Tropical Cyclone Herman has defied forecasts and rapidly strengthened into a category four severe tropical cyclone to the northwest of Australia.

The satellite images below show Herman gaining strength and becoming a well-formed symmetrical tropical cyclone over the last 15 hours.

Video: Enhanced infrared satellite images showing Tropical Cyclone Herman gaining strength to the northwest of Western Australia on Thursday into Friday morning.

At 8am AWST on Friday, Herman was a category four severe tropical cyclone located roughly 700 km south of Christmas Island and 1020 km northwest of Exmouth. At that time wind gusts near the centre of the powerful cyclone were reaching about 260 km/h.

Thankfully, Herman is likely to remain well away from Australia’s mainland and offshore territories, sparing communities from its destructive winds and the heaviest rain near its core.

Image: Observed satellite and forecast track map for Tropical Cyclone Herman, valid at 8:30am AWST.

However, as the satellite image below shows, large areas of western and central Australia are receiving cloud and rain that has been pumped into the atmosphere by Herman and dragged south by upper-level winds.

Some of this rain has already caused flooding in some inland parts of WA over the last couple of days. The 86mm that fell at Newman Airport during the 24 hours to 9am on Thursday was more than two months’ worth of rain for this time of year.

Images: The Fortescue River near Newman on March 28 (top) and after heavy rain on March 29 (bottom). Source: @kevinmitchellchasingstars / Instagram

You can find the latest weather and flood warnings here and tropical cyclone track maps and advisories here.