“Under the influence of cyclonic circulation over Southwest Bay of Bengal and adjoining Sri Lankan coast, Tamil Nadu and Puducherry will get rain for the next five days. Thunderstorm with lightning is likely to occur at isolated places over Tamil Nadu, Puducherry and Karaikal on February 19,” said S Balachander, director, Regional Meteorological Centre, Chennai. 

Over the next 24 hours, thunderstorms with moderate rain are expected over coastal districts of Tamil Nadu and Puducherry. Light to moderate rain can be expected over southern districts and districts surrounding the Western Ghats, said officials. In the next 48 hours, thunderstorms are expected in isolated parts of the State. 

In Chennai, the sky conditions are likely to be cloudy in the next 48 hours, with thunderstorms with light to moderate rain expected over certain parts of the city. The maximum and minimum temperatures will be between 30 and 23 degrees C respectively. 

“Unlike monsoon rains, these rains are difficult to predict as they don’t rain in widespread area. For Tamil Nadu, the lower level winds are still blowing from the east and it has to be seen where the westerly trough plays a role in creating instability. It is very difficult to pinpoint the areas of rainfall now, ” said weather blogger Pradeep John, who runs the page Tamil Nadu Weatherman.