRCULATION CENTER IS LOCATED NEAR 8.5N 84.5E. THE SYSTEM IS MOVING NORTHWESTWARD AT 08 KNOTS. 2. REMARKS:THE AREA OF CONVECTION (INVEST 90B) PREVIOUSLY LOCATED NEAR 7.2N 82.9E IS NOW LOCATED NEAR 8.5N 84.5E, APPROXIMATELY 291.7 NM EAST- NORTHEAST OF COLOMBO, SRI LANKA. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY AND A 302221Z SSMIS 91GHZ MICROWAVE PASS SHOWS FLARING CONVECTIVE BANDS WRAPPING INTO A FULLY OBSCURED, GRADUALLY CONSOLIDATING LLCC. ENVIRONMENTAL ANALYSIS REVEALS MARGINALLY FAVORABLE CONDITIONS FOR INTENSIFICATION AS INDICATED BY LOW TO MODERATE (15-20KT) VERTICAL WIND SHEAR, OFFSET BY WARM (28-29C) SST, IMPROVED POLEWARD OUTFLOW AND A FAVORABLE MJO SIGNAL WHICH WILL CONTINUE TO ENHANCE CONVECTIVE DEVELOPMENT OVER THE REGION. GLOBAL MODELS ARE IN AGREEMENT THAT 90B WILL CONTINUE WEST AND MAKE LANDFALL OVER SRI LANKA WITHIN 36 HOURS. DESPITE THE MARGINALLY FAVORABLE ENVIRONMENT, THERE REMAINS A LOW PROBABILITY THAT THE SYSTEM COULD REACH TROPICAL STORM STRENGTH PRIOR TO LANDFALL. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 25 TO 30 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 UPGRADED TO HIGH. 3. THIS ALERT WILL BE REISSUED, UPGRADED TO WARNING OR CANCELLED BY 010130Z. // NNNN