A rapidly deepening low pressure system over the eastern Indian Ocean is forecast to undergo explosive cyclogenesis, bringing severe weather to parts of southwest Western Australia over the weekend. The system is expected to produce damaging to destructive winds, heavy rain, thunderstorms, and dangerous seas.
Key Drivers of the Storm
- The low's central pressure is forecast to fall by about 25 hPa in 24 hours, exceeding the latitude-adjusted threshold for explosive cyclogenesis (16–17 hPa at 35–37°S).
- An upper-level jet stream with winds near 300–310 km/h (at 9–10 km altitude) is contributing to rapid pressure falls.
- Abnormally warm sea surface temperatures (anomalies of +1 to +2°C) off the WA coast are providing moisture and energy.
- A pool of cold air aloft is creating instability, aiding rapid deepening.
Forecast Impacts
- Winds: Damaging to destructive gusts expected, particularly on Sunday and Monday.
- Rain: Heavy rainfall with possible thunderstorms.
- Seas: Large surf and hazardous marine conditions.
- Timing: Conditions worsening through the weekend, with the system shifting away early next week.
Warnings
Residents are advised to secure loose outdoor items, avoid exposed beaches and coastal roads, not drive through floodwater, and monitor official warnings.