Weather FrontsWeather Fronts

ScienceScience 8 8thth Grade Grade

TeacherPage

Dew Point and Cloud Dew Point and Cloud FormationFormation

• Dew Point: The temperature at which Dew Point: The temperature at which water condenses (turns to liquid).water condenses (turns to liquid).– Like sweat on a can of soda.Like sweat on a can of soda.

• Usually happens at cold temperaturesUsually happens at cold temperatures

• Clouds form when water cools down Clouds form when water cools down to the dew point.to the dew point.– As air rises it gets colder, water As air rises it gets colder, water

condenses, and clouds form. condenses, and clouds form.

MAP TAP 2002-2003MAP TAP 2002-2003 Weather FrontsWeather Fronts 33

MAP TAP 2002-2003MAP TAP 2002-2003 Weather FrontsWeather Fronts 44

Air MassAir Mass• A large body A large body

of air with of air with similar similar temperature temperature and moisture.and moisture.

• Air masses Air masses form over form over large land or large land or water water masses.masses.

MAP TAP 2002-2003MAP TAP 2002-2003 Weather FrontsWeather Fronts 55

Frontal BoundariesFrontal Boundaries

• Where air Where air masses interact – masses interact – also known as a also known as a front.front.

• 4 kinds of fronts:4 kinds of fronts:– Cold frontCold front– Warm frontWarm front– Occluded frontOccluded front– Stationary frontStationary front

Cold FrontCold Front• A cold air A cold air

mass is mass is replacing a replacing a warmer air warmer air mass.mass.

• Shown on a Shown on a weather map weather map by a blue line by a blue line with triangles with triangles pointing the pointing the direction the direction the cool air is cool air is moving.moving.

Back toactivity

MAP TAP 2002-2003MAP TAP 2002-2003 Weather FrontsWeather Fronts 77

Warm FrontWarm Front

• Warm air mass Warm air mass replacing a replacing a cooler air cooler air mass.mass.

• Shown on a Shown on a weather map weather map by a red line by a red line with half with half circles pointing circles pointing the direction the direction the warm air is the warm air is moving.moving.

Back toactivity

MAP TAP 2002-2003MAP TAP 2002-2003 Weather FrontsWeather Fronts 88

Occluded FrontsOccluded Fronts• When a warm When a warm

front is trapped front is trapped by 2 cold fronts.by 2 cold fronts.

• Shown on a Shown on a weather map weather map by a purple line by a purple line with alternating with alternating triangles and triangles and semicircles semicircles pointing the pointing the direction the direction the front is moving.front is moving.

Back toactivity

MAP TAP 2002-2003MAP TAP 2002-2003

Stationary FrontsStationary Fronts• A front that stops moving or is moving very A front that stops moving or is moving very

slowly.slowly.

• Shown on a weather map with alternating red Shown on a weather map with alternating red semicircles pointing away from the warm air and semicircles pointing away from the warm air and blue triangles pointing away from the cold air.blue triangles pointing away from the cold air.

Back toactivity

IsobarsIsobars

• Isobars: Lines connecting equal Isobars: Lines connecting equal points of air pressure. points of air pressure.

• H: High PressureH: High Pressure

• L: Low PressureL: Low Pressure

-Where is the rain?-Where is the rain?

High or Low pressure? High or Low pressure?

MAP TAP 2002-2003MAP TAP 2002-2003 Weather FrontsWeather Fronts 1010

IsothermsIsotherms

• Isotherms: Lines connecting equal Isotherms: Lines connecting equal points of temperature.points of temperature.

MAP TAP 2002-2003MAP TAP 2002-2003 Weather FrontsWeather Fronts 1111

Locate the 4 types of fronts on Locate the 4 types of fronts on this weather map.this weather map.

Hint1

Hint2

Hint3

Hint4

Cold FrontsCold Fronts

Warm FrontWarm Front

Stationary FrontStationary Front

Occluded FrontOccluded Front

Weather FrontsWeather Fronts 1717

Be a Weather ForecasterBe a Weather Forecaster

You are planning to travel to Alabama in 2 days. The high temperature there for today is 68º F.

You are planning to travel to Alabama in 2 days. The high temperature there for today is 68º F.

Use the map to help you predict whether the temperature in Alabama will increase, decrease, or stay the same. Explain why you think so.

1818

Be a Weather ForecasterBe a Weather Forecaster

There is a cold front approaching. The temperatures will probably be cooler behind the front.

There is a cold front approaching. The temperatures will probably be cooler behind the front.

MAP TAP 2002-2003MAP TAP 2002-2003 Weather FrontsWeather Fronts 1919

Be a Weather ForecasterBe a Weather Forecaster

• Of course, meteorologists Of course, meteorologists (weather forecasters) use (weather forecasters) use much more data than fronts much more data than fronts and air masses to help them and air masses to help them forecast the weather more forecast the weather more accurately. But any forecast accurately. But any forecast is just a prediction of what is just a prediction of what might might happen. Even with happen. Even with the best data, weather the best data, weather forecasts can be wrong. forecasts can be wrong.