The National Weather Service issued a severe thunderstorm watch for 11 eastern Colorado counties— including El Paso, Elbert, Cheyenne, Kit Carson, Lincoln, Logan, Morgan, Phillips, Sedgwick, Washington and Yuma — until 9 p.m. MDT on Friday. Forecasters warned of storms capable of producing wind gusts up to 70 mph, hail up to two inches in diameter and isolated tornadoes. Through the afternoon and early evening, the agency escalated the threat with successive severe-thunderstorm warnings that stretched from Weld and Adams counties on the northern plains to Lincoln and Cheyenne counties to the south. Radar indicated several storms with apple-sized hail, and damage-threat tags were added as tennis-ball-sized hail was expected in parts of Lincoln County after 6 p.m. Tornado warnings were posted for Elbert and Lincoln counties from 4:27 p.m. to 5 p.m., and for Yuma County from 5:26 p.m. to 6:15 p.m. MDT, covering communities such as Limon, Vernon and Karval. While the weather service had not yet confirmed any touchdowns, residents were urged to seek immediate shelter as the warned cells moved east at 25–30 mph. The outbreak followed several days of hot, humid conditions on the High Plains, providing the instability for long-lived supercells. Emergency managers advised motorists along Interstate 70 and U.S. Highway 34 to monitor local media and NOAA weather radio for updates, and warned that large hail could shatter windshields and damage crops at peak harvest time.