WEATHER FACTORS KEY TERMS Flashcards
Condition of the atmosphere at a specific time and place.
Weather
High pressure center in the northern hemisphere with winds blowing clockwise outward from the middle causing clear skies.
Anticyclone
Low pressure center in the northern hemisphere with winds blowing counterclockwise toward the middle causing clouds and precipitation.
Cyclone
Deflection of curving of winds and ocean currents due to the rotation of the earth.
Coriolis Effect
Movement of air along Earth’s surface.
Wind
Air that moves up and down.
Air Current
Line on a map connecting points of equal air pressure.
Isobar
Line on a map connecting points of equal temperature.
Isotherm
Amount of water vapor in the air.
Humidity
Measure of the amount of thermal (heat) energy.
Temperature
Temperature at which condensation occurs.
Dew Point
The weight of air pressing on a surface.
Air Pressure
Change from a gas to liquid.
Condensation
Change from a liquid to a gas.
Evaporation
Clouds along the ground.
Fog
Gray, thick blanket-like clouds that bring rain.
Nimbostratus
White, fluffy, cotton ball-like clouds that mean fair weather.
Cumulus
Low, flat, expansive, blanket-like clouds.
Stratus
High, feather clouds made of ice crystals.
Cirrus
Tall, anvil-shaped clouds that form during thunderstorms; thunderhead clouds.
Cumulonimbus
Instrument used to measure wind speed.
Anemometer
Instrument used to measure wind direction.
Wind Vane
Instrument used to measure air pressure.
Barometer
Instrument used to measure temperature.
Thermometer
Instrument used to measure relative humidity.
Psychrometer
Instrument used to measure the amount of precipitation.
Rain gauge
Rain, snow, sleet, and hail.
Precipitation
Precipitation in which raindrops freeze as the fall to earth; above freezing in clouds but below freezing at ground level.
Sleet
Precipitation in which strong winds repeatedly blow raindrops up high in clouds where a new layer of frost forms forming a small to large ball of ice which falls to earth.
Hail
Precipitation in which raindrops freeze after they hit the ground; above freezing in clouds but below freezing at ground level.
Freezing Rain
Precipitation in which water vapor condenses directly into ice crystals in the clouds which fall to the surface; below freezing in clouds.
Snow
Precipitation in which liquid drops of water fall from clouds. It is above freezing in clouds and at ground level.
Rain
Fast moving west-to-east flowing “river” of air high in the troposphere that influences weather.
Jetstream
