Residents in part of East Belfast have been warned to prepare for flooding because of high tides and heavy rain predicted for tomorrow.
Tidal surges are predicted for midday tomorrow, Saturday and Sunday across Northern Ireland and police asked members of the public to avoid coastal paths and to drive with extreme caution.
High risk areas include the densely-packed residential streets of Sydenham in the east of Belfast and around the docks.
Police Service of Northern Ireland (PSNI) Assistant Chief Constable Stephen Martin said: “The combination of heavy rain, strong winds and high tides beginning tomorrow and lasting throughout the weekend has created the potential for flooding in a number of coastal areas across Northern Ireland.”
Police are coordinating a major planning operation involving many public services.
The Office of First Minister and Deputy First Minister, Belfast City Council, Northern Ireland Fire and Rescue Service, the Rivers Agency, Belfast HealthTrust, Road Service, Northern Ireland Water, Northern Ireland Electricity, British Telecom and Translink are cooperating.
Mr Martin said: “We would ask residents in Sydenham to consider making preparations for potential flooding in the area. We will be working to provide assistance for those who may be affected.
“In general, over the weekend we would ask all members of the public to stay away from coastal paths and walkways and to drive with extreme caution.
“Over the rest of the day we will issue further information and we will, as usual, be issuing regular traffic and travel updates via the media.”
Other areas that could be affected to a lesser extent than Belfast include Larne, Newry, Newtownards and Clough in counties Antrim and Down.