Flash storm rampages through St. Petersburg Stadium before Russia-Egypt match (VIDEO)

In an as-yet-undeciphered omen prior to the key clash between hosts Russia and Egypt, a sudden summer storm shook up St.Petersburg, nearly blowing gathering fans off their feet, and forcing others into cover.

So far, the weather during Russia 2018 has been near-flawless, but St.Petersburg, situated on the Baltic coast, is known for its temperamental elements during all seasons, and had recently enjoyed an unusually long dry spell.

READ MORE: Superstar Salah back in Egypt's starting line-up vs Russia after passing late fitness test

Then, just as the first supporters poured onto the streets on Tuesday afternoon, the skies were unleashed.

"It's a little humid around here," wrote one Twitter user, next to a video of him and his friends running for their lives, already drenched from head to toe. "Welcome to the World Cup."

City authorities have stationed a dozen pumps outside St.Petersburg Stadium, but FIFA has ordered that the roof over the pitch should not be closed, perhaps on advice of forecasters, who predicted that the storm will calm down by the 18:00 GMT kick-off.