Thunderstorms and high winds are expected to cause to further travel chaos and cancellations of high-profile events across Britain this weekend.

Yellow warnings for stormy weather in Scotland and Northern Ireland, and for strong winds across Wales and most of England, have been predicted by the Met Office.

Gusts of up to 50mph were recorded on Saturday morning in coastal areas, according to the forecaster Craig Snell.

Heavy rain caused flooding on the west coast mainline between Carlisle and Lockerbie, leading to its closure. Network Rail Scotland tweeted pictures of the flooding and reported that the water level was up to 30cm above the rails.

Rainfall has affected the northern border areas of England and Scotland generally, with further rain expected as heavy and slow-moving thunderstorms roll through the region.

Snell said: “No matter where you are in the UK you’re at risk of seeing some kind of localised disruption from wind. It’s a case of staying in touch with weather forecasts and being prepared for extra travel time as there may be road closures due to localised flooding.”

While Sunday was expected to be less windy, Snell said the weather would still be unsettled.

A nine-year-old was in police protection after being found under Brighton pier during the storms in the early hours of Saturday. Two adults who were with the child were arrested on suspicion of neglect and remain in custody. Volunteers from Brighton beach patrol said: “The child is now safe, which is a great outcome for us all.”

A fallen tree on the line between Ashford International and Hastings train stations caused service cancellations on Saturday morning, although the obstruction had since been cleared.

Trees were brought down across Sussex, with at least two cars badly damaged after part of a tree collapsed in Old Shoreham Road in West Sussex. Another tree fell on Dyke Road in Brighton.

Elsewhere, services have resumed between Guildford and Reading after a fallen tree was removed from the line near North Camp.

In Russell Square in London, a short walk from Euston and Kings Cross stations where thousands were left stranded on Friday night after a nationwide power cut, a tree was blown over in the wind, forcing authorities to close the area.

Further north, heavy rain flooded the line between Penrith North Lakes and Carlisle, meaning trains were running at a reduced speed with many services delayed or cancelled.

Music festivals and smaller events have been cancelled because of the bad weather. Boardmasters, a surfing and music festival in Cornwall, was the first to be cancelled when organisers blamed “severe weather conditions”.

Some people had travelled from as far as the US to attend the event, but only found out about the cancellation late on Tuesday. The event was expected to draw 50,000 people, and featured bands including the Wu-Tang Clan.

A second music festival, Houghton, in Norfolk, was called off the following day after the weather dramatically worsened the already waterlogged site.

Organisers of Bristol’s international balloon fiesta scaled back the event, including cancelling Friday’s mass ascent.

Several weekend LGBT+ Pride events, including in Chester, Milton Keynes and Plymouth, were postponed for reasons of safety. Organisers for all three said they were working to rearrange the events.

The first day of Blackpool air show on Saturday was cancelled when afternoon winds of 45mph were forecast. “The safety of the pilots and the watching public is paramount,” a spokesman said, adding that Sunday’s events were still scheduled to go ahead.

The nearby St Anne’s international kite festival was also cancelled.

The London wildlife festival, scheduled on Saturday and Sunday at Walthamstow Wetlands, was cancelled after winds of 40mph were forecast. Organisers said they were unable to “proceed safely” but promised to refund tickets.

On Saturday, Nantwich antiques market in Cheshire was cancelled due to the weather warning for strong winds.

At the National Eisteddfod of Wales, organisers of the week-long cultural festival closed part of the event early due to the conditions. Other performances and events carried on, including Friday’s Crowning of the Bard ceremony in which the poet T James Jones was presented with the 2019 Eisteddfod chair.