Tuesday, August 10, 2010

Changing weather pattern signals more rain for Ahmedabad

August 10, 2010 - Daily News Analysis

Amdavadis looking for respite from torrential rains have some bad news — though not for tomorrow or the day after. Weather pattern is changing and the city could be lashed by more heavy rains this monsoon and in coming years as it has been noted in the last decade that heavy rainfall events are increasing in the city.

On August 8, 2010 - 237.4 mm rainfall was recorded in Ahmedabad. The all-time record for 24-hour rainfall in August for the city is 250 mm recorded on August 30 in 1976. In the last decade, Sunday's rainfall was next only to the heaviest 24-hour rainfall ever recorded at Ahmedabad observatory at 325.9 mm on July 14, 2000.

An overview of the past decade shows that the frequency of heavy rainfall in the city has increased from 39 in 1979-88 to 50 in 1999-2008. As the city limped back to normalcy on Monday, it was learnt that the torrential rainfall that lashed the city on Sunday was the highest 24-hour rainfall in the last 10 years. With this, the city has recorded 930.4 mm rainfall till Monday, which is 130 mm more than normal. This figure exceeds the average annual seasonal rainfall in the city. With the change in formation of rain mechanisms, a significant rise in the number of average rainy days in month of July has also been noted. "The total average rainy days during the month of July for Gujarat were 15," said Kamaljit Ray, director of India meteorological department, Gujarat. The average rainy days in the state in July for the last 50 years are 11.

Moreover, for the last three decades, due to climate change, the state gets more rains from Arabian Sea than the Bay of Bengal. With this, a gradual rise in heavy rainfall events and city's average rainfall has been observed by the state's weather office. The city has witnessed a series of heavy rainfalls this season. It received 85.8 mm rain within 24 hours on August 2, 2010 which was also a heavy rainfall event of this monsoon for the city as well as the third highest 24-hour rainfall event in August during the last decade.

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