Cyclone Mora keeps city on course for showers

Rith Basu, TT, May 29: Calcutta was today 610km away from the eye of a cyclonic storm brewing over the Bay of Bengal, meteorologically a safe distance but close enough for moderate rain in the next 48 hours to wrap up a parched pre-monsoon month.

Cyclone Mora's journey towards Chittagong in Bangladesh brought little more than a drizzle, but the weather office said the storm was playing by the script.

"The city should get moderate rainfall starting Tuesday afternoon. Spells of rain are expected to continue till Wednesday, although the cyclone itself will weaken into a depression by then," said Ganesh Kumar Das, director of the India Meteorological Department, Calcutta.

The deep depression that intensified into a cyclonic storm today had triggered short but heavy spells of rain yesterday, ending an unusually dry fortnight for this time of the year. The storm has since been progressing slowly in a north north-westerly direction towards Chittagong, where it is expected to make landfall a little before noon on Tuesday.

The system is tipped to turn into a severe cyclonic storm late tonight and generate wind speeds of up to 130kmph near its centre. Calcutta falls outside what the weather office calls "area of maximum sustained wind speed". At the time of landfall, the eye of the storm would be 380km from the city.

According to weather scientists, Calcutta did not receive heavy rain today despite appearing to be close to the cyclonic storm because a deep depression and a cyclone work differently.

"Rainfall and winds are experienced in a wider area in the event of a depression or deep depression. When the system concentrates into a cyclone, rainfall and wind speed increase but the affected area becomes smaller," a senior Met official explained.

The skies wore a blanket of cloud almost all day, thanks to continuous moisture incursion from the Bay. Thunderclouds from the coastal areas of south Bengal began blowing into the city as well, albeit slowly.

The forecast is for rainfall to increase on Tuesday when Mora makes landfall and weakens to become a deep depression and, finally, a depression. South Bengal's distance from the eye of the storm would ensure that winds do not reach 40kmph even in the coastal areas of the state.

Wind speeds would be much higher at sea, though. Fishermen have been warned against venturing out on Tuesday, said Das.

Sunday had brought 23.7mm of rain to the city and relief from the sweltering conditions. The minimum temperature dipped from 28.6 to 23.7 degrees Celsius and the maximum reading from 38.3 to 36.2 degrees.

Expect the Celsius to fall further over the next couple of days.