Severe Tropical Cyclone Zelia was a powerful

tropical cyclone A tropical cyclone is a rapidly rotating storm system with a low-pressure area, a closed low-level atmospheric circulation, strong winds, and a spiral arrangement of thunderstorms that produce heavy rain and squalls. Depending on its locat ...

that impacted

Western Australia Western Australia (WA) is the westernmost state of Australia. It is bounded by the Indian Ocean to the north and west, the Southern Ocean to the south, the Northern Territory to the north-east, and South Australia to the south-east. Western Aust ...

Pilbara The Pilbara () is a large, dry, sparsely populated regions of Western Australia, region in the north of Western Australia. It is known for its Indigenous Australians, Aboriginal people; wealth disparity; its ancient landscapes; the prevailing r ...

region in mid-February 2025. The fifteenth tropical low, fifth tropical cyclone, fourth severe tropical cyclone, and first Category 5 tropical cyclone of the

2024–25 Australian region cyclone season The 2024–25 Australian region cyclone season was the most active, and first above-average season in the Australian region since 2005–06 Australian region cyclone season, 2005–06. This season also had the highest amount of severe tropical cy ...

, Zelia originated as a tropical low near the Kimberley region of Western Australia.

Meteorological history

A tropical low, initially designated as ''18U'', formed on 7 February, near the

Kimberley region The Kimberley is the northernmost of the nine regions of Western Australia. It is bordered on the west by the Indian Ocean, on the north by the Timor Sea, on the south by the Great Sandy Desert, Great Sandy and Tanami Desert, Tanami deserts in t ...

. The system tracked west-southwest with no significant development in the coming days. Deep

convection Convection is single or Multiphase flow, multiphase fluid flow that occurs Spontaneous process, spontaneously through the combined effects of material property heterogeneity and body forces on a fluid, most commonly density and gravity (see buoy ...

increased over the southwest quadrant of the center, and the system turned to the south-southwest as steered mid-level ridge to the east on 11 February. Despite deep convection was sheared to the southwest due to

wind shear Wind shear (; also written windshear), sometimes referred to as wind gradient, is a difference in wind speed and/or direction over a relatively short distance in the atmosphere. Atmospheric wind shear is normally described as either vertical ...

, persistent

gale A gale is a strong wind; the word is typically used as a descriptor in nautical contexts. The U.S. National Weather Service defines a gale as sustained surface wind moving at a speed between .

-force winds were observed to the west of the center, which prompted the

Bureau of Meteorology The Bureau of Meteorology (BOM or BoM) is an executive agency of the Government of Australia, Australian Government that is responsible for providing Weather forecasting, weather forecasts and Meteorology, meteorological services to Australia a ...

(BoM) to upgraded the system to a Category 1 tropical cyclone and assigned the name ''Zelia'' later that day. Benefit from very warm waters of and good

outflow Outflow may refer to: *Capital outflow, the capital leaving a particular economy *Bipolar outflow, in astronomy, two continuous flows of gas from the poles of a star * Outflow (hydrology), the discharge of a lake or other reservoir system *Outflow ...

and divergence, Zelia strengthened to a Category 2 tropical cyclone at 06:00 UTC on 12 February. Zelia also reduced its motion to the south as it entered a weak steering environment. As wind shear decreased, Zelia began a period of

rapid intensification Rapid intensification (RI) is any process wherein a tropical cyclone strengthens very dramatically in a short period of time. Tropical cyclone forecasting agencies utilize differing thresholds for designating rapid intensification events, th ...

, and the BoM upgraded it to a high-end Category 3 severe tropical cyclone later that day while the JTWC upgraded it to a Category 3 tropical cyclone with 1-minute sustained winds of . Situated between two

anticyclone A high-pressure area, high, or anticyclone, is an area near the surface of a planet where the atmospheric pressure is greater than the pressure in the surrounding regions. Highs are middle-scale meteorological features that result from interpl ...

s, Zelia continued to move slowly and drifted slightly westward. At 00:00 UTC on 13 February, the BoM upgraded Zelia to a Category 4 severe tropical cyclone, while the JTWC estimated it to have attained its peak intensity with 1-minute sustained winds of . Radar imagery indicated that Zelia underwent an

eyewall replacement cycle In meteorology, eyewall replacement cycles, also called concentric eyewall cycles, naturally occur in intense tropical cyclones with maximum sustained winds greater than , or hurricane-force, and particularly in major hurricanes of Saffir–Simps ...

, but it didn't manage to complete it before making landfall. At 00:00 UTC on 14 February, Zelia attained peak intensity with sustained winds of 205 km/h (125 mph) and a

barometric pressure Atmospheric pressure, also known as air pressure or barometric pressure (after the barometer), is the pressure within the atmosphere of Earth. The standard atmosphere (symbol: atm) is a unit of pressure defined as , which is equivalent to 1,013.2 ...

of by the Bureau of Meteorology but the JTWC said that it weakened to . At 12:30 p.m. AWST (04:30 UTC), Zelia made

landfall Landfall is the event of a storm moving over land after being over water. More broadly, and in relation to human travel, it refers to 'the first land that is reached or seen at the end of a journey across the sea or through the air, or the fact ...

as a Category 4 cyclone, near De Grey, or northeast of

Port Hedland A port is a maritime law, maritime facility comprising one or more wharves or loading areas, where ships load and discharge Affreightment, cargo and passengers. Although usually situated on a sea coast or estuary, ports can also be found far inla ...

. Zelia quickly weakened after landfall, and it dropped below tropical cyclone intensity later that day. Due to the sparsity of land-based radar systems in the Pilbara, no official measurement beyond a wind gust of 120km/ph at Port Hedland was recorded on land.

Preparations and impact

Western Australia

In the state, more than a dozen schools were closed. Two evacuation centers would be opened due to the storm. Multiple highways were closed, while trade in the ports of Dampier and Varanus Island was postponed. A cyclone emergency warning was issued from Pardoo Roadhouse to

Whim Creek Whim may refer to: * Whim, U.S. Virgin Islands, a settlement * Whim (mining), a capstan or drum with a vertical axle used in mining * Whim (carriage), a type of carriage * ''Whim'', a reissue of ''Adventures of Wim'', a book by George Cockroft as ...

. Dozens of people were being evacuated from remote communities, with helicopters having airlifted 63 people from Warralong, 120km south-east of Port Headland. 13 people from Gooda Binya community self-evacuated overnight to a civic centre at Marble Bar. A major flood warning was issued for the De Grey River catchment, including nearby towns. Zelia made landfall near De Grey River, northeast of Port Hedland, causing $733 million USD damage worth of economic losses in the Pilbara and Kimberley regions, specifically causing damage in Port Hedland. Rainfall and flooding caused major impacts, especially at De Gray and Pardoo stations, receiving over 500mm of total rainfall lasing 3 days. The cyclone brought heavy rain and damaging winds near Port Headland, causing flash flooding, prompting evacuation in the Gooda Binya and Warralong communities during the floods. The storm caused significant damage to houses, powerlines and disrupted road access. Zelia also prompted closures of ports at Port Headland, Cape Lambert and Dampier for three days, disrupting shipping and offshore oil and gas operations resulted in major economic costs to industry.

References

External links

{{DEFAULTSORT:Zelia (2025) 2025 meteorology Tropical cyclones in Western Australia

Meteorological history

Preparations and impact

Western Australia

See also

References

External links