Meteorologists need to capitalize on radars and weather satellites to monitor colossal storms, which are usually unpredictable, and set off early warnings for Olympic weather services.

One main strategy of the meteorologists is to engineer weather in order to keep the Olympics dry for at least the first three and half hours. Such research and experiments have been conducted since 2001 when Beijing successfully bade for the Olympic host.

Many meteorologists agree that cloud seeding technology is only effective to small or mid-sized clouds and thus impossible to influence giant storm systems, which can cover up to a hundred square kilometers. The methodology is employed basically to speed up rain, delay rain, or change the place where rain falls, one Beijing-based expert said.

Some meteorologists, meanwhile, argue the study on cloud formation and large-scale weather conditions is insufficient to effective weather modification. Others dispute on the negative impact of spreading silver iodide in the sky on environment.

Yu Xinwen, a China Meteorological Administration (CMA) spokesman, said in Beijing Monday that the statistical probability of 41 percent, based on the meteorological data collected in the past 33 years, just offers a rough idea on a historical chance of precipitation.

An instant case is the 15th Asian Games in December 2006 in Doha, Qatar. In a country where rain has been rarely seen, a deluge soaked athletes and spectators during the expensive and breathtaking opening ceremony.

However, Yu said, "It's possible to predict the weather at the opening night one week in advance, and prediction accuracy will scale up leading to Aug 8." He expected more precise predictions within two days before the Olympics.

As historical data indicate, early August is often warm and humid, and might not be an ideal timing for the Olympic opening. Many thought the Beijing Olympic organizers deliberately chose the auspicious eighth day of the eighth month. However, organizers said it was not the fact.

Fortune-conscious Chinese do care lucky numbers, among others 8 is the best to represent prosperity and wealth. But decision makers were briefed by meteorologists that the week beginning with August 8 usually falls in the wettest period each year in Beijing.

It was reported that the Beijing organizers proposed the International Olympic Committee (IOC) to kick off the Games, ideally, on Aug 15. The final decision of the Aug 8 option from the IOC left Beijing the only choice to prevent rain, at least around the sky of the Bird's Nest.

The urgency on weather engineering for the Olympic opening is based on one assumption that the main sports venue has no roof. Architects did include a controlled full roof in their original design. The roofless version, which now stands in north of the city, allegedly saved taxpayers 300 million yuan (43 million US dollars).

(Xinhua News Agency July 28, 2008)