Why cyclones hit the east coast of India often in October?

Recently cyclone Titli became the third major cyclone to hit the Odisha-Andhra coastal zone in the last five years, all in October. Cyclones have always been frequent in the region.But what has risen is the frequency of intense cyclones in the area .

Adjacent to the northwest Pacific, which is one of the world’s most active basins for typhoons, the 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.

The reason that cyclones such as Titli(2018), Phailin (2013) and Hudhud (2014) typically strike in October is that wind shear (the difference within wind speeds and direction at two different levels) is low during this time. Low wind shear, when combined with surface sea temperatures greater than 26°C, raises the likelihood of cyclones. In monsoon season, cyclones are rare because of high wind shear.

Why cyclones are hard to predict?

Prediction is difficult because of budgetary and meteorological factors. In the Atlantic basin, the US has dedicated aircraft that fly directly into the clouds to study moisture levels and gather various data on cyclone profile. For Indian cyclones developing over the ocean, scientists have to largely rely on satellite images (a top view) that reveals little data on moisture content and intensity.

Indian scientists get a more detailed picture only when a cyclone is 300-400 km from the coast, which reduces preparation time. Cyclone Titli was additionally hard to read because it turned into a recurving cyclone (it changed direction). India acquires storm prediction models from the US and Europe but lacks the resources to upgrade the models regularly.