Flooding downpours threaten Sri Lanka, India as widespread first rain of season soaks region

A tropical low pressure system will slowly move across Sri Lanka and southern India through early this week leading to the threat of flooding and widespread travel delays.

The tropical low began to bring heavy rain across Sri Lanka on Sunday while most of southern India remained free of heavy rainfall. As the low drifts northwestward over the next few days, heavy rain will spread into Tamil Nadu, Puducherry and Kerala.

Due to the close proximity to land, AccuWeather meteorologists think that there is a minimal threat for this low to become a significant tropical cyclone; however, that will not diminish the flooding threat.

Heavy rain will spread into Tamil Nadu, Puducherry and southern Kerala on Monday. By Tuesday, heavy rain will also fall in northern Kerala and far southern Karnataka. Rounds of rain will continue to fall into the middle of the week.

Through Wednesday, widespread rainfall of 100-200 mm (4-8 inches) of rain will fall across the region.

The heaviest rain will fall in northern and western Sri Lanka as well as along the southwestern coast of India and in southern portions of the Western Ghats. These areas could see locally 300 mm (12 inches) of rain.

Cities such as Jaffna and Colombo, Sri Lanka as well as Nagapattinam, Madurai and Kochi, India will be some of the areas threatened by the heaviest rain and threat for flooding.

In Chennai, India, rain will wet the city from through the middle of the week. While rain could be heavy at times, the greatest flooding threat will be to the south.

The 2015 monsoon brought below average rainfall to Kerala, so this early season rainfall is needed across the region. However, too much rain in some areas will lead to flooding. May is typically when southern India and Sri Lanka see an increase in rain from tropical lows and cyclones, which tend to develop during the leading edge of the monsoon.

As the low sits across southern India during the second half of the week, bouts of rain will continue in southern India which may extend the flooding threat. However, later in the week, the heaviest of the rain should become more scattered, in contrast to the widespread heavy rain early in the week.