15 to 20 per cent chance of rain during Games (Hindu 15 September 2010)

MONSOON MAGIC:The Yamuma flows near the Taj Mahal in Agra again. - PHOTO: PTI
NEW DELHI: It is now official. The India Meteorological Department on Tuesday confirmed that there was a reasonable possibility of rains during the coming Commonwealth Games.
Addressing a press conference, IMD Director-General Ajit Tyagi said an analysis of the weather data for the past 110 years showed that there was a 15 to 20 per cent chance of rains during the first half of October: the Games are scheduled to be held from October 3 to 14.
The analysis also shows that Delhi, on an average, had two rainy days during the entire month of October over the past 110 years and that average rainfall for the month was 25.8 mm, with the larger share of it — 22.4 mm falling in the first fortnight.
The analysis further showed that a rainfall of 20 to 40 mm was “not common” during October: the highest 24-hour rain for the month occurred in 1954 — on October 1 that year the city had received a whopping 172.7 mm of rainfall.
The analysis also showed that though thundershowers are not very common during the first fortnight of October, the period was also not totally devoid of these.
During the past 30 years alone, a total of 23 thunderstorms had occurred in the first fortnight of October. Of these, 12 had occurred between October 1 and 5, six between October 6 and 10 and the balance five between October 11 and 15. About 43 per cent of the thundershowers had occurred between afternoon and late evening [3 p.m. to 9 p.m.], with a “secondary maxima'' observed in the early morning hours [3a.m. to 6 a.m.].
Asked as to what was expected this year, Mr. Tyagi declined to make any forecast, on the ground that it was too early for any prediction.
He would only say that the south-west monsoon was likely to withdraw before the Games begin. “Indications are that it is likely to start withdrawing by the end of the month — around September 28 plus or minus three to four days.”
He also indicated that in the meantime there could be a fresh spell of rains over Delhi and other parts of north-west India from September 18 to 21.
Mr. Tyagi announced that the IMD would provide venue-specific nowcasts or very short range forecasts for up to six hours during the Games. The forecasts would be able to provide information on the possibility of any severe weather phenomenon at a very high spatial resolution. The nowcasts would be updated every three hours.
In addition, short range forecasts for up to three days would be provided and these would be updated twice a day. Further, a medium range forecast for up to five days would be issued for Delhi and its neighbourhood.
He also announced that a detailed guide on the climatological analysis for the past 110 years would be released by Union Minister for Science and Technology Prithviraj Chavan on September 23 for the benefit of sportspersons.
Apart from the long-term trend with regard to rains and thunderstorms, the guide would provide details on aspects such as wind speed and direction, relative humidity, which would help the sportspersons plan out their strategies.
Replying to a question, Mr. Tyagi ruled out any plan to undertake cloud seeding or any other such procedure to try and prevent rains during the games, even if there were sure signs of an impending downpour.