THE AREA OF CONVECTION (INVEST 99W) PREVIOUSLY LOCATED NEAR
6.2N 109.8E IS NOW LOCATED NEAR 6.0N 108.6E, APPROXIMATELY 624 NM EAST OF PHUKET. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY AND A 231033Z SSMIS 91 GHZ MICROWAVE IMAGE DEPICT A BROAD LOW-LEVEL CIRCULATION (LLC) WITH FORMATIVE BANDING IN THE NORTHERN AND SOUTHERN PERIPHERIES. THE CIRCULATION IS LOCATED ADJACENT TO A 20-25 KNOT NORTHEAST SURGE EVENT. ENVIRONMENTAL ANALYSIS INDICATES THAT 99W IS IN A FAVORABLE ENVIRONMENT FOR DEVELOPMENT WITH GOOD OUTFLOW ALOFT, LOW TO MODERATE (15-20 KTS) VERTICAL WIND SHEAR, AND WARM (29-30 C) SEA SURFACE TEMPERATURES. GLOBAL MODELS ARE IN GOOD AGREEMENT THAT 99W WILL TRACK WESTWARD OVER THE NEXT 48 HOURS BUT DISAGREE ON DEVELOPMENT. GFS HAS 99W CONTINUING TO DEEPEN BEFORE CROSSING THE MALAY PENINSULA WHILE ECMWF HAS VERY LITTLE IN TERMS OF INTENSIFICATION. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 15 TO 20 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1006 MB. THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS IS UPGRADED TO MEDIUM.