ABIO10 PGTW 290230
(1) THE AREA OF CONVECTION (INVEST 99B) PREVIOUSLY LOCATED
NEAR 6.2N 83.3E, IS NOW LOCATED NEAR 4.8N 77.1E, APPROXIMATELY 310
NM SOUTH OF COCHIN, INDIA. ANIMATED ENHANCED INFRARED SATELLITE
IMAGERY AND A 282352Z 91GHZ SSMIS MICROWAVE IMAGE SHOW FLARING
CONVECTION WITH SOME MID-LEVEL ROTATION ABOVE A CONSOLIDATING LOW-
LEVEL CIRCULATION CENTER (LLCC). THE ENVIRONMENT IS FAVORABLE FOR
DEVELOPMENT WITH LOW (10-15KT) VERTICAL WIND SHEAR (VWS), STRONG UL
DIVERGENCE DUE TO WESTWARD FLOW, AND WARM (29-31C) SSTS. GLOBAL
MODELS ARE SPLIT ON DEVELOPMENT POTENTIAL AND TRACK. ECMWF SHOWS THE
SYSTEM TRACKING NORTH AND TURNING WESTWARD TOWARD THE ARABIAN
PENINSULA WHILE NAVGEM SHOWS INVEST 99B TRACKING MORE NORTHWARD
ALONG THE WEST COAST OF THE INDIAN SUBCONTINENT. NAVGEM CALLS FOR
DEVELOPMENT INTO A SIGNIFICANT TROPICAL CYCLONE BY TAU 72, WHILE GSM
AND GFS MAINTAIN A WEAK SURFACE CIRCULATION. MAXIMUM SUSTAINED
SURFACE WINDS ARE ESTIMATED AT 20 TO 25 KNOTS. MINIMUM SEA LEVEL
PRESSURE IS ESTIMATED TO BE NEAR 1007 MB. THE POTENTIAL FOR THE
DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24
HOURS IS UPGRADED TO MEDIUM.
(1) AN AREA OF CONVECTION (INVEST 99B) HAS PERSISTED NEAR 6.2N
83.3E, APPROXIMATELY 205 NM EAST OF COLOMBO, SRI LANKA. ANIMATED
ENHANCED INFRARED SATELLITE IMAGERY AND A 271315Z 91GHZ SSMIS
MICROWAVE IMAGE SHOW FLARING CONVECTION WITH SOME MIDLEVEL ROTATION
ABOVE A CONSOLIDATING LLC. A 271533Z ASCAT PASS FURTHER SHOWS THE
ELONGATED NATURE OF THE LLC, WITH 15-20 KT WINDS BELOW THE
CONVECTION AND A WEAK BUT DEFINED RETURN FLOW. THE ENVIRONMENT IS
OVERALL FAVORABLE FOR DEVELOPMENT, WITH LOW-MODERATE (10-20KT) VWS,
STRONG UL DIVERGENCE DUE TO WESTWARD FLOW, AND WARM (29-31C) SSTS.
GLOBAL MODELS ARE SPLIT ON DEVELOPMENT POTENTIAL BUT AGREE ON TRACK,
PREDICTING 99B WILL CONTINUE TRACKING WEST THEN NORTHWEST AFTER
ROUNDING THE INDIAN SUBCONTINENT. ECMWF AND UKMO CALL FOR
DEVELOPMENT INTO A TROPICAL CYCLONE BY TAU 84, WHILE GFS AND NAVGEM
MAINTAIN A WEAK SURFACE CIRCULATION. MAXIMUM SUSTAINED SURFACE
WINDS ARE ESTIMATED AT 15 TO 20 KNOTS. MINIMUM SEA LEVEL PRESSURE IS
ESTIMATED TO BE NEAR 1007 MB. THE POTENTIAL FOR THE DEVELOPMENT OF A
SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS IS LOW.