THIRUVANANTHAPURAM: As the annual monsoon season in Kerala is drawing to a close, Kasaragod, Kannur and Kozhikode have become the Cherrapunji of the state by netting around 3500 mm rain against the normal average of around 2730 mm. The extremely heavy rainfall in these districts is attributed to the rise in low pressure formations over the Bay of Bengal.
Kerala used to get around 204.9 cm rain during the 120-day south west monsoon season. This year the state has received 9 per cent above normal rainfall with 222.79 cm rain against the average of 204.92 cm.
But Kozhikode, Kannur and Kasaragod districts received 344, 336 and 360 cm rainfall respectively during this period with Kozhikode registering 33 per cent excess rainfall, the highest in the state. In 2019 as well, Kozhikode, Kannur and Kasaragod districts recorded a rainfall of 346, 313, and 342 cm against the average of 257, 263, and 297 cm respectively.
P S Biju, joint director and head-in-charge, Indian Meteorological Department, Thiruvananthapuram, said, “Traditionally north Kerala used to net more rains than south Kerala as it lies in the track of the north-westerly wind coming from the Bay of Bengal. So rise in low pressure formations over Bay of Bengal is expected to have bearing on the weather in North Kerala, especially these districts,” he said.
In 2019, the Bay of Bengal witnessed a total of 13 low pressure formations during the south west and north east monsoon periods. In 2020, the south west monsoon period alone witnessed 13 low pressure formations over Bay of Bengal. And another low pressure will form in the Bay of Bengal by Friday. There are a lot of factors associated with the rise in low pressure formations, but this would bring more rains to northern Kerala and coastal Karnataka, said a senior scientist with the IMD.
Out of the 120-day long south west monsoon season, 55 days of Kerala's weather were influenced by the low pressures. There is also a rise in extreme rainfall days in the state. A day which receives 20 cm or more rainfall is considered an extreme rainfall day. Even in 2018, which witnessed the mega floods, the highest rainfall of 379 cm was recorded in Idukki against the average of 227 cm, which worsened the flood situation in the state.