Hail bombarded Rome on Sunday night, wreaking havoc in parts of the city.

Photos and video showed the hail piling up knee-deep, making some roads impassable. Torrential rain accompanied the hail, and some roads resembled ice-jammed rivers:

The hail “was particularly heavy in the eastern part of the Italian capital, where hail covered some roads as [if] it were snow,” wrote EuroNews, which described an “unprecedented” storm.

“Several motorists found themselves stranded in high water or ice, while the runoff poured into underground stations and forced the closure of at least six Metro stops and one overground station,” the Local Italy reported. “All stations had reopened by Monday morning.”

The hailstorm followed unseasonably mild weather in Rome. High temperatures had been in the mid- to upper 70s for the prior week, compared with the average of about 70.

After the storm, highs on Monday were only in the low 60s.

The culprit for the event was a cold front and an associated vigorous high-altitude disturbance that dropped in from the northeast, shown in the animation below:

According to the BBC, severe weather broke out over large parts of Italy, “from Milan in the north to Sicily in the south.” In Milan, the BBC reported that strong winds downed trees, while the airport in Bologna experienced delays.

Find some more scenes from Rome below: