Monsoon in Kerala: State stares at worst deficit in a decade

The current spell of rains notwithstanding, experts predict this year's monsoon deficit will be well over 50%

ByK A Shaji

Published Jul 12, 2022 | 12:47 PM Updated Jul 12, 2022 | 4:38 PM

Kerala rain 1

Though Kerala has been witnessing heavy rains for the past week, experts say the data suggest a 53-percent deficiency in the southwest monsoon in the state this year.

Meteorologists say this is the highest deficit the state has witnessed in the past 10 years.

The monsoon hit Kerala on 29 May, three days ahead of schedule, but the state received scanty rainfall on most days in June and in the first week of July.

It entered a weak phase in the first week of June after widespread rain for a few days.

The reason, according to meteorologists, was that the westerly winds that carry monsoon clouds were erratic and failed to gain strength.

A 53% deficit

Although there has been widespread rain this past week, experts attributed it to a cyclonic circulation in the Bay of Bengal, and said it could not be considered part of the usual southwest-monsoon downpours.

In India, other than Kerala, eight states and one Union Territory are covered by the southwest monsoon. Of them, only Kerala has registered a deficit this year.

India Meteorological Department (IMD) data shows that Kerala received 291.9 mm of rainfall till 29 June, which is 53 percent less than the average rainfall of 621.9mm.

A large monsoon deficit has been recorded in the high-range districts of the Western Ghats in Kerala, and it remains a matter of grave concern.

The hilly Idukki district has reported a deficit of 69 percent, while the other hill district, Wayanad, received 61-percent less rainfall.

In the traditional rice bowl of Palakkad, the deficit is 66 percent.

Shift in Kerala rain pattern

Kerala rain 2

Experts say Kerala has witnessed a monsoon rainfall pattern shift since the 2018 flood. (Creative Commons)

Experts say the state has witnessed a monsoon rainfall pattern shift since the 2018 flood.

According to Thiruvananthapuram-based environmental scientist Sridhar Radhakrishnan, the monsoon has been mostly inactive during June and July — the months that usually witness the most rain — for the past four years.

The pattern since 2018 has been short spells of heavy rain in August and September, triggering floods and landslides across the state.

According to Gopakumar Cholayil, senior scientific officer with the College of Climate Change and Environmental Science at Kerala Agricultural University, the state will have an overall deficient monsoon this time.

According to him, the current rain spell will last another four days, and the monsoon is unlikely to pick up at the end of July or the first week of August.

He told South First that experts at his college predict the state is staring at its highest rainfall deficit in 10 years.

“The rainfall deficit this time will be the largest the state has seen in the recent past,” Abhilash S, director of the Advanced Centre for Atmospheric Radar Research at the Cochin University of Science and Technology, told South First.

Expect extreme weather

CP Priju, hydrology and climatology scientist with the Centre for Water Resources Development and Management in Kozhikode, said the state can expect cloudbursts of high intensity and small duration in August and September, triggering landslides and floods.

The state is now prone to unusual and extreme weather events, and those that could happen in the coming months might compensate for the existing deficit, but the damage they could cause was a grave concern, he told South First.

Kerala is commonly regarded as the entry point for the southwest monsoon to the Indian subcontinent.

During the summer months of April and May, the state received excess rainfall as pre-monsoon showers — caused by cyclones and cyclonic circulations in both the Arabian Sea and the Bay of Bengal.

Experts believe such weather changes before the onset of the southwest monsoon might have caused the deficiency witnessed during the traditionally rainy days.

“It is a proven fact that the presence of cyclones before the advent of the monsoon in a particular region disrupts the monsoon pattern there,” said Priju.