Amaravati, Nov 2 (IANS): The Met department has forecast isolated thunderstorms with lightning for coastal Andhra Pradesh, Yanam and Rayalaseema on Thursday and Friday.

It forecast similar weather on Wednesday in coastal Andhra Pradesh, barring Rayalaseema districts.

"A cyclonic circulation lies over the central parts of south Bay of Bengal and extends up to 1.5 km above mean sea level," said a Met official.

However, the cyclonic circulation over southwest Bay of Bengal off north Tamil Nadu coast, extending up to 1.5 km above mean sea level, has become less marked.

Similar is the case with the cyclonic circulation over interior Tamil Nadu between 3.1 km and 3.6 km above mean sea level.

Likewise, the low pressure area over northeast and adjoining east central Bay of Bengal has also become less marked.

"However, the associated cyclonic circulation now lies over north of Bay of Bengal and adjoining Bangladesh and extends up to 2.1 km above mean sea level," the official said.

Meanwhile, the winter season has arrived in the southern state with cooler nights and foggy mornings at several places.