Mar 4, 2019 - Science

Alabama twisters cause deadliest tornado day in U.S. since 2013

Residents look for belongings March 4, 2019 at a home after a tornado in Beauregard, Alabama.

Residents look for belongings March 4 at a home after it was destroyed in a tornado in Beauregard, Alabama. Photo: Tami Chappell AFP/Getty Images

The tornadoes that ripped through Lee County, Alabama, on Sunday evening, tearing homes apart like a half-mile-wide buzzsaw, are being blamed for at least 23 fatalities.

Why it matters: This death toll makes Sunday the deadliest tornado day in the U.S. since an EF-5 tornado struck Moore, Oklahoma, in May 2013, killing 24.

  • The Lee County tornadoes devastated rural communities in that state, with more than 100 rescue crews continuing to search for survivors on Monday morning.
  • Other severe thunderstorms and possible tornadoes struck in Georgia and Florida as well, as a severe weather outbreak swept through the region.
  • The storms were well-forecast, including more than 90 tornado warnings issued across the Southeast — and two dire "tornado emergency" alerts denoting an imminent threat of loss of life and/or "catastrophic damage."

The big picture: National Weather Service forecasters are surveying damage across at least 3 states to determine how many tornadoes touched down and how strong they were. One of the Lee County tornadoes was given a preliminary rating of an EF-4, with estimated maximum winds of 170 mph.

  • The storms resulted from a clash in air masses as cold, dry Arctic air pushed southward out of Canada, while warm, moist air and a fast-moving flow of air raced up the East Coast in association with a storm system that rippled along this boundary.
  • The low-level winds provided plenty of wind shear, which allowed the severe thunderstorms to develop the persistent rotation necessary for producing tornadoes.

Go deeper: California's "fire tornado" had 143 mile-per-hour winds

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