Update 5:12 p.m.: The FAA issued a ground stop for flights out of DIA until at least 5:30 p.m. due to thunderstorms.
Update 3:45 p.m.: A is in effect for a large swath of southeast Colorado, with tornadoes, 2-inch hail and high winds possible, forecasters said.
The storm could impact people living near Colorado Springs, Pueblo, Burlington, La Junta and Lamar -- roughly 1 million residents altogether, according to the National Weather Service.
Wind gusts up to 70 mph are also possible through 10 p.m.
Update at 3:35 p.m.: More than 500 flights were delayed at Denver International Airport on Thursday afternoon as thunderstorms brought high winds, hail and the threat of tornadoes to metro Denver and the Eastern Plains.
Update 3:15 p.m.: National Weather Service forecasters issued a until 3:30 p.m.
A tornado is indicated on the weather radar and quarter-sized hail is also possible, forecasters said.
The area includes five schools and around 6,200 people.
Update 2:55 p.m.: A severe thunderstorm could bring half-dollar-sized hail, strong winds and a tornado to portions of Arapahoe, Douglas and Elbert counties this afternoon, according to the National Weather Service.
Forecasters issued a for the northeast corner of Douglas County, southern Arapahoe County and northwest Elbert County until 3:15 p.m.
There's also a severe thunderstorm warning in effect for people living north of Denver International Airport along Interstate 76, including Lochbuie, Hudson and Keenesburg.
This is a developing story and may be updated.
Previous reporting: Severe thunderstorms will continue Thursday across Colorado's Eastern Plains, bringing up to tennis-ball-sized hail and damaging winds, according to the National Weather Service.
The strongest chance for severe weather will be between 2 p.m. and 8 p.m. Thursday in southeastern Colorado, . There will also be a low risk of tornadoes during that time, mostly along the Colorado-Kansas border.
Tennis-ball-sized hail, about 2 1/2 inches in diameter, was recorded Wednesday near Matheson in Elbert County, . Hail about 1 3/4 inches in diameter, the size of a golf ball, fell in Elbert, Limon and along the Colorado-Kansas border.
Any hail that's larger than an inch across, about the size of a quarter, is considered "," according to meteorologists.
Forecasters expect hail of that size to return Thursday afternoon across the Eastern Plains.
Strong winds up to 65 mph will also buffet eastern Colorado, forecasters said. Non-tornado winds above 50 mph are classified as “” by NWS meteorologists.
Rain showers are forecast for Denver between noon and 3 p.m. Thursday, with thunderstorms developing later in the afternoon and lasting through midnight, . It's unlikely the metro area will see the same level of hail and wind as the Eastern Plains.
Cool, rainy weather will continue across Colorado on Friday before warm, dry weather returns for the weekend, forecasters said.
The sudden drop in precipitation could bring elevated fire danger, according to a .
