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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.
- Hail
- Precipitation (falling) of particles of ice (hailstones). Usually spheroid, conical or irregular in form and with a diameter varying generally between 5 and 50 millimetres.
Hail falls from clouds either separately or collected into irregular lumps. - Haze
- State of atmospheric obscurity due to the suspension in the air of extremely small dry particles invisible to the naked eye. Haze resembles a uniform veil over the landscape that subdues its colours. When viewed against a dark background (e.g. a mountain) it has a bluish tinge but it has a dirty yellow or orange tinge against a bright background (e.g. sun, clouds). Haze is distinguished from mist when the humidity is less than 90% at the time.
- Heat wave
- A period of abnormally hot weather lasting several days.
- High pressure
- Atmospheric circulations that rotate anti-clockwise in the Southern Hemisphere. Anticyclones are areas of higher pressure and are generally associated with lighter winds and fine and settled conditions.
- Humid
- Relatively high water vapour content in the air, often associated with warmer temperatures. Relative Humidity (RH) and the Dewpoint Temperature can be used as indicators of humidity.
- Humidity
- A measure of water vapour in the air. See the Humidity calculator to calculate relative humidity and for more detailed information.
- Hurricane Force Wind Warning
- A Hurricane Force Wind Warning is a statement which warns of winds averaging 64 knots or more in coastal waters and high seas areas.
- Hydrology
- An earth science concerned with the occurrence, distribution and circulation of waters on and under the earth's surface, both in time and space, their biological, chemical and physical properties, their reaction with the environment, including their relation to living beings.
- Hydrometeorology
- The study of the atmospheric processes that affect the water resources of the earth, including the study of the atmospheric and land phases of the hydrological cycle with emphasis on the interrelationships involved.