Right after the withdrawal of Southwest Monsoon, the winter or the Northeast Monsoon enters the mainland of India. Northeast Monsoon mainly affects five subdivisions of Peninsular India namely, Tamil Nadu, Kerala, Coastal Andhra Pradesh, Rayalaseema and South Interior Karnataka.
During El Nino years, Southwest Monsoon brings poor rains in India but Northeast Monsoon brings normal or above normal rains. Besides this, there are no other established linkages between the performances of Southwest and Northeast Monsoon.
Analyzing the data available from 2004 to 2011, we can say that Northeast Monsoon is going through a positive rainfall epoch. To be precise, the five subdivisions of Peninsular India have received normal or more than the normal average rainfall during this period.
The Southwest Monsoon season, on the other hand, is known for bringing widespread rainfall throughout the country. But, Tamil Nadu generally receives less rainfall during the four-month-long summer Monsoon season. Moreover, we are now going through a drought epoch when it comes to Southwest Monsoon season. So much so that the country has witnessed 4 drought years (2015, 2014, 2004 and 2009) in the last decade. In the recent history, Southwest Monsoon has hardly received double-digit excess rains.
The Summer Monsoon generally receives +/- 10% rains than the LPA of 887 mm. But, Northeast Monsoon witnesses large variations. The long period average NEMR (Northeast Monsoon Rainfall) is 312 mm, with a standard deviation of 84 mm.
In 2014, Southwest Monsoon received 12% less rains than normal, while Northeast Monsoon was just 2% deficient. The year before, Northeast Monsoon witnessed 33% less rains even though Southwest Monsoon received normal rains to the tune of 6%.
The strength of El Nino is not directly linked to the quantum of rainfall during the Winter Monsoon. Just that its existence is connected to Monsoon performance. Thus, we can conclude that Northeast Monsoon 2015 will receive at least normal rains.
Image credit - Indian Express
