The circulation in the Bay of Bengal has intensified into a low pressure system and could further intensify into a well-marked low. It may merge with another system that has formed in the southeast Bay of Bengal.
Forecasts at Skymet suggest that the well-marked low could intensify into a depression in the next 48 hours. “These new developments will bring good amounts of rain in Chennai and Tamil Nadu for four to five days”, says a senior meteorologist at Skymetweather.com
Rain in Chennai in the last two weeks has shown an interesting pattern of change. The middle week of November from 14th to 20th showed that Chennai received 63% of excess rain due to a series of systems and cyclones, whereas the week from 20th to 27th saw a deficit of about 68% in the city. This is because of Cyclone Lehar having hit Andhra brought more rain there, instead of Tamil Nadu coast.
Weather models at Skymet further suggest that Chennai has been facing a rain deficit of about 39% from the beginning of the northeast monsoon season, i.e. from the 1st October till the 27th of November. The actual average rainfall during this period has been recorded at 369 mm, against the normal average rainfall figure of 610 mm. In fact the entire state of Tamil Nadu has been facing a rain deficit of about 38%, with interiors being the driest parts.
“The inefficiency of tropical disturbances in giving rain over Chennai and Tamil Nadu coupled with the lack of sufficient number of easterly waves is the reason behind deficit rainfall faced by the state”, added the senior meteorologist at Skymet.
Chennai has received only 11 mm of rain in over a week. The new and intense system in the Bay has raised hopes of more rain and thundershowers in the state.
As the system over the sea nears the shores of Tamil Nadu, the wind speed is expected to pick pace and reach around 40 kmph, making days and nights quite breezy. A thick cloud cover has already dropped the maximum temperature by a couple of notches, (from 32⁰C to 28⁰C). Temperatures are expected to maintain as rainfall continues in Chennai this week. The variation between the day and night temperatures has already fallen from 9 degrees to 4 degrees. High humidity of above 90% will fail to bother people since the winds will be strong and the temperatures will maintain quite low levels.
The good news is that we are expecting four to five days of rainy weather in Tamil Nadu which could most likely cover up the rain deficit in the state. But the bad news is that this rain activity will wane out by the end of the week making the days quite dry in Chennai once again.
Photo by bangalorelivenews.