Sri Vijaya Puram, Sept. 11: Thunderstorm and lightning with gusty wind (speed reaching 30-40 kmph) is very likely to occur at one or two places over A&N Islands. Swell waves in the range of 17.0 – 21.0 sec period with 1.2 – 1.6 m height are forecasted up to 23:30 hours on 12-09-2026. It is advised that there is a possibility of surging of waves, boats to ply with utmost vigilance.