Flights were grounded Friday, Sept. 26 at Phoenix Sky Harbor International Airport because of severe weather, as the National Weather Service forecasted a high chance of thunderstorms .

A ground stop at Sky Harbor took effect just before 10 a.m. Friday and will remain through 11:30 a.m., with a 30% to 60% chance of the ground stop being extended, according to the Federal Aviation Administration's National Airspace System .

The ground stop has delayed flights by about 49 minutes on average, according to an FAA advisory.

Here's what air travelers should know if they're flying on Friday.

Why are flights grounded?

The FAA grounded flights at Sky Harbor because of severe weather and thunderstorms. Looking for a free mini puzzle? Play the USA TODAY Quick Cross now.

The National Weath

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