North-east monsoon in deficit again
New Delhi: The North-east monsoon withdrew from the country last week with a deficit despite the Indian Meteorological Department (IMD) forecasting a normal monsoon.
The deficit was as high as 60-70% in all the regions with Tamil Nadu—the state which receives the bulk of the rainfall during this season, reporting a deficit of 62%.
The deficit in the north-east monsoon was despite the fact that three cyclones formed over the Bay of Bengal during this period. However, none of them—with the exception of cyclone Vardah—led to substantial rainfall in the region.
Typically, any rainfall-inducing cyclonic system that forms over the south central Bay of Bengal during this period assumes a trajectory wherein it travels up to the coast of Andhra Pradesh and Tamil Nadu. However, this year, barring Vardah, which hit the coast of Tamil Nadu, others—Nanda and Kyant—moved north east towards Bangladesh.
Easterly winds, which are usually strong during the North-East monsoon season, were also not active this season.
“Less number of systems were formed this year as compared to the last year. Last year, El Nino was prevalent, which made the systems move westwards while this year we had a weak La Nina due to which systems didn’t move westwards and missed the southern peninsula,” said D.S. Pai, head of the long-range forecasting division at IMD Pune.
North-east monsoon provides rainfall in the subdivisions of the peninsular region including Tamil Nadu, Kerala,Coastal Andhra Pradesh, South Interior Karnataka, and Rayalaseema. The deficit in these regions was 62%, 61%, 67%, 70% and 66% respectively during this season and all these regions, barring Telengana, have been categorized as large deficit regions.
A deficit in the north-east monsoon has affected paddy sowing, specially in Tamil Nadu. Area under paddy sowing in the state has fallen by 39% so far to 7.18 lakh.