Weather Basics
Build a better vocabulary for forecasts and warnings.
air mass
a large body of air with similar temperature and moisture levels throughout
jet stream
a fast-flowing, narrow current of air in the upper atmosphere
convection
the transfer of heat by the upward movement of warmed air or liquid
ultraviolet (UV) index
a scale used to estimate the risk of skin damage from solar radiation
adiabatic cooling
the process of reducing heat through a change in air pressure as air rises
hygrometer
an instrument used to measure the amount of humidity in the air
visibility
the distance at which objects can be clearly seen
troposphere
the lowest layer of Earth's atmosphere where weather occurs
wind chill
how cold it feels outside based on the rate of heat loss from exposed skin caused by wind
dew point
the temperature at which air becomes saturated and water vapor condenses into liquid
anemometer
an instrument used to measure wind speed
barometer
an instrument used to measure air pressure
meteorology
the scientific study of the atmosphere and weather patterns
isobar
a line on a map connecting points of equal atmospheric pressure
condensation
the process by which water vapor turns into liquid water
front
a boundary between air masses
precipitation
water falling from clouds, such as rain or snow
humidity
the amount of water vapor in the air