Tropical Cyclone Threat Looms Over Australia‘s Northwest Coast
A swarm of tropical lows is brewing to the northwest of Australia, fuelled by unusually warm ocean waters and raising the risk of tropical cyclone development before Christmas.
Troubling Conditions Prime the Region for Cyclone Formation
Image: Visible satellite image showing clouds over Australia on Monday morning.
Satellite imagery reveals abundant cloud cover blanketing the northwest coast of Australia early this week. This tropical cloud formation is a direct consequence of warmer-than-average sea surface temperatures off Australia’s northwest coast and a powerful pulse of the Madden-Julian Oscillation in the region.
This cluster of clouds acts as a breeding ground for tropical cyclones. Individual areas of convection within these clouds behave like seeds, with the potential to grow into more organized tropical low-pressure systems and eventually strengthen into full-fledged cyclones.
Adding to the concern, forecast models predict the development of two or three distinct low-pressure systems in the region this week. Two of these lows carry a moderate risk of intensifying into tropical cyclones.
Image: Enhanced infrared satellite images showing two developing tropical lows northwest of Australia on Monday.
Tropical Lows Form, Bringing Increased Risk
The first tropical low has already emerged near the Cocos (Keeling) Islands. While this system is expected to bring increased showers and thunderstorms to the islands over the next few days, it currently has a low chance of developing into a tropical cyclone.
Closer to the Australian mainland, another low is forming north of the Pilbara coast. This system is expected to strengthen as it travels west-southwest in the coming days, maintaining a roughly parallel course to the Western Australian coastline but remaining offshore. This low carries a moderate risk of becoming a tropical cyclone on Tuesday or Wednesday. Given its predicted path, it is not expected to directly impact the Australian mainland, but communities in northern Western Australia should stay alert and monitor updates throughout the week.
A third tropical low could emerge over the Timor or Arafura Seas later this week, potentially forming north of Western Australia’s Kimberley coast. While it is still too early to have a high level of confidence in this system’s development, some computer models suggest it could evolve into a tropical cyclone off the north coast of Western Australia by the end of this week or early next week. At this stage, there is a moderate chance of this system developing into a tropical cyclone this weekend or early next week.
Unusually Warm Waters Fuel Cyclone Potential
Image: Sea surface temperature anomalies off the northwest coast of Australia on December 7. Source: Bureau of Meteorology
One factor amplifying the risk of tropical cyclone activity is the abnormally warm sea surface temperatures in the region. In some areas, temperatures are currently exceeding 32°C, more than 2°C warmer than average for this time of year.
Warm ocean waters act like fuel for developing storms and low pressure systems, providing them with the energy needed to strengthen into tropical cyclones.
What are the potential benefits and drawbacks of preemptively implementing evacuation plans for Western Australia coastal communities before cyclone warnings are issued, given the unusually warm water temperatures and increased cyclone risk?
## Is there such a thing as being *too* prepared for cyclone season?
Given these unusually warm waters and the potential for multiple cyclones to form before Christmas, should coastal communities in Western Australia be considering evacuation plans even before any cyclone warnings are issued?
