Severe convective storms (SCS) that struck parts of the US and Canada from July 13-17, as well as several countries in Europe between July 11-17, are each expected to result in economic and insured losses totaling hundreds of millions of USD, according to Aon’s weekly catastrophe report.
In the US, severe weather hit hardest between July 15-16 with a powerful derecho affecting Iowa, Illinois, and Indiana. This led to over 300,000 power outages throughout the Chicago metro area, with strong winds and tornadoes causing widespread downed trees, property and vehicle damage.
In Rockford, Illinois, heavy flash flooding affected numerous homes, businesses, and vehicles, and resulted in one fatality. Washington County experienced even more severe flooding due to a partial dam failure, forcing around 200 residents in Nashville to evacuate. Nearby Jersey County, just outside St. Louis, saw additional flooding that resulted in two more fatalities.
Central and southern Minnesota also faced severe weather, with 135,000 people losing power. Monticello and Big Lake experienced extensive hail damage to homes and vehicles, and downed trees were widespread in the Minneapolis-St. Paul area.
The Northeast US was also affected, with over 140,000 people losing power. Intense winds and at least four tornadoes caused significant damage in central New York, particularly in Rome and Canastota. One person was killed, and New York State declared a state of emergency.
In north-central Arkansas, flash flooding led to evacuations. The town of Yellville saw 86 residents evacuated from a nursing home, while 70 more were evacuated from Greenbrier and Flippin. Southern Missouri also faced flooding that damaged homes, businesses, and roads, including those in Branson and some localised flooding in St. Louis.
In Canada, southern Ontario, especially Toronto, was heavily impacted by flash flooding. Over 167,000 people lost power, and many vehicles and buildings were inundated, including Toronto’s Union Station. Major downtown routes were closed as the Don River overflowed, causing widespread flooding in low-lying areas. The flooding disrupted flights, local buses, and trains.
Toronto Fire Department reported over 1,700 flooding incidents and rescued more than 20 people from flooded vehicles and buildings.
Aon stated, “Due to significant impacts within multiple large metropolitan areas, including Chicago, Toronto, and Minneapolis-St. Paul, total economic and insured losses could reach into the hundreds of millions USD. Future damage assessments may drive aggregated losses higher.”
Further rounds of severe convective storms impacted multiple European countries. The first significant damage occurred in France on July 11, with multiple regions, including NouvelleAquitaine, Occitanie, Auvergne-Rhone-Alpes reporting instances of damage due to large hail.
On July 12, Germany experienced significant hailstorm damage, particularly north of Stuttgart. Hailstones up to 5-6 cm in diameter caused extensive property damage. Southern Baden and Bayern, along with other scattered regions, also suffered from hail damage.
In Czechia, storms led to over 1,200 fire brigade emergency responses, mainly for fallen trees and flooded basements. About 17,000 households lost power.
Northern Italy also saw severe hail damage, particularly around Novara and Milan in Lombardia. In Upper Austria and Poland, emergency services conducted hundreds of operations, including over 170 interventions in Warsaw. The storms resulted in four injuries in northern Italy and around 30 injuries at a festival near Trenčín in northwestern Slovakia. In Austria, hail damaged thousands of hectares of crops in Vorarlberg, Carinthia, and Upper and Lower Austria, leading to significant agricultural losses.
On July 13-14, eastern Slovenia experienced very large hail, with the most damage around Slovenska Bistrica, Ptuj, and Ormoz. Localised hail damage was also reported in eastern Slovakia, Slovenia, Croatia, and Hungary. In Belarus, three people died and at least 11 were injured due to wind-related incidents. Tornadoes caused damage to houses and vehicles in Lithuania and Latvia.
On July 16, storm-related wind gusts caused damage across various parts of Poland, including downed trees, power lines, and flooded roadways. Tens of thousands of people were left without power. Local fire brigades conducted over 1,300 emergency responses, including about 800 in the Mazovian Voivodeship and more than 560 in the Warmian-Masurian Voivodeship.
Further hail damage occurred on July 16-17 in eastern Czechia, Zvolen in central Slovakia, and near Budapest in Hungary.
Aon estimates that the total economic and insured losses from these storms could reach hundreds of millions of euros, primarily due to hailstorms, strong winds, and intense rainfall causing localised flash flooding.
Yesterday, Aon released a report estimating that total insured catastrophe losses for the first half of 2024 will be at least $58 billion, largely driven by SCS events. Given the impact of the storms in July, it already appears to be a costly start to the second half of the year, suggesting a strong likelihood that annual insured losses will once again exceed the $100 billion mark.
