Updated May 22, 2024 - Energy & Environment

Tornado kills 4, injures 35 in Iowa as storms shift south and east

An aerial view shows the devastation left behind after a tornado tore through town Tuesday.

An aerial view shows the devastation left behind after a tornado tore through Greenfield, Iowa, on Tuesday. Photo: Scott Olson/Getty Images

A tornado that struck Greenfield, Iowa, killed four people and wounded at least 35 others, officials said Wednesday.

The big picture: It was one of several tornadoes to hit Iowa on Tuesday in a damaging outbreak of severe thunderstorms, with several tornadoes, powerful straight-line winds and other deadly hazards striking the Midwest into Wednesday.

State of play: As officials in Iowa responded to the destruction in Greenfield, a town located about 60 miles southwest of Des Moines, and other places including Carbon, Red Oak, Corning and Villisca, the storm system moved east on Tuesday night — leaving many without power.

  • In Adams County, Iowa, one woman died in a storm-related incident, a local medical examiner told media.
  • The heaviest damage occurred in Greenfield as the tornado, which NWS data indicated had EF-3 intensity, tore bark off trees, tossed cars and piled them like pancakes while sweeping homes off their foundations.
  • On radar, debris was lofted to 40,000 feet, with pieces of sheet metal reportedly falling from the sky about 30 miles away. Videos shared online showed wind turbines downed and bent.
  • A hospital in Greenfield sustained damage from the tornado and injured patients were transported to nearby medical centers, authorities said.
A satellite gif of intense supercells sweeping across the state of Iowa this afternoon
Satellite view of intense supercells sweeping across the state of Iowa on Tuesday. Image: CIRA/RAMMB

Zoom in: Iowa Gov. Kim Reynolds authorized an emergency for 15 counties, including Adair County.

  • Reynolds said in a statement late Tuesday that state and local officials were "on the ground, assessing the situation and setting up temporary shelters for those whose homes were damaged or destroyed," as utility crews worked to restore power to thousands.

Between the lines: The storms were being set off by an area of low pressure moving into Minnesota, along with a trailing cold front.

  • There was also support for storms in the form of upper-level winds, which were encouraging the formation of long-lasting severe thunderstorms with rotating updrafts, also known as supercells.
  • Storm research scientists have been deployed to the storms using specialized instruments, gathering unique data to try to determine how to better predict tornadoes.

Threat level: The threat of tornadoes, along with showers and severe thunderstorms, shifted southward Wednesday into Texas.

  • Dallas, Ft. Worth and Arlington were each in an "Enhanced Risk" zone, which is a 3 out of 5 on the storm risk scale.
  • Thunderstorms may erupt for a considerable distance to the northeast along a frontal zone, into the Ohio Valley and Great Lakes.
  • By Wednesday evening, the threat had moved to the Southern Plains, Arkansas, Louisiana and Texas, where the National Weather Service noted tornadoes were possible, along with large hail and damaging winds.

Zoom out: Tuesday's severe weather outbreak comes during a month that has seen a slew of severe thunderstorms and tornadoes.

The intrigue: There is an element of climate change in this trend. As the air warms and carries more water vapor, there is greater atmospheric instability.

  • This can result in more frequent severe thunderstorms as well as larger outbreaks, with hail being an especially costly result.

Go deeper: Extreme weather is making power outages trend higher

Editor's note: This story has been updated with the latest conditions.

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