Chennai: With the well-marked low pressure turning into a trough over west central bay, weathermen expect rains to subside by this weekend. However, they expect rain activity to pick up by September 18 before hitting a dull period a week later.
“There will be some rainfall activity for the next two days before we can experience some decrease in rains,” said an official, who added that the Met office expects rains to increase towards the middle of next week.
“The intensity of the distribution will vary from place to place, but there will be some rain somewhere for a few days next week, before hitting another dry spell,” the official noted.
A few residents of Ayanavaram had reported to the Met office about hailstorms hitting their areas. “While tornado is unusual for Chennai, hailstorms are common in this part of the world,” said Dr Y. E. A. Raj, deputy director general of meteorology, Regional Meteorological Centre, Chennai.
Noting that the weather bloggers are very active now, Dr Raj said he had received three phone calls on Friday about the occurrence of hailstorms. Hailstorm is a form of solid precipitation that contains irregular lumps of ice that reaches the ground during thunderstorm.
On the rainfall activity in the city, Dr Raj said even though Chennai received only 0.5 cm rains on Friday morning, it got good rainfall during daytime registering 3.5 cm. “Overall, north Tamil Nadu received good rainfall on Friday,” he added.
The state has so far received 20 per cent excess mean rainfall at 29.3 cm as against the normal of 24.5 cm this southwest monsoon season starting June 1 ending September 13.
For a 24-hours period ended 8.30 am on Friday, Dharmapuri Town and Marandahalli in Dharmapuri district and Cholavaram in Tiruvallur district recorded the maximum rainfall in the state at 7 cm each.
Water managers rejoice as reservoir levels rise
Chennai: One group of people that celebrates the rains unconditionally consists of the city’s water managers, monitoring and rejoicing over the steady rise in the city’s water table, given the alarmingly low levels recorded a fortnight ago.
In barely three days, the joint storage level of the four city reservoirs has risen by 400mcft. The joint storage level of Poondi, Puzhal, Cholavaram and Chembarambakkam reservoirs rose to 1.877 tmcft on Friday from Tuesday’s 1.477tmcft, against the joint total storage capacity of 11.057tmcft.
The storage level at Chembarambakkam rose significantly from 511 mcft to 724 mcft and inflow to the lake increased from naught to 831cusecs during the three days.
Catchments of the lake received 44mm. While catchments of Chembarambakkam received 7mm rain, Poondi, Cholavaram and Puzhal received substantial rains, with the Met department recording 58.6mm, 65mm and 36mm respectively.
Except Cholavaram, which received 8mm last week, the other reservoirs recorded no more than 2mm rain early this week. With the monthly requirement hovering around 1.2tmcft, the existing 1.477tmcft should be sufficient to ensure normal water supply to the city till mid October, by when the northeast monsoon that brings copious rainfall to the city, would set in.
Chennai metro water has been maintaining 550mld supply (830mld is the normal average requirement) to the city for a month now owing to acute water deficit. Water managers who anticipate more rains in the coming days now fear that they would be unable to restore normal water supply immediately.