Play has started at Trent Bridge, with hosts Nottinghamshire taking eight runs from Oliver Hannon-Dalby's opening over.

They're under way at Bristol as well, with Chris Nash getting Sussex off to a bright start against Gloucestershire. Nash has hit 12 runs from six balls to help the visitors to 24-0 after two overs.

Former England captain Alec Stewart helps out with fielding practice before Surrey's game against Essex at Chelmsford - coming up in about 40 minutes.

Image source, Rex Features

Gloucestershire have won the toss at Bristol and will bowl first against Sussex Sharks.

The hosts welcome back captain Michael Klinger for his first appearance of the season, the Australian having averaged 81.75 in the T20 Blast in 2015.

Image source, Rex Features

Last year's quarter-finalists Sussex are without several star players, with England pace bowler Chris Jordan and Bangladesh seamer Mustafizur Rahman playing in the Indian Premier League, and captain Luke Wright missing with a back injury. 

Gloucestershire: Klinger, Marshall, Bancroft, Dent, Cockbain, Howell, Taylor, Smith, Miles, Payne, Liddle.

Sussex Sharks: Nash, Brown, Taylor, Cachopa, Machan, Salt, Beer, Robinson, Briggs, Shahzad, Mills.

Tom Kohler-Cadmore now has Worcestershire's highest ever score in T20 cricket - surpassing Graeme Hick's 116 not out in 2004.

He's up to 117 and doesn't look like stopping. Stunning.

Birmingham Bears have won the toss at Trent Bridge and elected to put hosts Nottinghamshire in to bat.

Notts are captained by all-rounder Dan Christian for the first time, with the former Australia international being named James Taylor's replacement as skipper for the T20 Blast prior to Taylor's unfortunate retirement.

Image source, Getty Images

New Zealand wicketkeeper Luke Ronchi makes his debut for the Bears, as they start their attempt to regain the title they last won with victory over Lancashire in 2014.

Outlaws: Lumb, Wessels, Smith, Christian (captain), Patel, Mullaney, Read, Wood, Hutton, Fletcher, Gurney.

Bears: Hain, Bell (captain), Porterfield, Evans, Ronchi, Woakes, Javid, Patel, Gordon, Hannon-Dalby, Wright.

Another over, another six to start it from Tom Kohler-Cadmore who is now up to 109.

Paul Coughlin has 1-29 off his three overs - not too bad considering the carnage that is going on at New Road!

Also, thanks to BBC Newcastle's Martin Emmerson for this little gem...

TOM KOHLER-CADMORE HITS A CENTURYpublished at 18:15 British Summer Time 20 May 2016

18:15 BST 20 May 2016

Worcestershire 131-3 v Durham (11.3 overs)

Forget Gayle. Forget De Villiers. Forget Kohli. That is one of the best T20 hundreds you will ever see from Worcestershire opener Tom Kohler-Cadmore.

He takes just 43 balls to get there, with 13 fours and five sixes. 

Whisper it quietly, but Chris Gayle's 175 not out is the highest ever score in T20 cricket. 

Tom Kohler-Cadmore is just two away from a maiden Twenty20 hundred.

He launches Keaton Jennings for his fifth maximum, with another wonderfully clean strike as 14 come off the over. 

This is relentless run-scoring.

Ross Whiteley continues the onslaught with a six off Scott Borthwick's first ball of the 10th over.

Worcestershire are on for a mammoth total.

The news at Grace Road is that Northants Steelbacks have won the toss and opted to bowl. There is no David Willey any more for the 2013 winners, with the all-rounder having joined Yorkshire over the winter, but they do have Sri Lankan signing Seekkuge Prasanna as they look to reach finals day for the third time in four years.

Leicestershire have Pakistan batsman Umar Akmal in their side, fresh from making 51 off 27 balls in a warm-up game earlier this week, and big-hitting Ireland all-rounder Kevin O'Brien makes his debut.

Foxes: Pettini (captain), Cosgrove, K O’Brien, Akmal, N O’Brien (w/k), Wells, Dexter, Taylor, Raine, McKay, Naik.

Steelbacks: Wakely (captain), Levi, Cobb, Duckett, Rossington (w/k), Prasanna, Kleinveldt, Crook, White, Azharullah, Stone.

Philip Mulligan on Twitter: "One of the handful of away fans at grace road. Come on Northants #bbccricket #t20blast."

Of the 40 batsmen to reach 300 or more runs last year, only Chris Gayle (192.9) managed a higher strike rate than Ross Whiteley.

I think Worcestershire need to up their run-rate, it's only at 11.33, so he's the ideal man!

Scott Borthwick removes Joe Clarke with his first ball as Clarke skies the spinner to Calum MacLeod for nine.

New Zealand all-rounder Mitchell Santner is the new batsman - now he can strike a ball too!

Just how many are Worcestershire going to get here? Another two boundaries come off Keaton Jennings first over and they're up to 90.

The run-rate is 12.85.

By my maths - that's about 250 off 20 overs. 

Erm, what on earth are we seeing here?! This is strokeplay from another planet.

Tom Kohler-Cadmore hits Durham spinner Ryan Pringle for three more boundaries in the sixth over and is up to 71 off 27 balls.

Kohler-Cadmore has 71 out of Worcestershire's total of 79. Unbelievable.

The thought of facing a hard ball coming towards you at over 80mph would be enough to give many non-cricketers the shakes - in this case GB athlete Perri Shakes-Drayton, who was at last week's T20 Blast launch in Loughborough.

Image source, Getty Images

Tom Kohler-Cadmore hits 50published at 17:50 British Summer Time 20 May 2016

17:50 BST 20 May 2016

Worcestershire 64-1 v Durham (4.5 overs)

Oh my word, this is sensational striking from Tom Kohler-Cadmore! After hitting Barry McCarthy for three fours, he launches him for two sixes to bring up his half-century.

It came off 21 balls with six fours and four sixes.

He rounds off the over with another four. 28 come off it. Wow.

If this is a taste of things to come, we're in for a feast!