DUBAI, United Arab Emirates (AP) — Intense rainfall swept across Dubai and the wider United Arab Emirates on Saturday, causing localized flooding and disrupting flights at the world’s busiest airport for international travel.

Nearly 50 millimeters (2 inches) of rain fell in Dubai over six hours — a heavy amount when the country as a whole averages under 120 millimeters (4.7 inches) of precipitation a year. Authorities sent crews out to collect downed tree limbs and open up drainage grates, though the rain quickly overwhelmed some areas.

Dubai police shut down portions of one major highway as traffic slowly crept through standing water on others. Rare lightning storms also lit up the afternoon sky.

At Dubai International Airport, the busiest for international travel, flights for both long-haul carrier Emirates and its low-cost sister airline, FlyDubai, were disrupted in the downpour.

Authorities had warned the public about the coming storm over a day in advance, with emergency personnel preparing for the rare rain.

Rain is unusual in this arid, Arabian Peninsula nation, but occurs periodically during the cooler winter months.