Rain and thunder rumbled through the Denver area Monday afternoon, with flashes of lightning and funnel clouds spotted in Aurora.

The National Weather Service issued a severe thunderstorm watch for Denver and the Eastern Plains until 9 p.m. Monday, indicating that funnel clouds, landspout tornadoes and dime-sized hail are possible.

At about 5 p.m., the severe weather caused 89 flight delays at Denver International Airport, according to the FlightAware.com.

The weather service asked Denverites to be aware of the possibility of wind gusts up to 70 mph as well as frequent lightning strikes.

Landspout tornadoes form with a developing thunderstorm before rain, hail and even thunder is observed, the weather service said.

The watch encompasses an area where 2.4 million Coloradans live. In the area there are 863 schools and 45 hospitals, the NWS said.

The high temperature in Denver reached 82 degrees at 12:12 p.m., the weather service said.

Cloudy skies and cool periods of rain helped drop Denver’s temperature to 61 degrees at 5 p.m., while the city’s humidity was at 56 percent.

Severe weather on the Eastern Plains was expected to last into the night.