The India Meteorological Department on Sunday issued a red alert for Kerala’s Pathanamthitta, Alappuzha, Kottayam and Idukki districts until Tuesday, and warned of heavy rainfall.

The weather agency has also announced an orange alert for Thiruvananthapuram, Kollam and Ernakulam until Wednesday while a yellow alert has been sounded in the districts of Thrissur, Palakkad, Malappuram, Kozhikode, Wayanad, Kannur and Kasargod till Thursday.

A red alert requires authorities to “take action” in view of an extreme weather event, while an orange alert means that the administration is expected to “be prepared”. A yellow alert means that authorities should “be updated” on the situation.

The India Meteorological Department said on Sunday that strong westerly and southwesterly winds at lower levels are likely to prevail over the Kerala region till Thursday because of a cyclonic circulation over the south interior region of Tamil Nadu.

On May 15, the India Meteorological Department had said that the southwest monsoon is likely to arrive in Kerala around May 31.

In April, the weather agency had predicted above-normal rainfall during the southwest monsoon season. This is the first time in nearly a decade that the India Meteorological Department has predicted “above normal” rainfall in its long-range forecast for the season.

The weather agency said in April that the country is expected to get 106% of the long period average rainfall. The measure is the mean rainfall during the four-month monsoon season over the last 50 years.