Network Rail has put 50mph speed restrictions in place for Southern Rail and Thameslink trains on coastal routes in Sussex and further west.
Littlehampton Harbour warned last night that a high tide was expected to cause flooding to boatyard and industrial areas, as well as local roads. It was predicted that, at 1.15pm, the tide would be 'higher than normal' due to Storm Barra, which brings Gale Force 8 Southerly winds.
The total forecast tide was 6.40 metres Chart Datum (3.35 mAOD) at Littlehampton.
The harbourmaster said: "We did have recordings of 6.60 metres, which is very high, and there has been some localised flooding over Climping way and Rope Walk way."
The early Wednesday morning tide, at 1.45am, is predicted to be 10cm lower, but will be accompanied by very large waves.
"We expect flood impacts could be similar," the harbourmaster said:
"Strong winds and large waves will continue until Thursday.
"We continue to monitor the forecast. If you have it, please install flood protection two hours before high tide."