The state of Bihar along with its adjoining areas has bid adieu to Southwest Monsoon around October 11. After the withdrawal, these pockets go silent as far as the rains are concerned. Withdrawal is never linked with total absence of rains but heavy showers are usually not seen immediately after the withdrawal of Monsoon.
However, Bihar is gearing up for some unseasonal rains. There were a series of systems coming from the Pacific, moving across Vietnam, Laos, Thailand, Myanmar and entering Bay of Bengal. The last system that gave rains over Delhi and Uttarakhand also had a similar journey.
A Cyclonic Circulation which is over West Bengal region is again a remnant of the system which travelled across the aforementioned regions. The earlier system which gave rains over Delhi is now a Circulation over West Uttar Pradesh and Uttarakhand region.
The combined effect of both these systems are causing strong easterlies over the Indo Gangetic Plains, covering right up to Bihar. Thus, unseasonal heavy rains are expected over Bihar today and tomorrow. These showers will be more over the eastern parts and the foothills of the state as compared to the western parts. Tomorrow also, some rains may be seen over Araria, Purnea, Kishanganj, Bhagalpur, Katihar.
Rains may be moderate around October 20 as well. Major clearance may be seen around October 21 only. These heavy showers may result in localised flooding, and may be accompanied with thunderstorm, lightning etc, as well.