Meteopedia — Weather glossary

Weather encyclopedia with 342 terms

Browse detailed definitions of atmospheric phenomena, cloud types, measurement instruments, regional winds, meteorological scales, climatology and more.

342 Meteopedia 16 categories
All (342) Atmospheric phenomena (50) Instruments (30) Scales and measurements (10) Clouds (36) Wind (34) Precipitation (24) Temperature (15) Cyclones and severe storms (14) Atmospheric optics (16) Meteorological astronomy (5) Climatology (34) Marine meteorology (15) Air quality (10) Agrometeorology (10) Hazards and safety (10) General (29)
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

A

Acid rain

Precipitation with pH below 5.6 caused by dissolution of atmospheric pollutants such as sulphur dioxide and nitrogen oxides.

Precipitation

C

Condensation

The process by which water vapour changes to liquid state upon cooling below its saturation point.

Precipitation

Convective precipitation

Precipitation generated by rapid ascent of warm, moist air in convective currents, typically intense, localised, and short-lived.

Precipitation

D

Dew

Water droplets that form on cold surfaces when the temperature drops to the dew point.

Precipitation

Drizzle

Uniform precipitation of very fine droplets (< 0.5 mm diameter) that fall slowly.

Precipitation

E

Evaporation

The process by which liquid water transforms into water vapour by absorbing heat energy.

Precipitation

Evapotranspiration

The total amount of water transferred to the atmosphere by soil evaporation and plant transpiration combined.

Precipitation

F

Freezing level

Altitude at which air temperature drops to 0 °C, determining the snow line and the type of precipitation reaching the ground.

Precipitation

Freezing rain

Rain that freezes on contact with surfaces below 0 °C, forming a transparent ice layer.

Precipitation

Frontal precipitation

Rain or snow generated by the lifting of warm air over cold air along a weather front, generally widespread and persistent.

Precipitation

G

Graupel

Precipitation in the form of soft, opaque pellets of rimed snow, intermediate between snow and hail, 2-5 mm in diameter.

Precipitation

H

Hail

Solid precipitation in the form of ice balls or irregular lumps that fall from intense convective clouds.

Precipitation

Hydrometeor

Any water particle, liquid or solid, in the atmosphere: includes rain, snow, hail, fog, dew, frost, and all forms of precipitation.

Precipitation

I

Ice pellets

Precipitation as transparent ice pellets 1–5 mm in diameter that bounce on impact, formed when snow partially melts then refreezes during its fall.

Precipitation

O

Orographic precipitation

Rain or snow caused when moist air is forced to rise over a mountain.

Precipitation

P

Powder snow

Light, dry snow with low density and high air content, ideal for winter sports, formed at very low temperatures.

Precipitation

Precipitable water

Total amount of water vapour in a vertical atmospheric column, expressed in millimetres if it were all condensed.

Precipitation

R

Rain

Precipitation in the form of liquid water drops with diameter exceeding 0.5 mm falling from clouds.

Precipitation

Rainfall intensity

Amount of rain fallen per unit time, expressed in mm/hour, determining the potential for runoff, flooding, and soil erosion.

Precipitation

Rime ice

Ice deposit formed by the freezing of supercooled fog or cloud droplets upon contact with solid surfaces.

Precipitation

S

Sleet

Mixed precipitation of rain and partially melted snow, or translucent ice pellets.

Precipitation

Snow

Solid precipitation in the form of hexagonal ice crystals that cluster into snowflakes.

Precipitation

Sublimation

The direct phase change from ice or snow to water vapour without passing through the liquid phase.

Precipitation

W

Wet snow

Snow with high liquid water content that readily adheres to surfaces, weighs more than powder snow, and can damage infrastructure with its weight.

Precipitation