Thunderstorms packing heavy rain, hail roll through parts of Colorado

In this photo taken with a fisheye lens, a massive storm cloud packing high winds, hail and heavy rains sweeps over downtown Denver as lightning strikes on the horizon on Monday, July 7, 2014. After a daytime high that reached 100 degree, forecasters predict that heavy thunderstorms will envelop Colorado's Front Range communities through the night. (AP Photo/David Zalubowski)

A storm packing large hail, wind and heavy rain rolled through parts of Colorado on Monday evening.

The storm brought an end to triple-digit temperatures but caused isolated flooding and power outages. KUSA-TV reports that there were also reports of downed trees.

National Weather Service meteorologist Jim Kalina says the hardest hit area was Arvada, where there were reports of golf ball-sized hail and 70 mph winds.

Kalina says in Byers, east of Denver, there were 3 inches of hail on the ground. The weather service also issued flash-flood warnings in Arapahoe and Elbert counties.

The storm started in northern Colorado in Larimer County, moved through Boulder County, and then the Denver area. It followed a day with a high of 100 degrees, which Kalina says was the hottest temperature of the year.

The Red Cross says about 100 Boy Scouts had to evacuate a camp near Walsenburg because of flooding early Tuesday morning.

The scouts left the Spanish Peaks Scout Ranch on school buses and sheriff's vehicles around 4 a.m. Tuesday after rain caused a creek running through the property near Walsenburg to rise.

They went to a Red Cross shelter set up in Walsenburg's community center and could be allowed back later in the day, depending on the prospects for more rain. Scout executive Michael Stewart says the scouts, most of them from southwestern Kansas, were camping in tents above Bear Creek and weren't in immediate danger.

Residents across Colorado took to social media to share photos from the storms. Here's what they shared:

The Associated Press contributed to this report.