A large tidal surge is pushing up through the Severn Estuary
The Severn Bore is a natural phenomenon that causes a series of waves and is hotly anticipated by surfers, kayakers and paddleboarders
It's the only expected "five-star" bore of the year – meaning it's the biggest possible one
Here is a general view from the River Severn today where people have flocked to see the bore
Pictures are coming in taken by the BBC's live camera crew who are on a boat following the bore
A number of surfers are already up and riding the bore
Fiona Lamdin
BBC West
It is very cold and wet here on the banks of the River Severn.
There are probably around 40 people all with their hoods on and under umbrellas sipping coffee.
They are looking out at the brown water - you cannot imagine why they are here, but it is going to get very exciting.
Jon Smith
BBC Radio Gloucestershire Breakfast presenter
The excitement here has been building all morning.
The car park, I have got to say, is almost pretty full.
There were about 26 campervans overnight, for what is set to be the only five star Severn Bore of the year, and the first since 2019.
Remember you can listen to our live coverage on BBC Sounds
And if you see me, give me a wave!
Ross Mckellar and Jack Pullinger have come from Bristol and Bude, in Cornwall, to surf the bore for the first time.
They told the BBC it is something that has been "on their bucket list" and they will be "very happy if they catch it".
The most popular spots to watch the Severn Bore are on the horseshoe of the River Severn where, travelling towards Gloucester, the waves pass Newnham and Broadoak.
This is because the wave strengthens and gains speed for surfers as the estuary around Newnham-on-Severn begins to bottleneck.
These spots are the quickest to become busy.
Steve Potter, a surfer who’s already in his wetsuit ready to go, told BBC Radio 5 Live he first tried riding the wave in 2004, "didn’t get on very well".
"My wife surfed three quarters of a mile and I came off straight away," he said.
"But since 2010 I’ve really got into it - going along the river and talking to locals, finding places to surf.
“Depending on the conditions, you can get a seven minute ride for a mile.
"A five star wave brings the whole circus to town.”
The BBC Radio Gloucestershire team have been broadcasting live on the River Severn since 6:00 GMT and will stay there for the morning - listen live on BBC Sounds.
Broadcasting live from Broadoak, BBC Radio Gloucestershire breakfast presenter Jon Smith said people were arriving shortly after 06:00 GMT in nearby car parks.
You can listen to our live radio broadcast on BBC Sounds.
The BBC's Maddie Simpson captures a four-star bore on the Severn and preludes the expected five-star bore
Daytime five star bores like today's do not happen often - the last of its kind was in March 2019. It is also expected to be the only one of its kind this year.
But small bores such as one and two star occur frequently, as do three stars.
Four star bores take place fairly occasionally, with the last being at night on Monday.
The size of the Severn Bore ranges from five - the largest, to one - the smallest.
A number of factors determine its size, such as wind speed and direction and the time of the high tide.
The rarest five star bore - like today's - has a range of at least 17.71ft (5.4m).
The time is neither the same nor guaranteed.
But the five star bore on 12 March is expected to be at its peak in Newnham at 08:21 GMT and 09:56 GMT on the Over Bridge in Gloucester.
Sometimes the bore can arrive early or late depending on the weather conditions.
This was the Severn Bore in February last year
Today's daytime five star Severn Bore is the first for five years - marking a special event for hundreds of fans.
The Severn Bore is caused by the tide from the Atlantic Ocean entering the Bristol Channel, pushing up through the Severn Estuary.
The tide filters into a narrow channel, causing them to rise up to 49.21ft (15 metres) and wave speeds can reach up to 21km/h (13mph).
What makes the spectacle even more attractive are the surfers, kayakers and paddleboarders who ride the waves.
We are here to guide you through this morning's exciting natural phenomenon - which hasn't happened in the day time for roughly five years.
But you may well be asking, what actually is the Severn Bore and what makes it "five-star"?
Keep following this page to find out!