The warning was issued last night as the army was deployed on the streets to help with the massive cleanup operation in the wake of hurricane-force Ophelia.
Council engineers are monitoring river levels and liaising closely with weather forecasters amid fears the region could take a direct hit from Storm Brian, which is expected to make its presence felt later today and tomorrow.
A status yellow weather warning for rain was issued yesterday for Munster, Dublin, Carlow, Kilkenny, Louth, Wexford, Wicklow and Meath, and is valid until midnight tonight, with heavy rain expected with accumulations between 30mm and 50mm possible.
City Hall said the latest estimate is that between 15mm and 20mm could fall in Cork City today.
“In addition there is also a possibility of heavy rain on Friday,” a spokesperson said.
“Wind speed won’t be as high as during Storm Ophelia but there is still a risk of further weather damage on Thursday and Friday due to the fragile status of trees and damaged built structures following the recent hurricane winds.
“Flooding is also possible at Morrisons Island, South Terrace and Wandesford Quay from 5.30pm to 7.30pm on Friday due to high tides.
“Over the next 24 hours the storm surge model will be monitored and a further update will issue today.”
Business and property owners in flood-risk areas have been advised to be on standby to take precautions to protect their property.
The news emerged last night as members of the Defence Forces — with specialist chainsaw skills — were deployed to help clear some of the city areas worst hit by Monday’s unprecedented hurricane-force winds.
They tackled fallen trees on Inchigaggin Lane and are due to focus their attention in some of the city’s parks, including Fitzgerald’s Park and Kennedy Park today.
There was significant clean-up progress in the Centre Park Road area where up to 30 historic trees, some over a century old, dating from the time Henry Ford established his first factory outside the US in the area, were knocked by Monday’s ferocious winds.
Their massive root systems ripped up tarmac and pavement, leaving gaping 15ft craters along one of the main access routes to the region’s flagship GAA stadium.
With the official opening of the revamped Páirc Uí Chaoimh due to take place on Sunday in association with its hosting of an intermediate hurling championship game and the Cork County Senior hurling championship final, a raft of meetings took place yesterday to organise access to and from the stadium for the thousands of fans expected to attend.
City Hall and the Defence Forces were working last night to co-ordinate a programme of clearance works, while the Cork County Board, city engineers and gardaí were all liaising on a traffic and pedestrian management plan.
The lost trees on Centre Park Rd are among an estimated 300-350 trees across the city which are expected to have been lost once clearance work is complete.
City Hall said it expects tree clearance work alone to continue well into next week.
Fitzgerald’s Park and Mahon Golf Course, where several trees fell, are expected to remain closed until after the weekend.
Meanwhile, the national emergency co-ordination group on severe weather met again last night for a briefing on the response to Storm Ophelia.
The number of people without water supply had been reduced from a peak of 109,000 to 66,000.
ESB Networks has restored power to 216,000 homes and businesses in the last 24 hours — about 60% of the 385,000 homes and businesses without power on Monday.
As of last night, 7% of homes and businesses nationwide were still without power.
Cork, Tipperary and Kerry have been worst affected, and it is anticipated that it will be early next week before power is fully restored to a small number of customers in these areas.
The company said it has deployed 2,500 staff in the recovery effort, and an additional 1,000 contractors have been drafted in, with additional resources from the North, Britain and France helping in the repair and reconnection effort.
ESB Networks said it will publish restoration times for all customers still without power on its PowerCheck app this morning.
The Defence Forces deployed personnel and vehicles from the 3rd Infantry Battalion to Kilkenny to help with road clearance and a 10,000-litre water tanker was dispatched to Killmagany in Kilkenny.
Two Air Corps EC 135 helicopters were helping ESB Networks with aerial inspections of powerlines in the Midlands and South-West. The operation is expected to continue today.
Local authorities confirmed most of the country’s regional roads have been cleared of fallen trees and the work now begins to assess damage caused to dwellings and other buildings and structures, coastal infrastructure, parks and amenities.
Health services are expected to gradually return to normal over the next few days, however some continued disruption is likely.
It is expected that emergency departments and GP clinics will be very busy over the next few days, with increased demands on those services.