CHENNAI: Cyclone Fengal, which took five days to cover 500 km, may be one of the slowest to reach the Tamil Nadu coast in Nov or Dec in 50 years, Deemed ‘erratic' by IMD, it made unexpected movements and stayed stationary with intensity for nine hours after making landfall.

Typically, former IMD deputy director general Y E A Raj said, cyclones travel 250km-300km daily at 10kmph-12 kmph, but Fengal slowed to 3 kmph, covering 500km in five days. Cyclones usually develop on the third day after a depression forms. However, Fengal developed on Nov 29, four days after a depression formed over the Bay of Bengal on Nov 25. "There has not been any cyclone track similar to that of Fengal in Nov or Dec in the past 50 years," he said. "Initially, the vertical wind shear was high which did not allow the system to intensify. That was why it was initially forecast that the cyclone may not form and the deep depression may weaken. What was unusual is that the system took a slow northeasterly movement before moving westwards."
Meteorologists said it remained stationary for nine hours after making landfall, retaining strength as the centre of the storm continued to be close to the sea, drawing moisture. This could be a reason for the record rainfall in TN and Puducherry. Normally, a cyclone weakens rapidly after it crosses the coast. "Clouding was on the western part of the system. There was a disconnect between the centre of the storm and the cloud centre, which shifted westwards. This shows the system was not strong," Raj said.
As the remnants of the cyclone are likely to emerge over the Arabian Sea on Tuesday, rain activity may continue over interior and western districts of the state as IMD issued a yellow alert for heavy rain for 15 districts from Tirupattur to Theni and adjoining western districts. "Chennai city and the suburbs may receive light to moderate rainfall with thunderstorms and lightning over some areas. The skies may be partly cloudy. Temperature may be a maximum of 25-26°C and a minimum of 31-32°C," an IMD bulletin said.
Cyclone Fengal pushed the annual rainfall in Nungambakkam and Meenambakkam to 164 cm and 160 cm against the average of 140 cm and 138 cm. "Kancheepuram, Tiruvallur, Chengalpet, and Chennai may experience sudden rain spells in the next two to three days," blogger Pradeep John posted.