An instrument to measure the altitude of an object above a fixed level.Generally, mean sea level is used for the reference level.
Mid-level cloud (bases generally 2000 - 8000m), made up of grey,puffy masses, sometimes appearing in parallel waves or bands. An indicatorof mid-level instability. Altocumulus can take on various forms such as AcLenticularis, Ac Undulatus, Ac Castellanus, Altocumulus 'mackerel sky'.
A middle level cloud with vertical development that forms from altocumulusclouds. It is composed primarily of ice crystals in its higher portions andcharacterised by its turrets, protuberances or crenulated tops.
Mid-level cloud composed of water droplets and ice crystals. Usuallygives the sun a watery or dimly visible appearance.
A local wind that flows up the side of valleys due to increased heating alongthe valley walls. Often the anabatic wind results in cumulus clouds along theridges either side of the valley. See also Katabatic winds.
A device used to measure wind speed.
The departure of an element from its long-term average for the locationconcerned. For example, if the average maximum temperature for
Melbourne in June is 14 degrees and on one particular day the temperature
only reaches 10 degrees, than the anomaly for that day is -4.
A large scale atmospheric circulation system in which the winds rotate anticlockwise in the Southern Hemisphere (clockwise in Northern Hemisphere).Anticyclones are areas of high atmospheric pressure and are generallyassociated with light winds and stable weather conditions. Interchangeablewith High pressure system.
Rotation in the opposite sense as the Earth's rotation, i.e., anticlockwise in