For the first time in recent years, all southern States recorded excess rainfall during the previous year's October-December, popularly called north-east monsoon.
In the north-east monsoon of 2005, parts of the southern region other than coastal Karnataka, north interior Karnataka and Kerala registered excess rainfall.
Though the Meteorological Department has not formally declared withdrawal of the monsoon of 2010, the period of October-December is regarded as north-east monsoon for accounting purposes. The Department has divided the southern States and Union Territory of Puducherry into eight sub-divisions: Coastal Andhra Pradesh, Telangana, Rayalaseema, Tamil Nadu-Puducherry, Coastal Karnataka, North Interior Karnataka, South Interior Karnataka and Kerala.
This time, Kerala received the highest amount of rainfall – 83 cm against the normal of 50 cm, a departure of 67 per cent. Tamil Nadu came next with 61 cm against the normal of 43 cm, a deviation of 42 cm. Coastal Karnataka was the third with 59 cm against the normal of 26 cm, a departure of 129 per cent, according to the website of the Meteorological Department.
South interior Karnataka recorded 33 cm rainfall (normal: 20 cm and departure: 66 per cent); Rayalaseema – 28 cm (21 cm and 30 per cent); north interior Karnataka – 17 cm (14 cm and 21 per cent) and Telengana – 17 cm (11 cm and 51 per cent).
Y.E.A. Raj, Deputy Director General of Meteorology, says several synoptic systems including the severe cyclonic storm, ‘Jal,' in early November were responsible for the entire southern region receiving excess rainfall.
The only odd region was the Union Territory of Puducherry, which registered normal rainfall. Against its normal rainfall of 87 cm, Puducherry recorded 94 cm, only eight per cent higher. As per the meteorological standards, the deviation of plus or minus 19 per cent of normal rainfall is regarded only as normal.
Traditionally, north-east monsoon is the principal rainy season for the sub-divisions of coastal Andhra Pradesh, Rayalaseema and Tamil Nadu-Puducherry. In respect of other sub-divisions, it is south-west monsoon (June-September), which is the main rainy season.
During October-December, these sub-divisions record nearly 20 per cent of their annual rainfall.
As far as Tamil Nadu is concerned, 27 districts received excess rainfall and five normal rainfall. Thiruvarur received the highest amount of 110 cm (departure: 65 per cent), followed by Cuddalore with 102 cm (42 cm) and Nagapattinam - 101 cm (14 cm). In terms of departure, Kanykumari and Madurai crossed the 100-per cent mark. While Kanyakumari received 97 cm rainfall (127 per cent), Madurai 75 cm (102 per cent). Tiruchi and Coimbatore were among the excess districts with the figures of actual rainfall 51 cm and 44 cm. The respective figures of deviation were 32 per cent and 28 per cent.
Against the normal of 75 cm, Chennai received only 65 cm, a deviation of minus 13 per cent.
