A slow-moving tropical cyclone, named Two, has formed at the northern end of the Bay of Bengal.
The winds from the storm are relatively light, with maximum gust of 75km/h, but of far greater concern is the rain falling from the cyclone.
A disturbance has been present in the area for more than a week, and over that time there have been massive rainfall accumulations.
Chittagong in Bangladesh has recorded more than 950mm, whilst Cox's Bazar received almost 800mm.
It is likely that comparable amounts of rain have fallen over coastal areas of neighbouring Myanmar, but rainfall observations here are hard to come by.
Typically, these weather systems, which are common in July and August, are between 1,000km and 1,250km across. Daily rainfall totals of 100mm to 200mm can be expected and they persist for two to five days.
They tend to move in a west to northwesterly direction as they are steered by the easterly winds which blow aloft.
Two is expected to take a similar track, according to predictions by the Joint Typhoon Warning Centre.
It suggests Two will head northwestwards towards Rajshahi in Bangladesh, and Farrakka in India.
Although rainfall intensity should decrease once it makes landfall, there is likely to be enough heavy rain to further swell the level of the River Ganges which is already causing concern in Varanasi.
Meanwhile, the low pressure centre affecting northwestern India has begun to show signs of weakening.
Gujarat has been badly hit by the rain, and the associated flooding has killed at least 26 people.
In the north of the state, 2,000 villages have been affected and rescue teams have been deployed to the worst hit areas.
Source: Al Jazeera