condensation

evaporation

the process by which a gas becomes a liquid. Water vapor turns into liquid water by condensation.

the process by which a liquid becomes a gas.

run-off

saturated

the flow of water, from rain, snowmelt, or other sources, over the land.

thoroughly full.

watershed

temperature

an area of land that is drained by a stream or river and its branches.

a measurement of the amount of heat a substance contains.

stratus

prevailing winds

a cloud belonging to a class characterized by horizontal layering with a uniform base. More specifically, the term stratus is used to describe flat, featureless clouds of low altitude varying in color from dark gray to nearly white.cloud

the trends in speed and direction of wind over a particular point on the earth's surface.windearth

Westerlies

Easterlies

Any semipermanent belt of westerly winds, especially those that prevail at latitudes lying between the tropical and polar regions of the earth

A storm or wind coming from the east

pattern

air mass

a repeating arrangement of shapes, colors, numbers, or other things.

a body of air that has the same temperature and/or humidity throughout.

air pressure

almanac

the pressure exerted by air per-unit surface area in the earths atmosphere. Also called barometric pressure.

a publication that contains astronomical and meteorological data and forecasts.

aneroid barometer

atmosphere

a barometer that does not require the use of a liquid.

the layer of air that surrounds the earth.

barometer

beaufort scale

a device used to measure air pressure.

a scale that relates the wind speed to its effects booth on land and at sea, classified from force 0 to force 12.

cirrus

climate

high level clouds made mostly of ice crystals.

the average weather over a long period of time.

cumulonimbus

cumulus

clouds that bring summer storms, usually with thunder, lighting, and strong winds.

mid-level, puffy clouds.

fog

forecast

clouds that form at ground level.

a prediction of the weather conditions for a given area and a given time period.

front

hurricane

the boundary between two unlike air masses.

a large rotating windstorm with a calm central eye and winds greater than 118 kph.

isobar

meteorologist

lines drawn on a weather map that connect areas of the same barometric pressure at a given time.

a person who studies meteorology.

meteorology

occluded front

the study of the earths atmosphere and what happens in it.

where a cold front catches up to and overtakes a warm front.

precipitation

rain gauge

any liquid or solid form of water that falls from the atmosphere. For example, rain, snow, hail, or sleet.

a device used to measure the amount of precipitation in a given area.

station model

stationary front

a weather symbol that represents the state of the weather at a particular place.

when a cold and a warm air mass meet, but neither moves.

stratus

tornado

lower level; layered-looking clouds.

a narrow, violently rotating column of air characterized by winds greater than 81 kph and a funnel cloud that reaches the ground.

vacuum

warm front

an area of no air pressure.

the leading edge of a moving mass of warm air.

weather

weather forecasting

the state of the atmosphere at a given time and place with respect to wind, temperature, cloudiness, moisture, pressure, and other factors.

predicting what future weather will be like.

weather front

weather station

the boundary where difficult air masses collide.

a place where weather data are recorded.