Postpublished at 17:00 British Summer Time 26 August 2023
Laura Harris and Tammy Beaumont then upped the tempo with some outrageous hitting, before lightning brought an early end to the match.
Well, I'm sorry to say we'll be leaving you there. Here's Stephan Shemilt's report from the ground.
Hopefully we'll get a better outcome for Manchester Originals v Southern Brave in the men's competition. us at 17:30 BST - we'll be on weather watch for that one.
See you soon.
Laura Harris and Tammy Beaumont then upped the tempo with some outrageous hitting, before lightning brought an early end to the match.
Sophia Dunkley had some big hits, but holed out to the boundary off the bowling of Lucy Higham. A disted Hayley Matthews followed, with Litchfield holding onto the catch.
Northern Superchargers captain Hollie Armitage on BBC Two: "Mother nature was on our side today. It's hard for the Welsh Fire and it's not how anyone would like to go out of a competition.
"But I'm proud of my team because we definitely deserve our place in the final. It's mixed emotions right now because of how it has come to an end here but the excitement will kick in soon.
"We are ready for a competitive game tomorrow. We've got a lot of confidence even though we know they are a very strong team.
"We are playing as a real unit and we showed that with the ball and in the field today. It was only 75 balls but it has given us a lot of confidence."
Tash Farrant
England bowler on BBC Two
It's not the way you want it to end.
There's nothing that can be done, though. It'll be a weird feeling for Superchargers because it's not how they would have envisioned getting through to the final.
The Welsh Fire players will be absolutely gutted.
We had some fun in the field before this match was brought to a premature conclusion.
Jemimah Rodrigues pulled off a remarkable retrieval at the boundary, but Phoebe Litchfield dropped opener Tammy Beaumont.
Carlos Brathwaite
West Indies all-rounder on BBC Two
It will be an emotional time for Alex Hartley and not the way she would have wanted to end her career.
But she can reflect on an incredible career. She will be ed for what she has given both on and off the field.
Tash Farrant
England bowler on BBC Two
Welsh Fire can still be so proud of their turnaround. This is a really sad way for it to end.
They were getting themselves into a brilliant position in the game, too.
This also sadly represents the end of Alex Hartley's career as a professional cricketer. She was set to retire at the end of the tournament and Fire's exit today confirms she will not have another chance to make it onto the field.
The spinner represented England between 2016 and 2019, winning the ODI World Cup at Lord's in 2017.
The players have shaken hands and are picking up their gear from the dug-outs. There's inevitably some very sad faces in the Fire group.
They've called it - there's still black skies over The Oval and if there's still lightning in those clouds then the players can't make it back onto the field prior to the 17:11 cut-off.
That means the Superchargers progress to tomorrow's final. A sad end to the Fire's tournament - having finished bottom last season, they'd make great progress this season.
Well, maybe I spoke too soon, it has now stopped raining at The Oval.
We now face a race against time for the teams to be back out by 17:11 BST.
It's raining at The Oval now. We've been told that the latest we can resume for a 25-ball game is 17:11 BST. I wouldn't hold out much hope for that.
Assuming we don't get back on, Northern Superchargers will advance to tomorrow's Lord's final with Southern Brave. They will do so by virtue of their league table position, having finished second to Fire's third.
We have further news - the Fire innings has been declared over and the players are taking their break. We'll have news of what target the Superchargers will chase (and from how many deliveries) once the weather es.
That's a big blow for Tammy Beaumont's charges. They'll be grateful they had that one explosive set at the close, but that partnership looked like they could have gone very big.
So we've got the official lightning regulations (who knew?) - the players will not return to field until 30 minutes after the last lightning or thunder strike or unless the match officials are confident the storm has ed.
There's currently a huge black cloud above The Oval, so I don't think we need to concern ourselves with the second part of that regulation.
Well, Tammy Beaumont and Laura Harris have brought the thunder, but the elements have offered up the lightning.
There's electricity in the air and that's not just because of the Fire batting.
The players are being taken off as a safety precaution and we've got some of our beloved plastic sheeting being brought onto the pitch.
Beaumont takes a leg-side single to finish the set.
15 from the set - Cross finishes with 0-34. Superchargers take their strategic timeout to regroup.
Tash Farrant
England bowler on BBC Two
It was just right in the slot and Tammy Beaumont lined it up perfectly.
Tammy Beaumont fancies a bit of the action!
Cross's ball sits up well for her and the Fire opener dispatches her first six over mid-wicket.
That's the Fire hundred up in style.
Carlos Brathwaite
West Indies all-rounder on BBC Two
Just a bit of arrogance from Laura Harris and I really like it. I'm speechless!