Forecasters say the potent system raises the risk of life-threatening flash flooding in parts of the U.S. starting Wednesday.

A viral video captured the moment a Gary resident and his son saved their family dog just moments before a tornado swept through and destroyed their backyard.

LOUISVILLE, Ky. — Heavy downpours, hail, lightning and tornadoes are all possible Wednesday evening in the Louisville Metro into the overnight hours. These storms have the potential to cause damage and life-threatening flash flooding.

A powerful, wide-reaching spring storm is threatening parts of the central and eastern US, with a life-threatening outbreak of long-lived and strong tornadoes possible in some areas. Follow here for live updates.

When a warning is issued, take action. This means tornado conditions are imminent and have been spotted either by someone on the ground or by radar. Warning areas are typically smaller than those within a watch and are issued for a shorter time period, typically about 15 minutes.

Forecasters issued some of their rarest and most extreme alerts on Wednesday as they warned a powerful storm system would stall over the central part of the country.

The National Weather Service has placed Johnson County under a moderate risk of severe weather for Wednesday. A moderate risk is the second-highest level on the weather service’s severe thunderstorm risk categories, and indicates there will likely be widespread severe storms that could be “long-lived” or intense.

Severe storms earlier this week produced five EF-1 tornadoes but powerful, long-lived tornadoes aren't uncommon either in Kentucky.

A round of fast-moving severe thunderstorms plowed through the Chicago area Sunday afternoon, producing hurricane-force winds and prompting tornado warnings in parts of Northwest Indiana. A tornado watch was issued throughout most the Chicago area and Northwest Indiana for much of the afternoon.