tornado season 2024 in full swing

The 2024 tornado season is set to become the most active in US history with more than 85 such events being reported mainly in the States of Nebraska and Iowa on 26 April alone.

In addition to this daily record, more than 350 other tornadoes had lashed the central USA from the beginning of January to 26 April, including 26 classified as very powerful, in other words EF2 ⁽¹⁾ and even EF4 ⁽²⁾.

By mid-May 2024, the total number of these disasters recorded on American soil had reached 781, up 42% on the national average of 549 disasters for the same period.

In addition to the human losses, which by mid-May had risen to 6, some events left behind devastated landscapes: entire cities razed to the ground, corporates driven out of business, cars and trucks overturned, trees uprooted, road and rail infrastructures damaged.

⁽¹⁾ EF2 : Force 2 on the enhanced Fujita scale: powerful winds of 179 to 218 km/h, causing considerable damage.

⁽²⁾ EF4 : Force 4 on the enhanced Fujita scale: devastating winds of 267 to 322 km/h, causing widespread damage.

Tornado Alley: a vast area of tornadoes in the central U.S

Tornado Alley is located in the central region of the American Great Plains, stretching from Canada to Mexico, that is, from North Dakota to Texas, via South Dakota, Nebraska, Kansas and Oklahoma.

Tornadoes form mainly between April and June, when three air masses meet: a cold, continental mass from the Canadian prairies; a hot, dry mass from the Sonora Desert (southwestern U.S., straddling the states of Arizona and California); and a warm, humid mass from the Gulf of Mexico.

A new climatic phenomenon “El Niña” is disrupting the 2024 season. Bringing warm, humid air along the Pacific coast, this event increases the number and intensity of disasters, resulting in more violent tornadoes.

As a reminder, between 800 and 1300 tornadoes occur annually in the United States, more than a third of them in Tornado Alley. In addition to this area, Dixie Alley ⁽³⁾ is also the scene of strong tornadoes throughout the year, with a peak during the cold season (October and November).

⁽³⁾ This region comprises Southern Mississippi (including the states of Arkansas, Mississippi and Louisiana), Western Tennessee, Northern Alabama and Georgia.

Tornado in the U.S: economic cost and insured losses

Economic cost

According to the National Ocean and Atmospheric Administration (NOAA), nearly 1 300 tornadoes struck the USA in 2022, claiming the lives of 25 people and causing 11.3 billion USD in property damage, mainly to farms. Each one generated an average of 8.7 million USD in economic losses.

For 2023, NOAA reported 1 350 tornadoes causing 83 deaths and over 38 billion USD in property damage.

At the end of April 2024, NOAA reported seven other large-scale events of such nature, each causing financial losses of at least one billion USD. Between January and April 2024, their economic cost reached 10.4 billion USD, with major destruction on April 26, 2024 in Elkhorn (Nebraska). The town of Minden (Nevada) also sustained considerable damage.

Insured losses

According to Swiss Re, natural disasters in 2023 caused 100 billion USD of insured losses worldwide, 64 billion USD of which were due to severe convective storms ⁽⁴⁾. 85% of this amount, or 54.26 billion USD, was accounted for in the USA

⁽⁴⁾ Severe convective storms include hail, tornadoes and high winds

Natural catastrophe coverage in the United States

In the United States, damage caused by natural events is covered in two ways. The first is coverage initiated and/or managed by specific government programs, while the second is the exclusive responsibility of private insurers. Some programs, in the form of partnerships, involve both public and private funds.

The two main programs that include flood risks are the Florida Hurricane Catastrophe Fund and the National Flood Insurance Program.

• The Florida Hurricane Catastrophe Fund (FHCF): Created in 1993 after Hurricane Andrew, this fund is designed to cover risks in Florida. It is financed by direct insurance companies and acts as a natural catastrophe risk mutual company with a capacity of 17 billion USD in 2024.
• National Flood Insurance Program (NFIP): Created in 1968 by the U.S. Congress, the NFIP is a federal flood insurance program funded by the State. Premiums vary according to the location of the risk. With a current capacity of 16 billion USD, it accounted for nearly 22 600 member communities as of 31 December 2022.

Coverage of tornado risk in the United States

In the USA, standard home insurance policies generally cover a wide range of risks, such as fire, water leakage, theft, storms and wind damage, including tornadoes, thunderstorms and high winds ⁽⁵⁾. There is no specific insurance policy for tornadoes.In the event of a loss, coverage generally includes reconstruction costs, replacement of damaged personal property, living expenses and temporary accommodation.

Most home insurance policies come with a deductible, which can either be a lump sum or a specific amount for certain situations. In many tornado-prone areas, for example, insurers have introduced index deductibles (based on wind speed). The deductible is often expressed as a percentage of the total capital covered, which can sometimes represent a substantial amount. Damage to motor vehicles is still covered by optional motor insurance policies.

⁽⁵⁾ Including hail, tornadoes and high winds

Lack of interest among U.S insurers

Following the upsurge in extreme weather events, several major US non-life insurers, including Allstate, American Family, AIG, Nationwide, Erie Insurance Group and Berkshire Hathaway, have suspended or completely terminated underwriting home and motor policies in high-risk regions. They have also excluded weather-related coverage.

The decision was prompted by rising repair costs and the high exposure of certain US States to extreme natural events.

Tornado in the USA: some record-breaking figures

• 378 km is the longest distance travelled by a tornado in 1925
• 541 km/h is the highest wind speed recorded in 2013
• 4,2 km is the widest tornado diameter observed in 2013
• 360 tornadoes in 24 hours is the record number of such events reported between 27 and 28 April 2011 in the southern States. This event resulted in the deaths of 348 people and property damage worth 12 billion USD
• 100 km is the length of the corridor of mass destruction, traced in Oklahoma following the passage of El Reno on May 24, 2011, one of the most powerful tornadoes ever observed