Fronts

Caroline, El, and Sarah

Warm Fronts • A warm front is the boundary between warm air and cool air as warm air replaces cool air.

• A warm front brings widespread precipitation.

• It brings days of bad weather: rain, snow, sleet, or freezing rain, often at the same time.

• The air behind a warm front is more moist and warm than the air ahead of it.

• Warm fronts move from southwest to northeast.

Cold Fronts

• When a cold air mass replaces a warm air mass it creates a cold front.

• Most of the time cold fronts move faster than any other front.

• Cold fronts usually are easier to find on a weather map than any other front.

• Cooler weather, clearing skies, and sharp change in one direction are usually caused by a cold front.

• Sometimes a good indicator that a cold front is near is that there is an abrupt change in temperature.

Stationary Fronts• Stationary fronts are the

boundaries between air masses that have stopped advancing.

• Stationary fronts often bring days of cloudy , wet weather.

• The boundary can be thousands of feet above the ground or a couple of miles away from the surface front.

• Clouds and precipitation will form as warm air runs over cool air along a stationary front if there is enough humidity in the air.

Occluded Fronts

• Occluded fronts involve 3 air masses of different temperatures: cold air, cool air, and warmer air.

• Occluded fronts can form when a cold air mass goes toward colder air with warmer air between the two.

• The cool air forces the warmer air up, closing off the warm air from the surface.

Conclusion

• Weather fronts are the boundaries between warm and cool air. The masses of air have different densities and are usually caused by temperature differences.

• When warm and cold air stop moving, it causes a stationary front.

• When a warm front catches a cold front, it produces an occluded front.

• When cold air replaces warm air in a transition zone, it makes a cold front.

• When warm air replaces cold air, it makes a warm front.

Bibliography

• www.wikipedia.com• www.usatoday.com• Alabama Science Book• http://ww2010.atmos.uiuc.edu