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The terms and definitions found in the glossary relate to the science of meteorology.
For descriptions and definitions of words used in the Bureau's forecasts and warnings, please refer to Weather Words.
- Land Breeze
- A local offshore wind. At night, when the land cools more quickly, and to a greater extent, than the sea, the land breeze circulation is set up.
Cooler air from the land flows offshore to replace the warm air rising over the sea.
The air in contact with the sea warms and expands and the resulting changes in the pressure and temperature differences and distributions cause the land breeze circulation. - La Niņa
- The extensive cooling of the central and eastern Pacific Ocean. In Australia (particularly eastern Australia), La Niņa events are associated with increased probability of wetter conditions.
Click here for more information. - Lightning
- The flash of light accompanying a sudden electrical discharge which takes place from or inside a cloud, or less often from high structures or the ground or from mountains. A large electrical spark.
Caused when the negative charge in the lower part of the cloud and the positive charge in the upper part of the cloud become so great that they can overcome the natural resistance of the air and discharge between negative and positive takes place. - Low latitudes
- The southern hemisphere low-latitudes are considered to be the areas of the Earth north of about 30 degrees latitude. For Australia, this means the area north of a line from halfway between Perth and Geraldton (in Western Australia) to Bourke (in New South Wales). This part of Australia generally experiences a subtropical to tropical climate.
- Low pressure
- Atmospheric circulations that rotate clockwise in the southern hemisphere. Cyclones are areas of lower pressure and generally associated with stronger winds, unsettled conditions, cloudiness and rainfall.
- LST - Local Standard Time
- The globe is divided into Standard time zones and Local Standard Time is the time specified for each zone. This is usually done in terms of hours ahead or behind UTC. The LST zones in Australia are as follows: EST - Australian Eastern Standard Time (+10 UTC) in Qld, NSW, Vic and Tas; CST - Australian Central Standard Time (+9.5 UTC) in NT and SA; and WST - Australian Western Standard Time (+8 UTC) in WA.