Two category 4 cyclones could make landfall this weekend simultaneously in Australia for the first time since reliable records began.

Catastrophe modeller Risk Frontiers says if the same scenario played out over large population centres, it would constitute a national disaster.

Cyclone Trevor, which is expected to intensify to category 4 before crossing the NT coast tomorrow, should affect a relatively small population of 10,000, many of whom have been evacuated.

The Bureau of Meteorology predicts gusts of 275 km/h near the cyclone’s centre, storm tides, damaging waves and heavy rainfall.

Cyclone Veronica should cross WA’s Pilbara coast tomorrow, also as a category 4 system. The bureau warns destructive winds of 165 km/h are forecast, along with major flooding and dangerous storm tides.

“While we have had two cyclones make landfall in Australia at the same time before, this is the first time we had two such intense cyclones simultaneously,” Risk Frontiers Senior Risk Scientist Thomas Mortlock told insuranceNEWS.com.au.

“We are quite fortunate that both are in areas that are not so populated. If one had hit Darwin, and the other further south in WA, then it could be devastating.”

Veronica is slow-moving, which could lead to extreme rainfall totals as the system stalls above affected areas.

Scientists believe climate change is contributing to an increase in damaging slow-moving weather systems across the globe, pointing to 2017’s Hurricane Harvey in the US and Cyclone Debbie in Queensland.

The monsoonal low that devastated Townsville was also an unusually slow-moving system.

The ways in which climate change is affecting cyclones will be the subject of the Analysis in Monday’s insuranceNEWS.com.au bulletin.