The Met Office has issued a severe weather warning for Northern Ireland.
Heavy rain is forecast throughout the day.
The weather warning applies to all counties throughout Northern Ireland and is valid from 12pm through to 8pm on Wednesday.
Spray and flooding on roads could lead to difficult driving conditions and longer journey times.
There is a lower likelihood of isolated property flooding.
"Rain will become more persistent and widespread across Northern Ireland this afternoon and into the early evening. 20-25 mm of rain may fall in some spots in less than six hours," said the Met Office's Chief Forecaster.