The India Meteorological Department (IMD) said rainfall would be accompanied by gale wind speed reaching 140 to 150 kmph and gusting to 165 kmph along and off Odisha and north Andhra Pradesh coasts.
The Centre has deployed 14 NDRF teams in 11 Odisha districts: Balasore, Sambhalpur, Gajapati, Nayagarh, Puri, Jajpur, Kendrapara, Bhadrak, Jagatsinghpur, Ganjam and Bhubaneswar. Four NDRF teams have been deployed in Andhra Pradesh's Visakhapatnam, Srikakulum and Vijaynagram districts.
Odisha Chief Minister Naveen Patnaik asked the collectors of Ganjam, Puri, Khurda, Kendrapara and Jagtsinghpur districts to start immediate evacuation of people in the low-lying areas in the coastal belt.
Patnaik also ordered closure of all schools, colleges and anganwadi centres on Thursday and Friday in view of IMD's forecast of heavy to very heavy rainfall across the state.
Railway Recruitment Board (RRB) exam that was scheduled to be held on October 11-12 in Bhubaneswar, Cuttack, Dhenkanal, Sambalpur, Khurda and Berhamapur has been cancelled.
"By Wednesday afternoon, as many as 50,000 people, mostly in Ganjam and Puri districts, have been evacuated," an official at the Special Relief Commissioners (SRC) said, adding the evacuation process was on full swing in 17 blocks of Ganjam district.
Official sources said 9,83,642 people were evacuated when Cyclone Philin hit the state in 2013 and 2,55,042 people were shifted to multi-purpose shelter centres during Cyclone Hudhud in 2014.
The IMD said Cyclone Titli has moved at a speed of about 18 kmph in the last six hours over west-central Bay of Bengal and lay centred at about 230 km south-southeast of Gopalpur in Odisha.
The storm is likely to move north-northwestwards and cross Odisha and adjoining north Andhra Pradesh coast between Gopalpur and Kalingapatnam around 5.30 am on Thursday morning, it said.
Thereafter, the cyclone is likely to re-curve north-eastward, move towards Gangetic West Bengal across Odisha and weaken gradually, H R Biswas, director of the meteorological centre in Bhubaneswar, said.
While several areas in coastal Odisha were lashed by rain on Wednesday, the IMD has forecast "heavy to very heavy rainfall" at several places and "extremely heavy rainfall" at isolated areas till Thursday under the impact of the 'very severe' cyclonic storm.
Districts like Ganjam, Gajapati, Puri, Jagatsinghpur, Kendrapara, Khurda, Nayagarh, Cuttack, Jajpur, Bhadrak and Balasore are likely to receive heavy to very heavy rainfall till Thursday, the IMD said.
It also forecast heavy to very heavy rainfall for Kandhamal, Boudh and Dhenkanal districts from Thursday.
(With PTI inputs)