Cyclone Arnab’s landfall was delayed by nearly six hours after an anticyclone over the China-Myanmar region, strong westerly winds and a low-pressure system over the south Bay of Bengal pulled and pushed the storm in different directions, according to India Meteorological Department director general Mrutyunjay Mohapatra.
The cyclone eventually made landfall between 2 am and 8 am, after the IMD revised its earlier forecast that the process would occur during the forenoon. Mohapatra said the three weather systems created an unusual atmospheric tug-of-war that made Arnab almost stationary and prolonged the landfall process.
“It’s unique and academically fascinating,” Mohapatra said, comparing the interaction to multiple forces influencing an individual’s decision. He explained that the anticyclone was steering the cyclone, while strong westerly winds, which are generally prominent in October, pushed it back. At the same time, the low-pressure system over the south Bay of Bengal pulled the cyclone towards itself.
A cyclone is an intense low-pressure system in which air rises and moves inward. An anticyclone operates in the opposite manner, with air sinking and spreading outward. The interaction between these contrasting systems affected Arnab’s movement and altered the timing of its landfall.
“The combined effect created an unusual atmospheric tug-of-war,” Mohapatra said. “These factors made the cyclone almost stationary, which prolonged the landfall process.” He compared the storm’s movement to a cyclist struggling uphill as shifting winds alternately push from behind and hold the cyclist back before a sharp bend changes direction.
The storm’s movement also showed a sharp right turn after landfall. Despite the delay and the complex track, Mohapatra said the IMD’s forecast of the landfall area and intensity was almost accurate. The agency had predicted that Arnab would cross the coast between Bapatla and Visakhapatnam, to the southwest of Yanam, with an intensity of 135 kmph. He said these factors had been incorporated into the forecast.
The delayed landfall illustrates the operational challenge posed by atmospheric systems that alter a cyclone’s speed without necessarily changing its broad forecast track. For coastal administrations and residents, the timing of landfall affects the duration of hazardous winds, rainfall and coastal disruption, making updates to warnings and response arrangements important as a storm approaches.
Mohapatra said such a phenomenon was rare but not unprecedented. The 1999 Odisha supercyclone remained almost stationary over the Odisha coast for around 30 hours. Cyclone Burevi also had a prolonged and complex landfall in December 2020.
The IMD’s explanation places Cyclone Arnab’s delayed crossing within that broader record of slow-moving and complicated landfall events, while confirming that the agency’s predicted landfall zone and intensity remained close to the eventual outcome.
