A low pressure that formed over southeast Arabian Sea, closer to Lakshadweep's Kavarati Islands, has triggered heavy and continuous rains in central and south Kerala. The Indian Meteorological Department has issued orange alert (warning just before action has to be taken) in five districts on Sunday: Kollam, Alappuzha, Ernakulam, Idukki and Malappuram.

Southwest monsoon, which had been in a lull after a destructive phase in early August, has suddenly picked up.

Heavy spells are expected for another two days. The cyclonic circulation associated with the low pressure formation extends up to 4.5 km above mean sea level, the IMD said. It is very likely to move slightly northwards during next 48 hours and weaken thereafter.

The IMD's models show that the intensity is likely to lessen on September 7. Nonetheless, it is also seen that the rainfall activity will intensify on September, can turn out to be more severe than on Sunday (September 6). The model shows excessive rainfall in large swathes of Idukki, Malappuram and Palakkad on September 9.

Since weather models are highly dynamic, the possibility of more severe rains on September 8 cannot be predicted with any measure of certainty at this point, top IMD officials said.

Though the IMD has predicted only 'light to medium' rainfall (2.5 mm to 64.4 mm) in Thiruvananthapuram, the district witnessed sustained heavy spells since afternoon. The shutters of Aruvikkara dam were opened by 20 cms, and low-lying areas, even in urban pockets, were inundated.

Coastal areas in the district were also badly affected. The onslaught of the waves was so severe that boats anchored along the Valiyathura beach were washed away. Fishermen who tried to rescue the boats were also swept away by the vicious waves. It took nearly an hour for them to be rescued. No casualties were reported but the fishing boats had reportedly suffered heavy damages.

'Moderate rainfall' (15.6 mm - 64.4 mm) with gusty wind upto 40 kmph were recorded at a few places in Malappuram, Palakkad, Thrissur, Ernakulam, Alappuzha, Idukki, Kottayam, Pathanamthitta, Kollam and Thiruvananthapuram districts and over Lakshadweep area.

In certain areas in Palakkad, Malappuram and Lakshadweep, thunderstorm with wind speed reaching 40 kmph, and accompanied by lightning, had occurred.

The orange alert sounded for Idukki is a matter of concern as a landslide had devastated Idukki's Pettimudi on August 7, killing 67 poor plantation workers and thoroughly destroying their old quarters.