It's a 15:10 BST start - any interruptions now will knock off some overs.

Hmmm, the groundstaff are poised to come on even though the sun is still out. We can only surmise that it's about to hoy it down - that's a technical term for 'raining'.

James Gulleford: Totally disagree with the comments that Hampshire got done by DLS! At the start of the Essex innings they needed 8.55 an over, after the rain they had to get over 10 an over! If anything Essex were done by DLS but overcame it!

There's a slight delay, they won't be starting at 15:00 BST but the sun is still out.

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There is an 11-year age gap between Laurie Evans and opening partner Will Jacks, but together they have scored 1,112 runs for Surrey in this season's T20 Blast.

Jacks heads the competition's six-hitting list with 31, but Evans is only six behind and hit a brilliant unbeaten 118 not out off 60 balls against Glamorgan in June.

When Jacks fell early in their quarter-final against Lancashire, it was Evans who laid the platform for a winning total of 187-5 by making 70 off 41 balls and sharing a stand of 72 with Jason Roy (50).

Evans was a member of the Birmingham Bears Blast-winning side in 2014, scoring 53 off 30 balls in the final, and made another half-century in a losing cause as Sussex Sharks lost to Worcestershire four years later.

Right, well after the main event (ahem), some cricket may break out soon.

The sun is back out, we could get a start shortly.

Image source, Rex Features

When Somerset signed New Zealand's Matt Henry for the first half of the 2023 season, they knew exactly what they were getting - a respected international pace bowler with considerable experience, capable of making an impact in any format.

Although his 24 wickets in this season's T20 Blast is three fewer than team-mate Ben Green, their strike rates are almost exactly the same, while Henry's economy rate is superior.

He saved his best performance for their group game against Surrey at the Oval, taking 4-30 including the vital wicket of Sam Curran for 47 in the 18th over.

In their five-wicket quarter-final win over Notts Outlaws, Henry's figures of 1-27 were tidy, rather than spectacular, but removing the dangerous Joe Clarke for two was an important contribution.

Lanky the Giraffe had a great start and romps home!

There were some appalling scenes of carnage at the obstacles, Freddie the Fox came second and Lanky is now milking it in front of the Hollies Stand.

No northern sides here today, but a momentous win for Lancashire there.

Image source, Rex Features

One of Somerset's two group defeats was a 28-run defeat by Surrey at Taunton last month.

After winning the inaugural T20 Cup in 2003, Surrey have been back to the final three times since without success, with their most recent appearance in 2018.

They bounced back from a run of three successive defeats at the end of the group stage to beat Lancashire by 13 runs in the last eight and book their eighth trip to Finals Day.

"We know lots about Somerset and they know lots about us," head coach Gareth Batty told BBC Radio London.

"Can we just have the edge? We believe we are in a very good place. It is about enjoying the occasion and coming away with two wins."

Image source, Rex Features

Somerset reached their third Finals Day in a row with a five-wicket win over Notts Outlaws, after setting a new record for the most matches won (12) en route to topping the South Group.

Beaten in the last four by Hampshire in 2022, the county won the competition for the only time in 2005 and have been runners-up a record four times since.

Head coach Jason Kerr said confidence is "incredibly high" and has been reflected in the side's performances this year.

"There's times when we've been under pressure and we've found a way to win," he told BBC Radio Bristol.

"We're arguably the best team in the country and we need to go and deliver that on Saturday. The true test is actually to bring the trophy home.

"Last year, looking back, we didn't turn up."

The mascot race has started just as the rain begins to fall again. Will it affect their performances?

The going - good to slippy.

Image source, Getty Images

Somerset and Surrey have met 21 times in the domestic T20 competition, with the men from London ahead by 13 wins to eight - two matches were abandoned.

Although the game's shortest format began in 2003, it was not until 2010 that they played each other for the first time.

They faced off in a last eight match in 2013, when Surrey chased down a target of 149 to win by three wickets, only to lose to Northants Steelbacks in the final.

This season, Surrey won by 28 runs at Taunton in June following Will Jacks' 60 off 43 balls, but Somerset gained revenge two weeks later at The Oval as Tom Banton's 84 off 44 balls saw them to 208-5.

Image source, Getty Images

Somerset have won 13 of their 15 games in the 2023 Blast, four more than Surrey, who lost three in a row before bouncing back to beat Lancashire Lightning in the quarter-finals.

Alex Hartley
Former England bowler on BBC Radio 5 Sports Extra

You might say Surrey might have stronger names on paper with the likes of Chris Jordan, Jason Roy and Will Jacks but Somerset have got the momentum and they have played some fantastic cricket.

They also have Will Smeed, Tom Banton and Tom Kohler-Cadmore who are three incredibly destructive players.

So it's 2005 winners Somerset against inaugural 2003 champions Surrey in the second semi, with Essex awaiting them in the final.

Surrey skipper Chris Jordan has won the toss and chosen to bowl first - "we want to get out there and make some early inroads," he tells BBC 5 Live Sports Extra.

They make two changes to the XI for their quarter-final as Tom Curran and Cameron Steel come in for Dan Moriarty and the absent Sunil Narine.

Somerset give 19-year-old spinner Shoaib Bashir only his fifth T20 appearance in place of Jack Brooks.

Somerset: Banton, Smeed, Kohler-Cadmore, Abell, Dickson, Gregory, Green, C Overton, Henry, Sodhi, Bashir.

Surrey: Jacks, Evans, Roy, S Curran, Smith, J Overton, Abbott, Jordan, T Curran, Atkinson, Steel.

Richard Vaughan: On paper, this is not an overly strong [Essex] team. But my god, they fight for each other, and it’s incredible to watch!

Image source, Getty Images

Matt Critchley speaking to BBC Radio 5 Sports Extra:

"A short chase favoured us. We'll wait around now, we'll watch the next game and try to relax a bit."

Glenn Maxwell
Australia all-rounder on BBC Radio 5 Sports Extra

It's that man Simon Harmer again! He has ice in his veins. What a way to finish the game.

The holders are out.

Another slower ball is picked by Simon Harmer who smashes it 20 rows back over Cow Corner to spark wild celebrations.

Only three balls of the final over needed. Heartbreak for Nathan Ellis, the hero last year.

Matt Critchley, so impressive with the ball earlier, finishes unbeaten on 26 from 14 deliveries, two of them clearing the ropes, with Harmer ending on eight not out from three delivieries with that six which will live in Essex folklore.

His side will face Surrey or Somerset in the T20 Blast Final later today (weather permitting!)

Image source, Getty Images

for Matt Critchleypublished at 11.1 overs

11.1 overs

Slower ball first ball, wide from Nathan Ellis, Matt Critchley slaps it deep into the stands.

Seven needed off five balls.