The state of West Bengal doesn't get much rainfall in the month of December. It is solely because of the Western Disturbances when they penetrate little deep, then West Bengal is on the receiving note of rainfall. However, October to December are the months of cyclones which form in the Bay of Bengal.
In October, cyclones go for West Bengal, Bangladesh and Myanmar and in November they go for Odisha. Finally, in the month of December they go for Andhra Pradesh and Tamil Nadu. All these storms, irrespective where they are, they do make a visit to West Bengal. The system weakens and recurves and the remnants cause rains. All these systems are of recurving nature.
The case and point now is Cyclone Phethai which just crossed the coast of Andhra Pradesh and made a landfall between Kakinada and Narsapur, thus giving heavy to very rains over the same.
In general, the system mostly recurves northeastward traveling almost parallel to the coast but over the land, thus bringing in rains for West Bengal. In past 24 hours, as the system moved further, light to moderate rains already started over the lower regions of West Bengal. Diamond Harbour, Digha, Kolkata, Midnapore, Bardhaman will be more prone to moderate rains with heavy rains over some places today itself. By tomorrow, i.e. December 18, the upper regions of West Bengal like Malda and Murshidabad will start receiving rainfall and by December 19, rains are expected to settle down.
Due to West Bengal’s proximity to sea, there is moisture available in the atmosphere and thus rains will continue for two to three days. Once this system shifts little away towards northeast India across Bangladesh as a cyclonic circulation, it will start finding clearance thereafter.
Image Credit: India
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