Cyclones in the East Coast - Cyclone Titli

What is the issue?

Cyclone Titli recently hit the Odisha-Andhra coastal zone.
Given the cyclone frequency in the Eastern Coast, it is essential to understand about cyclone formation and evacuation process.

How has the cyclone trend been?

Titli is the third major cyclone to hit the Odisha-Andhra coastal zone in the last five years, all in October.
The other two are the Phailin (2013) and Hudhud (2014) cyclones.
Cyclones have always been frequent in the Odisha-Andhra coastal region.
But notably, the frequency of intense cyclones in the area has increased over the years.

How do they form?

Pacific is one of the world’s most active basins for typhoons, and adjacent to the northwest of this is the Bay of Bengal.
Notably, Bay of Bengal receives the remnants of major landfalls in the Philippines, China and South Asia.
From these places come low-pressure systems that develop into a monsoon depression or a cyclone.
This is the reason why most of the cyclones such as Titli, Phailin and Hudhud typically struck in October.
The reason is that wind shear i.e. the difference within wind speeds and direction at two different levels is low during this time.
The low wind shear, when combined with surface sea temperatures greater than 26°C, raises the likelihood of cyclones.
This is because, if there’s too much wind, these weather systems have trouble organizing and developing into a tropical cyclone.
But with little to no wind shear, the turning within the tropical system is uniform.
So the storm becomes vertically aligned, helping to keep it intact and, likely, strengthening.

Why is it hard to predict?

India acquires storm prediction models from the US and Europe but lacks the resources to upgrade the models regularly.
The Odisha government was criticised for being unable to anticipate the landfall of Cyclone Titli or the very heavy rainfall.
But prediction is difficult here because of budgetary and meteorological factors.
In the Atlantic basin, the US has dedicated aircraft that fly directly into the clouds.
It studies moisture levels and gather various data on cyclone profile.
But for Indian cyclones developing over the ocean, the reliance is largely on satellite images (a top view).
This only reveals little data on moisture content and intensity.
So getting a more detailed picture is possible only when a cyclone is 300-400 km from the coast.
But this reduces the prediction and preparation time.
Specifically, Cyclone Titli was hard to read because it turned into a recurving cyclone (it changed direction).

How is evacuation done?

Evacuation exercises are classified as preventive, vertical, and shelter-in-place.
In preventive (or horizontal) evacuation, the impact area is meant to be completely evacuated.
But this is a measure rarely taken in India because of poor roads and inadequate public transportation.
Also, poor people rarely have the resources to find alternative accommodation.
In vertical evacuation, people are directed to specially designed buildings within the impact area, which was largely followed during Cyclone Titli.
Shelter-in-place evacuation involves fortification of existing houses and community buildings, which again required financial resources.

Concerns - Reportedly, the government does not have adequate multipurpose cyclone shelters.
The government claimed around 3 lakh people were successfully evacuated during Cyclone Titli.
But widely held parameters of success in disaster management, such as number of evacuees, are “misleading”.
Notably, the fewer casualties during Phailin and Hudhud were because of the limited severity of these cyclones than effective disaster planning.

Source: Indian Express