Gale force winds combined with high tides along parts of the coastline could lead to flooding, the Environment Agency (EA) has warned.
The west and south coast of Wales, and the coasts of Devon, Cornwall and Somerset are likely to experience gusts of up to 60mph.
The EA said the strong winds would cause stormy seas which, combined with some of the highest tides of the year, would lead to soaring sea levels and spray coming over sea walls.
Sky News weather presenter Nazaneen Ghaffar said: "Low-lying coastal roads, farmland and houses along these coastal areas could be vulnerable to flooding due to the strong winds given high tides and big surges, with spray coming over sea walls.
"The strong winds could also cause potential drainage problems due to some leaves and small branches from trees being blown off. The rain band will clear northwards tonight, leaving it drier but with some heavy showers."
Gusts of 50 to 55mph are expected throughout the day along the southwest coast of Wales and could reach up to 60mph in places.
In Devon and Cornwall winds of between 40 and 55mph are forecast.
The Met Office said winds were expected to increase to "gale or severe gale force" on exposed parts of the coast, which could lead to localised disruption to transport.
The EA said its teams had been out checking flood defences and closing tidal gates ahead of the high tides, and warned people to be careful driving or walking along the coast over the next few days.
People should be particularly careful on exposed areas, where there is a risk of being swept away by waves or being hit by debris thrown up by waves, the agency added.
The flood warnings in place are mainly across western areas, meaning flooding is expected and immediate action is required by people living in the affected areas.
Scores of less serious flood alerts are also in place.