Severe Weather Threat to Impact Over 40 Million Americans Across Central US [NOAA]

A severe weather threat is expected to impact more than 40 million Americans across the Central United States this week, according to the National Oceanic and Atmospheric Administration (NOAA). The inclement weather brings potential disruptive and life-threatening risks, especially powerful tornadoes.

Starting Tuesday, April 16, various weather hazards may occur in the affected region, particularly scattered severe thunderstorms across northern Missouri, Iowa, and northwestern Illinois. Similar weather conditions may occur as far as the southern states, the NOAA says.

Severe Weather Threat

The latest weather forecast comes after the National Weather Service (NWS) issued a severe thunderstorm alert for parts of the Eastern US on Monday, April 15. The NWS forecast involves the risk of tornadoes, damaging winds, and large hail in areas from the upper Ohio Valley to the Northeast US this week.

In the case of the Central US, the looming adverse weather poses a risk to multiple states such as Iowa, Illinois, Missouri, Nebraska, Wisconsin, Indiana, Ohio, Tennessee, and Kentucky, according to the NOAA's Storm Prediction Center (SPC).

In its convective outlook on Tuesday, the NOAA estimated that the severe weather threat hovering above the Central US could impact a total of approximately 42.3 million people in the following locations:

• Des Moines, Iowa
• Cedar Rapids, Iowa
• Davenport, Iowa
• Waterloo, Iowa
• Iowa City, Iowa
• Chicago, Illinois
• Aurora, Illinois
• Omaha, Nebraska
• Lincoln, Nebraska
• St. Louis, Missouri
• Madison, Wisconsin
• Indianapolis, Indiana
• Memphis, Tennessee
• Cincinnati, Ohio
• Louisville, Kentucky

The prediction center warns the severe weather in the affected regions and their surrounding areas could produce severe hazards, including a tornado outbreak risk. This can happen even if severe storms are isolated, the SPC explains.

Tornado Outbreak Risk

There are instances when an area or region experiences at least one or few twisters, which could result in potentially significant damage and destruction.

However, this phenomenon becomes a tornado outbreak when multiple tornadoes occur over a short period. According to the NWS, this can happen when key atmospheric ingredients for tornadoes intensify, including warm moist air near the ground, wind shear, wind speed, and wind direction.

Earlier in April, a tornado outbreak from Texas to Florida killed 14 people amid the issuance of severe storm warnings. In Mississippi, at least one person died when flash flooding due to heavy rain and severe thunderstorms wreaked havoc across the US Gulf Coast.

In previous years, experts say that the occurrence of tornado outbreaks has increased. In a 2016 study published in the journal Science, researchers found that, in the United States, the frequency of tornado outbreaks and the number of extremely powerful tornado events are rising since the last half-century.

In 2011, a colossal EF-5 tornado in Joplin, Missouri, resulted in the deaths of 158 people and injuries of more than 1,100 others. It is one of the deadliest tornadoes in US history since recordings started as early as 1643.