Sub-tropical Ridge (STR)
The STR is a natural high pressure belt that sits across the southern parts of Australia.
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Key things to know about STR
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- The sub-tropical ridge moves north and south seasonally over Australia
- This can affect the passage of cold fronts across southern Australia. Fronts are a good source of moisture and potential rainfall.
- Typically in winter the STR moves north, allowing fronts to pass over southern Australia.
- In summer, the STR typically moves south, blocking the passage of fronts.
- This is part of the reason why Victoria experiences rain bearing cold fronts during winter.
- The strength (or intensity) of the high pressure systems also affect rainfall. Higher pressure means less rainfall.
- Farmers know that the seasons with stronger or more frequent blocking high pressure systems over southeast Australia don’t tend to produce the regular rainfall we would like.
Where to go for more information
For more information about the STR visit some of the pages below.