Today's Paper

Near-normal NE monsoon likely

CHENNAI OCT. 10. After a normal southwest monsoon, Tamil Nadu may well experience a normal northeast monsoon.

Going by the present indications, the State is likely to get a near-normal or normal rainfall, say senior officials of the Meteorological department. The northeast monsoon provides the State nearly 50 per cent of annual rainfall of 100 cm.

Normally, it sets in around October 20, with an allowance of seven days on either side. "We will be able to say whether the weather conditions are conducive to the onset only after four or five days", says A.K. Bhatnagar, Deputy Director-General of Meteorology. This is because of the recent cyclonic system over the Bay of Bengal, which affected parts of Orissa.

The officials explain that the department does not carry out a long-range forecast for the northeast monsoon. For, it covers a smaller region, comprising Tamil Nadu and parts of Kerala and Andhra Pradesh, unlike as the southwest monsoon, which is relevant to the entire country.

Besides, the degree of variability is more as the monsoon comes in spells, often generated by depressions and storms in the Bay with fairly long periods of break between the spells.

However, the department makes a projection for an internal review.

The officials point out that a mere "normal rainfall" may not guarantee sufficient water availability. This could be seen from the rainfall realised in 2001 and 2002.

In meteorological parlance, normal rainfall means plus or minus 19 per cent of the expected precipitation. Excess relates to plus 20 per cent or more, while deficient rainfall pertains to minus 20 to minus 59 per cent, and scanty means minus 60 to minus 99 per cent.

The withdrawal of the southwest monsoon is not yet over. The process has got halted by the depression over Orissa. However, for statistical purposes, the department regards June-September as the southwest monsoon period. This year, the State received 35 cm against the expected amount of 32 cm, a variation of 8 per cent. The Union Territory of Pondicherry recorded 40 cm (normal 33 cm), a difference of 22 per cent.