A multi-day severe weather outbreak is hammering the Heartland and headed towards the East Coast with tornado watches in effect.

Heat is the number one killer -- and it’s heading to the most densely populated part of America for a prolonged period.

Temperatures are expected to be in the low-100s.

ABC News’ Chief Meteorologist Ginger Zee shares the latest on the dangerous storms on the move after parts of the Heartland were hit hard overnight.

Eight people are dead from the heavy rains and devastating flash flooding in West Virginia.

Powerful storms are threatening millions after a tornado outbreak across the Plains, where over a dozen tornadoes were reported in three states.

At least 16 tornadoes were reported from Colorado to Minnesota but, luckily, no widespread damage was reported.

ABC News’ Alex Perez reports on the fallout in the wake of heavy rain and devastating flash flooding in West Virginia.

Families from West Virginia to the Carolinas are on alert for more floods.

Parts of West Virginia are under a state of emergency after deadly flash flooding killed at least five people, including a 3-year-old.

There is a state of emergency in West Virgina where at least three people are dead and several missing from flash flooding Saturday night.

The death toll from heavy rains that inundated parts of San Antonio has risen to 13, and all those missing have been found

The first ever heat advisory has been issued in the state of Alaska

At least 11 people were killed in flooding that swept vehicles off the road and led to dozens of high-water rescues, authorities in San Antonio said Friday.

The fatalities were reported in northeast San Antonio in the Loop 410 area on Thursday morning, police said.

At least four people are dead after torrential rain and devastating floods inundated parts of Texas overnight. Firefighters in San Antonio made at least 60 high water rescues.

Smoke from Canadian wildfires is drifting east, triggering air quality alerts in parts of the Midwest and Northeast.

At least four people are dead in San Antonio and dozens of water rescues were made around the city after heavy rains flooded highways and stranded motorists, officials said Thursday

About 24 million people in Texas, Louisiana, Arkansas and Oklahoma are under a flash flood risk or flood watch as abundant moisture flows from the Gulf.

Tropical Storm Barbara continues to weaken as it heads northwest away from land and is likely to dissipate by Wednesday

More than 50 million people are on alert for severe storms from Texas to New York.

More than 50 million people from Mississippi to western New York are under a slight risk Monday of receiving damaging wind, large-sized hail, flash flooding.

ABC News Chief Meteorologist Ginger Zee has the latest on the severe weather threat continuing for millions in the Southeast. 

The alert stretches from Texas to the East Coast. Storms turned deadly, killing at least two people in Georgia and Mississippi and tens of thousands were left without power across the South.

Two people were killed by falling trees as a line of severe storms pushed through the South over the weekend

More than 40 million Americans are in the threat zone through Saturday night, stretching from Texas to the Carolinas.

WABC's Dani Beckstrom reports on the severe weather expected for Texas and Oklahoma, with destructive winds, giant hail and possible tornadoes.

Parts of the South are reeling from severe thunderstorms, flooding and damaging winds. 

The storm system has ravaged the Heartland as the massive system heads east this weekend.

SEE IT: Heavy flooding hit the streets of Lubbock, Texas, after storms moved through the region.

ABC News’ Chief Meteorologist Ginger Zee tracks the latest forecast as tornadoes touch down in Texas and new storms take aim at the East Coast this weekend.

The girls's family was recording a storm unfolding in their hometown of Huntington Beach when they captured the moment lightning struck a tree approximately 50 feet from their daughter.

Smoke from the Canadian wildfires continues to bring potentially dangerous air quality to parts of the northern U.S., with hazy skies possible.

ABC News Chief Meteorologist Ginger Zee has the latest on the air quality alerts across the Midwest caused by smoke from the Canadian wildfires and the severe storms possible across the South.

The dust mass, which forms in the Sahara Desert in northern Africa and blows thousands of miles across the Atlantic Ocean, is forecast to arrive in Florida this week.

The dust mass, which forms in the Sahara Desert in northern Africa and blows thousands of miles across the Atlantic Ocean, is forecast to arrive in Florida this week.

ABC News’ Chief Meteorologist Ginger Zee reports on the destructive storms over the Heartland, with more storms on the way in the coming days.

Powerful storms and torrential rain are inundating the Heartland – including Kansas, where first responders in Wichita used a boat to save a driver that was surrounded by flood waters inside her car.

Flash flooding in south Florida residents is expected to give way to brilliant sunsets later this week as Saharan dust is forecast to arrive in the state.

NOAA is predicting above-normal Atlantic hurricane activity this year. How can climate change impact these extreme weather events?

ABC News Chief Meteorologist Ginger Zee reports on the complex relationship between climate change and weather forecasts.

The latest summer season outlook by NOAA’s Climate Prediction Center shows above-average temperatures are favored across much of the country during the summer months.

ABC News Chief Meteorologist Ginger Zee shares the latest track and timing of the severe weather on the move and air quality alerts in effect due to smoke from Canadian wildfires.

As hundreds of wildfires continue to burn in Canada, the smoke from the flames is bringing potentially dangerous air quality to parts of the United States.

The Washington County Sheriff's Office reported a fatality and multiple injuries, with "severe damage" throughout the county.

Nearly 45 million are on alert for powerful storms targeting the East Coast after severe weather battered the Heartland.

Northern Minnesota, the Upper Peninsula of Michigan and most of Wisconsin are also under air quality alerts due to the smoke from wildfires in Canada. 

A father and son were sucked up inside a tornado in Georgia and at least one person was killed after being swept away in flood waters.

At least one person has been reportedly swept away and killed in raging flood waters after powerful storms slammed across central Texas and golf ball-sized hail plummeting across the region.

The severe weather and latest in-flight disturbances come as the TSA screened more than 3 million people on Friday, the third busiest day in TSA history.