New Delhi, Aug. 5: India’s weather scientists aren’t wise even after the event.
The meteorology experts, who had failed to predict last week’s deluge in Mumbai, today said they haven’t yet found out why it happened.
Still, at a post-mortem of the record 944 mm rain that traumatised the city on July 26, weather scientists tried to come up with a theory before science and technology minister Kapil Sibal. They said they suspect a meteorological condition called a “vortex” caused the freak rain.
They admitted they had no evidence for this.
A leading atmospheric scientist said this was just “guesswork” on the part of the Indian Meteorological Department.
“There is no data at all to indicate that a vortex had formed,” said Jayaraman Srinivasan, chairman of the centre for atmospheric sciences at the Indian Institute of Science, Bangalore.
“In the absence of any evidence, why invoke the term'”
The country’s weather scientists had come in for flak even after the December 26 tsunami for failing to inform disaster management authorities about an early warning from an American agency.
At today’s meeting, the suggestion that a 30-km vortex, embedded in the atmosphere somewhere off the Mumbai coast, was the likely explanation for the July 26 rain came from Akhilesh Gupta, a scientist with the National Centre for Medium Range Weather Forecasting.
A vortex is a meteorological condition caused by fast-moving, rotating winds. But a typical monsoon vortex might cause only about 300 mm of rainfall. So why did Mumbai get pummelled by 944 mm'
A vortex cannot be seen in satellite pictures. To detect a vortex, one needs a special weather radar as well as equipment that can measure wind speed and direction and track cloud movements in real time.
Equipment for better observation and new computer models to predict the weather over small areas could help us in the future, said Gupta. The long-term goal is to get computer models that can predict weather across an area of about 10 km at least 24 hours in advance.
Gupta said the UK weather office did manage to predict 800 mm rain over Mumbai when it ran a computer model; but it could do this only after the event, using weather parameters after the downpour. “It could not predict the Mumbai rain in real time,” Gupta said.
Sibal said the government has chalked out a three-year plan to improve weather observation and analysis.
There are gaps in technology and equipment that the government hopes to fill by upgrading the meteorological department. “If there’s a failure thereafter, it’ll be our failure,” Sibal said.
India will begin to fine-tune a US-developed weather forecasting and research model that is particularly suited to predict high-impact events such as cyclones.
The 944 mm downpour that pounded Mumbai was compressed into a few hours. Most of the rain fell between 2.30 pm and 11.30 pm. “We certainly failed to predict it,” said a weather scientist in Delhi.