The India Meteorological Department (IMD) has forecast heavy to very heavy rainfall across several parts of southern and central India as the southwest monsoon continues to linger over the peninsula.
Rain and thunderstorms lashed parts of the South Peninsula and Sri Lanka on October 6, with the withdrawal of the southwest monsoon showing little further progress. The IMD said conditions are expected to become favourable for the monsoon to withdraw from more parts of eastern and northeastern India and adjoining areas of north Peninsular India during this week and next.
However, the transition from the southwest to the northeast monsoon could overlap, creating an active weather pattern over southern India.
Heavy rain continues in South India
Tamil Nadu, Puducherry and Karaikal recorded heavy to very heavy rainfall from Monday to Tuesday. Heavy rain was also reported from Rayalaseema, south interior Karnataka, Kerala and Mahe.
The IMD said several weather systems are contributing to the continuing rainfall. Cyclonic circulations were present over south coastal Odisha and the adjoining northwest Bay of Bengal, the southeast Arabian Sea off the Kerala coast and north Tamil Nadu.
A trough extending from the Gulf of Mannar to Madhya Maharashtra through Tamil Nadu and interior Karnataka was also supporting moisture flow and unstable weather conditions.
The weather department has forecast fairly widespread to widespread rainfall, along with isolated heavy rain, thunderstorms, lightning and gusty winds across large parts of the South Peninsula over the coming days.
Bay of Bengal system may intensify
A more significant weather system is expected to develop over the Bay of Bengal next week.
According to the IMD a cyclonic circulation could emerge over the north Andaman Sea around Monday. It may develop into a low pressure area the following day and could further intensify into a depression over the central and adjoining south Bay of Bengal around October 15.
October 15 is also the normal date for the onset of the northeast monsoon over southern India.
The possible development of the Bay of Bengal system comes as the southwest monsoon is gradually withdrawing, while rainfall producing systems remain active over the peninsula. This could create a prolonged period of unsettled weather during the transition between the two monsoon seasons.
Tamil Nadu records heavy rainfall
Several locations in Tamil Nadu, Puducherry and Karaikal recorded significant rainfall. Valparai Taluk Office and Valparai PAP received 12 cm each, while Chinnakalar recorded 8 cm.
Palacode and Burliar received 7 cm each, while 6 cm was recorded at Thali, Uthagamandalam, Yercaud, Krishnarayapuram and Chamraj Estate.
In Rayalaseema, Royachoti recorded 9 cm, while Venkatagiri Kota, Arogyavaram and Penagaluru received 6 cm each.
Kerala and Karnataka also receive heavy rain
Kerala and Mahe recorded 8 cm at Neryamangalam ARG and 7 cm at Vellathooval AWS. Kurudamannil and Kanjirappally received 5 cm each.
In south interior Karnataka Bargur received 7 cm, while H D Kote and the KSNDMC Campus recorded 6 cm each. Begur and TG Halli HMS received 5 cm each.
Kollur in coastal Karnataka also recorded 5 cm of rainfall.
Sri Lanka may also see wetter conditions
The developing weather pattern is also being closely watched in neighbouring Sri Lanka. Forecast models show no clear countrywide rainfall signal for October and November, meaning the island could experience below near or above normal rainfall.
However, western and Sabaragamuwa provinces, along with Galle and Matara districts, have a higher likelihood of above normal rainfall in October. Most parts of Sri Lanka could see slightly above normal rainfall.
The signal is stronger for November, when much of the island is expected to have an increased probability of receiving above normal rainfall.