The Department of Meteorology said Naval and fishing communities are advised not to venture into the shallow and deep sea areas around the Island until further notice.
Amphan was about 600 kilometres off Trincomalee in the early hours of Sunday.
“It is very likely to intensify further into a Severe Cyclonic Storm during next 12 hours and a Very Severe Cyclonic Storm by 18th morning,” the Met department said.
“It is very likely to move north-northwest wards initially until 17th and then re-curve north-northeastwards towards west Bengal coast during 18th to 20th May.
"Due to the influence of the system the prevailing showery condition over the island particularly in the south-western part is likely to continue further. Very heavy showers above 150mm are likely at some places. Wind speed can be increase up to (50-60) kmph at times over the island. Cloudy skies can be expected over the island. Showers or thundershowers will occur in Southern, Western, Sabaragamuwa and Central provinces with isolated very heavy showers exceeding 150mm. Several spells of showers will occur in North-western province," the Met Department warns.
High waves and surges
Waves of up to 2.5 meters could develop resulting storm surges, the Met Department further warns.
“There is a possibility that near shore sea areas off the coast extending from Mannar to Pottuvil via Colombo, Galle and Hambantota may experience surges due to the effect of swell waves, having (2.0-2.5) m height.
Meanwhile, power supply to around 5,000 homes in the country has been disrupted due to adverse weather conditions, the power and energy ministry said.
According to ministry spokesman Sulakshana Jayawardena, disruptions have been reported from the districts of Hambantota, Galle, Kegalle and Ratnapura.
Prompt measures will be taken to restore power supply to these areas, he added.
Around 45,000 homes were without power on Friday and yesterday due to heavy showers and strong winds.