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Weather Glossary - J


Jet max

(Speed Max, Jet Streak) A point or area of relative maximum wind speeds within a jetstream.

Jet streak

A local wind speed maximum within a jetstream.


Relatively strong winds concentrated in a narrow stream in the atmosphere, normally referring to horizontal, high-altitude winds. The position and orientation of jetstreams vary from day to day. General weather patterns (hot/cold, wet/dry) are related closely to the position, strength and orientation of the jetstream (or jetstreams). A jetstream at low levels is known as a low level jet.


Joint Typhoon Warning Center. The JTWC issues warnings and forecasts for tropical systems across the Pacific and Indian Oceans.

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Cyclone Nora hits the Queensland coast as a category three system

01:30 EDT

Tropical Cyclone Nora has struck the far north Queensland coast as a category three system.

Gusty storms bring gloomy weekend to Victoria

15:53 EDT

A series of low pressure troughs have brought thundery showers to western and central Victoria on Saturday, with most of the rain associated with these systems falling over southern parts.

Tropical Cyclone Nora expected to reach category four before hitting Queensland

15:50 EDT

Rapidly intensifying Tropical Cyclone Nora is expected to become a category four system in Queensland's Gulf of Carpentaria later today, the Bureau of Meteorology (BOM) has warned.