Severn Bore 2024: What is it, what causes the huge tidal wave, where is it located - and will it be a five star?

This morning (Tuesday 12 March) surfers have flocked to Gloucestershire to ride the first five-star Severn Bore since March 2019. The huge tidal wave, which pushed up from the River Severn Estuary into Gloucester, attracts people from all over the UK.

The natural phenomenon is caused by the tide from the Atlantic Ocean into the Bristol Channel. The waves are expected to reach a height of 10.3 metres and fans were keen to get a glimpse, as well as people taking the opportunity to get out their surfboard and paddle boards to ride the waves.

Factors such as wind speed and direction at the time of the high tide determine how big the waves get. The scale of the Severn Bore is graded between five and one, depending on the size. One and two-star bores are frequent, four-stars happen occasionally, but a five-star bore is a rare event that hasn't happened on the Severn in five years.

People have camped overnight to get a good spot in the morning, with the busiest spots to watch the Severn Bore being Newnham and Broadoak where the wave strengthens and picks up pace. One surfer, Lloyd Russell, travelled all the way from Cornwall to take part.

He told the BBC's Today Programme: "It's muddy, it's dirty, it's not glamorous. Everything smells. A little bit of poo and muddy rivers. You get out of the river and you're absolutely caked in mud. It's quite fun really. Sliding down the river banks."

Colonel ‘Mad’ Jack Churchill, was the first person to surf the Severn Bore back in 1955. A group of Cornish lifeguards followed his feat in 1962, and the longest successful surf now yields a spot in the Guinness Book of Records. The current top spot holder is Steve King, a Gloucestershire rail engineer, who surfed the Severn for 7.6 miles in 2006.

There is a full timetable at the Severn Bore website, which predicts bore time and quality a year in advance. Participants should enter the water at least 20 minutes before the bore’s ETA, as the surges do not always keep to schedule.