A developing tropical depression in the northern Bay of Bengal is expected to bring flooding rain to Myanmar and Bangladesh in the coming days.
According to the Indian Meteorological Department, the depression will track northeastwards towards Myanmar through Sunday, before curving northwestwards towards Bangladesh.
Torrential rain is likely to cause flooding across much of coastal Myanmar, Bangladesh and some of India’s eastern states.
The depression is gathering energy from the warm waters of the Indian Ocean. Sea surface temperatures are between 29 and 30C, warm enough for further development of this system.
Winds of at least 119 kilometres per hour are required for this depression to become a cyclone. Even if these wind speeds are not reached, it will remain a dangerous system as flooding is often a greater threat to life than winds alone. In excess of 250mm of rain is possible as this system brings moisture-laden winds in from the Bay of Bengal.
According the United Nations Risk Model, Myanmar is the most at risk country for natural disasters. The two million inhabitants of the Ayeyarwady Delta region alone are vulnerable to flooding.
There are two cyclone seasons in the Bay of Bengal. This first is between April and June, when the air is becoming moister, but the upper atmospheric winds of the impending southwesterly monsoon are still relatively light. This allows cyclones to form unhindered.
A second peak occurs between September and early December, as the southwesterly monsoon retreats.
For Myanmar, flooding is statistically a greater risk during the early cyclone season. In May 2008, Cyclone Nargis was responsible for the deaths of more than 138,000 people in Myanmar.
In Bangladesh, the cyclone severity is greatest during the second peak. One of the deadliest cyclones ever recorded, hit Bangladesh in November 1970, killing an estimated 300,000 people.