Understanding Weather Fronts and Air Masses

Fronts

Boundaries between air masses that cause storms and unpredictable weather.

Air Masses

Zones of similar temperature, pressure, and humidity that form over surface and multiple days.

Cold Front

Faster cold air mass pushes under slower warm air mass, leading to heavy precipitation, thunderstorms, and violent storms, followed by cooler drier air.

Warm Front

Warm air mass moves gently over a cold air mass, leading to more gentle rain or snow and long periods of precipitation.

Occluded Front

Cold air with warm front; cold front catches up with warm front causing warm air to be pushed up, bringing strong winds and heavy precipitation, usually creating a complex storm system.

Stationary Front

Cold and warm air masses meet and stay in place, leading to many days of clouds and precipitation, as neither air mass is strong enough to move the other.

Jet Stream

Wind and Jet Streams push air masses; they move weather faster and cause air masses to move diagonally due to the Coriolis Effect.

Coriolis Effect

Causes air masses to move diagonally.

Maritime Tropical (mT)

A type of air mass that is warm and moist, originating over water.

Continental Polar (cP)

A type of air mass that is cold and dry, originating over land.

Maritime Polar (mP)

A type of air mass that is cool and moist, originating over water.

Continental Tropical (cT)

A type of air mass that is warm and dry, originating over land.

Continental Arctic (cA)

A type of air mass that is very cold, originating over land.

Maritime Equatorial (mE)

A type of air mass that is very warm, originating over water.

Convection Currents

Drive the movement of weather fronts.

Weather Forecast Map

A front is usually part of a weather forecast map.

Air Mass Naming

Air masses are named based on moisture content and temperature.

Continental (C)

Air masses that are dry and form over land.

Maritime (M)

Air masses that are moist and form over water.

Weather Change

A front means a change in weather is coming.