Heavy monsoon rains in the month of June and July triggered widespread of floods over many districts of Bihar. In the third week of June the trough sifted to the foothills of Himalaya. Heavy rain occurred over Nepal Hills as well as foothills of Bihar. This resulted in widespread flooding over west Champaran, Bettiah, Motihari, Sitamarhi, Saran, Muzaffarpur and adjoining districts of Bihar.
Incessant rains occurred during first two weeks of July over Nepal and Bihar. Gandak, Kosi and Ghagra rivers were flowing above the danger level mark and inundated many districts of Bihar.
Two successive low-pressure areas are forming over Bay of Bengal. First one will be around in July 23rd and second around July 26. Rain activities are expected to increase over many districts of Bihar by July 26th. The low-pressure area is expected to move in north westerly direction across Bihar and axis of monsoon trough will also be passing via Bihar.
Thus, there may be heavy to very heavy rain with isolated extremely heavy spells over northern districts of Bihar as well as Nepal Hills. Peak intensity may be on July 27th. This heavy rainfall is expected to continue until July 29.
Therefore, Bihar is at the risk of heavy flooding during that period. Skymet wants to issue a red alert for Bihar between July 26th and 29. Rain activities are expected to decrease post July 29. But on and off rains are expected to continue which may not allow the flood water to recede anytime soon.