Strong winds are expected to hit Sussex on Wednesday (March 13).
The Met Office, which issued the yellow weather warning today, said strong northwesterly winds may cause possible road and rail disruption in the county.
It added the winds across Northern Ireland are expected to extend across much of England and Wales throughout Wednesday.
Gusts of up to 50-55mph are likely inland and 65mph along the coasts.
But the Met Office added winds will gradually ease during the afternoon.