Cyclone Fengal was unusually hard to predict and track | Analysis

Unpredictable weather patterns in 2024 challenge forecasters, highlighting the impact of global warming on cyclones and monsoons.

As of December 2, Cyclone Fengal was still alive and kicking, and was predicted  to soak parts of north Kerala and south Karnataka (including Bengaluru) in the following days. It appeared to have retained its identity in the forecasts as it crossed peninsular India en route to the Arabian Sea. It may not reorganise into a cyclone again over the ocean, but considering the way this year has unfolded thus far, anything seems possible.

In fact, nothing has been typical during 2024.

The year 2023 produced a stream of headlines — often days in a row — pointing out the record warming, the strong El Niño, and a litany of extreme weather events strewn around the planet. On the other hand 2024 was expected to continue to be warm but also transition to being a La Niña year. In fact, given that they had successfully predicted the early El Niño, weather models’ confidence ran high when they predicted a strong La Niña in 2024.

Alas, it turned out to be wrong — and fantastically so. The pattern of sea surface temperature anomalies in the eastern tropical Pacific Ocean have been quite unusual, with no significant cooling along the equator and a slight warming just to the north of the band. This situation is best described as “disorganised” — and the same label would hold for the post-monsoon circulation over the North Indian Ocean. Chennai has continued to get doused by the northeast monsoon as well as the rain brought by Cyclone Fengal. But the rest of the country, but especially the peninsula, remains much drier than normal as far as the northeast monsoon is concerned.

Weather models had also predicted an Indian Ocean Dipole but it did not make an appearance either.

Mother Nature has developed a habit of delivering a whiplash just as researchers are riding high on a year of successful forecasts, and this occasion is no different. At the same time, researchers and lawmakers alike are faced with new puzzles now.

Cyclone Fengal remained a low-pressure system after forming in the far eastern Indian Ocean on November 14 and became a depression in the Bay of Bengal only after 10 days. It moved relatively slowly for another week before the India Meteorological Department said it had become a cyclone and ready for a name.