The Department said there may be temporary localized strong winds during these thundershowers.
The general public is kindly requested to stay vigilant in preparation for adequate precautions to minimize damages caused by lightning activity.
Meanwhile, the coastal communities are requested to stay vigilant amid the prevailing tense weather conditions.
Showers or thundershowers may occur at several places in the sea line extending from Puttalam to Hambantota, via Colombo and Galle, the Department said.
The winds may follow a South-Westerly direction speeding up to 20 - 40 kmph in the sea line across the country.
The Department further informs wind speed may increase up to 50 kmph at times in the sea line extending from Puttalam to Kankasanturai, via Mannar, and in the sea line extending from Matara to Batticaloa, via Pottuvil.
There may be temporarily strong gusty winds during thundershowers, and seas can be expected rough, the Department said.