cold front
A FAST-MOVING cold air mass overtakes a warm air mass.
Weather it brings: Abrupt weather changes; Heavy rain or snow; Thunderstorms
Warm front
A fast-moving WARM air mass overtakes a SLOWLY moving cold air mass.
Weather it brings: WARM & HUMID
HUMID: light rain or snow
DRY: scattered clouds
Stationary front
Cold and warm air masses meet, but neither can move the other.
Weather it brings: many days of clouds & precipitation
Occluded front
A warm air mass is caught between two cooler air masses.
Weather it brings: Turn cloudy & rain or snow may fall