Flights at the Denver International Airport were temporarily grounded on Wednesday as thunderstorms dumped hail and even created several tornadoes.

About 40 incoming flights to Denver were diverted to either airports in Grand Junction and Colorado Springs during an hour and a half period where there were strong winds and hail, reports The Associated Press.

The hail was reportedly the size of ping pong balls and snow plows were required to clear the roads as some cars slid while driving on the Interstate 70.

According to Reuters, the Denver-area also had to contend with about five tornadoes for a short period. Three of the tornadoes were reported in Aurora, the National Weather Service's Boulder office meteorologist Jim Kalina said.

He noted that despite a tornado warning that remained in effect until 8 p.m. local time, "Denver's kind of in the clear right now unless something else develops."

The Denver International Airport tweeted earlier that flights were expected to be delayed about 90 minutes, though another tweet a couple hours later said that flights were starting to leave closer to their original times.