Bengaluru: The convergence of two low-pressure systems over Bengaluru and adjoining districts of south-interior Karnataka Sunday night triggered intense thunderstorm activity across the region. Ranging from 100mm to 132mm of rainfall, the whole of Bengaluru experienced a uniform share of thundershowers, with heavy rain pounding the south, north, and eastern parts of the city, according to Indian Meteorological Department (IMD). Four places in Bengaluru were among the top 10 locations for the highest rainfall across Karnataka, which is said to be a rare phenomenon. Kengeri, Kodigehalli, Madanayakanahalli, and Madavara in Bengaluru Urban district were among the top 10 locations in Karnataka with the highest rainfall.CS Patil, a scientist at the IMD Bengaluru, said the city observatory on Palace Road received 103.9mm of rain. According to the historic climatological data of the IMD, Sunday's rainfall was the third highest at Bengaluru observatory. "Historically, this was the fourth time that Bengaluru breached the 100 mm-mark in a single day of rain. The previous highest rainfall in May includes 153.9mm (May 6, 1909), followed by 114.6mm (May 18, 2022), and 105mm (May 18, 2022)," said a weather tracker.

The officials attributed this to a prevailing upper air cyclonic circulation over the Karnataka region, extending from Maharashtra, and a trough over the south interior peninsular part. "Besides these systems, there is yet another UAC circulation over the Bay of Bengal, along with a trough extending up to the north interior Karnataka region, that resulted in thunder activity. The advancement of the southwest monsoon over some parts of the Arabian Sea, Maldives, and parts of the Bay of Bengal has further intensified rain," Patil said.Officials from the state weather agency—Karnataka State Natural Disaster Monitoring Centre said nearly 60% of Bengaluru witnessed heavy rain, while the remaining areas reported moderate rain. "The whole of RR Nagar, Dasarahalli, Yelahanka, and East zones, along with parts of West and South zones, received very heavy rain. Koramangala (96 mm), Vidyapeetha (91 mm), Marathahalli (90.50 mm), Hampi Nagar (90 mm), HAL (90 mm), Cottonpet (86.50 mm), and Sampangiramanagar (78.50 mm) received heavy rain," said a meteorologist.