Category 4: Cyclone Ilsa could bring a year’s worth of rain in little more than a day

Cyclone Ilsa is now a category 4 storm and is set to smash parts of WA within 24 hours, with warnings it could bring a year’s worth of rain in little more than a day.

A ferocious cyclone bearing down on Western Australia is intensifying at such a strength meteorologists are concerned it could surpass its current category 4 maximum power and become a category 5 super storm – the highest possible classification.

There are warnings Ilsa could bring a year’s rain in little more than a day and be so strong caravans could become airborne.

Cyclone Ilsa has powered up to a category 4 storm. It was 290 kilometres north of Port Hedland at 9:00am Thursday morning.

🚨1PM NZST / 9AM AWST Update:

🌀Tropical Cyclone #ILSA
- Strengthening
- Category4⃣

📽️Animation shows:
- 🌪️Current winds (pink near the centre = sustained winds around 200km/h, gusting 240km/h).
- 🌡️Current temperatures
- ⚡️Current Lightning

🌀https://t.co/gb7E1qu1nD🌀 pic.twitter.com/lzvPtfeOY6

— WeatherWatch.co.nz (@WeatherWatchNZ) April 13, 2023

It’s expected to gear up even further on Thursday before turning and hitting land, likely between Broome and Port Headland near the Pardoo Roadhouse, in the early hours of Friday.

It will then head inland towards central Australia, towards Alice Springs, remaining at tropical cyclone strength hundreds of kilometres from the sea.

A cyclone warning for Broome has been cancelled.

The last category four cyclone to make landfall in mainland Australia was Cyclone Debbie in 2017, which crossed the coast near Airlie Beach, Queensland, with wind gusts of up to 263km/h.

Cyclone Ilsa is huge. Picture: Windy.

Could become category 5 storm

The Western Australian Department of Fire and Emergency Service (DFES) has issued a “yellow alert” for the strengthening weather system.

The alert upgrade from blue to yellow means those in the warning area need to act now in order to stay safe.

It covers the coastal area from Bidyadanga to De Drey, while a blue alert has been extended inland as far as the Gibson Desert North.

“A lot of the heat is remaining in the north and this is very important because the heat in northern parts of the country as well as the oceans is helping to intensify Ilsa,” said Sky News Weather meteorologist Bradlyn Oakes.

“We are watching for it to undergo rapid intensification as we head through the next couple of days before it makes landfall potentially as a category 4, but it also could actually intensify so much it gets to category 5.”

Category 4 storms have sustained winds of 209 km/h while cat 5 sees winds of 252 km or higher in the weather system. Both categories can cause “catastrophic damage” with homes destroyed, trees uprooted and power outages.

Cyclone Ilsa is expected to reach Western Australia by Thursday or Friday. Picture: BOM.

‘Year’s rain in a couple of days’

Winds of more than 200km/h are expected in the impact zone. High tides, flash flooding, storm surges are also a possibility.

Recent satellite images have shown the huge size of the cyclone brooding off the WA coast, with cloud cover stretching far into the Indian Ocean.

Up to 200mm of rain in some areas is also on the cards.

Authorities say coastal areas of WA will begin feeling the outer edges of Ilsa on Thursday.

“We’re likely to see winds pick up in coastal areas and conditions continue to deteriorate,” the Bureau of Meteorology’s (BOM) Todd Smith said.

“Some parts of the Pilbara might see a year’s rain in the next couple of days”.

BOM meteorologist Jessica Lingard said objects including outdoor furniture, trampolines and even caravans could be sucked into the cyclone unless they were put away or tethered.

“Tie them down so these items don’t become dangerous projectiles as the system moves.

“It will be enough to pick up a caravan and move it around.”

The storm will likely remain at cyclone strength for hundreds of kilometres inland. Picture: Windy.

There have been concerns for the residents of two caravan parks along Eighty Mile Beach, with DFES Commissioner Darren Klemm having pleaded with those still there on Wednesday morning to leave

“I’d like to see those caravan sites cleared. There are still 60 caravans at Eight Mile. I would urge them to get out now,” Commissioner Klemm said.

In Port Hedland, supermarket shelves were stripped almost bare as Ilsa approached.

“Look at that guys. Everyone is getting ready for the cyclone. Oh god, even the brown onion is gone,” said local Jennifer Morales at Woolworths on a social media video she uploaded.

Pilbara ABC reporter Michelle Stanley tweeted from inside a Port Hedland Woolworths store on Tuesday.

Thoughts and prayers for Port Hedland supermarket staff today,” she wrote with a video of bare meat and bread shelves.

“Needless to say, the water aisle was also rather bare.”