What are Fronts An interface boundary between 2

What are Fronts? • An interface (boundary) between 2 air masses. Where 2 different air masses meet. • Conditions at the front are unstable and usually associated with precipitation

Types of Fronts: Page 13 in E. S. R. T. Icicles Half Suns

Cold Fronts: • Cold air moves into an area occupied by warm air Warm air is already in place.

• The colder, denser air pushes against and under the warm air • The warm, less dense air rises, producing thick, tall clouds • Wind speed increases, air pressure drops • Precipitation occurs – moves quickly and violently

Temperatures are cooler behind a cold front, and warmer ahead of the cold front.

Cold Front Animation

Warm Fronts: • Warm air mass moves into an area occupied by cool air

Warm air slides over the cold air.

• The warmer, less dense air moves on top of cold air mass • Warm air rises, expands, cools, and clouds form • Air pressure falls, and precipitation follows • Lasts for a longer period of time

Temperatures are warmer behind a warm front, and cooler ahead of the front.

Warm Front Animation

Warm Front Animation

Stationary Fronts: • A cold air mass and a warm air mass collide, with no movement

• Widespread rain will last for many days

Stationary Front Animation

A collision of air masses – warm and cold fronts meet

Occluded Front: • Faster moving cold front overtakes a slower moving warm front

• Warm front gets caught in between 2 cold fronts Widespread rain and thunderstorms • Widespread rain and thunderstorms

Precipitation occurs right along the frontal boundary

On a weather map, fronts attach at a low pressure. Knowing this we can predict where each of the fronts will be next. What direction is this low pressure system rotating? Counter-clockwise

Front Questions • Q: Towards what direction is the cold front moving? • A: South East • Q: Towards what direction is the warm front moving? • A: North

Front Questions: • Q: Is it colder in Los Angeles or El Paso? • A: Los Angeles • Q: Is it warmer in Memphis or New York? • A: Memphis • Q: What cities have high pressure? • A: Houston, Seattle • Q: What cities might be experiencing rain? • A: El Paso, Memphis