Cyclone Fengal, which made landfall near Puducherry on November 30, was a low-intensity storm as it maintained wind speeds of around 75-95 kmph. However, the cyclone has left a trail of destruction. At least 12 people died, mostly in Tamil Nadu, many properties were damaged, and large areas of standing crops were destroyed.
Why did Cyclone Fengal cause widespread destruction even though it was a low intensity storm?
First, what are the different categories of cyclones?
The India Meteorological Department (IMD) classifies cyclones based on the associated wind speed. These categories are: Low Pressure (<31 kmph), Depression (31-49 kmph), Deep Depression (50-61 kmph), Cyclonic Storm (62-88 kmph), Severe Cyclonic Storm (89-117 kmph), Very Severe cyclonic storms (118-221 km per hour), and super cyclones (> 222 km per hour).
How does Fengal compare to past cyclones?
Over the years, the Indian coasts have witnessed several severe storms that caused massive destruction. Associated maximum wind speeds reached 260 kmph (Odisha Super Cyclone, October 1999), 215 kmph (Cyclone Phailin, May 2013), and 185 kmph (Cyclone Amphan, May 2020). Therefore, compared to many previous cyclones, Cyclone Fengal was a low intensity storm.
What was Fengel’s influence?
Fengal caused exceptionally heavy rains and floods in Tamil Nadu and Puducherry.
Krishnagiri and Villupuram in northern Tamil Nadu, where Fengal made landfall, were the worst-hit areas between November 29 and December 1. Mailam village in Villupuram received 510 mm of rain in 24 hours. Puducherry received 490 mm of rain in a day, breaking the previous record of 211 mm set on October 31, 2004.
Air, rail and road transport were affected, highways were flooded, and lakes and rivers overflowed.
Why was Fengal so destructive?
According to the IMD, this is mainly due to the movement of Cyclone Fengal. From its origin to landfall, Fengal moved slowly. At times, it moved slower than 6 kmph while at sea. Fengal also remained stationary for about 12 hours after making landfall near Puducherry. Retaining its intensity as a cyclone, the storm produced heavy rainfall and incapacitating wind conditions in the region.
Typically, after landfall, cyclones weaken as they strike obstacles and experience friction from buildings and trees. In Fengal’s case, while the storm remained stationary, the devastation was very apparent, leading to numerous deaths.
Notably, during recent cyclones (such as Dana in October this year), which were more intense than Fengal, human losses were either zero or limited to single digits.