Southeast U.S. tornadoes may drive billion dollar losses: Aon

The outbreak of severe convective weather that affected the U.S. south and eastern states this week may result in both economic and insured losses that surpass $1 billion, according to the latest update from Aon’s Impact Forecasting.

At least 121 confirmed tornado touchdowns were seen in the severe weather outbreak that impacted states from Texas to Maryland, the insurance and reinsurance broker’s risk modelling, analytics and meteorological unit explained.

The severe weather outbreak, which Impact Forecasting calls “prolific”, hit the southeastern United States through April 10th to 14th, bringing numerous tornadoes, large hail, damaging straight-line winds and torrential rainfall that caused flash flooding.

The worst hit states were Mississippi, Alabama, Louisiana, Georgia, Tennessee, South Carolina, and North Carolina, where tornadoes and the weather killed some 41 or more people, while non-tornadic winds of hurricane strength were seen, as well as large hail.

Aon’s Impact Forecasting explains that this is expected to be the fifth billion dollar severe weather event in the United States of 2020 so far, as the convective storm season gets off to an active start.

The multi-day severe weather event had been well-forecasted in advance by NOAA and the period of convective weather resulted in hail larger than baseball sized, with 79 tornadoes that had 100mph or greater winds and 16 that saw winds of over 130mph, Impact Forecasting said.

Mississippi experienced the most significant damage, as nearly a dozen tornadoes touched down across the state.

The most intense tornado was rated an EF4 and seen to be some 2 miles wide at one stage, packing at least 170 mph (275 kph) winds. It touched down in Jefferson Davis County and tracked for 67.77 miles (109.06 kilometers) before lifting in Clarke County, Impact Forecasting said.

It was one of the widest tornadoes ever observed and caused at least four fatalities and “exceptional damage to structures in Jefferson Davis, Covington, Jones, Jasper, and Clarke counties.”

A second, “twin”, tornado struck soon after this first, at a mile wide and tracking for some 82.61 miles (132.95 km) with at least EF-3 winds and also affected Jasper County, causing multiple fatalities and injuries.

he Mississippi Emergency Management Agency (MEMA) estimates that 1,206 homes were impacted by the severe weather event.

Louisiana also experienced a raft of tornadoes and further damage to properties, with the most severe event seen in the City of Monroe where some 300 homes were damaged or destroyed and several planes were destroyed at the airport with officials saying that would cost at least $30 million.

Another tornado impacted Ouachita Parish, Louisiana, where the Office of Homeland Security and Emergency Preparedness (OHSEP) estimated a total of 458 homes were affected by three tornadoes, with 23 destroyed, 108 seeing major damage, 243 minor damage, and another 84 were affected to varying degrees.

In Tennessee, a tornado near Chattanooga damaged or destroyed more than 150 homes and commercial structures, while in Georgia a single tornado damaged 159 structures, 38 with minor damage, 20 with major damage, and 7 were reported destroyed.

South Carolina also saw tornadoes, with the South Carolina Emergency Management Division (SCEMD) estimating that 911 homes were impacted, of which 111 were destroyed, and 181 sustained major damage.

Other impacts were seen in Alabama, North Carolina and parts of Florida, Virginia, Maryland, Pennsylvania, and Delaware, where tornado warnings were all issued.

“Given the extensive damage footprint across much of the Southern and Eastern U.S. – which included catastrophic effects from tornado touchdowns, large hail, straight-line winds, and flash flooding – it is anticipated that the financial toll will be significant,” Aon’s Impact Forecasting unit explained.

At this stage it’s too early for an accurate estimate of insurance and reinsurance market losses, but the cost will be substantial it is assumed.

Impact Forecasting said that the “total economic and insured losses were expected to minimally reach into the hundreds of millions (USD); though likely to approach or surpass USD1 billion.”