Kalsi said El Nino and La Nina have not made any effect on Indian monsoon so far. He said IMD has been watching the behavioural pattern of monsoons over many years and has a strong data base and analysis system. Hence, it is the only authoritative organisation to comment on monsoons.

Rainfall over the country during the monsoon shows a wide range of spatial variation which is mainly due to orographic influences and preferential occurrence of rain bearing systems in certain regions. North-eastern and west coast regions receive the highest rainfall. Parts of north-west India, particularly Rajasthan, get less than 50 cm rainfall while Tamil Nadu receives most of its rainfall during the north-east monsoon and Jammu and Kashmir gets significant winter precipitation.

He saidthose who said El Nino and La Nina have a one-to-one relationship with monsoons in the country have so far not presented any evidence to substantiate their argument. These comments are more or less speculative in nature.

He said the country had good monsoons in El Nino years. Similarly in La Nino years the average rainfall in the country had been within the normal range.

Usually, in El Nino years, we had floods in the northeast, north Bihar and east Uttar Pradesh. But at present the El Nino effects are receding and La Nina effect is pervading. The country is having flood in the eastern and north-eastern areas. We are having deficient rainfall in western Orissa and east Madhya Pradesh.

All these are due to aberrations in local weather conditions and cannot be attributed to either El Nino or La Nina effect. Not all the past El Nino years have been associated with drought over India.

There have been El Nino years with normal rainfall and drought years without El Nino. This shows that neither EL Nino orLa Nina has any major effects on Indian monsoons, he said.

Kalsi said rainfall this year is normal. The area weighted cumulative average rainfall for the country as a whole so far is 103 per cent of its long period average which is 88 cm. The normal rainfall for the country is defined within 10 per cent of the long period average.

For individual meteorological subdivisions, rainfall within 19 per cent of the long period average is defined as normal.

The rainfall in the country is normal and usual and does not cause flood. He said there may be excess rainfall in Nepal which might have contributed to the flood situation in the country.

Lack of proper management of water resources and deforestation in the region can be other factors contributing to the problem, he said.

Kalsi said the IMD follows the time-tested 16-parameter long range forecast model developed by VR Gowariker in 1988. The model has so far been able to forecast monsoon accurately. The model, while making long-range forecast for thecurrent monsoon, had considered all the 16 factors responsible for monsoons. It was estimated that out of 16 factors, 9 factors were favourable for the current monsoon. In the previous year only 8 factors were favourable. The nine favourable factors this year were the 50 hPa (20 km) northern hemisphere wind pattern in January-February, 500 HPa (6km) wind pattern in April, high temperature over central India in May, high temperature in eastern coastal India in March, northern hemisphere surface pressure anomaly in the period January-April, Argentina pressure in April, northern hemisphere high surface temperature over northern hemisphere in January-February and El Nino effects of the previous year and high northern India temperature in March.

The eight unfavourable factors were the high Eurasian snow cover in December, 10 HPa (30km) zonal wind in January, which moved more easterly in direction, southern oscillation index (Tahiti-Darwin) in March-May, Indian Ocean equatorial pressure in January-May, El Ninoeffect of the current year, high Himalayan snow cover in January-March and Darwin Pressure in March-May.

El Nino phenomena is an anomalous rise in sea surface temperature by one to 5 degree centigrade off Peru coast and in the region of equatorial Pacific Ocean.

It is observed quasi-periodically with a frequency varying between 2-7 years and lasts as long as 22 months.

Sea-saw variation in atmospheric pressure between the Indian Ocean region and Southern Pacific Ocean associated with El Nino is called Southern Oscillation. It is recognised as the atmospheric counterpart of the El Nino and the two are together referred to as ENSO -- a coupled phenomenon of the ocean and the atmosphere. East-west circulation over the Pacific and Indian oceans is known as `Walker Circulation'. A major shift of the ENSO circulation pattern at times occurs in the West Pacific Ocean with far-reaching impacts on weather over the globe.