An increase in thunderstorm activity can be expected over Kerala in the next few days with the commencement of northeast monsoon rainfall, the India Meteorological Department (IMD) has warned.
The weather agency on Monday announced the withdrawal of the southwest monsoon and the simultaneous commencement of the northeast monsoon rainfall over the southern parts of peninsular India.
In Kerala, all districts, except Kannur and Kasaragod, are on yellow alert on Tuesday for isolated heavy rainfall. Yellow alert has been sounded in all districts, except Thiruvananthapuram, Kollam and Alappuzha, on Wednesday.
Low-pressure area
A low-pressure area is likely to form over south Bay of Bengal later this week.
During the June 1-September 30 period — the official southwest monsoon season — the State had recorded a 16% deficit, which nevertheless is deemed ‘normal rainfall’ as percentage departures between -19% and +19% are classified as ‘normal.’
Officially, the northeast monsoon season lasts from October 1 to December 31.
Delayed withdrawal
This year, the withdrawal of the southwest monsoon was delayed by weeks and the State experienced sustained rainfall activity with heavy to extremely heavy rainfall events from October 1 to 25. Rainfall peaked on October 16 triggering landslips and floods in Kottayam and Idukki districts, claiming several lives.
During the 25-day period, the State recorded a 111% excess rainfall with all districts, except Alappuzha, recording a ‘large excess,’ or over 60% excess rainfall. Alappuzha recorded an excess of 41%. Against a normal of 250.2 mm for the 25-day period, the State received 528.9 mm rain.
In 2020, the northeast monsoon rainfall had commenced over Kerala on October 28. The State had recorded a 26% deficit at the end of the season on December 31. The Kerala and Mahe region had recorded 31% excess in NE monsoon rainfall in 2019.
