Precipitation

rainfallhydrometeorannual precipitationprecipitationshydrometeorsPrecipitation (meteorology)wetorographic precipitationprecipitateprecipitated
In meteorology, precipitation is any product of the condensation of atmospheric water vapour that falls under gravity.wikipedia
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Drizzle

drizzlydrizzlingorballo
The main forms of precipitation include drizzle, rain, sleet, snow, graupel and hail.
Drizzle is a light liquid precipitation consisting of liquid water drops smaller than those of rain – generally smaller than 0.5 mm in diameter.

Hail

hailstormhailstoneshailstone
The main forms of precipitation include drizzle, rain, sleet, snow, graupel and hail. Frozen forms of precipitation include snow, ice needles, ice pellets, hail, and graupel.
Hail is a form of solid precipitation.

Graupel

Snow pelletssmall hailsoft hail
The main forms of precipitation include drizzle, rain, sleet, snow, graupel and hail. Frozen forms of precipitation include snow, ice needles, ice pellets, hail, and graupel.
Graupel (Enɡlish: ), also called soft hail or snow pellets, is precipitation that forms when supercooled water droplets are collected and freeze on falling snowflakes, forming 2 - 5 mm balls of rime.

Thundersnow

Heavy snowfall, accompanied by lightning and thundersnowthunder
Thundersnow is possible within a cyclone's comma head and within lake effect precipitation bands.
Thundersnow, also known as a winter thunderstorm or a thundersnowstorm, is an unusual kind of thunderstorm with snow falling as the primary precipitation instead of rain.

Fog

advection fogfreezing fogground fog
Thus, fog and mist are not precipitation but suspensions, because the water vapor does not condense sufficiently to precipitate.
Fog commonly produces precipitation in the form of drizzle or very light snow.

Water vapor

water vapourvaporevaporation
In meteorology, precipitation is any product of the condensation of atmospheric water vapour that falls under gravity.
In some countries, the evaporation rate far exceeds the precipitation rate.

Water cycle

hydrological cyclewaterhydrologic cycle
Precipitation is a major component of the water cycle, and is responsible for depositing the fresh water on the planet.
The water moves from one reservoir to another, such as from river to ocean, or from the ocean to the atmosphere, by the physical processes of evaporation, condensation, precipitation, infiltration, surface runoff, and subsurface flow.

Climate

climaticclimatesaverage annual temperature
Climate classification systems such as the Köppen climate classification system use average annual rainfall to help differentiate between differing climate regimes.
Some of the meteorological variables that are commonly measured are temperature, humidity, atmospheric pressure, wind, and precipitation.

Orographic lift

orographicorographic liftingrelief precipitation
Mechanisms of producing precipitation include convective, stratiform, and orographic rainfall.
As the air mass gains altitude it quickly cools down adiabatically, which can raise the relative humidity to 100% and create clouds and, under the right conditions, precipitation.

Rain gauge

pluviometerrain gaugestipping bucket rain gauge
;Liquid precipitation: Rainfall (including drizzle and rain) is usually measured in millimeters (mm) using a rain gauge, which is equivalent to kilogram per square meter (kg/m 2 ).
A rain gauge (also known as an udometer, pluviometer, or an ombrometer) is an instrument used by meteorologists and hydrologists to gather and measure the amount of liquid precipitation over an area in a predefined period of time.

Wet season

rainy seasonmonsoon seasonwet
The movement of the monsoon trough, or intertropical convergence zone, brings rainy seasons to savannah climes.
When the wet season occurs during a warm season, or summer, precipitation falls mainly during the late afternoon and early evening.

Fresh water

freshwaterfreshlimnic
Precipitation is a major component of the water cycle, and is responsible for depositing the fresh water on the planet.
The source of almost all fresh water is precipitation from the atmosphere, in the form of mist, rain and snow.

Ice pellets

sleetice pelletrefreezed snow
Frozen forms of precipitation include snow, ice needles, ice pellets, hail, and graupel.
Ice pellets are a form of precipitation consisting of small, translucent balls of ice.

Diamond dust

ice crystalsice needles
Frozen forms of precipitation include snow, ice needles, ice pellets, hail, and graupel.
Diamond dust generally forms under otherwise clear or nearly clear skies, so it is sometimes referred to as clear-sky precipitation.

Cyclone

cyclonescycloniccyclonic storm
Where relatively warm water bodies are present, for example due to water evaporation from lakes, lake-effect snowfall becomes a concern downwind of the warm lakes within the cold cyclonic flow around the backside of extratropical cyclones.
Such fronts form west of the circulation center and generally move from west to east; warm fronts form east of the cyclone center and are usually preceded by stratiform precipitation and fog.

Snow gauge

Snow depth
;Solid precipitation: A snow gauge is usually used to measure the amount of solid precipitation.
A snow gauge is a type of instrument used by meteorologists and hydrologists to gather and measure the amount of solid precipitation (as opposed to liquid precipitation that is measured by a rain gauge) over a set period of time.

Water

H 2 OHOliquid water
Like other precipitation, hail forms in storm clouds when supercooled water droplets freeze on contact with condensation nuclei, such as dust or dirt.
It forms precipitation in the form of rain and aerosols in the form of fog.

Stratus cloud

stratusstratiformstratus clouds
Mechanisms of producing precipitation include convective, stratiform, and orographic rainfall. Provided necessary and sufficient atmospheric moisture content, the moisture within the rising air will condense into clouds, namely stratus and cumulonimbus.
They mostly appear under the precipitation of major rain-bearing clouds.

Ocean

marineoceansmaritime
Approximately 505000 km3 of water falls as precipitation each year; 398000 km3 of it over the oceans and 107000 km3 over land.
Transferring warm or cold air and precipitation to coastal regions, winds may carry them inland.

METAR

SPECIaviation flight categoryaviation
The METAR code for ice pellets is PL.
A typical METAR contains data for the temperature, dew point, wind direction and speed, precipitation, cloud cover and heights, visibility, and barometric pressure.

Cumulonimbus cloud

cumulonimbusthundercloudcumulonimbus clouds
Provided necessary and sufficient atmospheric moisture content, the moisture within the rising air will condense into clouds, namely stratus and cumulonimbus.
Most storm cells die after about 20 minutes, when the precipitation causes more downdraft than updraft, causing the energy to dissipate.

Rain shadow

rainshadowrainshadow effectlow snowfall
Moisture is removed by orographic lift, leaving drier air (see katabatic wind) on the descending and generally warming, leeward side where a rain shadow is observed.
At the adiabatic dew point, moisture condenses onto the mountain and it precipitates on the top and windward sides of the mountain.

Squall line

quasi-linear convective systemrain bandbanding
In mid-latitudes, convective precipitation is intermittent and often associated with baroclinic boundaries such as cold fronts, squall lines, and warm fronts.
It contains heavy precipitation, hail, frequent lightning, strong straight-line winds, and possibly tornadoes and waterspouts.

Synoptic scale meteorology

synoptic scalesynopticsynoptic-scale
Stratiform or dynamic precipitation occurs as a consequence of slow ascent of air in synoptic systems (on the order of cm/s), such as over surface cold fronts, and over and ahead of warm fronts.
Most precipitation areas occur near frontal zones.

Tropical cyclone

hurricanetropical stormhurricanes
Similar ascent is seen around tropical cyclones outside of the eyewall, and in comma-head precipitation patterns around mid-latitude cyclones.
Tropical cyclones also draw in air from a large area—which can be a vast area for the most severe cyclones—and concentrate the precipitation of the water content in that air (made up from atmospheric moisture and moisture evaporated from water) into a much smaller area.