According to officials at the India Metrological Department (IMD), Pune, the clouds are non-rainy in nature and have been formed due to an unusual interaction between the easterly and westerly systems.

“The northern part of India is seeing westerly winds while the western parts have a lot of easterly activities. A clash of these two systems is causing the unseasonal, non-rainy clouds to appear over Mumbai,” explained Dr A B Majumdar, deputy director general, meteorology, weather observation centre, Pune. While last year too winter set in only in January, dipping below normal to as low as 8.5 degree, Majumder agreed that the overall weather disturbances this year have been peculiar.

“This year, we have seen at least four different cyclonic storms in the Bay of Bengal that have moved towards the west since monsoon. Such systems cause changes in circulation the impact of which lasts for a while. Cities like Mumbai and Pune are still reeling under the impact of these systems,” he said.