anticyclone arabian sea atmospheric circulation atmospheric pressure bay of bengal cape guardafui ceel huur colombo coordinated universal time coriolis effect equator horn of africa india meteorological department indian ocean joint typhoon warning center kilometre latitude maximum sustained wind mile miles per hour regional specialized meteorological centre saffir-simpson hurricane scale saudi arabia sea surface temperature somalia sri lanka tropical cyclone formation alert tropical storm vamei tropical cyclogenesis tropical cyclone tropical cyclone naming university of pune vorticity wind shear