Tropical Cyclones Veronica and Trevor are on course to make landfall as category-4 storms this weekend in WA and the NT respectively, bringing destructive winds and storm surges to the regions.

A state of emergency is in place in the NT as the Australian Defence Force begins evacuating hundreds of residents from Groote Eylandt to Darwin before Trevor, presently a category-1 system, arrives on Saturday with category-4 intensity.

Trevor will intensify rapidly today, the Bureau of Meteorology says, and current projections suggest the cyclone will make landfall along the Gulf or east Arnhem Land coastlines.

Damaging winds, heavy rainfalls and dangerous storm tides are expected when the cyclone hits.

“The warm waters of the Gulf and favourable conditions in the atmosphere mean there isn't a lot to stop cyclone Trevor from becoming a large, powerful and extremely dangerous cyclone,” Senior Meteorologist Adam Morgan said.

“Trevor may maintain tropical cyclone intensity for at least 24 hours as it moves inland, with those heavy rains and damaging winds continuing.”

Meanwhile, Cyclone Veronica has strengthened overnight from a category-1 storm to a category-4, packing sustained winds of 185km/h near the eye of the storm and wind gusts of 260km/h.

It is heading towards the central Pilbara coast, where some of Australia’s largest resources projects are located.

“This dangerous system is slow-moving,” Senior Meteorologist Andrea Peace said. “As the cyclone approaches the Pilbara coast over the weekend, communities are likely to experience very destructive winds, very dangerous storm surge and heavy rain that's conducive to major flooding.

“Tides are also likely to rise significantly, particularly on the eastern side of the system, with damaging waves resulting in very dangerous coastal inundation.”

As the regions brace for the twin threats, global mutual insurer FM Global has called for tougher guidelines to ensure the commercial solar farms being increasingly introduced into northern Australia are cyclone-proof.

It has called for a review of building codes, which in its present form “don’t actually give clear guidance” on the design and building of commercial solar farms in cyclone-prone areas.

“Until our standards get better, I think the insurer, the owner, the designer and installer need to work more closely together to make sure that what is being built is cyclone-resilient,” Senior Account Engineer Terence Lee told insuranceNEWS.com.au.

“Australia has very good codes on how to build houses that are cyclone-resilient. What we at FM Global would love to see is that same level of standards for solar farms.”

Mr Lee says FM Global was asked by a client to look at its solar farm in Townsville, and the insurer found existing codes provide little clarity.

“There is really no specific guidance on these large-scale ground-mounted solar farms,” he told insuranceNEWS.com.au.

“Australian standards do reference them but they don’t actually provide clear guidance on how you should design the solar farm to withstand the impact of a one-in-500 year wind event.”