Weather Patterns Review

Ms. Luginbuhl

What is an air mass?

What is an air mass?

• A huge body of air that has similar temperature, humidity, and air pressure throughout it.

What are the types of air masses?

What are the types of air masses?

• Tropical– Warm, form in the tropics, have low air pressure

• Polar– Cold, form north of 50 degrees north latitude and couth

of 50 degrees south latitude (the poles!), high air pressure

• Maritime– Form over oceans, very humid

• Continental– Form over land, dry

What are the four types of fronts?

What are the four types of fronts?

• A front is an area where air masses meet and do not mix.– Warm– Cold– Stationary– Occluded

What are the four types of fronts?

• Cold– Dense– cold air mass moves into a warm air mass -> the

warm air is pushed upward– Clouds form and rain or snow may occur– Abrupt (quick) weather, including thunder storms– AFTER: cool, dry air -> clear skies and cooler

temperatures

What are the four types of fronts?

• Warm– Warm air moves over cold air– May cause showers and light rain or scattered

clouds, snow in the winter– Warm fronts move more slowly than cold air

fronts -> may be rainy or foggy for several days– AFTER: warm and humid

Why does a cold front move faster than a warm front?

• A cold front moves faster than a warm front because it is easer for a cold (dense) air mass to move the warm (less dense) air mass up and out of the way than it is for a warm air mass to move a cold air mass.

What are the four types of fronts?

• Occluded– Warm air mass is caught between two cooler air

masses– Weather may turn cloudy and rainy or snowy

What are the four types of fronts?

• Stationary– Warm and cold air masses me and do not move

one another– A “standoff”– Causes rain, snow, fog, or clouds– May bring many days of clouds and precipitation

Tornados, Hurricanes, & Thunderstorms

• Review p. 108 question # 17• Thunderstorms form within large cumulonimbus

clouds, or thunderheads.• Lightning is a sudden spark, or energy discharge, as

charges jump between parts of a cloud or between the cloud and the ground

• A tornado is a rapidly whirling, funnel-shaped could that reaches down from a storm cloud to touch Earth’s surface.

• A hurricane is a tropical storm with very strong winds.

What is a meteorologist?

What is a meteorologist?

• A meteorologist is a scientist that studies the causes of weather and tries to predict it.

What are isobars and isotherms?

What are isobars and isotherms?

• Isobars are lines joining places on the map that have the same air pressure.

• Isotherms are lines joining places that have the same temperature.

What moves weather across the United States? What direction does it move?

What moves weather across the United States? What direction does it move?

• The prevailing westerlies generally push air masses from west to east in North America.

High and Low air pressure

• High Pressure – generally good weather• Low Pressure – typically bad or wet weather

http://usatoday30.usatoday.com/weather/tg/whighlow/whighlow.htm

Weather Maps

• Textbook page 103