These Clouds Only Predictably Form in Australia

| |

While all clouds are categorized based on the type, there are not many clouds that are named. Australia is home to two of these named clouds: Morning Glory clouds and Hector. Learn about these two very different types of clouds that predictably form in Australia.

Morning Glory Clouds

Morning Glory clouds are long tubular formations that can stretch up to a 1,000 kilometers in length.  A type of roll cloud, similar formations have been spotted around the world but the area around Burketown in Queensland Australia is the only place in the world where the formation of Morning Glory clouds can be predicted.

Each spring (from late September to early November), this rare and unique cloud formation appears in the southern part of the Gulf of Carpentaria in Northern Australia and is visible from Burketown.  

The altitude at which these clouds form can range from a few hundred meters high to up to two kilometers up in the atmosphere.

For a few weeks during the spring months in the Gulf of Carpentaria in Australia, Morning Glory cloud formations can be seen. Map showing the location of the Gulf of Carpentaria in Australia.  Map: Equal Earth Physical Map, public domain.
For a few weeks during the spring months in the Gulf of Carpentaria in Australia, Morning Glory cloud formations can be seen. Map showing the location of the Gulf of Carpentaria in Australia. Map: Equal Earth Physical Map, public domain.

These Morning Glory clouds were captured by Mick Petroff in 2009 flying near the Gulf of Carpentaria, Australia.

Morning glory clouds over the ocean.
Morning glory clouds over the ocean. Photo: Coachwood/stock.adobe.com.

How do Morning Glory Clouds Form?

This graphic provides a simplistic view of how Morning Glory clouds form.  These clouds form when waves of moist air from the sea rise and meet drier air. The cloud forms at the condensation level. The air descending at the back of the wave evaporates.  

This continual cycle results in the Morning Glory cloud formation.

Annotated morning glory cloud formation at Las Olas Beach in Uruguay.  Photo: Daniela Mirner Eberl, CC BY-SA 3.0
Annotated morning glory cloud formation at Las Olas Beach in Uruguay. Photo: Daniela Mirner Eberl, CC BY-SA 3.0

For more detail, you can learn about how Morning Glory clouds are formed:

Hector the Convector

Another predictable cloud formation that occurs in Australia has the nickname “Hector the Convector“. Every afternoon at around 3pm from about September through March, a cumulonimbus thundercloud develops over Melville and Bathurst islands that make up the Tiwi Islands in Australia’s Northern Territory.

Satellite image of the Tiwi Islands in Australia.
Melville and Bathurst make up the Tiwi Islands. Mainland Australia is located at the bottom of this Landsat satellite image. Image: NASA

Moist tropical air, sea breeze caused by the differential heating between the islands and the ocean, and the pyramid shape of the islands all contribute to this meteorological phenomenon. Sea breeze air moving between where the two islands meet forms the thunderstorm cloud.

Hector can reach up to 20 kilometers high.

References

Crook, N. A. (2001). Understanding Hector: The dynamics of island thunderstorms. Monthly weather review129(6), 1550-1563.

Meet Hector, the thunderstorm that can tell time. (2020, September 19). Scientific Scribbles – The University of Melbourne. https://blogs.unimelb.edu.au/sciencecommunication/2020/09/19/meet-hector-the-thunderstorm-that-can-tell-time/

See Also

Share:


Enter your email to receive the Geography Realm newsletter: