Alabama tornadoes: what are twisters, what's the storm forecast and damage explained

The tornadoes struck on Thursday, March 25 as part of a system of extreme storms currently sweeping southern parts of the US.

Bad weather also hit the nearby states of Kentucky, Tennessee, Mississippi and North and South Carolina, with weather warnings issued across several areas.

When did the tornadoes strike - and what damage did they do?

Warnings of significant weather disruption were issued on Wednesday, March 24, and tornado sirens began sounding across Alabama early on the morning of Thursday.

By 1 a.m local time on Thursday, more than 26,000 houses in Alabama were reported to be without power because of the storms.

Hundreds of homes have been damaged or totally destroyed, with power lines down and trees uprooted. Many people have been evacuated to safety.

In Oatchee, a small town in Calhoun County, five people were killed. Hundreds more across Alabama have been reported as injured.

What is a twister?

A twister is another name for a tornado - a column of air which rotates rapidly, stretching from clouds at the base of a thunderstorm all the way to the ground.

They are extremely dangerous, sometimes producing winds of more than 300 miles an hour. Even weaker tornadoes can create a huge amount of damage when they hit towns and cities.

In Alabama, one radar showed a tornado staying on the ground for around an hour and 20 minutes, covering a path of 100 miles.

How long will the weather continue?

The same areas have already been threatened by tornadoes, with more than 50 reported in Alabama and Mississippi last week.

Alabama remains under the highest risk category for severe weather, with further storms expected.

The National Oceanic and Atmospheric Administration’s (NOAA) Storm Prediction Centre has said “numerous tornadoes and several intense tornadoes” across the storm watch area.

Damaging winds of up to 80mph are also expected, along with large hail and isolated incidences of very large hail.

“Storms are expected to form over the next couple hours over central and western Mississippi,” said forecasters, adding that “supercells are likely, with tornado threat increasing as cells mature and move northeast toward Alabama.”

“Supercells” are a type of thunderstorm characterised by a deep, persistently rotating updraft. They are sometimes referred to as rotating thunderstorms and cause tornadoes along with other destructive types of weather like hail storms.

Are storms like this common in Alabama?

Supercells are one of the rarest types of thunderstorm, but they are most common in the central part of America.

Storms in Alabama and surrounding states are usually most destructive in spring, between March and May.

In 2020 a similarly widespread and deadly series of tornadoes swept through the Southeastern United States over the Easter weekend.

These states are often hit with storms, but in recent years, storms have become more destructive and more frequent.

Some studies and evidence have linked the higher prevalence of destructive weather events like the one Alabama is currently experiencing.