A low pressure system over Chambal and Bundelkhand brought the first intense spell of rain to Delhi this monsoon. Palam received 87 millimetres of rainfall between 5-20 p.m. and 8-30 p.m. on Thursday while Safdarjung recorded 41.2 mm. It continued to rain even later in the evening.
At Delhi airport, visibility reduced to 300 metres before 6-30 p.m. This coupled with a slippery runway tested the landing skills of pilots although only a few flights were delayed. Unlike the deluge of 2011 and 2013, Terminal 3 did not get flooded on Thursday. The city’s drainage system, however, “collapsed” despite the sewer clearance drive.
“The Lala Lalpat Rai Road and Defence Colony flyover were flooded as the storm water channels were blocked and this despite the Barapullah drain being nearby,” said Delhi Jal Board member B.M. Dhaul. Flooding was also reported from several parts of the city including theatre hub Mandi House.
After monsoon was declared on July 6, the city has seen only light and moderate showers. “No significant low pressure systems occurred until this system, which had formed over North Madhya Pradesh and surrounding areas, moved closer to the National Capital Region,” G.P. Sharma, vice-president of private forecaster SkyMet told The Hindu .
Palam Meteorological Director R.K. Jenamani said this cyclonic system, which extends up to 4.5 km above sea level attracted rain clouds from both the South-West and South-East.
“These are migratory clouds and rainfall is expected on Friday also. There was not much wind associated with this heavy rain. This confirms that it is only from the large-scale effect of monsoon rainfall. Interestingly, noon heat remained high with temperatures touching 39 degrees at Palam airport on Thursday and hence the role of enhancing convection activity as clouds move from South-West and South-East is not ruled out,” Mr. Jenamani explained.
To put it simply, while the thrust of rain was attracted by atmospheric activity over Chambal, local convection currents due to high temperatures may have also contributed to the spell. Minimum temperatures also hovered around 29 degree Celsius although accurate data of mercury falling after the rains will only be available on Friday.
