High winds and heavy rain caused disruption as Storm Brian battered parts of Britain with gusts of almost 80mph.

The weather threatened to impact half-term travel plans as trees blocked roads and some flights were cancelled, less than a week after ex-hurricane Ophelia wreaked havoc.

The Great South Run in Portsmouth and Southsea was cancelled but Sunday’s events are due to go ahead amid a better forecast.

Gusts of 78mph, the highest recorded on Saturday afternoon, struck the Llyn Peninsula on the north west coast of Wales, the Met Office said.

A yellow weather warning for winds across a swathe of Britain, including Wales and southern England up to the Midlands and North West, will remain in place until midnight on Saturday.

Forecaster Luke Miall said: “There has been some travel disruption and some trees down. We have also seen coastal impacts, with waves breaking over sea walls.”

British Airways warned passengers of disruption due to the adverse weather, saying “a very small number of customers will be rebooked onto alternative flights”.

People have been advised to stay away from exposed coastal areas and urged not to take so-called “storm selfies” as high tides and a storm surge create dangerous conditions along some coasts.

The Environment Agency has issued dozens of flood alerts, as well as two flood warnings urging “immediate action”

Waves were seen crashing at Porthcawl in south Wales on Saturday morning, while Environment Agency workers were pictured erecting temporary flood barriers in Yarmouth on the Isle of Wight.

Up to 8.4mm (0.3ins) of rain fell in an hour in Port Logan, south west Scotland on Saturday afternoon with heavy rain expected in the North West of England as Storm Brian moves across from Ireland.

While the effects are already being felt, the storm is expected to make landfall in Britain in the Lancashire area later this evening, the Met Office said.

National flood duty manager for the Environment Agency Ben Lukey warned members of the public against posing for photos during the hazardous conditions.

He said: “We urge people to stay safe along the coast and warn against putting yourself in unnecessary danger by taking ‘storm selfies’ or driving through flood water – just 30cm is enough to move your car.”

National Rail warned the stormy weather could impact on train services, with emergency speed restrictions imposed on most of the routes in Wales.

Drivers were also urged to take extra care on the roads during high winds, as vehicle recovery and insurance firm the AA reminded motorists that surface spray, reduced visibility and potential flooding remained high risks.

The Energy Networks Association, representing the UK’s energy infrastructure, said residents could call the free 105 advice telephone number in case of damage to local network and power supplies.

Storm Brian is the result of a “weather bomb” of low pressure in the Atlantic Ocean.

It follows Storm Aileen, the first UK-named storm of the season, which left thousands of homes without power last month.