Natural Disasters

Cyclone Sitrang forms, may intensify by Oct 24 night

The cyclone is expected to stay a severe cyclone for around six hours or so

By Akshit Sangomla
Published: Monday 24 October 2022

Cyclone Sitrang that formed in the evening of October 23, is likely to intensify into a severe cyclone by the night of October 24, according to the India Meteorological Department (IMD). This is happening a day before the national weather agency had predicted earlier.

The cyclone is expected to stay a severe cyclone for around six hours or so before de-intensifying into a cyclone, IMD added. Its current track is towards the Bangladesh coast, where it may make landfall between Tinkona and Sandwip islands in the early morning hours of October 25, it noted. The intensity of the storm is likely to be that of a cyclone. 

In the early morning hours (8:30 am) of October 24, the cyclone lay 380 kilometres south of Sagar Island in West Bengal and 520 km south-south west of Barisal in Bangladesh. 

The entire storm system is moving at a considerable speed of 21 km / hour towards the coast. This means that it won’t get much time to sit on the sea and gain strength. Slow moving cyclones generally gain more strength and also carry more rainfall. 

Even then, the IMD has issued rainfall warnings for Odisha, West Bengal, Assam, Arunachal Pradesh, Nagaland, Manipur, Meghalaya, Mizoram and Tripura. The weather agency forecasts extremely heavy rainfall over southern Assam, eastern Meghalaya, Mizoram and Tripura. 

Assam (35 per cent) and Tripura (20 per cent) have already received excess rainfall in October, while Meghalaya received normal (-18 per cent) rainfall and Mizoram deficient rainfall. 

Tripura may also be the only Indian state that would have to bear the brunt of cyclonic wind speeds of 62-88 km/hr as the landfall of the cyclone is likely to happen along the Bangladesh coast that is very close to the state. IMD has predicted that the cyclone would de-intensify into depression some 12 hours after landfall. 

This, though, would depend on the sea-surface and atmospheric conditions present at the time of landfall. Depending on the availability of warm waters and moisture, the cyclone may stay at strength for much longer than usual. This had happened in the case of extremely severe cyclone Tauktae in 2021 that had stayed a cyclone for 18 hours over land. 

The main scare at the time of landfall is the accompanying storm surge, which is the increase in the height of sea waves due to the energy brought in by the cyclone. This generally inundates low lying areas near the location of landfall of the cyclone. 

IMD has predicted that the storm surge for cyclone Sitrang would be 2-2.4 metres above the astronomical sea tide along the Bangladesh coast and about one metre above the astronomical sea tide along the West Bengal coast in the North and South 24 Parganas districts. 

Storm surge inundation is especially damaging for agriculture and fisheries along the coast in the long term as it increases the salinity of the region, making both livelihood activities difficult to perform.

This was especially observed in the case of super cyclone Amphan which had impacted West Bengal and Bangladesh coasts in May 2020. The storm surge had brought sea waters as far as 25 km inland. 

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