Tropical cyclone Helen was located approximately 220 km south of Visakhapatnam this morning.
The storm nucleus has shown improved structuring and the intensity has increased to 111 km/hr, according to the US Navy.
Sea-surface temperatures in the vicinity of the storm centre remain supportive at 28 to 29 deg Celsius.
This is what will help sustain the process of deep convection (cloud-building) which fuels the storm.
India Met Department had yesterday kept a watch for Helen intensifying one round to a severe cyclonic storm.
But there is a suspicion if the decreasing sea-surface temperatures closer to coast will cause Helen to wear down as it approaches for a landfall.
The landfall is expected to happen tonight across the south Andhra Pradesh coast near Kavali by tonight/early tomorrow morning, an India Met Department outlook said.
Another development impeding Helen’s strength is increase in vertical wind shear over the next 36 hours.
Vertical wind shear refers to sudden change in wind height and strength as the storm gains in height into the atmosphere.
Strong vertical shear can lop the top of a cyclonic storm tower that rises 10-12 km into the atmosphere.