But the moment Cyclone Helen makes landfall, heavy to very heavy rain could be experienced along the 230 km long coastline between Ongole and Machlipatnam.
According to the forecast several areas including Ongole, Kavali, Bapatla, Machilipatnam, Prakasam, Tedapali in Andhra Pradesh are expected to receive more than 100 mm of rain with wind speeds of 100 kmph. Nellore, close to Ongole is also expected to receive over 60 mm of rain accompanied with strong winds.
Tamil Nadu too is likely to bear the brunt of the cyclone with Chennai expected to receive heavy rain with wind speeds of more than 60 kmph. Sea waves along the coastal areas of Andhra Pradesh could be as high as 1.5 meters, causing floods in low lying areas.
As cyclone Helen is moving at a very slow speed of less than 5 kmph, it has gained more time to pick up moisture from the sea- vital for increasing strength and momentum. The sea surface temperature which is around 28 degrees is also helping create more moisture that adds to the tropical storm. The ideal sea surface temperature for intensification of a low pressure area into storm is 26.5 degrees.
This tropical storm is part of northeast monsoon in south India which prevails from late October to December. Last month another tropical storm, Phailin had caused immense damage in Odisha and north coastal Andhra Pradesh.
Below is a list of places expected to be affected by Cyclone Helen:
| Places | Rain (approximately) | Winds speed (approximately) |
| Ongole | Exceeding 100 mm | Exceeding 100 kmph |
| Kavali | Exceeding 100 mm | Exceeding 100 kmph |
| Bapatla | Exceeding 100 mm | Exceeding 100 kmph |
| Machilipatnam | Exceeding 100 mm | Exceeding 100 kmph |
| Prakasam | Exceeding 100 mm | Exceeding 100 kmph |
| Tedapali | Exceeding 100 mm | Less than 100 kmph |
| Nellore | 60 mm | 60 kmph |
| Kakinada | 70 mm | 60 kmph |
| Chennai | 60 mm | 60 kmph |
| Vizag | 70 mm | 60 kmph |