Farmers in districts like Ariyalur, Dharmapuri, Krishnagiri, Salem, and Namakkal rely on transition thunderstorms to cultivate pulses and vegetables.
Published Oct 31, 2023 | 10:00 AM ⚊ Updated Oct 31, 2023 | 10:22 AM
Chennai city. Much of Tamil Nadu saw deficient rains in October. (iStock)
Tamil Nadu saw a 47 percent deficit in rainfall at the end of October. The deficiency is higher in districts such as Chennai and Cuddalore, which saw a 78 percent and 88 percent deficit, respectively, according to the data from the India Meteorological Department (IMD) on 29 October.
Even though the Northeast Monsoon was set to hit on 21 October, the state failed to make something out of it, due to the prevalence of two cyclones — Cyclone Tej that formed in the central-south area of the Arabian Sea and hit the Yemen coast, and Cyclone Hamoon that formed in the Bay of Bengal and made landfall in Bangladesh.
But how did these cyclones affect the October rainfall in Tamil Nadu?
“The easterly winds were absent as these cyclones pulled moisture towards them. The sky was hazy due to the dry land winds from the north,” Srikanth K, an independent weather blogger from Chennai, explained to South First.
He has been running the popular social media page Chennaiyil Oru Mazhaikkalam (COMK) for over nine years now.
Transition season thunderstorms — the period when the southwest monsoon makes a transition to the northeast monsoon — was weak in October. It may be noted that the northeast monsoon has been typically arriving in the last week of October for over three years now.
However, farmers in districts like Ariyalur, Dharmapuri, Krishnagiri, Salem, and Namakkal rely on transition thunderstorms to cultivate pulses and vegetables.
“Unfortunately, the occurrence of these transition thunderstorms was not significant. Only certain parts of Coimbatore and Kanniyakumari were able to enjoy these thunderstorms this October,” Srikanth said.
Even though it has been a month since farmers tilled their lands and sowed seeds, there are no saplings yet.
“These are rain-dependent crops. As water in the Mettur Dam is less due to the poor Southwest Monsoon and the non-release of Cauvery water from Karnataka, the dependency on transition thunderstorms was high. However, October month was a let down for farmers,” said AP Raveendran, General Secretary, Joint Movement of Tamil Nadu Farmers’ Association.
The Mettur Dam, with its capacity of 93.47 TMC, had only 18.73 TMC of water as of 29 October.
November is a crucial month for rainfall in Tamil Nadu. Districts in Tamil Nadu, including the state capital Chennai, woke up to scattered rains on Monday, 30 October.
#COMK Nowcast Alert 9:00 AM, 30th Oct. '23 #NEM2023 #ChennaiRains
A squall line of #Thunderstorms of the coast of #TamilNadu between Mahabalipuram and Chidambaram, similarly rain bands seen off South TN coast too. Places in #Villupuram, #Cuddalore dts and #Pondicherry may come… pic.twitter.com/EBDXiCP7aw— Chennai Rains (COMK) (@ChennaiRains) October 30, 2023
This year, weather experts predict that November could be near or above normal for most of Tamil Nadu. However, it still remains uncertain if November can compensate for the deficiency from the Southwest Monsoon and transition thunderstorms.
The main rainy season for the Tamil Nadu Subdivision — comprising Tamil Nadu, Puducherry, and Karaikal — is the northeast monsoon, which occurs from October to December. During this season, 48 percent (443.3 mm) of the annual rainfall in the area is received.
The performance of the northeast monsoon is crucial for the success of regional agricultural activities in this subdivision. “Only if we get enough rains for the next two months can we get good profits in paddy,” Muthuvel K, a farmer from Ariyalur, told South First.
For the Tamil Nadu Subdivision, the normal southwest seasonal rainfall realised is only about 36 percent (336.1 mm) of its annual rainfall (939.3 mm) as this subdivision comes under the rain-shadow region during this monsoon, as per the annual report by the IMD.
Last year, the Tamil Nadu Subdivision received 445.6 mm rainfall during the Northeast Monsoon months between October and December.
In November 2022 alone, the Northeast Monsoon bestowed the subdivision with 178.5 mm of rainfall.
