Rain Check

So weathermen send a messenger—a balloon bloated with three kilos of hydrogen and gadgets to detect which way the wind blows, how fast—and how wet.

‘‘It predicts the approaching monsoon and weather,’’ says S. Samant, an old hand at balloons sent skyward twice daily from 35 weather stations nationwide. From 30 km high, the balloon’s gizmos beam the day’s weather to a ground station before crashing, lost forever.

This ritual is as turbulent as that business of forecasting the Indian southwest monsoon, affected by faraway phenomena like the warming of the Pacific waters.

A moody, enigmatic and mind-of-its-own national event, the monsoon holds 75-90 per cent of India’s total water requirement for drinking, agriculture and power generation.

Climate variability of the Asian monsoon impacts half the globe’s population, so a lab in Columbia University is studying thousand-year-old tree-rings to crack its mysteries.

But weathermen back home still run into rough weather forecasting the monsoon despite over 100 years of practise since the India Meteorological Department’s (IMD) first monsoon forecast—June 4, 1886—for India and Burma.

BUT 1886 was long ago: 19 major flood years and 22 major drought years swept the nation from 1871 to 2003. But for 44 years during 1921-1964, only three years witnessed drought—as per a Pune-based Indian Institute of Tropical Meteorology (IITM) index.

And there’s the planet’s wettest place Cherrapunji. A weatherman tells us a‘‘world record’’—156 cm rainfall on June 16, 1995, with 42 cm in 60 minutes.

‘‘Pressure on us is tremendous,’’ confesses M. Rajeevan, director, National Climate Centre, Pune, annually besieged by calls from industry and finance. Last year, he admits, the IMD could not anticipate 13 per cent deficiency in rainfall.

The June-September monsoon—from mausim, Arabic for season—forecast is India’s best-kept secret until release, plotted feverishly by Rajeevan’s 11-member team that’s come a long way from sending weather telegrams and securing one of India’s first computers.

The season’s bestseller for big business, the forecast is a guide to predict sale of scooters, cement, soaps or stock profits if rural incomes fall or rise based on rainfall. (Agriculture makes a quarter of the economy).

This businesslike cloudwatching, industrialist Adi Godrej’s team subscribes to the World Meteorological Organisation, is far from simpler days of the wise men. Kautilya’s Arthashastra lectured on rainfall and revenue; Kalidasa’s Meghdoot boldly mentioned a date of onset, tracing the monsoon’s path.

Governments have grappled with the monsoon since East India Company days, and a certain Sir H.F. Blandford who studied snowfall over the Himalayas established IMD in 1875.

This April the IMD forecast 75 per cent probability of ‘‘near normal and above’’ rainfall based on a statistical method of ocean, land, atmospheric parameters. Same time, a Bangalore-based Centre for Mathematical Modelling and Computing Simulation (CMMACS) used a dynamical method to predict 22 per cent excess June rainfall.

But soon CMMACS revised its forecast to 34 per cent June deficiency. The monsoon arrived late in Kerala on June 5, evaded its June 10 date with Mumbai and seemed stuck in Goa. The sensex dipped and scientists complained: The Bangalore team was confusing the nation.

Now wait for Monday’s action. IMD will update its forecast, based on 10 parameters.The clouds must be grinning.