Cyclone Seroja, which attracted widespread attention when it crossed the WA coastline unusually far south, has caused insured losses estimated at $434 million, catastrophe data company Perils says.

The Zurich-based firm says it has released an initial estimate well after the April 11-12 event as a result of recent significant claims development, following early delays, and Seroja is now the largest comparable WA event since hailstorms in 2010.

The losses remain below Perils usual $500 million reporting threshold, but the firm notes a high level of interest in the cyclone, which was unusual from a meteorological and insurance perspective, and says it is monitoring further claims activity.

A phenomenon known as the the Fujiwhara effect caused Seroja to interact with nearby Cyclone Odette, pushing it south so it made landfall at an unusually strong intensity for the latitude.

“From an insurance industry perspective, Cyclone Seroja presented considerable challenges, given the degree of destruction in remote and sparsely populated areas, causing claims inflation due to building material supply issues and attracting labour to the region,” Perils Asia-Pacific Head Darryl Pidcock said.

Perils says WA hasn’t experienced a comparable loss since the 2010 Perth hailstorms, and a number of damaging cyclones in the 1970s, including Cyclone Joan in 1975, Alby in 1978, and Hazel in 1979.

Seroja made landfall just south of Kalbarri on April 11, generating damaging winds that affected the Mid-West coastline and inland properties and communities as it travelled on a south-south-easterly track the following morning.

Kalbarri reported gusts of 170 km/h, while many other locations in the region, where properties are not built to withstand cyclones, experienced gusts above 125 km/h.

Perils’ loss number covers the property and motor hull lines of business.