The key factor affecting the Red Bull vs Mercedes battle in Austria

The 2021 Formula 1 season battle between Red Bull and Mercedes has seen the momentum swing between each team at different races. But the matter of who will have the upper hand at the upcoming Styrian Grand Prix could be more difficult to predict due to a factor out of anybody's control.

According to pundits Paul di Resta and Karun Chandok, the weather might play a crucial role in the fight when the first of two back-to-back races at Austria's Red Bull Ring takes place this weekend.

"The weather can play such a key part," di Resta told Sky Sports F1. "Whether it's very hot, it cost Mercedes a couple of years ago. And equally it can be wet, thunderstorms, all these things in the mix.

Chandok added: "Actually, on that point, the forecast for the first of the two races is for thunderstorms. I think it's thunderstorms from Thursday until Sunday next weekend in Austria, so it could be a very unpredictable weekend."

Despite this, Chandok believes that Red Bull could have the advantage over Mercedes given their solid performances at the track in the past, with Max Verstappen having won there twice.

"It's a circuit where they've been very strong before," the former F1 driver said. "I think he's [Verstappen] won there twice now.

"I would say the momentum is with them. They'll take a lot of confidence from the way the whole team works strategically, engineering, the whole operation worked so well this weekend [at the French Grand Prix].

"They carry that confidence into the next two."

Meanwhile di Resta is not willing to rule out the ability of Mercedes and Lewis Hamilton to come back strong.

"I don't think you can pick a favourite and that's what's absolutely supreme about this year," di Resta explained. "Hamilton always bounces back, Mercedes always bounce back.

"They will be going at it this week to try and extract as much as they can going into that Grand Prix."

Verstappen currently leads Hamilton in the Drivers' Championship by 12 points, whilst Red Bull are 37 points ahead of Mercedes in the Constructors' Standings.