Damage will be worst in the west

A TROPICAL cyclone would cause the most damage to homes west of the Pacific Motorway rather than suburbs along the coastline, new weather modelling shows.

The Severe Wind Hazard Assessment for Queensland report considers the impact of Category 3 and 5 cyclones in a special case study on the Gold Coast.

A minimum of 23,578 homes would be completely destroyed and in the worst scenario, almost 35,000 extensively damaged and 100,455 flattened in a Category 5.

A Category 3 weather event would still create winds of around 220km/h, much higher than the 170km/h reached during the 1954 Gold Coast Cyclone which saws roofs lost off Southport homes and jetties destroyed.

Mapping shows the most impacted areas would be in the hinterland, at Ferny Glen and the Numinbah Valley south to the Tallebudgera Valley.

Mudgeeraba along with Nerang, Maudsland and Oxenford just west of the M1 would have extensive residential home damage.

Parts of Jacobs Well and Norwell in the cane fields in the city’s north are also impacted under this modelling.

But growing northern suburbs like Ormeau and Kingsholme escape with no damage.

Mapping shows homes sitting on the coastline, south of Paradise Point to Runaway Bay along with those at Parkwood and Arundel could expect major damage.

The reason is wind speeds along the coast where a cyclone was predicted to cross at South South Stradbroke Island reach greater than 280km/h through to Main Beach and Surfers Paradise.

The winds behind the foreshore then drop to around 200km/h in suburban areas.

But they top 300km/h in the hinterland as winds pick up speed climbing up the terrain. The report suggests in a Category 5 scenario, the cyclone forms well in the Coral Sea, slowly building about 1000km off Mackay, drifts at a slow pace before crossing the Coast.

“This brings the southern eyewall over South Stradbroke Island and the northern end of Main Beach. It should also be noted that this track is similar to the initial forecasts for TC Oma in 2019,” the report said.

“In this case, local winds exceed 260km/h along the Main Beach area down to Surfers Paradise. Behind the foreshore, most of the suburban areas experience winds in excess of 200km/h.

“There are isolated points along the coastline where wind gusts may exceed 250km/h, such as around Burleigh Heads. Further inland, maximum wind speeds over the hinterland exceed 300km/h due to the local topographic enhancement as far inland as Springbrook.”

In a Category 3 cyclone, the hinterland continues to be hammered.

“In some areas, the maximum local wind speed may exceed 250km/h,” the report says.

“Those wind speed exceed the current regional design standards for residential housing which is for 205km/h.”