'Heat pump' is fueling the blistering temperatures across the U.S.

Bernie Rayno explains the weather pattern that's behind a heat wave that will enveloped the Midwest and peak in the Northeast on Saturday, and why the nighttime low temps will be staying remarkably high.
Published: 11:31 AM PDT July 17, 2019
Updated: 11:00 AM PDT July 17, 2019