The India Meteorological Department (IMD) recently announced the onset of the northeast monsoon over South India.

 

What is the Northeast monsoon?

  • India receives rainfall during two seasons. About 75 per cent of the country’s annual rainfall is received from the Southwest monsoon between June and September. The Northeast monsoon, on the other hand, occurs during October to December, and is a comparatively small-scale monsoon, which is confined to the Southern peninsula.
  • Also called the winter monsoon, the rainfall associated with the Northeast monsoon is important for Tamil Nadu, Puducherry, Karaikal, Yanam, coastal Andhra Pradesh, Kerala, north interior Karnataka, Mahe and Lakshadweep.
  • Some South Asian countries such as Maldives, Sri Lanka and Myanmar, too, record rainfall during October to December.

 

Why is it important?

  • Tamil Nadu records about 48 per cent (447.4 mm) of its annual rainfall (943.7 mm) during these months, making it the key factor for undertaking agricultural activities and reservoir management in the state.
  • After the complete withdrawal of the Southwest monsoon from the country takes place by mid-October, the wind pattern rapidly changes from the south-westerly to the north-easterly direction. The period after the Southwest monsoon season, from October to December, is the peak time for cyclonic activity in the North Indian Ocean region — covering the Arabian Sea and the Bay of Bengal.
  • The winds associated with the formation of low pressure systems, depressions, or cyclones influence this monsoon, and therefore, the rainfall. Timely information on cyclones thus become vital for governments and disaster management teams to plan contingency.