Fronts Interface (Boundary) between 2 air masses Colder air mass begins to wedge under the warmer air mass Fronts are always a sign of a change in the weather Fronts are always associated with On a weather map, fronts extend from the LOW pressure Center of the Low

Low pressure Warm front Cold front mT cP L

Cold Front Cold air is MORE dense than warm air so cold air displaces warm air Steep slope Moves quickly Showery precipitation (doesn’t last long) cP air mass mT air mass

Conditions before a cold front Warm More ______________ Winds usually from ______________ direction Pressure ____________ humid southerly decreases

Conditions after the cold front cold Air is more_____ Winds usually from ______________ direction Pressure ____________ drier North west increases

Vertical clouds Cumulus Towering Cumulus Cumulonimbus (thunderstorm)

Warm Front Warm air is LESS dense than cooler air so warm air rises up and over the cool air Gentle slope Extended hours of precipitation mT cP

Conditions before a warm front cool Winds usually from ______________ direction easterly

Conditions after a warm front warm Winds usually from ______________ direction southerly

Cirrus Cirrocumulus Cirrostratus High level clouds

Mid-level clouds Altocumulus Altostratus

Stratus Nimbostratus Low-Level Clouds

Occluded Front Faster, colder air overtakes slower, warm air Warm air is forced up off the ground Extended hours of precipitation

Stationary Front Neither air mass is moving Cold and warm air Precipitation similar to warm front

COLD FRONT WARM FRONT cP mT