Bhubaneswar, Oct. 9: The regional meteorological centre here today predicted that the formation of a deep depression over the Bay of Bengal would bring heavy to very heavy rainfall to the northern and southern belts of the state over the next 24 hours.

The Met centre, which has also raised a local cautionary cyclone warning at all its ports, traced a depression over the Bay of Bengal off the Odisha coast this morning. Sources in the department said the depression had since intensified into a deep depression by the evening.

'A depression has formed over Bengal and adjoining north Bay of Bengal. It lay centred about 220km off Balasore and about 350km off Paradip at 5.30am. The system is likely to move towards the west-northwest and intensify into a deep depression during the next 24 hours,' said the bulletin issued by the weatherman.

The bulletin also said heavy to very heavy rainfall would occur at one or two places in Balasore, Bhadrak, Jajpur, Keonjhar, Sundargarh, Angul, Dhenkanal and Mayurbhanj districts, while Sonepur, Deogarh, Boudh, Jharsuguda and Sambalpur districts would receive heavy rainfall during the next 24 hours.

'The system over the sea remains strong as of now. It will trigger rainfall at most places in the northern and southern parts of the state over the next 24 to 48 hours. Many places will also witness heavy flow of wind as part of the system. Such weather conditions will continue till mid-October. The situation will improve thereafter,' said Met director Sarat Chandra Sahu.

The inclement weather has already forced six Calcutta-bound flights to make emergency landings at Biju Patnaik International Airport here in quick succession today. The six flights included four IndiGo planes and one Air India and GoAir flight each. The flights landed at the city airport between 9.30am and 10.30am.

Airport sources said that while two Delhi-Calcutta IndiGo flights made emergency landings at the airport, two other Calcutta-bound IndiGo flights, one from Hyderabad and another from Guwahati - also made emergency landings. Similarly, a Bangalore-Calcutta Air India flight and a Ahmedabad-Calcutta GoAir flight also made emergency landings. Airport officials said all the flights took off after two-and-a-half hours.

The airport's acting director Yudhisthir Sahoo said the flights made emergency landings because of zero visibility at Calcutta airport. 'The scheduled operation of flights from here was not hampered because of the emergency landings. Passengers of only one flight were deplaned,' he said.

Rain continued to lash several parts of the state over the past 24 hours with Talcher recording the highest amount at 95mm, followed by Bhawanipatna with 48mm, Titilagarh with 30.6mm, Bhubaneswar with 18.4mm and Baripada with 15mm. Few other places also recorded minor rainfall during the same period.

The average minimum and maximum temperature across the state also fluctuated. The average maximum temperature remained 1 to 3°C below normal, while the minimum temperature remained 1.6 to 3°C above normal.