The amount of water vapor in the air
Humidity
a measure of what the temperature feels like because of the humidity
Heat Index
The temperature at which water vapor condenses
Dew Point
Clouds that form on the ground
Fog
forms when snow melts as it falls through a layer of warm air then refreezes and turns into clear ice particles
Sleet
falls as liquid water it freezes on contact with cold surfaces near the ground
Freezing rain
forms in thunderstorms when strong updrafts carry rain high into the troposphere then the rain freezes into balls of ice
Hail
a large body of air that has about the same conditions throughout
Air mass
The boundary between two air masses
front
occurs when a cold air mass runs into a warm air mass the cold air moves faster than warm air`
Cold Front
When war air mass runs into a cold air warmer air moves faster than the cold air
Warm front
a warm air mass becomes trapped between two cold air masses
Occluded front
sometimes two air masses stop moving when they meet
stationary front