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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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Weather News

Outlook not great for SA firefighters

15:39 EDT

Conditions will not be favourable for fires burning north of Adelaide as warming temperatures, little rain and strengthening winds move across the region early next week.

Publican tells of "frightening" fire that swept through Olary

13:33 EDT

The publican in the South Australian town of Olary said historic buildings and cottages stood no chance against a fire that tore through the town.

Thunderstorms crack dawn in Darwin

13:10 EDT

A severe thunderstorm tore through Darwin early this morning, bringing damaging winds and heavy rainfall totals.