A cloudy sky, coupled with thunder, lightning and cooling showers on Sunday, left many Bengalureans assuming that it was the onset of the southwest monsoon.

But India Meteorological Department (IMD) officials were seen clarifying to concerned citizens that these are actually pre-monsoon showers and that more rain could be expected in the coming days.

The city received 7.6 mm of rainfall until 5.30 pm on Sunday while HAL airport and Kempegowda International Airport received trace rainfall (up to 0.1 mm). By 8.30 pm, this increased to 17.9 mm in the city and 20 mm at the HAL airport.

The sudden downpour uprooted several trees in Vijayanagar, Magadi Road near Prasanna Theatre, KP Agrahara, near Jyoti Nivas College and in Nagarabhavi.

The BBMP control room reported at least eight tree falls. The control room did not receive any waterlogging cases.

Sunder M Metri, Director in–charge, IMD Bengaluru, said that the city and most parts of south interior Karnataka were experiencing rainfall because of the formation of various pressure systems. Under the influence of these systems, the IMD has also forecast thundershowers and gusty winds for the next three days across south interior Karnataka.

According to the department, there is a north-south wind discontinuity from Rayalaseema to south Tamil Nadu, extending up to 0.9 km above the mean sea level.

A low-pressure area is also forming over the south-west Arabian Sea and is likely to intensify and move north westwards.