The latest weather alert was issued by the Met Office shortly after 10.30am and is valid from 12.45pm to 6.00pm on Wednesday.
The warning applies to the vast majority of areas affected by flooding and torrential rain on Tuesday evening.
"Heavy showers and thunderstorms are likely to develop today, with some slow moving ones possible for a time, which could produce 20-30 mm of rain in an hour and 40 to 60 mm in 3 hours, along with lightning," reads the warning on the Met Office website.
Homes and businesses, including an Asda supermarket in the Ballyclare area, were badly affected by heavy rain and thunderstorms on Tuesday.
Some local businesses were forced to close to deal with the damage caused by the flooding.
The latest warning applies to every county in Northern Ireland except Fermanagh.
What to expect:
- There is a small chance that homes and businesses could be flooded quickly, with damage to some buildings from floodwater, lightning strikes, hail or strong winds.
- Where flooding or lightning strikes occur, there is a chance of delays and some cancellations to train and bus services.
- Spray and sudden flooding could lead to difficult driving conditions and some road closures.
- There is a slight chance that power cuts could occur and other services to some homes and businesses could be lost.