Inter-monsoon season brings thunderstorms and mini cyclones

By Nadia Fazlulhaq

The inter-monsoon seasons began with heavy thunderstorms and mini cyclones reported from many parts of the country causing floods in some areas and destruction from mini cyclones.

Met Deparment duty meteorologist K. D. Sujeewa said evening thundershowers and strong winds were quiet common during the inter-monsoon period.

He said the special features of the inter-monsoon period are that there is no consistent wind flow and thunder accompanied by heavy rains with showers take place mostly in the evenings.

"There is no consistent wind flow so it is difficult to pinpoint the exact places where showers could be expected," he said.

According to Mr. Sujeewa, thundershowers will develop at several places in the Central, Sabaragamuwa, Western and North-Western provinces during the afternoon or evening. A few showers are also likely in the Eastern Province and in the Hambantota district. Most of the winds will be from the north-east.

He said the humid atmosphere prevailing in the afternoon was due to the movement of the sun which is overhead Sri Lanka this week.

"On Friday the sun was overhead Hikkaduwa, yesterday overhead Maggona, Matugama and Kumana. Today the sun will be overhead Dehiwala and Mt. Lavinia, but the heat in these areas may depend on the climate," he said.

Speaking to The Sunday Times, Dr. B.R.S.B.Basnayake of the Centre for Climate Change Studies said that due to the land surface heating up during the daytime a low pressure is built up on the land, attracting a strong sea breeze.

"Sea breezes have a greater effect during the inter-monsoon period. The rain clouds form in the hilly areas and also create thunder and lightning .The clouds form around 10 or 11 a.m. and in areas like Nuwara Eliya afternoon showers could be experienced. In the evening the clouds shift towards the coastal areas of the western and south-western belt between 4 and 5 p.m," he said.

According to Dr. Basnayake, there is a possibility of small tornado clouds developing. Once they form they rotate very fast and get to the surface level accompanied by strong winds. The lifetime of these tornados is as short as 4 to 5 minutes but thunderclouds may remain for more than an hour.