weather

The state of the atmosphere: considering wind, temperature, cloudiness, moisture, pressure, and other factors.

forecast

A prediction of what the future weather will be like.

atmosphere

The layer of air that surrounds the earth.

temperature

A measurement of the amount of heat something contains.

weather pattern

When the weather repeats itself several days in a row.

climate

The average weather over a long period of time.

almanac

A book that contains weather data and forecasts.

water cycle

The journey water takes as it circulates from the land to the sky and back again.

water vapor

Water in its gaseous state- instead of liquid or solid. It is totally invisible.

condensation

When a gas becomes a liquid.

evaporation

When a liquid becomes a gas.

precipitation

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

stratus

Flat, featureless clouds low in the atmosphere that cover the sky like a blanket. They indicate rain.

cirrus

High level clouds made mostly of ice crystals. They indicate fair weather.

cumulonimbus

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

cumulus

Mid-level, puffy clouds. They indicate fair weather.

fog

Clouds that form at ground level.

wind isobars

Air flowing from high pressure to low pressure.

beaufort scale

A scale that relates the wind speed to its effects, classified from force 0 to force 12.

prevailing winds

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

Westerlies

The global winds that carry weather over the United States, traveling from West to East.

Easterlies

Global winds at the poles of the earth. These global winds sometimes affect our weather during the winter months.

air mass

A massive bubble of air that has the same temperature and pressure throughout.

air pressure

The force of air pushing down on Earth.

barometer

A device used to measure air pressure.

aneroid barometer

A barometer that uses liquid.

isobar

A line drawn on a weather map that connects locations with the same air pressure.

front

Where air masses meet, but do not mix and rain or storms occur.

cold front

The leading edge of a moving mass of cold air, brings thunderstorms, and leaves behind cooler air.

warm front

The leading edge of a moving mass of warm air, brings rain showers, leaves behind warmer air.

occluded front

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

stationary front

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

tornado

A narrow, violent funnel cloud that may form during a thunderstorm with winds greater than 65 kph.

hurricane

A large rotating windstorm with a calm central eye and winds greater than 75 mph.

meteorologist isobars

A person who studies the weather.

meteorology

The study of the earth’s atmosphere and what happens in it.

station model

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

rain gauge

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