A pinch of salt

IMD forecasts a normal monsoon, again

The forecast by the India Meteorological Department (IMD) of a normal monsoon in 2013, with total rainfall during the season (June-September) expected at 98 per cent of the long-term average, seems reassuring. It may soften food inflation and boost rural demand for industrial goods. The downside, however, is that this prognosis is not very different from what the IMD projected on the same date last year for the 2012 monsoon - a prediction that went sadly awry. It predicted 99 per cent of the long-term average last year; actually, the rains eluded most of India in the first half of the season and their rebound in the second half could not rid several areas of drought.

This year many of the other local and international public and private weather forecasters have also come out with similar conjectures about the 2013 monsoon. But some of these predictions do leave scope for concern over the distribution of the monsoon precipitation over time and space, by indicating below-normal rainfall in the country's peninsular region during the second half of the monsoon season. The South Asian Climate Outlook Forum, a body of South Asia's key weather watchers of which the IMD is also part, has warned of deficient rainfall in India's southern-most parts, including Kerala and south Tamil Nadu. Some other agencies have even included southern Karnataka in this category. Skymet, one of India's major private sector forecasters, has gone a step further. It has extended the warning of monsoon weakness to eastern Uttar Pradesh, Bihar and northern Madhya Pradesh, especially in June-July, while endorsing the possibility of sub-normal rainfall in the peninsular region in August. The redeeming feature, however, is that none of the main forecasters has prophesied the continuation of the present drought in Maharashtra, Gujarat and some other areas. The IMD will, of course, come out with its regional monsoon forecast only in June and also update its overall prediction then.

The IMD is today better equipped than in the past. It owns more automatic high-speed data collection and transmission stations, hi-tech Doppler radars and powerful computing equipment. This is reflected in its relatively more accurate short-term weather predictions for different regions. However, forecasting the monsoon - a global weather system that is influenced by sea water temperature in the Atlantic and Pacific Oceans and that of land surface in distant Europe - is different from predicting local weather. This year the chances of the impact of the dreaded El Nino (marked by warming of the Pacific Ocean) turning negative for the Indian monsoon appear dim; but the same cannot be said about the conditions nearer home in the Indian Ocean (technically called Indian Ocean Dipole), which may turn marginally unfavourable. Thus, given these uncertainties, fingers really need to be kept crossed till the actual performance of the monsoon is known by the end of the season in September.