This weather data is from multiple sources.  Choose your favorite!

The National Weather Service radar images from Fort Smith and Tulsa are excellent for watching approaching storms.

 

Weather Underground:  Various types of US weather maps like you might see on the weather channel.

Tulsa Weather Service Radar Image

Fort Smith Weather Service Radar Image

Weather.com moving radar image for Springdale, Arkansas

Accuweather.com weather for Springdale, Arkansas

National Weather Service weather for Springdale, Arkansas

Map of Lightning Activity in the United States